Subjects -> CHEMISTRY (Total: 928 journals)
    - ANALYTICAL CHEMISTRY (59 journals)
    - CHEMISTRY (661 journals)
    - CRYSTALLOGRAPHY (23 journals)
    - ELECTROCHEMISTRY (28 journals)
    - INORGANIC CHEMISTRY (45 journals)
    - ORGANIC CHEMISTRY (47 journals)
    - PHYSICAL CHEMISTRY (65 journals)

CHEMISTRY (661 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
Accounts of Materials Research     Hybrid Journal   (Followers: 8)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 32)
ACS Applied Polymer Materials     Hybrid Journal   (Followers: 16)
ACS Catalysis     Hybrid Journal   (Followers: 57)
ACS Chemical Neuroscience     Hybrid Journal   (Followers: 26)
ACS Combinatorial Science     Hybrid Journal   (Followers: 13)
ACS Environmental Au     Open Access   (Followers: 10)
ACS Macro Letters     Hybrid Journal   (Followers: 29)
ACS Materials Letters     Open Access   (Followers: 7)
ACS Medicinal Chemistry Letters     Hybrid Journal   (Followers: 45)
ACS Nano     Hybrid Journal   (Followers: 224)
ACS Photonics     Hybrid Journal   (Followers: 16)
ACS Symposium Series     Full-text available via subscription   (Followers: 5)
ACS Synthetic Biology     Hybrid Journal   (Followers: 39)
Acta Chemica Malaysia     Open Access   (Followers: 2)
Acta Chimica Slovaca     Open Access   (Followers: 4)
Acta Chimica Slovenica     Open Access   (Followers: 4)
Acta Chromatographica     Full-text available via subscription   (Followers: 9)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 10)
Acta Scientifica Naturalis     Open Access   (Followers: 4)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 9)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 12)
Adsorption Science & Technology     Open Access   (Followers: 9)
Advanced Electronic Materials     Hybrid Journal   (Followers: 13)
Advanced Functional Materials     Hybrid Journal   (Followers: 76)
Advanced Journal of Chemistry, Section A     Open Access   (Followers: 4)
Advanced Journal of Chemistry, Section B     Open Access   (Followers: 1)
Advanced Science Focus     Free   (Followers: 8)
Advanced Theory and Simulations     Hybrid Journal   (Followers: 5)
Advanced Therapeutics     Hybrid Journal   (Followers: 1)
Advances in Chemical Engineering and Science     Open Access   (Followers: 131)
Advances in Chemical Science     Open Access   (Followers: 52)
Advances in Chemistry     Open Access   (Followers: 37)
Advances in Chemistry     Full-text available via subscription   (Followers: 9)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 15)
Advances in Environmental Chemistry     Open Access   (Followers: 13)
Advances in Enzyme Research     Open Access   (Followers: 10)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 8)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 34)
Advances in Nanoparticles     Open Access   (Followers: 17)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Polymer Science     Hybrid Journal   (Followers: 49)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 18)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Sample Preparation     Open Access   (Followers: 6)
Advances in Science and Technology     Full-text available via subscription   (Followers: 18)
Aerosol Science and Engineering     Hybrid Journal   (Followers: 2)
African Journal of Chemical Education     Open Access   (Followers: 6)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 6)
Aggregate     Open Access   (Followers: 1)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alchemy : Journal of Chemistry     Open Access   (Followers: 2)
Alchemy : Jurnal Penelitian Kimia     Open Access  
Alfarama Journal of Basic & Applied Sciences     Open Access   (Followers: 8)
Alotrop     Open Access  
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 45)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 21)
American Journal of Chemistry     Open Access   (Followers: 37)
American Journal of Plant Physiology     Open Access   (Followers: 9)
Analyst     Hybrid Journal   (Followers: 35)
Analytical Science Advances     Open Access   (Followers: 2)
Angewandte Chemie     Hybrid Journal   (Followers: 169)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 275)
Annales Universitatis Mariae Curie-Sklodowska, sectio AA – Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 6)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 4)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 5)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 14)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 13)
Antiviral Chemistry and Chemotherapy     Open Access   (Followers: 1)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7)
Applied Spectroscopy     Full-text available via subscription   (Followers: 20)
Applied Surface Science     Hybrid Journal   (Followers: 31)
Arabian Journal of Chemistry     Open Access   (Followers: 4)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Applied Chemistry Research     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 2)
Asian Journal of Chemical Sciences     Open Access   (Followers: 1)
Asian Journal of Chemistry and Pharmaceutical Sciences     Open Access  
Asian Journal of Physical and Chemical Sciences     Open Access   (Followers: 2)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 8)
Autophagy     Hybrid Journal   (Followers: 8)
Biochemical Pharmacology     Hybrid Journal   (Followers: 10)
Biochemistry     Hybrid Journal   (Followers: 248)
Biochemistry Insights     Open Access   (Followers: 6)
Biochemistry Research International     Open Access   (Followers: 5)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 5)
Biointerface Research in Applied Chemistry     Open Access  
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 2)
Biomacromolecules     Hybrid Journal   (Followers: 24)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 3)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 85)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 61)
Bioorganic Chemistry     Hybrid Journal   (Followers: 7)
Biopolymers     Hybrid Journal   (Followers: 15)
Biosensors     Open Access   (Followers: 3)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 3)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of Institute of Chemistry and Chemical Technology, Mongolian Academy of Sciences     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 1)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 25)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 5)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 1)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 11)
Canadian Mineralogist     Full-text available via subscription   (Followers: 5)
Carbohydrate Polymer Technologies and Applications     Open Access  
Carbohydrate Polymers     Hybrid Journal   (Followers: 11)
Carbohydrate Research     Hybrid Journal   (Followers: 23)
Carbon     Hybrid Journal   (Followers: 64)
Carbon Capture Science & Technology     Open Access   (Followers: 1)
Carbon Trends     Open Access   (Followers: 7)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 9)
Catalysis Science and Technology     Hybrid Journal   (Followers: 10)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 4)
Catalysts     Open Access   (Followers: 12)
Cell Reports Physical Science     Open Access   (Followers: 1)
Cellulose     Hybrid Journal   (Followers: 8)
Cereal Chemistry     Full-text available via subscription   (Followers: 4)
Chem     Hybrid Journal   (Followers: 7)
Chem Catalysis     Hybrid Journal   (Followers: 1)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 3)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 22)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Hybrid Journal   (Followers: 83)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 27)
Chemical Physics Impact     Full-text available via subscription   (Followers: 1)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 4)
Chemical Research in Toxicology     Hybrid Journal   (Followers: 22)
Chemical Reviews     Hybrid Journal   (Followers: 214)
Chemical Science     Open Access   (Followers: 43)
Chemical Science International Journal     Open Access  
Chemical Technology     Open Access   (Followers: 75)
Chemical Thermodynamics and Thermal Analysis     Open Access   (Followers: 4)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 4)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 39)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 18)
ChemInform     Hybrid Journal   (Followers: 5)
Chemistry     Open Access  
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Industry     Full-text available via subscription   (Followers: 6)
Chemistry - A European Journal     Hybrid Journal   (Followers: 145)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 20)
Chemistry Africa : A Journal of the Tunisian Chemical Society     Hybrid Journal  
Chemistry and Materials Research     Open Access   (Followers: 19)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 7)
Chemistry Education Review     Open Access   (Followers: 2)
Chemistry in Education     Open Access   (Followers: 5)
Chemistry Letters     Full-text available via subscription   (Followers: 43)
Chemistry of Heterocyclic Compounds     Hybrid Journal   (Followers: 5)
Chemistry of Materials     Hybrid Journal   (Followers: 186)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 10)
Chemistry World     Hybrid Journal   (Followers: 20)
Chemistry-Didactics-Ecology-Metrology     Open Access  
ChemistryOpen     Open Access   (Followers: 1)
ChemistrySelect     Hybrid Journal  
Chemistry–Methods     Open Access   (Followers: 3)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
ChemNanoMat     Hybrid Journal   (Followers: 1)
Chemoecology     Hybrid Journal   (Followers: 2)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 13)
Chemosensors     Open Access   (Followers: 1)
ChemPhotoChem     Hybrid Journal  
ChemPhysChem     Hybrid Journal   (Followers: 12)
ChemPhysMater     Full-text available via subscription  
ChemPlusChem     Hybrid Journal   (Followers: 2)
Chempublish Journal     Open Access  
ChemSystemsChem     Hybrid Journal   (Followers: 1)
ChemTexts     Hybrid Journal   (Followers: 1)
CHIMIA International Journal for Chemistry     Open Access   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 9)
Chromatographia     Hybrid Journal   (Followers: 21)
Chromatography     Open Access   (Followers: 3)
Chromatography Research International     Open Access   (Followers: 4)
Ciencia     Open Access  
Clay Minerals     Hybrid Journal   (Followers: 9)
Cogent Chemistry     Open Access   (Followers: 3)
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 6)
Colloids and Interfaces     Open Access  
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 8)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 2)
Combustion Science and Technology     Hybrid Journal   (Followers: 26)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 1)
Communications Chemistry     Open Access   (Followers: 2)
Communications Materials     Open Access  
Composite Interfaces     Hybrid Journal   (Followers: 6)

        1 2 3 4 | Last

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Journal Prestige (SJR): 0.829
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Number of Followers: 3  

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ISSN (Print) 2079-6374
Published by MDPI Homepage  [258 journals]
  • Biosensors, Vol. 13, Pages 571: Insight into the Mode of Action of
           8-Hydroxyquinoline-Based Blockers on the Histamine Receptor 2

    • Authors: Amisha Patel, Paola L. Marquez-Gomez, Lily R. Torp, Lily Gao, Pamela Peralta-Yahya
      First page: 571
      Abstract: Histamine receptor 2 (HRH2) blockers are used to treat peptic ulcers and gastric reflux. Chlorquinaldol and chloroxine, which contain an 8-hydroxyquinoline (8HQ) core, have recently been identified as blocking HRH2. To gain insight into the mode of action of 8HQ-based blockers, here, we leverage an HRH2-based sensor in yeast to evaluate the role of key residues in the HRH2 active site on histamine and 8HQ-based blocker binding. We find that the HRH2 mutations D98A, F254A, Y182A, and Y250A render the receptor inactive in the presence of histamine, while HRH2:D186A and HRH2:T190A retain residual activity. Based on molecular docking studies, this outcome correlates with the ability of the pharmacologically relevant histamine tautomers to interact with D98 via the charged amine. Docking studies also suggest that, unlike established HRH2 blockers that interact with both ends of the HRH2 binding site, 8HQ-based blockers interact with only one end, either the end framed by D98/Y250 or T190/D186. Experimentally, we find that chlorquinaldol and chloroxine still inactivate HRH2:D186A by shifting their engagement from D98 to Y250 in the case of chlorquinaldol and D186 to Y182 in the case of chloroxine. Importantly, the tyrosine interactions are supported by the intramolecular hydrogen bonding of the 8HQ-based blockers. The insight gained in this work will aid in the development of improved HRH2 therapeutics. More generally, this work demonstrates that Gprotein-coupled receptor (GPCR)-based sensors in yeast can help elucidate the mode of action of novel ligands for GPCRs, a family of receptors that bind 30% of FDA therapeutics.
      Citation: Biosensors
      PubDate: 2023-05-23
      DOI: 10.3390/bios13060571
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 572: Flexible Passive Sensor Patch with
           Contactless Readout for Measurement of Human Body Temperature

    • Authors: Marco Zini, Marco Baù, Alessandro Nastro, Marco Ferrari, Vittorio Ferrari
      First page: 572
      Abstract: A passive flexible patch for human skin temperature measurement based on contact sensing and contactless interrogation is presented. The patch acts as an RLC resonant circuit embedding an inductive copper coil for magnetic coupling, a ceramic capacitor as the temperature-sensing element and an additional series inductor. The temperature affects the capacitance of the sensor and consequently the resonant frequency of the RLC circuit. Thanks to the additional inductor, the dependency of the resonant frequency from the bending of the patch has been reduced. Considering a curvature radius of the patch of up to 73 mm, the maximum relative variation in the resonant frequency has been reduced from 812 ppm to 7.5 ppm. The sensor has been contactlessly interrogated by a time-gated technique through an external readout coil electromagnetically coupled to the patch coil. The proposed system has been experimentally tested within the range of 32–46 °C, giving a sensitivity of −619.8 Hz/°C and a resolution of 0.06 °C.
      Citation: Biosensors
      PubDate: 2023-05-23
      DOI: 10.3390/bios13060572
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 573: Metal-Multilayered Nanomechanical
           Cantilever Sensor for Detection of Molecular Adsorption

    • Authors: Masaya Toda, Takahito Ono, Jun Okubo
      First page: 573
      Abstract: A metal-multilayered nanomechanical cantilever sensor was proposed to reduce the temperature effect for highly sensitive gas molecular detection. The multilayer structure of the sensor reduces the bimetallic effect, allowing for the detection of differences in molecular adsorption properties on various metal surfaces with higher sensitivity. Our results indicate that the sensor exhibits higher sensitivity to molecules with greater polarity under mixed conditions with nitrogen gas. We demonstrate that stress changes caused by differences in molecular adsorption on different metal surfaces can be detected and that this approach could be used to develop a gas sensor with selectivity for specific gas species.
      Citation: Biosensors
      PubDate: 2023-05-23
      DOI: 10.3390/bios13060573
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 574: One Single Tube Reaction of
           Aptasensor-Based Magnetic Sensing System for Selective Fluorescent
           Detection of VEGF in Plasma

    • Authors: Hwang-Shang Kou, Shao-Tsung Lo, Chun-Chi Wang
      First page: 574
      Abstract: In this study, a simple, easy and convenient fluorescent sensing system for the detection of the vascular endothelial growth factor (VEGF) based on VEGF aptamers, aptamer-complementary fluorescence-labeled probe and streptavidin magnetic beads was developed in one single tube. The VEGF is the most important biomarker in cancer, and it is investigated that the serum VEGF level varied according to the different types and courses of cancers. Hence, efficient quantification of VEGF is able to improve the accuracy of cancer diagnoses and the precision of disease surveillance. In this research, the VEGF aptamer was designed to be able to bind with the VEGF by forming G-quadruplex secondary structures; then, the magnetic beads would capture the non-binding aptamers due to non-steric interference; and finally, the fluorescence-labeled probes were hybridized with the aptamers captured by the magnetic beads. Therefore, the fluorescent intensity in the supernatant would specifically reflect the present VEGF. After an overall optimization, the optimal conditions for the detection of VEGF were as followed, KCl, 50 μM; pH 7.0; aptamer, 0.1 μM; and magnetic beads, 10 μL (4 μg/μL). The VEGF could be well quantified within a range of 0.2-2.0 ng/mL in plasma, and the calibration curve possessed a good linearity (y = 1.0391x + 0.5471, r = 0.998). The detection limit (LOD) was calculated to be 0.0445 ng/mL according to the formula (LOD = 3.3 × σ/S). The specificity of this method was also investigated under the appearance of many other serum proteins, and the data showed good specificity in this aptasensor-based magnetic sensing system. This strategy provided a simple, sensitive and selective biosensing platform for the detection of serum VEGF. Finally, it was expected that this detection technique can be used to promote more clinical applications.
      Citation: Biosensors
      PubDate: 2023-05-24
      DOI: 10.3390/bios13060574
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 575: Non-Destructive Screening of Sodium
           Metabisulfite Residue on Shrimp by SERS with Copy Paper Loaded with AgNP

    • Authors: Chao Yuan, Yanan Zhao, Xingjun Xi, Yisheng Chen
      First page: 575
      Abstract: In order to prompt the appearance of the shrimp color, sodium metabisulfite is frequently added in shrimp processing, which is, however, prohibited in China and many other countries. This study aimed to establish a surface-enhanced Raman spectroscopy (SERS) method for screening sodium metabisulfite residues on shrimp surfaces, in a non-destructive manner. The analysis was carried out using a portable Raman spectrometer jointly with copy paper loaded with silver nanoparticles as the substrate material. The SERS response of sodium metabisulfite gives two fingerprint peaks at 620 (strong) and 927 (medium) cm−1, respectively. This enabled unambiguous confirmation of the targeted chemical. The sensitivity of the SERS detection method was determined to be 0.1 mg/mL, which was equal to residual sodium metabisulfite on the shrimp surface at 0.31 mg/kg. The quantitative relationship between the 620 cm−1 peak intensities and the concentrations of sodium metabisulfite was established. The linear fitting equation was y = 2375x + 8714 with R2 = 0.985. Reaching an ideal balance in simplicity, sensitivity, and selectivity, this study demonstrates that the proposed method is ideally suitable for in-site and non-destructive screening of sodium metabisulfite residues in seafood.
      Citation: Biosensors
      PubDate: 2023-05-25
      DOI: 10.3390/bios13060575
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 576: In Vitro Biofouling Performance of
           Boron-Doped Diamond Microelectrodes for Serotonin Detection Using
           Fast-Scan Cyclic Voltammetry

    • Authors: Bhavna Gupta, Mason L. Perillo, James R. Siegenthaler, Isabelle E. Christensen, Matthew P. Welch, Robert Rechenberg, G M Hasan Ul Banna, Davit Galstyan, Michael F. Becker, Wen Li, Erin K. Purcell
      First page: 576
      Abstract: Neurotransmitter release is important to study in order to better understand neurological diseases and treatment approaches. Serotonin is a neurotransmitter known to play key roles in the etiology of neuropsychiatric disorders. Fast-scan cyclic voltammetry (FSCV) has enabled the detection of neurochemicals, including serotonin, on a sub-second timescale via the well-established carbon fiber microelectrode (CFME). However, poor chronic stability and biofouling, i.e., the adsorption of interferent proteins to the electrode surface upon implantation, pose challenges in the natural physiological environment. We have recently developed a uniquely designed, freestanding, all-diamond boron-doped diamond microelectrode (BDDME) for electrochemical measurements. Key potential advantages of the device include customizable electrode site layouts, a wider working potential window, improved stability, and resistance to biofouling. Here, we present a first report on the electrochemical behavior of the BDDME in comparison with CFME by investigating in vitro serotonin (5-HT) responses with varying FSCV waveform parameters and biofouling conditions. While the CFME delivered lower limits of detection, we also found that BDDMEs showed more sustained 5-HT responses to increasing or changing FSCV waveform-switching potential and frequency, as well as to higher analyte concentrations. Biofouling-induced current reductions were significantly less pronounced at the BDDME when using a “Jackson” waveform compared to CFMEs. These findings are important steps towards the development and optimization of the BDDME as a chronically implanted biosensor for in vivo neurotransmitter detection.
      Citation: Biosensors
      PubDate: 2023-05-25
      DOI: 10.3390/bios13060576
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 577: A Chemiluminescence Enzyme Immunoassay
           Based on Biotinylated Nanobody and Streptavidin Amplification for Diazinon
           Sensitive Quantification

    • Authors: Pengyan Guo, Kaiyin Huang, Zijian Chen, Zhenlin Xu, Aifen Ou, Qingchun Yin, Hong Wang, Xing Shen, Kai Zhou
      First page: 577
      Abstract: The advantages of genetic modification and preferable physicochemical qualities make nanobody (Nb) easy to develop a sensitive and stable immunosensor platform. Herein, an indirect competitive chemiluminescence enzyme immunoassay (ic-CLEIA) based on biotinylated Nb was established for the quantification of diazinon (DAZ). The anti-DAZ Nb, named Nb-EQ1, with good sensitivity and specificity, was obtained from an immunized library via a phage display technique, where the molecular docking results indicated that the hydrogen bond and hydrophobic interactions between DAZ and complementarity-determining region 3 and framework region 2 in Nb-EQ1 played a critical role in the Nb-DAZ affinity processes. Subsequently, the Nb-EQ1 was further biotinylated to generate a bi-functional Nb-biotin, and then an ic-CLEIA was developed for DAZ determination via signal amplification of the biotin–streptavidin platform. The results showed that the proposed method based on Nb-biotin had a high specificity and sensitivity to DAZ, with a relative broader linear range of 0.12–25.96 ng/mL. After being 2-folds dilution of the vegetable samples matrix, the average recoveries were 85.7–113.9% with a coefficient of variation of 4.2–19.2%. Moreover, the results for the analysis of real samples by the developed ic-CLEIA correlated well with that obtained by reference method GC-MS (R2 ≥ 0.97). In summary, the ic-CLEIA based on biotinylated Nb-EQ1 and streptavidin recognition demonstrated itself to be a convenient tool for the quantification of DAZ in vegetables.
      Citation: Biosensors
      PubDate: 2023-05-25
      DOI: 10.3390/bios13060577
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 578: Electrochemical Sensing of Dopamine Using
           Polypyrrole/Molybdenum Oxide Bilayer-Modified ITO Electrode

    • Authors: Nadiyah Alahmadi, Waleed Ahmed El-Said
      First page: 578
      Abstract: The electrochemical sensing of biomarkers has attracted more and more attention due to the advantages of electrochemical biosensors, including their ease of use, excellent accuracy, and small analyte volumes. Thus, the electrochemical sensing of biomarkers has a potential application in early disease diagnosis diagnosis. Dopamine neurotransmitters have a vital role in the transmission of nerve impulses. Here, the fabrication of a polypyrrole/molybdenum dioxide nanoparticle (MoO3 NP)-modified ITO electrode based on a hydrothermal technique followed by electrochemical polymerization is reported. Several techniques were used to investigate the developed electrode’s structure, morphology, and physical characteristics, including SEM, FTIR, EDX, N2 adsorption, and Raman spectroscopy. The results imply the formation of tiny MoO3 NPs with an average diameter of 29.01 nm. The developed electrode was used to determine low concentrations of dopamine neurotransmitters based on cyclic voltammetry and square wave voltammetry techniques. Furthermore, the developed electrode was used for monitoring dopamine in a human serum sample. The LOD for detecting dopamine by using MoO3 NPs/ITO electrodes based on the SWV technique was around 2.2 nmol L−1.
      Citation: Biosensors
      PubDate: 2023-05-26
      DOI: 10.3390/bios13060578
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 579: Graphene-Based Sensors for the Detection
           of Microorganisms in Food: A Review

    • Authors: Jingrong Gao, Aniket Chakraborthy, Shan He, Song Yang, Nasrin Afsarimanesh, Anindya Nag, Shanggui Deng
      First page: 579
      Abstract: There is a constant need to maintain the quality of consumed food. In retrospect to the recent pandemic and other food-related problems, scientists have focused on the numbers of microorganisms that are present in different food items. As a result of changes in certain environmental factors such as temperature and humidity, there is a constant risk for the growth of harmful microorganisms, such as bacteria and fungi, in consumed food. This questions the edibility of the food items, and constant monitoring to avoid food poisoning-related diseases is required. Among the different nanomaterials used to develop sensors to detect microorganisms, graphene has been one of the primary materials due to its exceptional electromechanical properties. Graphene sensors are able to detect microorganisms in both a composite and non-composite manner, due to their excellent electrochemical characteristics such as their high aspect ratios, excellent charge transfer capacity and high electron mobility. The paper depicts the fabrication of some of these graphene-based sensors, and their utilization to detect bacteria, fungi and other microorganisms that are present in very small amounts in different food items. In addition to the classified manner of the graphene-based sensors, this paper also depicts some of the challenges that exist in current scenarios, and their possible remedies.
      Citation: Biosensors
      PubDate: 2023-05-26
      DOI: 10.3390/bios13060579
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 580: Modeling of Paper-Based Bi-Material
           Cantilever Actuator for Microfluidic Biosensors

    • Authors: Ashutosh Kumar, Hojat Heidari-Bafroui, Nassim Rahmani, Constantine Anagnostopoulos, Mohammad Faghri
      First page: 580
      Abstract: This research explores the dynamics of a fluidically loaded Bi-Material cantilever (B-MaC), a critical component of μPADs (microfluidic paper-based analytical devices) used in point-of-care diagnostics. Constructed from Scotch Tape and Whatman Grade 41 filter paper strips, the B-MaC’s behavior under fluid imbibition is examined. A capillary fluid flow model is formulated for the B-MaC, adhering to the Lucas–Washburn (LW) equation, and supported by empirical data. This paper further investigates the stress–strain relationship to estimate the modulus of the B-MaC at various saturation levels and to predict the behavior of the fluidically loaded cantilever. The study shows that the Young’s modulus of Whatman Grade 41 filter paper drastically decreases to approximately 20 MPa (about 7% of its dry-state value) upon full saturation. This significant decrease in flexural rigidity, in conjunction with the hygroexpansive strain and coefficient of hygroexpansion (empirically deduced to be 0.008), is essential in determining the B-MaC’s deflection. The proposed moderate deflection formulation effectively predicts the B-MaC’s behavior under fluidic loading, emphasizing the measurement of maximum (tip) deflection using interfacial boundary conditions for the B-MaC’s wet and dry regions. This knowledge of tip deflection will prove instrumental in optimizing the design parameters of B-MaCs.
      Citation: Biosensors
      PubDate: 2023-05-26
      DOI: 10.3390/bios13060580
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 581: Exonuclease III Can Efficiently Cleave
           Linear Single-Stranded DNA: Reshaping Its Experimental Applications in

    • Authors: Yi Shen, Haoyu Yuan, Zixuan Guo, Xiu-Qing Li, Zhiqing Yang, Chengli Zong
      First page: 581
      Abstract: Exonuclease III (Exo III) has been generally used as a double-stranded DNA (dsDNA)-specific exonuclease that does not degrade single-stranded DNA (ssDNA). Here, we demonstrate that Exo III at concentrations above 0.1 unit/μL can efficiently digest linear ssDNA. Moreover, the dsDNA specificity of Exo III is the foundation of many DNA target recycling amplification (TRA) assays. We demonstrate that with 0.3 and 0.5 unit/μL Exo III, the degradation of an ssDNA probe, free or fixed on a solid surface, was not discernibly different, regardless of the presence or absence of target ssDNA, indicating that Exo III concentration is critical in TRA assays. The study has expanded the Exo III substrate scope from dsDNA to both dsDNA and ssDNA, which will reshape its experimental applications.
      Citation: Biosensors
      PubDate: 2023-05-26
      DOI: 10.3390/bios13060581
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 582: Development of a Redox-Polymer-Based
           Electrochemical Glucose Biosensor Suitable for Integration in Microfluidic
           3D Cell Culture Systems

    • Authors: L. Navarro-Nateras, Jancarlo Diaz-Gonzalez, Diana Aguas-Chantes, Lucy L. Coria-Oriundo, Fernando Battaglini, José Luis Ventura-Gallegos, Alejandro Zentella-Dehesa, Goldie Oza, L. G. Arriaga, Jannu R. Casanova-Moreno
      First page: 582
      Abstract: The inclusion of online, in situ biosensors in microfluidic cell cultures is important to monitor and characterize a physiologically mimicking environment. This work presents the performance of second-generation electrochemical enzymatic biosensors to detect glucose in cell culture media. Glutaraldehyde and ethylene glycol diglycidyl ether (EGDGE) were tested as cross-linkers to immobilize glucose oxidase and an osmium-modified redox polymer on the surface of carbon electrodes. Tests employing screen printed electrodes showed adequate performance in a Roswell Park Memorial Institute (RPMI-1640) media spiked with fetal bovine serum (FBS). Comparable first-generation sensors were shown to be heavily affected by complex biological media. This difference is explained in terms of the respective charge transfer mechanisms. Under the tested conditions, electron hopping between Os redox centers was less vulnerable than H2O2 diffusion to biofouling by the substances present in the cell culture matrix. By employing pencil leads as electrodes, the incorporation of these electrodes in a polydimethylsiloxane (PDMS) microfluidic channel was achieved simply and at a low cost. Under flow conditions, electrodes fabricated using EGDGE presented the best performance with a limit of detection of 0.5 mM, a linear range up to 10 mM, and a sensitivity of 4.69 μA mM−1 cm−2.
      Citation: Biosensors
      PubDate: 2023-05-27
      DOI: 10.3390/bios13060582
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 583: Synthesis of Fe-Doped Peroxidase Mimetic
           Nanozymes from Natural Hemoglobin for Colorimetric Biosensing and In Vitro
           Anticancer Effects

    • Authors: Zahra Mohammadpour, Esfandyar Askari, Farhad Shokati, Hosna Sadat Hoseini, Mojtaba Kamankesh, Yasser Zare, Kyong Yop Rhee
      First page: 583
      Abstract: : Despite their efficiency and specificity, the instability of natural enzymes in harsh conditions has inspired researchers to replace them with nanomaterials. In the present study, extracted hemoglobin from blood biowastes was hydrothermally converted to catalytically active carbon nanoparticles (BDNPs). Their application as nanozymes for the colorimetric biosensing of H2O2 and glucose and selective cancer cell-killing ability was demonstrated. Particles that were prepared at 100 °C (BDNP-100) showed the highest peroxidase mimetic activity, with Michaelis–Menten constants (Km) of 11.8 mM and 0.121 mM and maximum reaction rates (Vmax) of 8.56 × 10−8 mol L−1 s−1 and 0.538 × 10−8 mol L−1 s−1, for H2O2 and TMB, respectively. The cascade catalytic reactions, catalyzed by glucose oxidase and BDNP-100, served as the basis for the sensitive and selective colorimetric glucose determination. A linear range of 50–700 µM, a response time of 4 min, a limit of detection (3σ/N) of 40 µM, and a limit of quantification (10σ/N) of 134 µM was achieved. In addition, the reactive oxygen species (ROS)-generating ability of BDNP-100 was employed for evaluating its potential in cancer therapy. Human breast cancer cells (MCF-7), in the forms of monolayer cell cultures and 3D spheroids, were studied by MTT, apoptosis, and ROS assays. The in vitro cellular experiments showed dose-dependent cytotoxicity of BDNP-100 toward MCF-7 cells in the presence of 50 µM of exogenous H2O2. However, no obvious damage was induced to normal cells in the same experimental conditions, verifying the selective cancer cell-killing ability of BDNP-100.
      Citation: Biosensors
      PubDate: 2023-05-27
      DOI: 10.3390/bios13060583
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 584: Prospects of Microfluidic Technology in
           Nucleic Acid Detection Approaches

    • Authors: Zilwa Mumtaz, Zubia Rashid, Ashaq Ali, Afsheen Arif, Fuad Ameen, Mona S. AlTami, Muhammad Zubair Yousaf
      First page: 584
      Abstract: Conventional diagnostic techniques are based on the utilization of analyte sampling, sensing and signaling on separate platforms for detection purposes, which must be integrated to a single step procedure in point of care (POC) testing devices. Due to the expeditious nature of microfluidic platforms, the trend has been shifted toward the implementation of these systems for the detection of analytes in biochemical, clinical and food technology. Microfluidic systems molded with substances such as polymers or glass offer the specific and sensitive detection of infectious and noninfectious diseases by providing innumerable benefits, including less cost, good biological affinity, strong capillary action and simple process of fabrication. In the case of nanosensors for nucleic acid detection, some challenges need to be addressed, such as cellular lysis, isolation and amplification of nucleic acid before its detection. To avoid the utilization of laborious steps for executing these processes, advances have been deployed in this perspective for on-chip sample preparation, amplification and detection by the introduction of an emerging field of modular microfluidics that has multiple advantages over integrated microfluidics. This review emphasizes the significance of microfluidic technology for the nucleic acid detection of infectious and non-infectious diseases. The implementation of isothermal amplification in conjunction with the lateral flow assay greatly increases the binding efficiency of nanoparticles and biomolecules and improves the limit of detection and sensitivity. Most importantly, the deployment of paper-based material made of cellulose reduces the overall cost. Microfluidic technology in nucleic acid testing has been discussed by explicating its applications in different fields. Next-generation diagnostic methods can be improved by using CRISPR/Cas technology in microfluidic systems. This review concludes with the comparison and future prospects of various microfluidic systems, detection methods and plasma separation techniques used in microfluidic devices.
      Citation: Biosensors
      PubDate: 2023-05-27
      DOI: 10.3390/bios13060584
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 585: Iodide-Mediated Etching of Gold Nanostar
           for the Multicolor Visual Detection of Hydrogen Peroxide

    • Authors: Yunping Lai, Beirong Yu, Tianran Lin, Li Hou
      First page: 585
      Abstract: A multicolor visual method for the detection of hydrogen peroxide (H2O2) was reported based on the iodide-mediated surface etching of gold nanostar (AuNS). First, AuNS was prepared by a seed-mediated method in a HEPES buffer. AuNS shows two different LSPR absorbance bands at 736 nm and 550 nm, respectively. Multicolor was generated by iodide-mediated surface etching of AuNS in the presence of H2O2. Under the optimized conditions, the absorption peak Δλ had a good linear relationship with the concentration of H2O2 with a linear range from 0.67~66.67 μmol L−1, and the detection limit is 0.44 μmol L−1. It can be used to detect residual H2O2 in tap water samples. This method offered a promising visual method for point-of-care testing of H2O2-related biomarkers.
      Citation: Biosensors
      PubDate: 2023-05-28
      DOI: 10.3390/bios13060585
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 586: Recent Advances in Conjugated
           Polymer-Based Biosensors for Virus Detection

    • Authors: Thanh Ngoc Nguyen, Viet-Duc Phung, Vinh Van Tran
      First page: 586
      Abstract: Nowadays, virus pandemics have become a major burden seriously affecting human health and social and economic development. Thus, the design and fabrication of effective and low-cost techniques for early and accurate virus detection have been given priority for prevention and control of such pandemics. Biosensors and bioelectronic devices have been demonstrated as promising technology to resolve the major drawbacks and problems of the current detection methods. Discovering and applying advanced materials have offered opportunities to develop and commercialize biosensor devices for effectively controlling pandemics. Along with various well-known materials such as gold and silver nanoparticles, carbon-based materials, metal oxide-based materials, and graphene, conjugated polymer (CPs) have become one of the most promising candidates for preparation and construction of excellent biosensors with high sensitivity and specificity to different virus analytes owing to their unique π orbital structure and chain conformation alterations, solution processability, and flexibility. Therefore, CP-based biosensors have been regarded as innovative technologies attracting great interest from the community for early diagnosis of COVID-19 as well as other virus pandemics. For providing precious scientific evidence of CP-based biosensor technologies in virus detection, this review aims to give a critical overview of the recent research related to use of CPs in fabrication of virus biosensors. We emphasize structures and interesting characteristics of different CPs and discuss the state-of-the-art applications of CP-based biosensors as well. In addition, different types of biosensors such as optical biosensors, organic thin film transistors (OTFT), and conjugated polymer hydrogels (CPHs) based on CPs are also summarized and presented.
      Citation: Biosensors
      PubDate: 2023-05-28
      DOI: 10.3390/bios13060586
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 587: Flavocytochrome b2-Mediated Electroactive
           Nanoparticles for Developing Amperometric L-Lactate Biosensors

    • Authors: Olha Demkiv, Galina Gayda, Nataliya Stasyuk, Anna Moroz, Roman Serkiz, Asta Kausaite-Minkstimiene, Mykhailo Gonchar, Marina Nisnevitch
      First page: 587
      Abstract: L-Lactate is an indicator of food quality, so its monitoring is essential. Enzymes of L-Lactate metabolism are promising tools for this aim. We describe here some highly sensitive biosensors for L-Lactate determination which were developed using flavocytochrome b2 (Fcb2) as a bio-recognition element, and electroactive nanoparticles (NPs) for enzyme immobilization. The enzyme was isolated from cells of the thermotolerant yeast Ogataea polymorpha. The possibility of direct electron transfer from the reduced form of Fcb2 to graphite electrodes has been confirmed, and the amplification of the electrochemical communication between the immobilized Fcb2 and the electrode surface was demonstrated to be achieved using redox nanomediators, both bound and freely diffusing. The fabricated biosensors exhibited high sensitivity (up to 1436 A·M−1·m−2), fast responses, and low limits of detection. One of the most effective biosensors, which contained co-immobilized Fcb2 and the hexacyanoferrate of gold, having a sensitivity of 253 A·M−1·m−2 without freely diffusing redox mediators, was used for L-Lactate analysis in samples of yogurts. A high correlation was observed between the values of analyte content determined using the biosensor and referenced enzymatic-chemical photometric methods. The developed biosensors based on Fcb2-mediated electroactive nanoparticles can be promising for applications in laboratories of food control.
      Citation: Biosensors
      PubDate: 2023-05-28
      DOI: 10.3390/bios13060587
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 588: Low Overpotential Amperometric Sensor
           Using Yb2O3.CuO@rGO Nanocomposite for Sensitive Detection of Ascorbic Acid
           in Real Samples

    • Authors: Jahir Ahmed, Mohd Faisal, Jari S. Algethami, Mabkhoot A. Alsaiari, Saeed A. Alsareii, Farid A. Harraz
      First page: 588
      Abstract: The ultimate objective of this research work is to design a sensitive and selective electrochemical sensor for the efficient detection of ascorbic acid (AA), a vital antioxidant found in blood serum that may serve as a biomarker for oxidative stress. To achieve this, we utilized a novel Yb2O3.CuO@rGO nanocomposite (NC) as the active material to modify the glassy carbon working electrode (GCE). The structural properties and morphological characteristics of the Yb2O3.CuO@rGO NC were investigated using various techniques to ensure their suitability for the sensor. The resulting sensor electrode was able to detect a broad range of AA concentrations (0.5–1571 µM) in neutral phosphate buffer solution, with a high sensitivity of 0.4341 µAµM−1cm−2 and a reasonable detection limit of 0.062 µM. The sensor’s great sensitivity and selectivity allowed it to accurately determine the levels of AA in human blood serum and commercial vitamin C tablets. It demonstrated high levels of reproducibility, repeatability, and stability, making it a reliable and robust sensor for the measurement of AA at low overpotential. Overall, the Yb2O3.CuO@rGO/GCE sensor showed great potential in detecting AA from real samples.
      Citation: Biosensors
      PubDate: 2023-05-29
      DOI: 10.3390/bios13060588
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 589: Miniaturized Rapid Electrochemical
           Immunosensor Based on Screen Printed Carbon Electrodes for Mycobacterium
           tuberculosis Detection

    • Authors: Noura Zouaghi, Shahid Aziz, Imran Shah, Ahmed Aamouche, Dong-won Jung, Brahim Lakssir, El Mostafa Ressami
      First page: 589
      Abstract: In 2019, over 21% of an estimated 10 million new tuberculosis (TB) patients were either not diagnosed at all or diagnosed without being reported to public health authorities. It is therefore critical to develop newer and more rapid and effective point-of-care diagnostic tools to combat the global TB epidemic. PCR-based diagnostic methods such as Xpert MTB/RIF are quicker than conventional techniques, but their applicability is restricted by the need for specialized laboratory equipment and the substantial cost of scaling-up in low- and middle-income countries where the burden of TB is high. Meanwhile, loop-mediated isothermal amplification (LAMP) amplifies nucleic acids under isothermal conditions with a high efficiency, helps in the early detection and identification of infectious diseases, and can be performed without the need for sophisticated thermocycling equipment. In the present study, the LAMP assay was integrated with screen-printed carbon electrodes and a commercial potentiostat for real time cyclic voltammetry analysis (named as the LAMP-Electrochemical (EC) assay). The LAMP-EC assay was found to be highly specific to TB-causing bacteria and capable of detecting even a single copy of the Mycobacterium tuberculosis (Mtb) IS6110 DNA sequence. Overall, the LAMP-EC test developed and evaluated in the present study shows promise to become a cost-effective tool for rapid and effective diagnosis of TB.
      Citation: Biosensors
      PubDate: 2023-05-29
      DOI: 10.3390/bios13060589
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 590: MoBioS: Modular Platform Technology for
           High-Throughput Construction and Characterization of Tunable
           Transcriptional Biological Sensors

    • Authors: Wouter Demeester, Jasmine De Baets, Dries Duchi, Marjan De Mey, Brecht De Paepe
      First page: 590
      Abstract: All living organisms have evolved and fine-tuned specialized mechanisms to precisely monitor a vast array of different types of molecules. These natural mechanisms can be sourced by researchers to build Biological Sensors (BioS) by combining them with an easily measurable output, such as fluorescence. Because they are genetically encoded, BioS are cheap, fast, sustainable, portable, self-generating and highly sensitive and specific. Therefore, BioS hold the potential to become key enabling tools that stimulate innovation and scientific exploration in various disciplines. However, the main bottleneck in unlocking the full potential of BioS is the fact that there is no standardized, efficient and tunable platform available for the high-throughput construction and characterization of biosensors. Therefore, a modular, Golden Gate-based construction platform, called MoBioS, is introduced in this article. It allows for the fast and easy creation of transcription factor-based biosensor plasmids. As a proof of concept, its potential is demonstrated by creating eight different, functional and standardized biosensors that detect eight diverse molecules of industrial interest. In addition, the platform contains novel built-in features to facilitate fast and efficient biosensor engineering and response curve tuning.
      Citation: Biosensors
      PubDate: 2023-05-30
      DOI: 10.3390/bios13060590
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 591: Discriminating Glioblastoma from
           Peritumoral Tissue by a Nanohole Array-Based Optical and Label-Free

    • Authors: Víctor García-Milán, Alfredo Franco, Margarita Estreya Zvezdanova, Sara Marcos, Rubén Martin-Laez, Fernando Moreno, Carlos Velasquez, José L. Fernandez-Luna
      First page: 591
      Abstract: In glioblastoma (GBM) patients, maximal safe resection remains a challenge today due to its invasiveness and diffuse parenchymal infiltration. In this context, plasmonic biosensors could potentially help to discriminate tumor tissue from peritumoral parenchyma based on differences in their optical properties. A nanostructured gold biosensor was used ex vivo to identify tumor tissue in a prospective series of 35 GBM patients who underwent surgical treatment. For each patient, two paired samples, tumor and peritumoral tissue, were extracted. Then, the imprint left by each sample on the surface of the biosensor was individually analyzed, obtaining the difference between their refractive indices. The tumor and non-tumor origins of each tissue were assessed by histopathological analysis. The refractive index (RI) values obtained by analyzing the imprint of the tissue were significantly lower (p = 0.0047) in the peritumoral samples (1.341, Interquartile Range (IQR) 1.339–1.349) compared with the tumor samples (1.350, IQR 1.344–1.363). The ROC (receiver operating characteristic) curve showed the capacity of the biosensor to discriminate between both tissues (area under the curve, 0.8779, p < 0.0001). The Youden index provided an optimal RI cut-off point of 0.003. The sensitivity and specificity of the biosensor were 81% and 80%, respectively. Overall, the plasmonic-based nanostructured biosensor is a label-free system with the potential to be used for real-time intraoperative discrimination between tumor and peritumoral tissue in patients with GBM.
      Citation: Biosensors
      PubDate: 2023-05-30
      DOI: 10.3390/bios13060591
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 592: Mach-Zehnder Interferometric Immunosensor
           for Detection of Aflatoxin M1 in Milk, Chocolate Milk, and Yogurt

    • Authors: Michailia Angelopoulou, Dimitra Kourti, Konstantinos Misiakos, Anastasios Economou, Panagiota Petrou, Sotirios Kakabakos
      First page: 592
      Abstract: Aflatoxin M1 (AFM1) is detected in the milk of animals after ingestion of aflatoxin B1-contaminated food; since 2002, it has been categorized as a group I carcinogen. In this work, a silicon-based optoelectronic immunosensor for the detection of AFM1 in milk, chocolate milk, and yogurt has been developed. The immunosensor consists of ten Mach–Zehnder silicon nitride waveguide interferometers (MZIs) integrated on the same chip with the respective light sources, and an external spectrophotometer for transmission spectra collection. The sensing arm windows of MZIs are bio-functionalized after chip activation with aminosilane by spotting an AFM1 conjugate with bovine serum albumin. For AFM1 detection, a three-step competitive immunoassay is employed, including the primary reaction with a rabbit polyclonal anti-AFM1 antibody, followed by biotinylated donkey polyclonal anti-rabbit IgG antibody and streptavidin. The assay duration was 15 min with limits of detection of 0.005 ng/mL in both full-fat and chocolate milk, and 0.01 ng/mL in yogurt, which are lower than the maximum allowable concentration of 0.05 ng/mL set by the European Union. The assay is accurate (% recovery values 86.7–115) and repeatable (inter- and intra-assay variation coefficients <8%). The excellent analytical performance of the proposed immunosensor paves the way for accurate on-site AFM1 determination in milk.
      Citation: Biosensors
      PubDate: 2023-05-30
      DOI: 10.3390/bios13060592
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 593: A Magnetic-Bead-Based Immunoassay with a
           Newly Developed Monoclonal Antibody for Rapid and Highly Sensitive
           Detection of Forchlorfenuron

    • Authors: Yubao Shan, Ting He, Ying Li, Jiang Zhu, Xiali Yue, Yunhuang Yang
      First page: 593
      Abstract: Forchlorfenuron (CPPU) is a widely used plant growth regulator in agriculture, and CPPU residue in food can cause harm to human health. Thus, it is necessary to develop a rapid and sensitive detection method for CPPU monitoring. In this study, a new monoclonal antibody (mAb) against CPPU with high affinity was prepared by a hybridoma technique, and a magnetic bead (MB)-based analytical method was established for the determination of CPPU by a one-step procedure. Under optimized conditions, the detection limit of the MB-based immunoassay was as low as 0.0004 ng/mL, which was five times more sensitive than the traditional indirect competitive ELISA (icELISA). In addition, the detection procedure took less than 35 min, a significant improvement over the 135 min required for icELISA. The selectivity test of the MB-based assay also showed negligible cross-reactivity with five analogues. Furthermore, the accuracy of the developed assay was assessed by the analysis of spiked samples, and the results agreed well with those obtained by HPLC. The excellent analytical performance of the proposed assay suggests its great potential for routine screening of CPPU, and it provides a basis for promoting the application of more immunosensors in the quantitative detection of low concentrations of small organic molecules in food.
      Citation: Biosensors
      PubDate: 2023-05-30
      DOI: 10.3390/bios13060593
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 594: Simple, Fast and Convenient Magnetic
           Bead-Based Sample Preparation for Detecting Viruses via Raman-Spectroscopy

    • Authors: Susanne Pahlow, Marie Richard-Lacroix, Franziska Hornung, Nilay Köse-Vogel, Thomas G. Mayerhöfer, Julian Hniopek, Oleg Ryabchykov, Thomas Bocklitz, Karina Weber, Ralf Ehricht, Bettina Löffler, Stefanie Deinhardt-Emmer, Jürgen Popp
      First page: 594
      Abstract: We introduce a magnetic bead-based sample preparation scheme for enabling the Raman spectroscopic differentiation of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2)-positive and -negative samples. The beads were functionalized with the angiotensin-converting enzyme 2 (ACE2) receptor protein, which is used as a recognition element to selectively enrich SARS-CoV-2 on the surface of the magnetic beads. The subsequent Raman measurements directly enable discriminating SARS-CoV-2-positive and -negative samples. The proposed approach is also applicable for other virus species when the specific recognition element is exchanged. A series of Raman spectra were measured on three types of samples, namely SARS-CoV-2, Influenza A H1N1 virus and a negative control. For each sample type, eight independent replicates were considered. All of the spectra are dominated by the magnetic bead substrate and no obvious differences between the sample types are apparent. In order to address the subtle differences in the spectra, we calculated different correlation coefficients, namely the Pearson coefficient and the Normalized cross correlation coefficient. By comparing the correlation with the negative control, differentiating between SARS-CoV-2 and Influenza A virus is possible. This study provides a first step towards the detection and potential classification of different viruses with the use of conventional Raman spectroscopy.
      Citation: Biosensors
      PubDate: 2023-05-30
      DOI: 10.3390/bios13060594
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 595: Evaluating Hyperbolic Dispersion Materials
           for Cancer Detection

    • Authors: Syed Muhammad Sohaib Zafar, Igor Iatsunskyi
      First page: 595
      Abstract: Current biosensors have limited application in clinical diagnostics as they lack the high order of specificity needed to detect low molecular analytes, especially in complex fluids (such as blood, urine, and saliva). In contrast, they are resistant to the suppression of non-specific binding. Hyperbolic metamaterials (HMMs) offer highly sought- after label-free detection and quantification techniques to circumvent sensitivity issues as low as 105 M concentration in angular sensitivity. This review discusses design strategies in detail and compares nuances in conventional plasmonic techniques to create susceptible miniaturized point-of-care devices. A substantial portion of the review is devoted to developing low optical loss reconfigurable HMM devices for active cancer bioassay platforms. A future perspective of HMM-based biosensors for cancer biomarker detection is provided.
      Citation: Biosensors
      PubDate: 2023-05-30
      DOI: 10.3390/bios13060595
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 596: Fluorescent Alloyed CdZnSeS/ZnS Nanosensor
           for Doxorubicin Detection

    • Authors: Svetlana A. Mescheryakova, Ivan S. Matlakhov, Pavel D. Strokin, Daniil D. Drozd, Irina Yu. Goryacheva, Olga A. Goryacheva
      First page: 596
      Abstract: Doxorubicin (DOX) is widely used in chemotherapy as an anti-tumor drug. However, DOX is highly cardio-, neuro- and cytotoxic. For this reason, the continuous monitoring of DOX concentrations in biofluids and tissues is important. Most methods for the determination of DOX concentrations are complex and costly, and are designed to determine pure DOX. The purpose of this work is to demonstrate the capabilities of analytical nanosensors based on the quenching of the fluorescence of alloyed CdZnSeS/ZnS quantum dots (QDs) for operative DOX detection. To maximize the nanosensor quenching efficiency, the spectral features of QDs and DOX were carefully studied, and the complex nature of QD fluorescence quenching in the presence of DOX was shown. Using optimized conditions, turn-off fluorescence nanosensors for direct DOX determination in undiluted human plasma were developed. A DOX concentration of 0.5 µM in plasma was reflected in a decrease in the fluorescence intensity of QDs, stabilized with thioglycolic and 3-mercaptopropionic acids, for 5.8 and 4.4 %, respectively. The calculated Limit of Detection values were 0.08 and 0.03 μg/mL using QDs, stabilized with thioglycolic and 3-mercaptopropionic acids, respectively.
      Citation: Biosensors
      PubDate: 2023-05-31
      DOI: 10.3390/bios13060596
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 597: Imunocapture Magnetic Beads Enhanced and
           Ultrasensitive CRISPR-Cas13a-Assisted Electrochemical Biosensor for Rapid
           Detection of SARS-CoV-2

    • Authors: Yao Han, Fan Li, Lan Yang, Xudong Guo, Xue Dong, Mengwei Niu, Yaxuan Jiang, Lin Li, Hao Li, Yansong Sun
      First page: 597
      Abstract: The rapid and ongoing spread of the coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emphasizes the urgent need for an easy and sensitive virus detection method. Here, we describe an immunocapture magnetic bead-enhanced electrochemical biosensor for ultrasensitive SARS-CoV-2 detection based on clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins, collectively known as CRISPR-Cas13a technology. At the core of the detection process, low-cast and immobilization-free commercial screen-printed carbon electrodes are used to measure the electrochemical signal, while streptavidin-coated immunocapture magnetic beads are used to reduce the background noise signal and enhance detection ability by separating the excessive report RNA, and a combination of isothermal amplification methods in the CRISPR-Cas13a system is used for nucleic acid detection. The results showed that the sensitivity of the biosensor increased by two orders of magnitude when the magnetic beads were used. The proposed biosensor required approximately 1 h of overall processing time and demonstrated an ultrasensitive ability to detect SARS-CoV-2, which could be as low as 1.66 aM. Furthermore, owing to the programmability of the CRISPR-Cas13a system, the biosensor can be flexibly applied to other viruses, providing a new approach for powerful clinical diagnostics.
      Citation: Biosensors
      PubDate: 2023-05-31
      DOI: 10.3390/bios13060597
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 598: Unlocking the Power of Nanopores: Recent
           Advances in Biosensing Applications and Analog Front-End

    • Authors: Miao Liu, Junyang Li, Cherie S. Tan
      First page: 598
      Abstract: The biomedical field has always fostered innovation and the development of various new technologies. Beginning in the last century, demand for picoampere-level current detection in biomedicine has increased, leading to continuous breakthroughs in biosensor technology. Among emerging biomedical sensing technologies, nanopore sensing has shown great potential. This paper reviews nanopore sensing applications, such as chiral molecules, DNA sequencing, and protein sequencing. However, the ionic current for different molecules differs significantly, and the detection bandwidths vary as well. Therefore, this article focuses on current sensing circuits, and introduces the latest design schemes and circuit structures of different feedback components of transimpedance amplifiers mainly used in nanopore DNA sequencing.
      Citation: Biosensors
      PubDate: 2023-05-31
      DOI: 10.3390/bios13060598
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 599: Affordable Portable Platform for Classic
           Photometry and Low-Cost Determination of Cholinesterase Activity

    • Authors: Ondřej Keresteš, Miroslav Pohanka
      First page: 599
      Abstract: Excessive use of pesticides could potentially harm the environment for a long time. The reason for this is that the banned pesticide is still likely to be used incorrectly. Carbofuran and other banned pesticides that remain in the environment may also have a negative effect on human beings. In order to provide a better chance for effective environmental screening, this thesis describes a prototype of a photometer tested with cholinesterase to potentially detect pesticides in the environment. The open-source portable photodetection platform uses a color-programmable red, green and blue light-emitting diode (RGB LED) as a light source and a TSL230R light frequency sensor. Acetylcholinesterase from Electrophorus electricus (AChE) with high similarity to human AChE was used for biorecognition. The Ellman method was selected as a standard method. Two analytical approaches were applied: (1) subtraction of the output values after a certain period of time and (2) comparison of the slope values of the linear trend. The optimal preincubation time for carbofuran with AChE was 7 min. The limits of detection for carbofuran were 6.3 nmol/L for the kinetic assay and 13.5 nmol/L for the endpoint assay. The paper demonstrates that the open alternative for commercial photometry is equivalent. The concept based on the OS3P/OS3P could be used as a large-scale screening system.
      Citation: Biosensors
      PubDate: 2023-05-31
      DOI: 10.3390/bios13060599
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 600: Improved Differential Evolution Algorithm
           for Sensitivity Enhancement of Surface Plasmon Resonance Biosensor Based
           on Two-Dimensional Material for Detection of Waterborne Bacteria

    • Authors: Lei Han, Wentao Xu, Tao Liu, Yong Zhang, Yanhua Ma, Min Jin, Chaoyu Xu
      First page: 600
      Abstract: Due to the large number of waterborne bacteria presenting in drinking water, their rapid and accurate identification has become a global priority. The surface plasmon resonance (SPR) biosensor with prism (BK7)-silver(Ag)-MXene(Ti3T2Cx)-graphene- affinity-sensing medium is examined in this paper, in which the sensing medium includes pure water, vibrio cholera (V. cholera), and escherichia coli (E. coli). For the Ag-affinity-sensing medium, the maximum sensitivity is obtained by E. coli, followed by V. cholera, and the minimum is pure water. Based on the fixed-parameter scanning (FPS) method, the highest sensitivity is 246.2 °/RIU by the MXene and graphene with monolayer, and with E. coli sensing medium. Therefore, the algorithm of improved differential evolution (IDE) is obtained. By the IDE algorithm, after three iterations, the maximum fitness value (sensitivity) of the SPR biosensor achieves 246.6 °/RIU by using the structure of Ag (61 nm)-MXene (monolayer)-graphene (monolayer)-affinity (4 nm)-E. coli. Compared with the FPS and differential evolution (DE) algorithm, the highest sensitivity is more accurate and efficient, and with fewer iterations. The performance optimization of multilayer SPR biosensors provides an efficient platform.
      Citation: Biosensors
      PubDate: 2023-05-31
      DOI: 10.3390/bios13060600
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 601: Cultured Vagal Afferent Neurons as Sensors
           for Intestinal Effector Molecules

    • Authors: Gregory Girardi, Danielle Zumpano, Noah Goshi, Helen Raybould, Erkin Seker
      First page: 601
      Abstract: The gut–brain axis embodies the bi-directional communication between the gastrointestinal tract and the central nervous system (CNS), where vagal afferent neurons (VANs) serve as sensors for a variety of gut-derived signals. The gut is colonized by a large and diverse population of microorganisms that communicate via small (effector) molecules, which also act on the VAN terminals situated in the gut viscera and consequently influence many CNS processes. However, the convoluted in vivo environment makes it difficult to study the causative impact of the effector molecules on VAN activation or desensitization. Here, we report on a VAN culture and its proof-of-principle demonstration as a cell-based sensor to monitor the influence of gastrointestinal effector molecules on neuronal behavior. We initially compared the effect of surface coatings (poly-L-lysine vs. Matrigel) and culture media composition (serum vs. growth factor supplement) on neurite growth as a surrogate of VAN regeneration following tissue harvesting, where the Matrigel coating, but not the media composition, played a significant role in the increased neurite growth. We then used both live-cell calcium imaging and extracellular electrophysiological recordings to show that the VANs responded to classical effector molecules of endogenous and exogenous origin (cholecystokinin serotonin and capsaicin) in a complex fashion. We expect this study to enable platforms for screening various effector molecules and their influence on VAN activity, assessed by their information-rich electrophysiological fingerprints.
      Citation: Biosensors
      PubDate: 2023-05-31
      DOI: 10.3390/bios13060601
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 602: Ultrafast Cancer Cells Imaging for Liquid
           Biopsy via Dynamic Self-Assembling Fluorescent Nanoclusters

    • Authors: Jinpeng Wang, Qingxiu Xia, Ke Huang, Lihong Yin, Hui Jiang, Xiaohui Liu, Xuemei Wang
      First page: 602
      Abstract: Lung cancer-specific clinical specimens, such as alveolar lavage fluid, are typically identified by microscopic biopsy, which has limited specificity and sensitivity and is highly susceptible to human manipulation. In this work, we present an ultrafast, specific, and accurate cancer cell imaging strategy based on dynamically self-assembling fluorescent nanoclusters. The presented imaging strategy can be used as an alternative or a complement to microscopic biopsy. First, we applied this strategy to detect lung cancer cells, and established an imaging method that can rapidly, specifically, and accurately distinguish lung cancer cells (e.g., A549, HepG2, MCF-7, Hela) from normal cells (e.g., Beas-2B, L02) in 1 min. In addition, we demonstrated that the dynamic self-assembly process that fluorescent nanoclusters formed by HAuCl4 and DNA are first generated at the cell membrane and then gradually enter the cytoplasm of lung cancer cells in 10 min. In addition, we validated that our method enables the rapid and accurate imaging of cancer cells in alveolar lavage fluid samples from lung cancer patients, whereas no signal was observed in the normal human samples. These results indicate that the dynamic self-assembling fluorescent nanoclusters-based cancer cells imaging strategy could be an effective non-invasive technique for ultrafast and accurate cancer bioimaging during liquid biopsy, thus providing a safe and promising cancer diagnostic platform for cancer therapy.
      Citation: Biosensors
      PubDate: 2023-05-31
      DOI: 10.3390/bios13060602
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 603: In Situ Fabricated Liquid Metal Capacitors
           for Plant Sensing

    • Authors: Sen Chen, Muzhi Jiang, Bo Wang, Xiyu Zhu, Xiaohui Shan, Jing Liu
      First page: 603
      Abstract: Capacitive sensors are essential to promoting modernization and intelligence in agriculture. With the continuous advancement of this sensor technology, the demand for materials with high conductivity and flexibility is rapidly increasing. Herein, we introduce liquid metal as a solution for the in-site fabrication of high-performance capacitive sensors for plant sensing. As a comparison, three pathways have been proposed for the preparation of flexible capacitors inside plants, as well as on their surfaces. Specifically, concealed capacitors can be constructed by directly injecting liquid metal into the plant cavity. Printable capacitors are prepared via printing Cu-doped liquid metal with better adhesion on plant surfaces. A composite liquid metal-based capacitive sensor is achieved by printing liquid metal on the plant surface and injecting it into the interior of the plant. While each method has limitations, the composite liquid metal-based capacitive sensor provides an optimal trade-off between signal capture capability and operability. As a result, this composite capacitor is chosen as a sensor for monitoring water changes within plants and demonstrates the desired sensing performance, making it a promising technology for monitoring plant physiology.
      Citation: Biosensors
      PubDate: 2023-06-01
      DOI: 10.3390/bios13060603
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 604: From Biochemical Sensor to Wearable
           Device: The Key Role of the Conductive Polymer in the Triboelectric

    • Authors: Zequan Zhao, Yajun Mi, Yin Lu, Qiliang Zhu, Xia Cao, Ning Wang
      First page: 604
      Abstract: Triboelectric nanogenerators (TENGs) have revolutionized energy harvesting and active sensing, holding tremendous potential in personalized healthcare, sustainable diagnoses, and green energy applications. In these scenarios, conductive polymers play a vital role in enhancing the performance of both TENG and TENG-based biosensors, enabling the development of flexible, wearable, and highly sensitive diagnostic devices. This review summarizes the impact of conductive polymers on TENG-based sensors, focusing on their contributions to triboelectric properties, sensitivity, detection limits, and wearability. We discuss various strategies for incorporating conductive polymers into TENG-based biosensors, promoting the creation of innovative and customizable devices tailored for specific healthcare applications. Additionally, we consider the potential of integrating TENG-based sensors with energy storage devices, signal conditioning circuits, and wireless communication modules, ultimately leading to the development of advanced, self-powered diagnostic systems. Finally, we outline the challenges and future directions in developing TENGs that integrate conducting polymers for personalized healthcare, emphasizing the need to improve biocompatibility, stability, and device integration for practical applications.
      Citation: Biosensors
      PubDate: 2023-06-01
      DOI: 10.3390/bios13060604
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 605: Application of Shear Horizontal Surface
           Acoustic Wave (SH-SAW) Immunosensor in Point-of-Care Diagnosis

    • Authors: Chia-Hsuan Cheng, Hiromi Yatsuda, Mikihiro Goto, Jun Kondoh, Szu-Heng Liu, Robert Y. L. Wang
      First page: 605
      Abstract: Point-of-care testing (POCT), also known as on-site or near-patient testing, has been exploding in the last 20 years. A favorable POCT device requires minimal sample handling (e.g., finger-prick samples, but plasma for analysis), minimal sample volume (e.g., one drop of blood), and very fast results. Shear horizontal surface acoustic wave (SH-SAW) biosensors have attracted a lot of attention as one of the effective solutions to complete whole blood measurements in less than 3 min, while providing a low-cost and small-sized device. This review provides an overview of the SH-SAW biosensor system that has been successfully commercialized for medical use. Three unique features of the system are a disposable test cartridge with an SH-SAW sensor chip, a mass-produced bio-coating, and a palm-sized reader. This paper first discusses the characteristics and performance of the SH-SAW sensor system. Subsequently, the method of cross-linking biomaterials and the analysis of SH-SAW real-time signals are investigated, and the detection range and detection limit are presented.
      Citation: Biosensors
      PubDate: 2023-06-01
      DOI: 10.3390/bios13060605
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 606: Exploring the Application of
           Multi-Resonant Bands Terahertz Metamaterials in the Field of Carbohydrate
           Films Sensing

    • Authors: Min Zhang, Guanxuan Guo, Yihan Xu, Zhibo Yao, Shoujun Zhang, Yuyue Yan, Zhen Tian
      First page: 606
      Abstract: Terahertz spectroscopy is a powerful tool for investigating the properties and states of biological matter. Here, a systematic investigation of the interaction of THz wave with “bright mode” resonators and “dark mode” resonators has been conducted, and a simple general principle of obtaining multiple resonant bands has been developed. By manipulating the number and positions of bright mode and dark mode resonant elements in metamaterials, we realized multi-resonant bands terahertz metamaterial structures with three electromagnetic-induced transparency in four-frequency bands. Different carbohydrates in the state of dried films were selected for detection, and the results showed that the multi-resonant bands metamaterial have high response sensitivity at the resonance frequency similar to the characteristic frequency of the biomolecule. Furthermore, by increasing the biomolecule mass in a specific frequency band, the frequency shift in glucose was found to be larger than that of maltose. The frequency shift in glucose in the fourth frequency band is larger than that of the second band, whereas maltose exhibits an opposing trend, thus enabling recognition of maltose and glucose. Our findings provide new insights into the design of functional multi-resonant bands metamaterials, as well as new strategies for developing multi-band metamaterial biosensing devices.
      Citation: Biosensors
      PubDate: 2023-06-02
      DOI: 10.3390/bios13060606
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 607: A Fast and Reliable Method Based on QCM-D
           Instrumentation for the Screening of Nanoparticle/Blood Protein

    • Authors: Mariacristina Gagliardi, Laura Colagiorgio, Marco Cecchini
      First page: 607
      Abstract: The interactions that nanoparticles have with blood proteins are crucial for their fate in vivo. Such interactions result in the formation of the protein corona around the nanoparticles, and studying them aids in nanoparticle optimization. Quartz crystal microbalance with dissipation monitoring (QCM-D) can be used for this study. The present work proposes a QCM-D method to study the interactions on polymeric nanoparticles with three different human blood proteins (albumin, fibrinogen and γ-globulin) by monitoring the frequency shifts of sensors immobilizing the selected proteins. Bare PEGylated and surfactant-coated poly-(D,L-lactide-co-glycolide) nanoparticles are tested. The QCM-D data are validated with DLS and UV-Vis experiments in which changes in the size and optical density of nanoparticle/protein blends are monitored. We find that the bare nanoparticles have a high affinity towards fibrinogen and γ-globulin, with measured frequency shifts around −210 Hz and −50 Hz, respectively. PEGylation greatly reduces these interactions (frequency shifts around −5 Hz and −10 Hz for fibrinogen and γ-globulin, respectively), while the surfactant appears to increase them (around −240 Hz and −100 Hz and −30 Hz for albumin). The QCM-D data are confirmed by the increase in the nanoparticle size over time (up to 3300% in surfactant-coated nanoparticles), measured by DLS in protein-incubated samples, and by the trends of the optical densities, measured by UV-Vis. The results indicate that the proposed approach is valid for studying the interactions between nanoparticles and blood proteins, and the study paves the way for a more comprehensive analysis of the whole protein corona.
      Citation: Biosensors
      PubDate: 2023-06-02
      DOI: 10.3390/bios13060607
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 608: Multi-Probe Nano-Genomic Biosensor to
           Detect S. aureus from Magnetically-Extracted Food Samples

    • Authors: Chelsie Boodoo, Emma Dester, Jeswin David, Vedi Patel, Rabin KC, Evangelyn C. Alocilja
      First page: 608
      Abstract: One of the most prevalent causes of foodborne illnesses worldwide is staphylococcal food poisoning. This study aimed to provide a robust method to extract the bacteria Staphylococcus aureus from food samples using glycan-coated magnetic nanoparticles (MNPs). Then, a cost-effective multi-probe genomic biosensor was designed to detect the nuc gene of S. aureus rapidly in different food matrices. This biosensor utilized gold nanoparticles and two DNA oligonucleotide probes combined to produce a plasmonic/colorimetric response to inform users if the sample was positive for S. aureus. In addition, the specificity and sensitivity of the biosensor were determined. For the specificity trials, the S. aureus biosensor was compared with the extracted DNA of Escherichia coli, Salmonella enterica serovar Enteritidis (SE), and Bacillus cereus. The sensitivity tests showed that the biosensor could detect as low as 2.5 ng/µL of the target DNA with a linear range of up to 20 ng/µL of DNA. With further research, this simple and cost-effective biosensor can rapidly identify foodborne pathogens from large-volume samples.
      Citation: Biosensors
      PubDate: 2023-06-02
      DOI: 10.3390/bios13060608
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 609: Raman Spectroscopy for Urea Breath Test

    • Authors: Evgeniy Popov, Anton Polishchuk, Anton Kovalev, Vladimir Vitkin
      First page: 609
      Abstract: The urea breath test is a non-invasive diagnostic method for Helicobacter pylori infections, which relies on the change in the proportion of 13CO2 in exhaled air. Nondispersive infrared sensors are commonly used for the urea breath test in laboratory equipment, but Raman spectroscopy demonstrated potential for more accurate measurements. The accuracy of the Helicobacter pylori detection via the urea breath test using 13CO2 as a biomarker is affected by measurement errors, including equipment error and δ13C measurement uncertainty. We present a Raman scattering-based gas analyzer capable of δ13C measurements in exhaled air. The technical details of the various measurement conditions have been discussed. Standard gas samples were measured. 12CO2 and 13CO2 calibration coefficients were determined. The Raman spectrum of the exhaled air was measured and the δ13C change (in the process of the urea breath test) was calculated. The total error measured was 6% and does not exceed the limit of 10% that was analytically calculated.
      Citation: Biosensors
      PubDate: 2023-06-02
      DOI: 10.3390/bios13060609
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 610: A Novel Aggregation-Induced Emission
           Fluorescent Probe for Detection of β-Amyloid Based on
           Pyridinyltriphenylamine and Quinoline–Malononitrile

    • Authors: Yan Fang, Qi Wang, Chenlong Xiang, Guijin Liu, Junjian Li
      First page: 610
      Abstract: β-amyloid is an important pathological feature of Alzheimer’s disease. Its abnormal production and aggregation in the patient’s brain is an important basis for the early diagnosis and confirmation of Alzheimer’s disease. In this study, a novel aggregation-induced emission fluorescent probe, PTPA-QM, was designed and synthesized based on pyridinyltriphenylamine and quinoline–malononitrile. These molecules exhibit a donor–donor–π–acceptor structure with a distorted intramolecular charge transfer feature. PTPA-QM displayed the advantages of good selectivity toward viscosity. The fluorescence intensity of PTPA-QM in 99% glycerol solution was 22-fold higher than that in pure DMSO. PTPA-QM has been confirmed to have excellent membrane permeability and low toxicity. More importantly, PTPA-QM exhibits a high affinity towards β-amyloid in brain sections of 5XFAD mice and classical inflammatory cognitive impairment mice. In conclusion, our work provides a promising tool for the detection of β-amyloid.
      Citation: Biosensors
      PubDate: 2023-06-02
      DOI: 10.3390/bios13060610
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 611: A SERS Composite Hydrogel Device for
           Point-of-Care Analysis of Neurotransmitter in Whole Blood

    • Authors: Lei Wu, Xuefeng Liu, Shenfei Zong, Zhuyuan Wang, Yiping Cui
      First page: 611
      Abstract: Point-of-care analysis of neurotransmitters in body fluids plays a significant role in healthcare improvement. Conventional approaches are limited by time-consuming procedures and usually require laboratory instruments for sample preparation. Herein, we developed a surface enhanced Raman spectroscopy (SERS) composite hydrogel device for the rapid analysis of neurotransmitters in whole blood samples. The PEGDA/SA composite hydrogel enabled fast separation of small molecules from the complex blood matrix, while the plasmonic SERS substrate allowed for the sensitive detection of target molecules. 3D printing was employed to integrate the hydrogel membrane and the SERS substrate into a systematic device. The sensor achieved highly sensitive detection of dopamine in whole blood samples with a limit of detection down to 1 nM. The whole detection process from sample preparation to SERS readout can be finished within 5 min. Due to the simple operation and rapid response, the device shows great potential in point-of-care diagnosis and the monitoring of neurological and cardiovascular diseases and disorders.
      Citation: Biosensors
      PubDate: 2023-06-02
      DOI: 10.3390/bios13060611
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 612: Recent Aptamer-Based Biosensors for Cd2+

    • Authors: Zihan Gao, Yin Wang, Haijian Wang, Xiangxiang Li, Youyang Xu, Jieqiong Qiu
      First page: 612
      Abstract: Cd2+, a major environmental pollutant, is heavily toxic to human health. Many traditional techniques are high-cost and complicated; thus, developing a simple, sensitive, convenient, and cheap monitoring approach is necessary. The aptamer can be obtained from a novel method called SELEX, which is widely used as a DNA biosensor for its easy acquisition and high affinity of the target, especially for heavy metal ions detection, such as Cd2+. In recent years, highly stable Cd2+ aptamer oligonucleotides (CAOs) were observed, and electrochemical, fluorescent, and colorimetric biosensors based on aptamers have been designed to monitor Cd2+. In addition, the monitoring sensitivity of aptamer-based biosensors is improved with signal amplification mechanisms such as hybridization chain reactions and enzyme-free methods. This paper reviews approaches to building biosensors for inspecting Cd2+ by electrochemical, fluorescent, and colorimetric methods. Finally, many practical applications of sensors and their implications for humans and the environment are discussed.
      Citation: Biosensors
      PubDate: 2023-06-02
      DOI: 10.3390/bios13060612
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 613: Development and Validation of Aptasensor
           Based on MnO2 for the Detection of Sulfadiazine Residues

    • Authors: Xiaoling Zheng, Lulan Yang, Qi Sun, Lei Zhang, Tao Le
      First page: 613
      Abstract: The monitoring of sulfadiazine (SDZ) is of great significance for food safety, environmental protection, and human health. In this study, a fluorescent aptasensor based on MnO2 and FAM-labeled SDZ aptamer (FAM-SDZ30-1) was developed for the sensitive and selective detection of SDZ in food and environmental samples. MnO2 nanosheets adsorbed rapidly to the aptamer through its electrostatic interaction with the base, providing the basis for an ultrasensitive SDZ detection. Molecular dynamics was used to explain the combination of SMZ1S and SMZ. This fluorescent aptasensor exhibited high sensitivity and selectivity with a limit of detection of 3.25 ng/mL and a linear range of 5–40 ng/mL. The recoveries ranged from 87.19% to 109.26% and the coefficients of variation ranged from 3.13% to 13.14%. In addition, the results of the aptasensor showed an excellent correlation with high-performance liquid chromatography (HPLC). Therefore, this aptasensor based on MnO2 is a potentially useful methodology for highly sensitive and selective detection of SDZ in foods and environments.
      Citation: Biosensors
      PubDate: 2023-06-03
      DOI: 10.3390/bios13060613
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 614: Staphylococcus aureus Detection in Milk
           Using a Thickness Shear Mode Acoustic Aptasensor with an Antifouling Probe

    • Authors: Sandro Spagnolo, Katharina Davoudian, Brian De La Franier, Tibor Hianik, Michael Thompson
      First page: 614
      Abstract: Contamination of food by pathogens can pose a serious risk to health. Therefore, monitoring for the presence of pathogens is critical to identify and regulate microbiological contamination of food. In this work, an aptasensor based on a thickness shear mode acoustic method (TSM) with dissipation monitoring was developed to detect and quantify Staphylococcus aureus directly in whole UHT cow’s milk. The frequency variation and dissipation data demonstrated the correct immobilization of the components. The analysis of viscoelastic properties suggests that DNA aptamers bind to the surface in a non-dense manner, which favors the binding with bacteria. The aptasensor demonstrated high sensitivity and was able to detect S. aureus in milk with a 33 CFU/mL limit of detection. Analysis was successful in milk due to the sensor’s antifouling properties, which is based on 3-dithiothreitol propanoic acid (DTTCOOH) antifouling thiol linker. Compared to bare and modified (dithiothreitol (DTT), 11-mercaptoundecanoic acid (MUA), and 1-undecanethiol (UDT)) quartz crystals, the sensitivity of the sensor’s antifouling in milk improved by about 82–96%. The excellent sensitivity and ability to detect and quantify S. aureus in whole UHT cow’s milk demonstrates that the system is applicable for rapid and efficient analysis of milk safety.
      Citation: Biosensors
      PubDate: 2023-06-03
      DOI: 10.3390/bios13060614
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 615: Tablet-Based Wearable Patch Sensor Design

    • Authors: Nourelhuda Mohamed, Hyun-Seok Kim, Manal Mohamed, Kyu-Min Kang, Sung-Hoon Kim, Jae Gwan Kim
      First page: 615
      Abstract: Meticulous monitoring for cardiovascular systems is important for postoperative patients in postanesthesia or the intensive care unit. The continuous auscultation of heart and lung sounds can provide a valuable information for patient safety. Although numerous research projects have proposed the design of continuous cardiopulmonary monitoring devices, they primarily focused on the auscultation of heart and lung sounds and mostly served as screening tools. However, there is a lack of devices that could continuously display and monitor the derived cardiopulmonary parameters. This study presents a novel approach to address this need by proposing a bedside monitoring system that utilizes a lightweight and wearable patch sensor for continuous cardiovascular system monitoring. The heart and lung sounds were collected using a chest stethoscope and microphones, and a developed adaptive noise cancellation algorithm was implemented to remove the background noise corrupted with those sounds. Additionally, a short-distance ECG signal was acquired using electrodes and a high precision analog front end. A high-speed processing microcontroller was used to allow real-time data acquisition, processing, and display. A dedicated tablet-based software was developed to display the acquired signal waveforms and the processed cardiovascular parameters. A significant contribution of this work is the seamless integration of continuous auscultation and ECG signal acquisition, thereby enabling the real-time monitoring of cardiovascular parameters. The wearability and lightweight design of the system were achieved through the use of rigid–flex PCBs, which ensured patient comfort and ease of use. The system provides a high-quality signal acquisition and real-time monitoring of the cardiovascular parameters, thus proving its potential as a health monitoring tool.
      Citation: Biosensors
      PubDate: 2023-06-04
      DOI: 10.3390/bios13060615
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 616: An Ultrasensitive Voltammetric Genosensor
           for the Detection of Bacteria Vibrio cholerae in Vegetable and
           Environmental Water Samples

    • Authors: Dedi Futra, Ling Ling Tan, Su Yin Lee, Benchaporn Lertanantawong, Lee Yook Heng
      First page: 616
      Abstract: In view of the presence of pathogenic Vibrio cholerae (V. cholerae) bacteria in environmental waters, including drinking water, which may pose a potential health risk to humans, an ultrasensitive electrochemical DNA biosensor for rapid detection of V. cholerae DNA in the environmental sample was developed. Silica nanospheres were functionalized with 3-aminopropyltriethoxysilane (APTS) for effective immobilization of the capture probe, and gold nanoparticles were used for acceleration of electron transfer to the electrode surface. The aminated capture probe was immobilized onto the Si-Au nanocomposite-modified carbon screen printed electrode (Si-Au-SPE) via an imine covalent bond with glutaraldehyde (GA), which served as the bifunctional cross-linking agent. The targeted DNA sequence of V. cholerae was monitored via a sandwich DNA hybridization strategy with a pair of DNA probes, which included the capture probe and reporter probe that flanked the complementary DNA (cDNA), and evaluated by differential pulse voltammetry (DPV) in the presence of an anthraquninone redox label. Under optimum sandwich hybridization conditions, the voltammetric genosensor could detect the targeted V. cholerae gene from 1.0 × 10−17–1.0 × 10−7 M cDNA with a limit of detection (LOD) of 1.25 × 10−18 M (i.e., 1.1513 × 10−13 µg/µL) and long-term stability of the DNA biosensor up to 55 days. The electrochemical DNA biosensor was capable of giving a reproducible DPV signal with a relative standard deviation (RSD) of <5.0% (n = 5). Satisfactory recoveries of V. cholerae cDNA concentration from different bacterial strains, river water, and cabbage samples were obtained between 96.5% and 101.6% with the proposed DNA sandwich biosensing procedure. The V. cholerae DNA concentrations determined by the sandwich-type electrochemical genosensor in the environmental samples were correlated to the number of bacterial colonies obtained from standard microbiological procedures (bacterial colony count reference method).
      Citation: Biosensors
      PubDate: 2023-06-04
      DOI: 10.3390/bios13060616
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 617: Aptameric Fluorescent Biosensors for Liver
           Cancer Diagnosis

    • Authors: Seonga Park, Euni Cho, Sy-Tsong Dean Chueng, June-Sun Yoon, Taek Lee, Jin-Ho Lee
      First page: 617
      Abstract: Liver cancer is a prevalent global health concern with a poor 5-year survival rate upon diagnosis. Current diagnostic techniques using the combination of ultrasound, CT scans, MRI, and biopsy have the limitation of detecting detectable liver cancer when the tumor has already progressed to a certain size, often leading to late-stage diagnoses and grim clinical treatment outcomes. To this end, there has been tremendous interest in developing highly sensitive and selective biosensors to analyze related cancer biomarkers in the early stage diagnosis and prescribe appropriate treatment options. Among the various approaches, aptamers are an ideal recognition element as they can specifically bind to target molecules with high affinity. Furthermore, using aptamers, in conjunction with fluorescent moieties, enables the development of highly sensitive biosensors by taking full advantage of structural and functional flexibility. This review will provide a summary and detailed discussion on recent aptamer-based fluorescence biosensors for liver cancer diagnosis. Specifically, the review focuses on two promising detection strategies: (i) Förster resonance energy transfer (FRET) and (ii) metal-enhanced fluorescence for detecting and characterizing protein and miRNA cancer biomarkers.
      Citation: Biosensors
      PubDate: 2023-06-04
      DOI: 10.3390/bios13060617
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 618: Recent Progress in Diboronic-Acid-Based
           Glucose Sensors

    • Authors: Ke Nan, Yu-Na Jiang, Meng Li, Bing Wang
      First page: 618
      Abstract: Non-enzymatic sensors with the capability of long-term stability and low cost are promising in glucose monitoring applications. Boronic acid (BA) derivatives offer a reversible and covalent binding mechanism for glucose recognition, which enables continuous glucose monitoring and responsive insulin release. To improve selectivity to glucose, a diboronic acid (DBA) structure design has been explored and has become a hot research topic for real-time glucose sensing in recent decades. This paper reviews the glucose recognition mechanism of boronic acids and discusses different glucose sensing strategies based on DBA-derivatives-based sensors reported in the past 10 years. The tunable pKa, electron-withdrawing properties, and modifiable group of phenylboronic acids were explored to develop various sensing strategies, including optical, electrochemical, and other methods. However, compared to the numerous monoboronic acid molecules and methods developed for glucose monitoring, the diversity of DBA molecules and applied sensing strategies remains limited. The challenges and opportunities are also highlighted for the future of glucose sensing strategies, which need to consider practicability, advanced medical equipment fitment, patient compliance, as well as better selectivity and tolerance to interferences.
      Citation: Biosensors
      PubDate: 2023-06-04
      DOI: 10.3390/bios13060618
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 619: A Label-Free Carbohydrate-Based
           Electrochemical Sensor to Detect Escherichia coli Pathogenic Bacteria
           Using D-mannose on a Glassy Carbon Electrode

    • Authors: Sakineh Hargol Zadeh, Soheila Kashanian, Maryam Nazari
      First page: 619
      Abstract: Controlling water and food contamination by pathogenic organisms requires quick, simple, and low-cost methods. Using the affinity between mannose and type I fimbriae in the cell wall of Escherichia coli (E. coli) bacteria as evaluation elements compared to the conventional plate counting technique enables a reliable sensing platform for the detection of bacteria. In this study, a simple new sensor was developed based on electrochemical impedance spectroscopy (EIS) for rapid and sensitive detection of E. coli. The biorecogniton layer of the sensor was formed by covalent attachment of p-carboxyphenylamino mannose (PCAM) to gold nanoparticles (AuNPs) electrodeposited on the surface of a glassy carbon electrode (GCE). The resultant structure of PCAM was characterized and confirmed using a Fourier Transform Infrared Spectrometer (FTIR). The developed biosensor demonstrated a linear response with a logarithm of bacterial concentration (R2 = 0.998) in the range of 1.3 × 10 1~1.3 × 106 CFU·mL−1 with the limit of detection of 2 CFU·mL−1 within 60 min. The sensor did not generate any significant signals with two non-target strains, demonstrating the high selectivity of the developed biorecognition chemistry. The selectivity of the sensor and its applicability to analysis of the real samples were investigated in tap water and low-fat milk samples. Overall, the developed sensor showed to be promising for the detection of E. coli pathogens in water and low-fat milk due to its high sensitivity, short detection time, low cost, high specificity, and user-friendliness.
      Citation: Biosensors
      PubDate: 2023-06-05
      DOI: 10.3390/bios13060619
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 620: Molecularly Imprinted Polymer-Based
           Electrochemical Sensors for the Diagnosis of Infectious Diseases

    • Authors: Greta Pilvenyte, Vilma Ratautaite, Raimonda Boguzaite, Simonas Ramanavicius, Chien-Fu Chen, Roman Viter, Arunas Ramanavicius
      First page: 620
      Abstract: The appearance of biological molecules, so-called biomarkers in body fluids at abnormal concentrations, is considered a good tool for detecting disease. Biomarkers are usually looked for in the most common body fluids, such as blood, nasopharyngeal fluids, urine, tears, sweat, etc. Even with significant advances in diagnostic technology, many patients with suspected infections receive empiric antimicrobial therapy rather than appropriate treatment, which is driven by rapid identification of the infectious agent, leading to increased antimicrobial resistance. To positively impact healthcare, new tests are needed that are pathogen-specific, easy to use, and produce results quickly. Molecularly imprinted polymer (MIP)-based biosensors can achieve these general goals and have enormous potential for disease detection. This article aimed to overview recent articles dedicated to electrochemical sensors modified with MIP to detect protein-based biomarkers of certain infectious diseases in human beings, particularly the biomarkers of infectious diseases, such as HIV-1, COVID-19, Dengue virus, and others. Some biomarkers, such as C-reactive protein (CRP) found in blood tests, are not specific for a particular disease but are used to identify any inflammation process in the body and are also under consideration in this review. Other biomarkers are specific to a particular disease, e.g., SARS-CoV-2-S spike glycoprotein. This article analyzes the development of electrochemical sensors using molecular imprinting technology and the used materials’ influence. The research methods, the application of different electrodes, the influence of the polymers, and the established detection limits are reviewed and compared.
      Citation: Biosensors
      PubDate: 2023-06-05
      DOI: 10.3390/bios13060620
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 621: Biofunctionalisation of Polypyrrole
           Nanowires Array with Sulfite Oxidase Coupled with the Integration of
           Platinum Nanoparticles for Ultrasensitive Amperometric Detection of

    • Authors: Shahid Hussain, Samuel B. Adeloju
      First page: 621
      Abstract: Sulfite determination in foods and alcoholic beverages is a common requirement by food and drug administration organisations in most countries. In this study, the enzyme, sulfite oxidase (SOx), is used to biofunctionalise a platinum-nanoparticle-modified polypyrrole nanowire array (PPyNWA) for the ultrasensitive amperometric detection of sulfite. A dual-step anodisation method was used to prepare the anodic aluminum oxide membrane used as a template for the initial fabrication of the PPyNWA. PtNPs were subsequently deposited on the PPyNWA by potential cycling in a platinum solution. The resulting PPyNWA-PtNP electrode was then biofuntionalised by adsorption of SOx onto the surface. The confirmation of the adsorption of SOx and the presence of PtNPs in the PPyNWA-PtNPs-SOx biosensor was verified by scanning electron microscopy and electron dispersive X-ray spectroscopy. Cyclic voltammetry and amperometric measurements were used to investigate the properties of the nanobiosensor and to optimise its use for sulfite detection. Ultrasensitive detection of sulfite with the PPyNWA-PtNPs-SOx nanobiosensor was accomplished by use of 0.3 M pyrrole, 10 U mL−1 of SOx, adsorption time of 8 h, a polymerisation period of 900 s, and an applied current density of 0.7 mA cm−2. The response time of the nanobiosensor was 2 s, and its excellent analytical performance was substantiated with a sensitivity of 57.33 μA cm−2 mM−1, a limit of detection of 12.35 nM, and a linear response range from 0.12 to 1200 μM. Application of the nanobiosensor to sulfite determination in beer and wine samples was achieved with a recovery efficiency of 97–103%.
      Citation: Biosensors
      PubDate: 2023-06-05
      DOI: 10.3390/bios13060621
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 622: Novel Approaches to Enzyme-Based
           Electrochemical Nanobiosensors

    • Authors: Nur Melis Kilic, Sima Singh, Gulsu Keles, Stefano Cinti, Sevinc Kurbanoglu, Dilek Odaci
      First page: 622
      Abstract: Electrochemistry is a genuinely interdisciplinary science that may be used in various physical, chemical, and biological domains. Moreover, using biosensors to quantify biological or biochemical processes is critical in medical, biological, and biotechnological applications. Nowadays, there are several electrochemical biosensors for various healthcare applications, such as for the determination of glucose, lactate, catecholamines, nucleic acid, uric acid, and so on. Enzyme-based analytical techniques rely on detecting the co-substrate or, more precisely, the products of a catalyzed reaction. The glucose oxidase enzyme is generally used in enzyme-based biosensors to measure glucose in tears, blood, etc. Moreover, among all nanomaterials, carbon-based nanomaterials have generally been utilized thanks to the unique properties of carbon. The sensitivity can be up to pM levels using enzyme-based nanobiosensor, and these sensors are very selective, as all enzymes are specific for their substrates. Furthermore, enzyme-based biosensors frequently have fast reaction times, allowing for real-time monitoring and analyses. These biosensors, however, have several drawbacks. Changes in temperature, pH, and other environmental factors can influence the stability and activity of the enzymes, affecting the reliability and repeatability of the readings. Additionally, the cost of the enzymes and their immobilization onto appropriate transducer surfaces might be prohibitively expensive, impeding the large-scale commercialization and widespread use of biosensors. This review discusses the design, detection, and immobilization techniques for enzyme-based electrochemical nanobiosensors, and recent applications in enzyme-based electrochemical studies are evaluated and tabulated.
      Citation: Biosensors
      PubDate: 2023-06-05
      DOI: 10.3390/bios13060622
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 623: Proof-of-Concept: Smartphone- and
           Cloud-Based Artificial Intelligence Quantitative Analysis System (SCAISY)
           for SARS-CoV-2-Specific IgG Antibody Lateral Flow Assays

    • Authors: Samir Kumar, Taewoo Ko, Yeonghun Chae, Yuyeon Jang, Inha Lee, Ahyeon Lee, Sanghoon Shin, Myung-Hyun Nam, Byung Soo Kim, Hyun Sik Jun, Sungkyu Seo
      First page: 623
      Abstract: Smartphone-based point-of-care testing (POCT) is rapidly emerging as an alternative to traditional screening and laboratory testing, particularly in resource-limited settings. In this proof-of-concept study, we present a smartphone- and cloud-based artificial intelligence quantitative analysis system (SCAISY) for relative quantification of SARS-CoV-2-specific IgG antibody lateral flow assays that enables rapid evaluation (<60 s) of test strips. By capturing an image with a smartphone camera, SCAISY quantitatively analyzes antibody levels and provides results to the user. We analyzed changes in antibody levels over time in more than 248 individuals, including vaccine type, number of doses, and infection status, with a standard deviation of less than 10%. We also tracked antibody levels in six participants before and after SARS-CoV-2 infection. Finally, we examined the effects of lighting conditions, camera angle, and smartphone type to ensure consistency and reproducibility. We found that images acquired between 45° and 90° provided accurate results with a small standard deviation and that all illumination conditions provided essentially identical results within the standard deviation. A statistically significant correlation was observed (Spearman correlation coefficient: 0.59, p = 0.008; Pearson correlation coefficient: 0.56, p = 0.012) between the OD450 values of the enzyme-linked immunosorbent assay and the antibody levels obtained by SCAISY. This study suggests that SCAISY is a simple and powerful tool for real-time public health surveillance, enabling the acceleration of quantifying SARS-CoV-2-specific antibodies generated by either vaccination or infection and tracking of personal immunity levels.
      Citation: Biosensors
      PubDate: 2023-06-05
      DOI: 10.3390/bios13060623
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 624: Magnetic Relaxation Switching Assay Using
           IFNα-2b-Conjugated Superparamagnetic Nanoparticles for
           Anti-Interferon Antibody Detection

    • Authors: Boris Nikolaev, Ludmila Yakovleva, Viacheslav Fedorov, Natalia Yudintceva, Vyacheslav Ryzhov, Yaroslav Marchenko, Alexander Ischenko, Alexander Zhakhov, Anatoliy Dobrodumov, Stephanie E. Combs, Huile Gao, Maxim Shevtsov
      First page: 624
      Abstract: Type I interferons, particularly IFNα-2b, play essential roles in eliciting adaptive and innate immune responses, being implicated in the pathogenesis of various diseases, including cancer, and autoimmune and infectious diseases. Therefore, the development of a highly sensitive platform for analysis of either IFNα-2b or anti-IFNα-2b antibodies is of high importance to improve the diagnosis of various pathologies associated with the IFNα-2b disbalance. For evaluation of the anti-IFNα-2b antibody level, we have synthesized superparamagnetic iron oxide nanoparticles (SPIONs) coupled with the recombinant human IFNα-2b protein (SPIONs@IFNα-2b). Employing a magnetic relaxation switching assay (MRSw)-based nanosensor, we detected picomolar concentrations (0.36 pg/mL) of anti-INFα-2b antibodies. The high sensitivity of the real-time antibodies’ detection was ensured by the specificity of immune responses and the maintenance of resonance conditions for water spins by choosing a high-frequency filling of short radio-frequency pulses of the generator. The formation of a complex of the SPIONs@IFNα-2b nanoparticles with the anti-INFα-2b antibodies led to a cascade process of the formation of nanoparticle clusters, which was further enhanced by exposure to a strong (7.1 T) homogenous magnetic field. Obtained magnetic conjugates exhibited high negative MR contrast-enhancing properties (as shown by NMR studies) that were also preserved when particles were administered in vivo. Thus, we observed a 1.2-fold decrease of the T2 relaxation time in the liver following administration of magnetic conjugates as compared to the control. In conclusion, the developed MRSw assay based on SPIONs@IFNα-2b nanoparticles represents an alternative immunological probe for the estimation of anti-IFNα-2b antibodies that could be further employed in clinical studies.
      Citation: Biosensors
      PubDate: 2023-06-05
      DOI: 10.3390/bios13060624
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 625: Special Issue in “Nanomaterials and
           Their Applications in Sensing and Biosensing”

    • Authors: Shabi Abbas Zaidi, Faisal Shahzad, Asad Abbas
      First page: 625
      Abstract: The identification of the target molecule is required for rapid and reliable clinical diagnosis and disease monitoring [...]
      Citation: Biosensors
      PubDate: 2023-06-06
      DOI: 10.3390/bios13060625
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 626: Carbon Electrode Sensor for the
           Measurement of Cortisol with Fast-Scan Cyclic Voltammetry

    • Authors: Michelle Hadad, Nadine Hadad, Alexander G. Zestos
      First page: 626
      Abstract: Cortisol is a vital steroid hormone that has been known as the “stress hormone”, which is elevated during times of high stress and anxiety and has a significant impact on neurochemistry and brain health. The improved detection of cortisol is critically important as it will help further our understanding of stress during several physiological states. Several methods exist to detect cortisol; however, they suffer from low biocompatibility and spatiotemporal resolution, and they are relatively slow. In this study, we developed an assay to measure cortisol with carbon fiber microelectrodes (CFMEs) and fast-scan cyclic voltammetry (FSCV). FSCV is typically utilized to measure small molecule neurotransmitters by producing a readout cyclic voltammogram (CV) for the specific detection of biomolecules on a fast, subsecond timescale with biocompatible CFMEs. It has seen enhanced utility in measuring peptides and other larger compounds. We developed a waveform that scanned from −0.5 to −1.2 V at 400 V/s to electro-reduce cortisol at the surface of CFMEs. The sensitivity of cortisol was found to be 0.87 ± 0.055 nA/μM (n = 5) and was found to be adsorption controlled on the surface of CFMEs and stable over several hours. Cortisol was co-detected with several other biomolecules such as dopamine, and the waveform was fouling resistant to repeated injections of cortisol on the surface of the CFMEs. Furthermore, we also measured exogenously applied cortisol into simulated urine to demonstrate biocompatibility and potential use in vivo. The specific and biocompatible detection of cortisol with high spatiotemporal resolution will help further elucidate its biological significance and further understand its physiological importance and impact on brain health.
      Citation: Biosensors
      PubDate: 2023-06-06
      DOI: 10.3390/bios13060626
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 627: A Novel Urine Test Biosensor Platform for
           Early Lung Cancer Detection

    • Authors: Ory Wiesel, Sook-Whan Sung, Amit Katz, Raya Leibowitz, Jair Bar, Iris Kamer, Itay Berger, Inbal Nir-Ziv, Michal Mark Danieli
      First page: 627
      Abstract: Lung cancer is the leading cause of cancer-related mortality worldwide. Early detection is essential to achieving a better outcome and prognosis. Volatile organic compounds (VOCs) reflect alterations in the pathophysiology and body metabolism processes, as shown in various types of cancers. The biosensor platform (BSP) urine test uses animals’ unique, proficient, and accurate ability to scent lung cancer VOCs. The BSP is a testing platform for the binary (negative/positive) recognition of the signature VOCs of lung cancer by trained and qualified Long–Evans rats as biosensors (BSs). The results of the current double-blind study show high accuracy in lung cancer VOC recognition, with 93% sensitivity and 91% specificity. The BSP test is safe, rapid, objective and can be performed repetitively, enabling periodic cancer monitoring as well as an aid to existing diagnostic methods. The future implementation of such urine tests as routine screening and monitoring tools has the potential to significantly increase detection rate as well as curability rates with lower healthcare expenditure. This paper offers a first instructive clinical platform utilizing VOC’s in urine for detection of lung cancer using the innovative BSP to deal with the pressing need for an early lung cancer detection test tool.
      Citation: Biosensors
      PubDate: 2023-06-06
      DOI: 10.3390/bios13060627
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 628: Vertically-Ordered Mesoporous Silica Film
           Based Electrochemical Aptasensor for Highly Sensitive Detection of
           Alpha-Fetoprotein in Human Serum

    • Authors: Tongtong Zhang, Luoxiang Yang, Fei Yan, Kai Wang
      First page: 628
      Abstract: Convenient and rapid detection of alpha fetoprotein (AFP) is vital for early diagnosis of hepatocellular carcinoma. In this work, low-cost (0.22 USD for single sensor) and stable (during 6 days) electrochemical aptasensor was developed for highly sensitive and direct detection of AFP in human serum with the assist of vertically-ordered mesoporous silica films (VMSF). VMSF has silanol groups on the surface and regularly ordered nanopores, which could provide binding sites for further functionalization of recognition aptamer and also confer the sensor with excellent anti-biofouling capacity. The sensing mechanism relies on the target AFP-controlled diffusion of Fe(CN)63−/4− redox electrochemical probe through the nanochannels of VMSF. The resulting reduced electrochemical responses are related to the AFP concentration, allowing the linear determination of AFP with a wide dynamic linear range and a low limit of detection. Accuracy and potential of the developed aptasensor were also demonstrated in human serum by standard addition method.
      Citation: Biosensors
      PubDate: 2023-06-06
      DOI: 10.3390/bios13060628
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 629: Engineering of a Bacterial Biosensor for
           the Detection of Chlorate in Food

    • Authors: Alexandra Vergnes, Jérôme Becam, Laurent Loiseau, Benjamin Ezraty
      First page: 629
      Abstract: Chlorate can contaminate food due to the use of chlorinated water for processing or equipment disinfection. Chronic exposure to chlorate in food and drinking water is a potential health concern. The current methods for detecting chlorate in liquids and foods are expensive and not easily accessible to all laboratories, highlighting an urgent need for a simple and cost-effective method. The discovery of the adaptation mechanism of Escherichia coli to chlorate stress, which involves the production of the periplasmic Methionine Sulfoxide Reductase (MsrP), prompted us to use an E. coli strain with an msrP-lacZ fusion as a biosensor for detecting chlorate. Our study aimed to optimize the bacterial biosensor’s sensitivity and efficiency to detect chlorate in various food samples using synthetic biology and adapted growth conditions. Our results demonstrate successful biosensor enhancement and provide proof of concept for detecting chlorate in food samples.
      Citation: Biosensors
      PubDate: 2023-06-06
      DOI: 10.3390/bios13060629
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 630: Flexible and Wearable Biosensors for
           Monitoring Health Conditions

    • Authors: Zhimin Song, Shu Zhou, Yanxia Qin, Xiangjiao Xia, Yanping Sun, Guanghong Han, Tong Shu, Liang Hu, Qiang Zhang
      First page: 630
      Abstract: Flexible and wearable biosensors have received tremendous attention over the past decade owing to their great potential applications in the field of health and medicine. Wearable biosensors serve as an ideal platform for real-time and continuous health monitoring, which exhibit unique properties such as self-powered, lightweight, low cost, high flexibility, detection convenience, and great conformability. This review introduces the recent research progress in wearable biosensors. First of all, the biological fluids often detected by wearable biosensors are proposed. Then, the existing micro-nanofabrication technologies and basic characteristics of wearable biosensors are summarized. Then, their application manners and information processing are also highlighted in the paper. Massive cutting-edge research examples are introduced such as wearable physiological pressure sensors, wearable sweat sensors, and wearable self-powered biosensors. As a significant content, the detection mechanism of these sensors was detailed with examples to help readers understand this area. Finally, the current challenges and future perspectives are proposed to push this research area forward and expand practical applications in the future.
      Citation: Biosensors
      PubDate: 2023-06-07
      DOI: 10.3390/bios13060630
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 631: Recent Advances in Metaphotonic Biosensors

    • Authors: Dang Du Nguyen, Seho Lee, Inki Kim
      First page: 631
      Abstract: Metaphotonic devices, which enable light manipulation at a subwavelength scale and enhance light–matter interactions, have been emerging as a critical pillar in biosensing. Researchers have been attracted to metaphotonic biosensors, as they solve the limitations of the existing bioanalytical techniques, including the sensitivity, selectivity, and detection limit. Here, we briefly introduce types of metasurfaces utilized in various metaphotonic biomolecular sensing domains such as refractometry, surface-enhanced fluorescence, vibrational spectroscopy, and chiral sensing. Further, we list the prevalent working mechanisms of those metaphotonic bio-detection schemes. Furthermore, we summarize the recent progress in chip integration for metaphotonic biosensing to enable innovative point-of-care devices in healthcare. Finally, we discuss the impediments in metaphotonic biosensing, such as its cost effectiveness and treatment for intricate biospecimens, and present a prospect for potential directions for materializing these device strategies, significantly influencing clinical diagnostics in health and safety.
      Citation: Biosensors
      PubDate: 2023-06-07
      DOI: 10.3390/bios13060631
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 632: Progress in the Optical Sensing of Cardiac

    • Authors: Cristina Polonschii, Monica Potara, Madalina Iancu, Sorin David, Roberta Maria Banciu, Alina Vasilescu, Simion Astilean
      First page: 632
      Abstract: Biomarkers play key roles in the diagnosis, risk assessment, treatment and supervision of cardiovascular diseases (CVD). Optical biosensors and assays are valuable analytical tools answering the need for fast and reliable measurements of biomarker levels. This review presents a survey of recent literature with a focus on the past 5 years. The data indicate continuing trends towards multiplexed, simpler, cheaper, faster and innovative sensing while newer tendencies concern minimizing the sample volume or using alternative sampling matrices such as saliva for less invasive assays. Utilizing the enzyme-mimicking activity of nanomaterials gained ground in comparison to their more traditional roles as signaling probes, immobilization supports for biomolecules and for signal amplification. The growing use of aptamers as replacements for antibodies prompted emerging applications of DNA amplification and editing techniques. Optical biosensors and assays were tested with larger sets of clinical samples and compared with the current standard methods. The ambitious goals on the horizon for CVD testing include the discovery and determination of relevant biomarkers with the help of artificial intelligence, more stable specific recognition elements for biomarkers and fast, cheap readers and disposable tests to facilitate rapid testing at home. As the field is progressing at an impressive pace, the opportunities for biosensors in the optical sensing of CVD biomarkers remain significant.
      Citation: Biosensors
      PubDate: 2023-06-07
      DOI: 10.3390/bios13060632
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 633: Application of Metabolite-Responsive
           Biosensors for Plant Natural Products Biosynthesis

    • Authors: Jianli Zhang, Xinyu Gong, Qi Gan, Yajun Yan
      First page: 633
      Abstract: Plant natural products (PNPs) have shown various pharmaceutical activities, possessing great potential in global markets. Microbial cell factories (MCFs) provide an economical and sustainable alternative for the synthesis of valuable PNPs compared with traditional approaches. However, the heterologous synthetic pathways always lack native regulatory systems, bringing extra burden to PNPs production. To overcome the challenges, biosensors have been exploited and engineered as powerful tools for establishing artificial regulatory networks to control enzyme expression in response to environments. Here, we reviewed the recent progress involved in the application of biosensors that are responsive to PNPs and their precursors. Specifically, the key roles these biosensors played in PNP synthesis pathways, including isoprenoids, flavonoids, stilbenoids and alkaloids, were discussed in detail.
      Citation: Biosensors
      PubDate: 2023-06-07
      DOI: 10.3390/bios13060633
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 634: Electrical/Optical Biosensing and
           Regulating Technology

    • Authors: Ning Hu, Hao Wan
      First page: 634
      Abstract: Biosensing has emerged as a powerful tool for exploring biomedical mechanisms [...]
      Citation: Biosensors
      PubDate: 2023-06-08
      DOI: 10.3390/bios13060634
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 635: Rapid and Simple Buffer Exchange Using
           Cation-Exchange Chromatography to Improve Point-of-Care Detection of
           Pharmacological Agents

    • Authors: Michael C. Brothers, Maegan Kornexl, Barlow Guess, Yuri Kim, Darrin Ott, Jennifer A. Martin, Dara Regn, Steve S. Kim
      First page: 635
      Abstract: The current COVID-19 pandemic has highlighted the power, speed, and simplicity of point-of-care (POC) diagnostics. POC diagnostics are available for a wide range of targets, including both drugs of abuse as well as performance-enhancing drugs. For pharmacological monitoring, minimally invasive fluids such as urine and saliva are commonly sampled. However, false positives or negatives caused by interfering agents excreted in these matrices may confound results. For example, false positives have, in most cases, prevented the use of POC diagnostics for pharmacological agent detection; the consequence is that centralized labs are instead tasked to perform these screenings, resulting in significant delays between sampling and testing. Thus, a rapid, simple, and inexpensive methodology for sample purification is required for the POC to reach a field-deployable tool for the pharmacological human health and performance assessments. Buffer exchange is a simple, rapid approach to remove interfering agents, but has traditionally been difficult to perform on small pharmacological molecules. Therefore, in this communication, we use salbutamol, a performance-enhancing drug, as a case example to demonstrate the efficacy of ion-exchange chromatography as a technique to perform buffer exchange for charged pharmacological agents. This manuscript demonstrates the efficacy of this technique leveraging a commercial spin column to remove interfering agents found in simulant urines, such as proteins, creatinine, and urea, while retaining salbutamol. The utility and efficacy of the method was then confirmed in actual saliva samples. The eluent was then collected and run on the lateral flow assays (LFAs), improving the reported limit of detection by over 5× (new lower limit of detection of 10 ppb compared to reported 60 ppb by the manufacturer) while simultaneously removing noise due to background interfering agents.
      Citation: Biosensors
      PubDate: 2023-06-08
      DOI: 10.3390/bios13060635
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 636: Rational Fabrication of Ionic Covalent
           Organic Frameworks for Chemical Analysis Applications

    • Authors: Jing Yu, Liuna Luo, Hong Shang, Bing Sun
      First page: 636
      Abstract: The rapid development of advanced material science boosts novel chemical analytical technologies for effective pretreatment and sensitive sensing applications in the fields of environmental monitoring, food security, biomedicines, and human health. Ionic covalent organic frameworks (iCOFs) emerge as a class of covalent organic frameworks (COFs) with electrically charged frames or pores as well as predesigned molecular and topological structures, large specific surface area, high crystallinity, and good stability. Benefiting from the pore size interception effect, electrostatic interaction, ion exchange, and recognizing group load, iCOFs exhibit the promising ability to extract specific analytes and enrich trace substances from samples for accurate analysis. On the other hand, the stimuli response of iCOFs and their composites to electrochemical, electric, or photo-irradiating sources endows them as potential transducers for biosensing, environmental analysis, surroundings monitoring, etc. In this review, we summarized the typical construction of iCOFs and focused on their rational structure design for analytical extraction/enrichment and sensing applications in recent years. The important role of iCOFs in the chemical analysis was fully highlighted. Finally, the opportunities and challenges of iCOF-based analytical technologies were also discussed, which may be beneficial to provide a solid foundation for further design and application of iCOFs.
      Citation: Biosensors
      PubDate: 2023-06-08
      DOI: 10.3390/bios13060636
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 637: Respiratory Rate Estimation during Walking
           and Running Using Breathing Sounds Recorded with a Microphone

    • Authors: Chiara Romano, Andrea Nicolò, Lorenzo Innocenti, Marco Bravi, Sandra Miccinilli, Silvia Sterzi, Massimo Sacchetti, Emiliano Schena, Carlo Massaroni
      First page: 637
      Abstract: Emerging evidence suggests that respiratory frequency (fR) is a valid marker of physical effort. This has stimulated interest in developing devices that allow athletes and exercise practitioners to monitor this vital sign. The numerous technical challenges posed by breathing monitoring in sporting scenarios (e.g., motion artifacts) require careful consideration of the variety of sensors potentially suitable for this purpose. Despite being less prone to motion artifacts than other sensors (e.g., strain sensors), microphone sensors have received limited attention so far. This paper proposes the use of a microphone embedded in a facemask for estimating fR from breath sounds during walking and running. fR was estimated in the time domain as the time elapsed between consecutive exhalation events retrieved from breathing sounds every 30 s. Data were collected from ten healthy subjects (both males and females) at rest and during walking (at 3 km/h and 6 km/h) and running (at 9 km/h and 12 km/h) activities. The reference respiratory signal was recorded with an orifice flowmeter. The mean absolute error (MAE), the mean of differences (MOD), and the limits of agreements (LOAs) were computed separately for each condition. Relatively good agreement was found between the proposed system and the reference system, with MAE and MOD values increasing with the increase in exercise intensity and ambient noise up to a maximum of 3.8 bpm (breaths per minute) and −2.0 bpm, respectively, during running at 12 km/h. When considering all the conditions together, we found an MAE of 1.7 bpm and an MOD ± LOAs of −0.24 ± 5.07 bpm. These findings suggest that microphone sensors can be considered among the suitable options for estimating fR during exercise.
      Citation: Biosensors
      PubDate: 2023-06-08
      DOI: 10.3390/bios13060637
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 638: A Novel Polyurethane-Based Polyion Complex
           Material with Tunable Selectivity against Interferents for Selective
           Dopamine Determination

    • Authors: Zixin Zhang, Hongchen Guo, Yuugo Hirai, Katsunori Takeda, Chiho Asai, Naohiro Takamura, Osamu Niwa
      First page: 638
      Abstract: Polyion complex (PIC) materials have been widely used in biosensors due to their molecular selectivity. However, achieving both widely controllable molecular selectivity and long-term solution stability with traditional PIC materials has been challenging due to the different molecular structures of polycations (poly-C) and polyanions (poly-A). To address this issue, we propose a novel polyurethane (PU)-based PIC material in which the main chains of both poly-A and poly-C are composed of PU structures. In this study, we electrochemically detect dopamine (DA) as the analyte and L-ascorbic acid (AA) and uric acid (UA) as the interferents to evaluate the selective property of our material. The results show that AA and UA are significantly eliminated, while DA can be detected with a high sensitivity and selectivity. Moreover, we successfully tune the sensitivity and selectivity by changing the poly-A and poly-C ratios and adding nonionic polyurethane. These excellent results were employed in the development of a highly selective DA biosensor with a detection range from 500 nM to 100 μM and a 3.4 μM detection limit. Overall, our novel PIC-modified electrode has the potential to advance biosensing technologies for molecular detection.
      Citation: Biosensors
      PubDate: 2023-06-09
      DOI: 10.3390/bios13060638
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 639: Using a Smartphone-Based Colorimetric
           Device with Molecularly Imprinted Polymer for the Quantification of
           Tartrazine in Soda Drinks

    • Authors: Christian Jacinto, Ily Maza Mejía, Sabir Khan, Rosario López, Maria D. P. T. Sotomayor, Gino Picasso
      First page: 639
      Abstract: The present study reports the development and application of a rapid, low-cost in-situ method for the quantification of tartrazine in carbonated beverages using a smartphone-based colorimetric device with molecularly imprinted polymer (MIP). The MIP was synthesized using the free radical precipitation method with acrylamide (AC) as the functional monomer, N,N′-methylenebisacrylamide (NMBA) as the cross linker, and potassium persulfate (KPS) as radical initiator. The smartphone (RadesPhone)-operated rapid analysis device proposed in this study has dimensions of 10 × 10 × 15 cm and is illuminated internally by light emitting diode (LED) lights with intensity of 170 lux. The analytical methodology involved the use of a smartphone camera to capture images of MIP at various tartrazine concentrations, and the subsequent application of the Image-J software to calculate the red, green, blue (RGB) color values and hue, saturation, value (HSV) values from these images. A multivariate calibration analysis of tartrazine in the range of 0 to 30 mg/L was performed, and the optimum working range was determined to be 0 to 20 mg/L using five principal components and a limit of detection (LOD) of 1.2 mg/L was obtained. Repeatability analysis of tartrazine solutions with concentrations of 4, 8, and 15 mg/L (n = 10) showed a coefficient of variation (% RSD) of less than 6%. The proposed technique was applied to the analysis of five Peruvian soda drinks and the results were compared with the UHPLC reference method. The proposed technique showed a relative error between 6% and 16% and % RSD lower than 6.3%. The results of this study demonstrate that the smartphone-based device is a suitable analytical tool that offers an on-site, cost-effective, and rapid alternative for the quantification of tartrazine in soda drinks. This color analysis device can be used in other molecularly imprinted polymer systems and offers a wide range of possibilities for the detection and quantification of compounds in various industrial and environmental matrices that generate a color change in the MIP matrix.
      Citation: Biosensors
      PubDate: 2023-06-09
      DOI: 10.3390/bios13060639
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 640: Antibody Phage Display Technology for
           Sensor-Based Virus Detection: Current Status and Future Prospects

    • Authors: Olga I. Guliy, Stella S. Evstigneeva, Vitaly A. Khanadeev, Lev A. Dykman
      First page: 640
      Abstract: Viruses are widespread in the environment, and many of them are major pathogens of serious plant, animal, and human diseases. The risk of pathogenicity, together with the capacity for constant mutation, emphasizes the need for measures to rapidly detect viruses. The need for highly sensitive bioanalytical methods to diagnose and monitor socially significant viral diseases has increased in the past few years. This is due, on the one hand, to the increased incidence of viral diseases in general (including the unprecedented spread of a new coronavirus infection, SARS-CoV-2), and, on the other hand, to the need to overcome the limitations of modern biomedical diagnostic methods. Phage display technology antibodies as nano-bio-engineered macromolecules can be used for sensor-based virus detection. This review analyzes the commonly used virus detection methods and approaches and shows the prospects for the use of antibodies prepared by phage display technology as sensing elements for sensor-based virus detection.
      Citation: Biosensors
      PubDate: 2023-06-09
      DOI: 10.3390/bios13060640
      Issue No: Vol. 13, No. 6 (2023)
  • Biosensors, Vol. 13, Pages 541: Sensing High 17β-Estradiol
           Concentrations Using a Planar Microwave Sensor Integrated with a
           Microfluidic Channel

    • Authors: Supakorn Harnsoongnoen, Panida Loutchanwoot, Prayook Srivilai
      First page: 541
      Abstract: The global issue of pollution caused by endocrine-disrupting chemicals (EDCs) has been gaining increasing attention. Among the EDCs of environmental concern, 17β-estradiol (E2) can produce the strongest estrogenic effects when it enters the organism exogenously through various routes and has the potential to cause harm, including malfunctions of the endocrine system and development of growth and reproductive disorders in humans and animals. Additionally, in humans, supraphysiological levels of E2 have been associated with a range of E2-dependent disorders and cancers. To ensure environmental safety and prevent potential risks of E2 to human and animal health, it is crucial to develop rapid, sensitive, low cost and simple approaches for detecting E2 contamination in the environment. A planar microwave sensor for E2 sensing is presented based on the integration of a microstrip transmission line (TL) loaded with a Peano fractal geometry with a narrow slot complementary split-ring resonator (PF-NSCSRR) and a microfluidic channel. The proposed technique offers a wide linear range for detecting E2, ranging from 0.001 to 10 mM, and can achieve high sensitivity with small sample volumes and simple operation methods. The proposed microwave sensor was validated through simulations and empirical measurements within a frequency range of 0.5–3.5 GHz. The E2 solution was delivered to the sensitive area of the sensor device via a microfluidic polydimethylsiloxane (PDMS) channel with an area of 2.7 mm2 and sample value of 1.37 µL and measured by a proposed sensor. The injection of E2 into the channel resulted in changes in the transmission coefficient (S21) and resonance frequency (Fr), which can be used as an indicator of E2 levels in solution. The maximum quality factor of 114.89 and the maximum sensitivity based on S21 and Fr at a concentration of 0.01 mM were 1746.98 dB/mM and 40 GHz/mM, respectively. Upon comparing the proposed sensor with the original Peano fractal geometry with complementary split-ring (PF-CSRR) sensors without a narrow slot, several parameters were evaluated, including sensitivity, quality factor, operating frequency, active area, and sample volume. The results showed that the proposed sensor exhibited an increased sensitivity of 6.08% and had a 40.72% higher quality factor, while the operating frequency, active area, and sample volume showed decreases of 1.71%, 25%, and 28.27%, respectively. The materials under tests (MUTs) were analyzed and categorized into groups using principal component analysis (PCA) with a K-mean clustering algorithm. The proposed E2 sensor has a compact size and simple structure that can be easily fabricated with low-cost materials. With the small sample volume requirement, fast measurement with a wide dynamic range, and a simple protocol, this proposed sensor can also be applied to measure high E2 levels in environmental, human, and animal samples.
      Citation: Biosensors
      PubDate: 2023-05-12
      DOI: 10.3390/bios13050541
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 542: Metal Oxides Nanomaterials and
           Nanocomposite-Based Electrochemical Sensors for Healthcare Applications

    • Authors: Palanisamy Kannan, Govindhan Maduraiveeran
      First page: 542
      Abstract: Wide-ranging research efforts have been directed to prioritize scientific and technological inventions for healthcare monitoring. In recent years, the effective utilization of functional nanomaterials in various electroanalytical measurements realized a rapid, sensitive, and selective detection and monitoring of a wide range of biomarkers in body fluids. Owing to good biocompatibility, high organic capturing ability, strong electrocatalytic activity, and high robustness, transition metal oxide-derived nanocomposites have led to enhancements in sensing performances. The aim of the present review is to describe key advancements of transition metal oxide nanomaterials and nanocomposites-based electrochemical sensors, along with current challenges and prospects towards the development of a highly durable and reliable detection of biomarkers. Moreover, the preparation of nanomaterials, electrode fabrication, sensing mechanism, electrode-bio interface, and performance of metal oxides nanomaterials and nanocomposite-based sensor platforms will be described.
      Citation: Biosensors
      PubDate: 2023-05-12
      DOI: 10.3390/bios13050542
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 543: Hybridization Chain Reaction-Based
           Electrochemical Biosensors by Integrating the Advantages of Homogeneous
           Reaction and Heterogeneous Detection

    • Authors: Ning Xia, Jiayou Cheng, Linxu Tian, Shuo Zhang, Yunqiu Wang, Gang Li
      First page: 543
      Abstract: The conventional hybridization chain reaction (HCR)-based electrochemical biosensors usually require the immobilization of probes on the electrode surface. This will limit the applications of biosensors due to the shortcomings of complex immobilization processes and low HCR efficiency. In this work, we proposed astrategy for the design of HCR-based electrochemical biosensors by integrating the advantages of homogeneous reaction and heterogeneous detection. Specifically, the targets triggered the autonomous cross-opening and hybridization oftwobiotin-labeled hairpin probes to form long-nicked dsDNA polymers. The HCR products with many biotin tags were then captured by a streptavidin-covered electrode, thus allowing for the attachment of streptavidin-conjugated signal reporters through streptavidin–biotin interactions. By employing DNA and microRNA-21 as the model targets and glucose oxidase as the signal reporter, the analytical performances of the HCR-based electrochemical biosensors were investigated. The detection limits of this method were found to be 0.6 fM and 1 fM for DNA and microRNA-21, respectively. The proposed strategy exhibited good reliability for target analysis in serum and cellular lysates. The strategy can be used to develop various HCR-based biosensors for a wide range of applications because sequence-specific oligonucleotides exhibit high binding affinity to a series of targets. In light of the high stability and commercial availability of streptavidin-modified materials, the strategy can be used for the design of different biosensors by changing the signal reporter and/or the sequence of hairpin probes.
      Citation: Biosensors
      PubDate: 2023-05-12
      DOI: 10.3390/bios13050543
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 544: Biomolecular Monitoring Tool Based on
           Lab-on-Chip for Virus Detection

    • Authors: Francesca Costantini, Nicola Lovecchio, Manasa Nandimandalam, Ariana Manglli, Francesco Faggioli, Mara Biasin, Cesare Manetti, Pio Federico Roversi, Augusto Nascetti, Giampiero de Cesare, Domenico Caputo
      First page: 544
      Abstract: Lab-on-Chip (LoC) devices for performing real-time PCR are advantageous compared to standard equipment since these systems allow to conduct in-field quick analysis. The development of LoCs, where the components for performing the nucleic acid amplification are all integrated, can be an issue. In this work, we present a LoC-PCR device where thermalization, temperature control and detection elements are all integrated on a single glass substrate named System-on-Glass (SoG) obtained using metal thin-film deposition. By using a microwell plate optically coupled with the SoG, real-time reverse transcriptase PCR of RNA extracted from both a plant and human virus has been carried out in the developed LoC-PCR device. The limit of detection and time of analysis for the detection of the two viruses by using the LoC-PCR were compared with those achieved by standard equipment. The results showed that the two systems can detect the same concentration of RNA; however, the LoC-PCR performs the analysis in half of the time compared to the standard thermocycler, with the advantage of the portability, leading to a point-of-care device for several diagnostic applications.
      Citation: Biosensors
      PubDate: 2023-05-12
      DOI: 10.3390/bios13050544
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 545: Monoclonal Antibody-Based Colorimetric
           Lateral Flow Immunoassay for the Detection of Pyridaben in the Environment

    • Authors: He Chen, Hao Liu, Yanran Ji, Zekun Sha, Li An, Meng Li, Di Zhang, Xujin Wu, Xiude Hua
      First page: 545
      Abstract: Pyridaben, a broad-spectrum pyridazinone acaricide that is widely used in agricultural production, can induce neurotoxicity and reproductive abnormalities, and is highly toxic to aquatic organisms. In this study, a pyridaben hapten was synthesized and used to prepare monoclonal antibodies (mAbs), among which 6E3G8D7 showed the highest sensitivity in indirect competitive enzyme-linked immunosorbent assay, with a 50% inhibitory concentration (IC50) of 3.49 ng mL−1. The mAb, 6E3G8D7, was further applied to a gold nanoparticle-based colorimetric lateral flow immunoassay (CLFIA) for pyridaben detection, according to the signal intensity ratio of the test line to the control line, which showed a visual limit of detection of 5 ng mL−1. The CLFIA also showed high specificity and achieved excellent accuracy in different matrices. In addition, the amounts of pyridaben in blind samples detected by the CLFIA, were consistent with high-performance liquid chromatography. Therefore, the developed CLFIA is considered a promising, reliable, and portable method for pyridaben on-site detection in agro-products and environmental samples.
      Citation: Biosensors
      PubDate: 2023-05-13
      DOI: 10.3390/bios13050545
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 546: Rapid Prototyping Flexible Capacitive
           Pressure Sensors Based on Porous Electrodes

    • Authors: Tiancong Zhao, Huichao Zhu, Hangyu Zhang
      First page: 546
      Abstract: Flexible pressure sensors are widely applied in tactile perception, fingerprint recognition, medical monitoring, human–machine interfaces, and the Internet of Things. Among them, flexible capacitive pressure sensors have the advantages of low energy consumption, slight signal drift, and high response repeatability. However, current research on flexible capacitive pressure sensors focuses on optimizing the dielectric layer for improved sensitivity and pressure response range. Moreover, complicated and time-consuming fabrication methods are commonly applied to generate microstructure dielectric layers. Here, we propose a rapid and straightforward fabrication approach to prototyping flexible capacitive pressure sensors based on porous electrodes. Laser-induced graphene (LIG) is produced on both sides of the polyimide paper, resulting in paired compressible electrodes with 3D porous structures. When the elastic LIG electrodes are compressed, the effective electrode area, the relative distance between electrodes, and the dielectric property vary accordingly, thereby generating a sensitive pressure sensor in a relatively large working range (0–9.6 kPa). The sensitivity of the sensor is up to 7.71%/kPa−1, and it can detect pressure as small as 10 Pa. The simple and robust structure allows the sensor to produce quick and repeatable responses. Our pressure sensor exhibits broad potential in practical applications in health monitoring, given its outstanding comprehensive performance combined with its simple and quick fabrication method.
      Citation: Biosensors
      PubDate: 2023-05-14
      DOI: 10.3390/bios13050546
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 547: A Modified Electrochemical Sensor Based on
           N,S-Doped Carbon Dots/Carbon Nanotube-Poly(Amidoamine) Dendrimer Hybrids
           for Imatinib Mesylate Determination

    • Authors: Maryam Saleh Mohammadnia, Hossein Roghani-Mamaqani, Masoumeh Ghalkhani, Salar Hemmati
      First page: 547
      Abstract: Imatinib mesylate, an anticancer drug, is prescribed to treat gastrointestinal stromal tumors and chronic myelogenous leukemia. A hybrid nanocomposite of N,S-doped carbon dots/carbon nanotube-poly(amidoamine) dendrimer (N,S-CDs/CNTD) was successfully synthesized and used as a significant modifier to design a new and highly selective electrochemical sensor for the determination of imatinib mesylate. A rigorous study with electrochemical techniques, such as cyclic voltammetry and differential pulse voltammetry, was performed to elucidate the electrocatalytic properties of the as-prepared nanocomposite and the preparation procedure of the modified glassy carbon electrode (GCE). A higher oxidation peak current was generated for the imatinib mesylate on a N,S-CDs/CNTD/GCE surface compared to the GCE and CNTD/GCE. The N,S-CDs/CNTD/GCE showed a linear relationship between the concentration and oxidation peak current of the imatinib mesylate in 0.01–100 μM, with a detection limit of 3 nM. Finally, the imatinib mesylate’s quantification in blood-serum samples was successfully performed. The N,S-CDs/CNTD/GCE’s reproducibility and stability were indeed excellent.
      Citation: Biosensors
      PubDate: 2023-05-15
      DOI: 10.3390/bios13050547
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 548: Wearable Triboelectric Nanogenerator with
           Ground-Coupled Electrode for Biomechanical Energy Harvesting and Sensing

    • Authors: Kangyu Su, Xiaobo Lin, Zhangwei Liu, Yun Tian, Zhengchun Peng, Bo Meng
      First page: 548
      Abstract: Harvesting biomechanical energy for electricity as well as physiological monitoring is a major development trend for wearable devices. In this article, we report a wearable triboelectric nanogenerator (TENG) with a ground-coupled electrode. It has a considerable output performance for harvesting human biomechanical energy and can also be used as a human motion sensor. The reference electrode of this device achieves a lower potential by coupling with the ground to form a coupling capacitor. Such a design can significantly improve the TENG’s outputs. A maximum output voltage up to 946 V and a short-circuit current of 36.3 μA are achieved. The quantity of the charge that transfers during one step of an adult walking reaches 419.6 nC, while it is only 100.8 nC for the separate single-electrode-structured device. In addition, using the human body as a natural conductor to connect the reference electrode allows the device to drive the shoelaces with integrated LEDs. Finally, the wearable TENG is able to perform motion monitoring and sensing, such as human gait recognition, step count and movement speed calculation. These show great application prospects of the presented TENG device in wearable electronics.
      Citation: Biosensors
      PubDate: 2023-05-15
      DOI: 10.3390/bios13050548
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 549: A Novel SPR Immunosensor Based on Dual
           Signal Amplification Strategy for Detection of SARS-CoV-2 Nucleocapsid

    • Authors: Lirui Fan, Bin Du, Fubin Pei, Wei Hu, Shasha Feng, Bing Liu, Zhaoyang Tong, Wenyuan Tan, Xihui Mu
      First page: 549
      Abstract: Since the global outbreak of coronavirus disease 2019 (COVID-19), it has spread rapidly around the world. The nucleocapsid (N) protein is one of the most abundant SARS-CoV-2 proteins. Therefore, a sensitive and effective detection method for SARS-CoV-2 N protein is the focus of research. Here, we developed a surface plasmon resonance (SPR) biosensor based on the dual signal-amplification strategy of Au@Ag@Au nanoparticles (NPs) and graphene oxide (GO). Additionally, a sandwich immunoassay was utilized to sensitively and efficiently detect SARS-CoV-2 N protein. On the one hand, Au@Ag@Au NPs have a high refractive index and the capability to electromagnetically couple with the plasma waves propagating on the surface of gold film, which are harnessed for amplifying the SPR response signal. On the other hand, GO, which has the large specific surface area and the abundant oxygen-containing functional groups, could provide unique light absorption bands that can enhance plasmonic coupling to further amplify the SPR response signal. The proposed biosensor could efficiently detect SARS-CoV-2 N protein for 15 min and the detection limit for SARS-CoV-2 N protein was 0.083 ng/mL, with a linear range of 0.1 ng/mL~1000 ng/mL. This novel method can meet the analytical requirements of artificial saliva simulated samples, and the developed biosensor had a good anti-interference capability.
      Citation: Biosensors
      PubDate: 2023-05-15
      DOI: 10.3390/bios13050549
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 550: Unique Electron-Transfer-Mediated
           Electrochemiluminescence of AuPt Bimetallic Nanoclusters and the
           Application in Cancer Immunoassay

    • Authors: Huiwen Zhou, Ruanshan Liu, Guangxing Pan, Miaomiao Cao, Ling Zhang
      First page: 550
      Abstract: Noble Metal nanoclusters (NCs) are promising electrochemiluminescence (ECL) emitters due to their amazing optical properties and excellent biocompatibility. They have been widely used in the detection of ions, pollutant molecules, biomolecules, etc. Herein, we found that glutathione-capped AuPt bimetallic NCs (GSH-AuPt NCs) emitted strong anodic ECL signals with triethylamine as co-reactants which had no fluorescence (FL) response. Due to the synergistic effect of bimetallic structures, the ECL signals of AuPt NCs were 6.8 and 94 times higher than those of monometallic Au and Pt NCs, respectively. The electric and optical properties of GSH-AuPt NCs differed from those of Au and Pt NCs completely. An electron-transfer mediated ECL mechanism was proposed. The excited electrons may be neutralized by Pt(II) in GSH-Pt and GSH-AuPt NCs, resulting in the vanished FL. Furthermore, abundant TEA radicals formed on the anode contributed electrons to the highest unoccupied molecular orbital of GSH-Au2.5Pt NCs and Pt(II), booming intense ECL signals. Because of the ligand effect and ensemble effect, bimetallic AuPt NCs exhibited much stronger ECL than GSH-Au NCs. A sandwich-type immunoassay for alpha fetoprotein (AFP) cancer biomarkers was fabricated with GSH-AuPt NCs as signal tags, which displayed a wide linear range from 0.01 to 1000 ng·mL−1 and a limit of detection (LOD) down to 1.0 pg·mL−1 at 3S/N. Compared to previous ECL AFP immunoassays, this method not only had a wider linear range but also a lower LOD. The recoveries of AFP in human serum were around 108%, providing a wonderful strategy for fast, sensitive, and accurate cancer diagnosis.
      Citation: Biosensors
      PubDate: 2023-05-16
      DOI: 10.3390/bios13050550
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 551: Microenvironments Matter: Advances in

    • Authors: Gulden Akcay, Regina Luttge
      First page: 551
      Abstract: To highlight the particular needs with respect to modeling the unique and complex organization of the human brain structure, we reviewed the state-of-the-art in devising brain models with engineered instructive microenvironments. To acquire a better perspective on the brain’s working mechanisms, we first summarize the importance of regional stiffness gradients in brain tissue, varying per layer and the cellular diversities of the layers. Through this, one can acquire an understanding of the essential parameters in emulating the brain in vitro. In addition to the brain’s organizational architecture, we addressed also how the mechanical properties have an impact on neuronal cell responses. In this respect, advanced in vitro platforms emerged and profoundly changed the methods of brain modeling efforts from the past, mainly focusing on animal or cell line research. The main challenges in imitating features of the brain in a dish are with regard to composition and functionality. In neurobiological research, there are now methods that aim to cope with such challenges by the self-assembly of human-derived pluripotent stem cells (hPSCs), i.e., brainoids. Alternatively, these brainoids can be used stand-alone or in conjunction with Brain-on-Chip (BoC) platform technology, 3D-printed gels, and other types of engineered guidance features. Currently, advanced in vitro methods have made a giant leap forward regarding cost-effectiveness, ease-of-use, and availability. We bring these recent developments together into one review. We believe our conclusions will give a novel perspective towards advancing instructive microenvironments for BoCs and the understanding of the brain’s cellular functions either in modeling healthy or diseased states of the brain.
      Citation: Biosensors
      PubDate: 2023-05-16
      DOI: 10.3390/bios13050551
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 552: A Self-Powered Multifunctional Bracelet
           for Pulse Monitoring and Personal Rescue

    • Authors: Wei Sun, Jiangtao Xue, Puchuan Tan, Bojing Shi, Yang Zou, Zhou Li
      First page: 552
      Abstract: For outdoor workers or explorers who may be exposed to extreme or wild environments for a long time, wearable electronic devices with continuous health monitoring and personal rescue functions in emergencies could play an important role in protecting their lives. However, the limited battery capacity leads to a limited serving time, which cannot ensure normal operation anywhere and at any time. In this work, a self-powered multifunctional bracelet is proposed by integrating a hybrid energy supply module and a coupled pulse monitoring sensor with the inherent structure of the watch. The hybrid energy supply module can harvest rotational kinetic energy and elastic potential energy from the watch strap swinging simultaneously, generating a voltage of 69 V and a current of 87 mA. Meanwhile, with a statically indeterminate structure design and the coupling of triboelectric and piezoelectric nanogenerators, the bracelet enables stable pulse signal monitoring during movement with a strong anti-interference ability. With the assistance of functional electronic components, the pulse signal and position information of the wearer can be transmitted wirelessly in real-time, and the rescue light and illuminating light can be driven directly by flipping the watch strap slightly. The universal compact design, efficient energy conversion, and stable physiological monitoring demonstrate the wide application prospects of the self-powered multifunctional bracelet.
      Citation: Biosensors
      PubDate: 2023-05-16
      DOI: 10.3390/bios13050552
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 553: MICaFVi: A Novel Magnetic Immuno-Capture
           Flow Virometry Nano-Based Diagnostic Tool for Detection of Coronaviruses

    • Authors: Nosaibah Samman, Kheireddine El-Boubbou, Khawlah Al-Muhalhil, Rizwan Ali, Ahmed Alaskar, Naif Khalaf Alharbi, Atef Nehdi
      First page: 553
      Abstract: COVID-19 has resulted in a pandemic that aggravated the world’s healthcare systems, economies, and education, and caused millions of global deaths. Until now, there has been no specific, reliable, and effective treatment to combat the virus and its variants. The current standard tedious PCR-based tests have limitations in terms of sensitivity, specificity, turnaround time, and false negative results. Thus, an alternative, rapid, accurate, and sensitive diagnostic tool that can detect viral particles, without the need for amplification or viral replication, is central to infectious disease surveillance. Here, we report MICaFVi (Magnetic Immuno-Capture Flow Virometry), a novel precise nano-biosensor diagnostic assay for coronavirus detection which combines the MNP-based immuno-capture of viruses for enrichment followed by flow-virometry analysis, enabling the sensitive detection of viral particles and pseudoviruses. As proof of concept, virus-mimicking spike-protein-coated silica particles (VM-SPs) were captured using anti-spike-antibody-conjugated MNPs (AS-MNPs) followed by detection using flow cytometry. Our results showed that MICaFVi can successfully detect viral MERS-CoV/SARS-CoV-2-mimicking particles as well as MERS-CoV pseudoviral particles (MERSpp) with high specificity and sensitivity, where a limit of detection (LOD) of 3.9 µg/mL (20 pmol/mL) was achieved. The proposed method has great potential for designing practical, specific, and point-of-care testing for rapid and sensitive diagnoses of coronavirus and other infectious diseases.
      Citation: Biosensors
      PubDate: 2023-05-18
      DOI: 10.3390/bios13050553
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 554: An Update on the Use of Natural Pigments
           and Pigment Nanoparticle Adducts for Metal Detection Based on Colour

    • Authors: Raspati D. Mulyaningsih, Rimadani Pratiwi, Aliya N. Hasanah
      First page: 554
      Abstract: Natural pigments occur in plants as secondary metabolites and have been used as safe colourants in food. Studies have reported that their unstable colour intensity might be related to metal ion interaction, which leads to the formation of metal–pigment complexes. This underlines the need for further investigations on the use of natural pigments in metal detection using colorimetric methods, since metals are important elements and can be hazardous when present in large amounts. This review aimed to discuss the use of natural pigments (mainly betalains, anthocyanins, curcuminoids, carotenoids, and chlorophyll) as reagents for portable metal detection based on their limits of detection, to determine which pigment is best for certain metals. Colorimetric-related articles over the last decade were gathered, including those involving methodological modifications, sensor developments, and a general overview. When considering sensitivity and portability, the results revealed that betalains are best applied for copper, using a smartphone-assisted sensor; curcuminoids are best applied for lead, using a curcumin nanofiber; and anthocyanin is best applied for mercury, using anthocyanin hydrogel. This provides a new perspective on the use of colour instability for the detection of metals with modern sensor developments. In addition, a coloured sheet representing metal concentrations may be useful as a standard to support on-site detection with trials on masking agents to improve selectivity.
      Citation: Biosensors
      PubDate: 2023-05-18
      DOI: 10.3390/bios13050554
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 555: Oscillatory-Flow PCR Microfluidic Chip
           Driven by Low Speed Biaxial Centrifugation

    • Authors: Yunlong Fan, Rongji Dai, Shuyu Lu, Xinyu Liu, Taiyan Zhou, Chunhua Yang, Xiaoming Hu, Xuefei Lv, Xiaoqiong Li
      First page: 555
      Abstract: PCR is indispensable in basic science and biotechnology for in-orbit life science research. However, manpower and resources are limited in space. To address the constraints of in-orbit PCR, we proposed an oscillatory-flow PCR technique based on biaxial centrifugation. Oscillatory-flow PCR remarkably reduces the power requirements of the PCR process and has a relatively high ramp rate. A microfluidic chip that could perform dispensing, volume correction, and oscillatory-flow PCR of four samples simultaneously using biaxial centrifugation was designed. An automatic biaxial centrifugation device was designed and assembled to validate the biaxial centrifugation oscillatory-flow PCR. Simulation analysis and experimental tests indicated that the device could perform fully automated PCR amplification of four samples in one hour, with a ramp rate of 4.4 ∘C/s and average power consumption of less than 30 W. The PCR results were consistent with those obtained using conventional PCR equipment. Air bubbles generated during amplification were removed by oscillation. The chip and device realized a low-power, miniaturized, and fast PCR method under microgravity conditions, indicating good space application prospects and potential for higher throughput and extension to qPCR.
      Citation: Biosensors
      PubDate: 2023-05-18
      DOI: 10.3390/bios13050555
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 556: Label-Free Biosensor

    • Authors: Pengfei Zhang, Rui Wang
      First page: 556
      Abstract: Label-free biosensors have become an indispensable tool for analyzing intrinsic molecular properties, such as mass, and quantifying molecular interactions without interference from labels, which is critical for the screening of drugs, detecting disease biomarkers, and understanding biological processes at the molecular level [...]
      Citation: Biosensors
      PubDate: 2023-05-18
      DOI: 10.3390/bios13050556
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 557: Molecular Fingerprint Detection Using
           Raman and Infrared Spectroscopy Technologies for Cancer Detection: A
           Progress Review

    • Authors: Shuyan Zhang, Yi Qi, Sonia Peng Hwee Tan, Renzhe Bi, Malini Olivo
      First page: 557
      Abstract: Molecular vibrations play a crucial role in physical chemistry and biochemistry, and Raman and infrared spectroscopy are the two most used techniques for vibrational spectroscopy. These techniques provide unique fingerprints of the molecules in a sample, which can be used to identify the chemical bonds, functional groups, and structures of the molecules. In this review article, recent research and development activities for molecular fingerprint detection using Raman and infrared spectroscopy are discussed, with a focus on identifying specific biomolecules and studying the chemical composition of biological samples for cancer diagnosis applications. The working principle and instrumentation of each technique are also discussed for a better understanding of the analytical versatility of vibrational spectroscopy. Raman spectroscopy is an invaluable tool for studying molecules and their interactions, and its use is likely to continue to grow in the future. Research has demonstrated that Raman spectroscopy is capable of accurately diagnosing various types of cancer, making it a valuable alternative to traditional diagnostic methods such as endoscopy. Infrared spectroscopy can provide complementary information to Raman spectroscopy and detect a wide range of biomolecules at low concentrations, even in complex biological samples. The article concludes with a comparison of the techniques and insights into future directions.
      Citation: Biosensors
      PubDate: 2023-05-18
      DOI: 10.3390/bios13050557
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 558: Plasmonic Biosensor on the End-Facet of a
           Dual-Core Single-Mode Optical Fiber

    • Authors: Fatemeh Fouladi Mahani, Arash Mokhtari, Pierre Berini
      First page: 558
      Abstract: Optical biosensors target widespread applications, such as drug discovery, medical diagnostics, food quality control, and environmental monitoring. Here, we propose a novel plasmonic biosensor on the end-facet of a dual-core single-mode optical fiber. The concept uses slanted metal gratings on each core, interconnected by a metal stripe biosensing waveguide to couple the cores via the propagation of surface plasmons along the end facet. The scheme enables operation in transmission (core-to-core), thereby eliminating the need to separate the reflected light from the incident light. Importantly, this simplifies and reduces the cost of the interrogation setup because a broadband polarization-maintaining optical fiber coupler or circulator is not required. The proposed biosensor enables remote sensing because the interrogation optoelectronics can be located remotely. In vivo biosensing and brain studies are also enabled because the end-facet can be inserted into a living body, once properly packaged. It can also be dipped into a vial, precluding the need for microfluidic channels or pumps. Bulk sensitivities of 880 nm/RIU and surface sensitivities of 1 nm/nm are predicted under spectral interrogation using cross-correlation analysis. The configuration is embodied by robust and experimentally realizable designs that can be fabricated, e.g., using metal evaporation and focused ion beam milling.
      Citation: Biosensors
      PubDate: 2023-05-19
      DOI: 10.3390/bios13050558
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 559: An Integrated and Multi-Target Nucleic
           Acid Isothermal Analysis System for Rapid Diagnosis of Vulvovaginal

    • Authors: Xiangyu Jin, Meng Li, Zeyin Mao, Anni Deng, Wenqi Lv, Leyang Huang, Hao Zhong, Han Yang, Lei Zhang, Qinping Liao, Guoliang Huang
      First page: 559
      Abstract: Rapid identification of Candida species is significant for the diagnosis of vulvovaginal candidiasis (VVC). An integrated and multi-target system for the rapid, high-specificity, and high-sensitivity detection of four Candida species was developed. The system consists of a rapid sample processing cassette and a rapid nucleic acid analysis device. The cassette could process the Candida species to release nucleic acids in 15 min. The released nucleic acids were analyzed by the device as fast as within 30 min, using the loop-mediated isothermal amplification method. The four Candida species could be simultaneously identified, with each reaction using only 1.41 µL of reaction mixture, which was low cost. The RPT (rapid sample processing and testing) system could detect the four Candida species with high sensitivity (<2 CFU/reaction) and high specificity. The system also processed and analyzed 32 clinical samples, giving the results with high clinical sensitivity and specificity. Hence, the system was a significant and effective platform for the diagnosis of VVC. Furthermore, the period of validity of the reagents and chips used in the system was >90 days, and the system could also be used for the detection of bacteria.
      Citation: Biosensors
      PubDate: 2023-05-19
      DOI: 10.3390/bios13050559
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 560: Graphene-Based Metamaterial Sensor for
           Pesticide Trace Detection

    • Authors: Tingting Lang, Meiyu Xiao, Wenyang Cen
      First page: 560
      Abstract: Organophosphate insecticides with broad spectrum and high efficiency make a great difference to agricultural production. The correct utilization and residue of pesticides have always been important issues of concern, and residual pesticides can accumulate and pass through the environment and food cycle, resulting in safety and health hazards to humans and animals. In particular, current detection methods are often characterized by complex operations or low sensitivity. Fortunately, using monolayer graphene as the sensing interface, the designed graphene-based metamaterial biosensor working in the 0–1 THz frequency range can achieve highly sensitive detection characterized by spectral amplitude changes. Meanwhile, the proposed biosensor has the advantages of easy operation, low cost, and quick detection. Taking phosalone as an example, its molecules can move the Fermi level of graphene with π–π stacking, and the lowest concentration of detection in this experiment is 0.01 μg/mL. This metamaterial biosensor has great potential in detecting trace pesticides, and its application in food hygiene and medicine can provide better detection services.
      Citation: Biosensors
      PubDate: 2023-05-19
      DOI: 10.3390/bios13050560
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 561: Development of an Efficient FRET-Based
           Ratiometric Uranium Biosensor

    • Authors: Sandrine Sauge-Merle, Morgane Recuerda, Maria Rosa Beccia, David Lemaire, Rym Cherif, Nicolas Bremond, Fabienne Merola, Yasmina Bousmah, Catherine Berthomieu
      First page: 561
      Abstract: The dispersion of uranium in the environment can pose a problem for the health of humans and other living organisms. It is therefore important to monitor the bioavailable and hence toxic fraction of uranium in the environment, but no efficient measurement methods exist for this. Our study aims to fill this gap by developing a genetically encoded FRET-based ratiometric uranium biosensor. This biosensor was constructed by grafting two fluorescent proteins to both ends of calmodulin, a protein that binds four calcium ions. By modifying the metal-binding sites and the fluorescent proteins, several versions of the biosensor were generated and characterized in vitro. The best combination results in a biosensor that is affine and selective for uranium compared to metals such as calcium or other environmental compounds (sodium, magnesium, chlorine). It has a good dynamic range and should be robust to environmental conditions. In addition, its detection limit is below the uranium limit concentration in drinking water defined by the World Health Organization. This genetically encoded biosensor is a promising tool to develop a uranium whole-cell biosensor. This would make it possible to monitor the bioavailable fraction of uranium in the environment, even in calcium-rich waters.
      Citation: Biosensors
      PubDate: 2023-05-19
      DOI: 10.3390/bios13050561
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 562: Electrochemical Biosensing of L-DOPA Using
           Tyrosinase Immobilized on Carboxymethyl Starch-Graft-Polyaniline@MWCNTs

    • Authors: Fahimeh Mollamohammadi, Hassan Faridnouri, Ehsan Nazarzadeh Zare
      First page: 562
      Abstract: The electrochemical behavior of the immobilized tyrosinase (Tyrase) on a modified glassy carbon electrode with carboxymethyl starch-graft-polyaniline/multi-walled carbon nanotubes nanocomposite (CMS-g-PANI@MWCNTs) was investigated. The molecular properties of CMS-g-PANI@MWCNTs nanocomposite and its morphological characterization were examined by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM). A simple drop-casting method was employed to immobilize Tyrase on the CMS-g-PANI@MWCNTs nanocomposite. In the cyclic voltammogram (CV), a pair of redox peaks were observed at the potentials of +0.25 to −0.1 V and E°’ was equal to 0.1 V and the apparent rate constant of electron transfer (Ks) was calculated at 0.4 s−1. Using differential pulse voltammetry (DPV), the sensitivity and selectivity of the biosensor were investigated. The biosensor exhibits linearity towards catechol and L-dopa in the concentration range of 5–100 and 10–300 μM with a sensitivity of 2.4 and 1.11 μA μΜ−1 cm−2 and limit of detection (LOD) 25 and 30 μM, respectively. The Michaelis-Menten constant (Km) was calculated at 42 μΜ for catechol and 86 μΜ for L-dopa. After 28 working days, the biosensor provided good repeatability and selectivity, and maintained 67% of its stability. The existence of -COO− and -OH groups in carboxymethyl starch, -NH2 groups in polyaniline, and high surface-to-volume ratio and electrical conductivity of multi-walled carbon nanotubes in the CMS-g-PANI@MWCNTs nanocomposite cause good Tyrase immobilization on the surface of the electrode.
      Citation: Biosensors
      PubDate: 2023-05-21
      DOI: 10.3390/bios13050562
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 563: Electrodeposited rGO/AuNP/MnO2
           Nanocomposite-Modified Screen-Printed Carbon Electrode for Sensitive
           Electrochemical Sensing of Arsenic(III) in Water

    • Authors: Yanqing Wu, Tao Zhang, Lishen Su, Xiaoping Wu
      First page: 563
      Abstract: Herein, a simple and portable electrochemical sensor based on a reduced graphene oxide/gold nanoparticle/manganese dioxide (rGO/AuNP/MnO2) nanocomposite-modified screen-printed carbon electrode (SPCE) was constructed by the facile stepwise electrodeposition method and used for electrochemical detection of As(III). The resultant electrode was characterized for its morphological, structural, and electrochemical properties using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). From the morphologic structure, it can be clearly observed that the AuNPs and MnO2 alone or their hybrid were densely deposited or entrapped in thin rGO sheets on the porous carbon surface, which may favor the electro-adsorption of As(III) on the modified SPCE. It is interesting that the nanohybrid modification endows the electrode with a significant decrease in charge transfer resistance and an increase in electroactive specific surface area, which dramatically increases the electro-oxidation current of As(III). This improved sensing ability was ascribed to the synergistic effect of gold nanoparticles with excellent electrocatalytic property and reduced graphene oxide with good electrical conductivity, as well as the involvement of manganese dioxide with a strong adsorption property in the electrochemical reduction of As(III). Under optimized conditions, the sensor can detect As(III) via square wave anodic stripping voltammetry (SWASV) with a low limit of detection of 2.4 μg L−1 and a linear range of 25–200 μg L−1. The proposed portable sensor shows the advantages of a simple preparation procedure, low cost, good repeatability, and long-term stability. The feasibility of rGO/AuNPs/MnO2/SPCE for detecting As(III) in real water was further verified.
      Citation: Biosensors
      PubDate: 2023-05-21
      DOI: 10.3390/bios13050563
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 564: Selection of a Novel DNA Aptamer Specific
           for 5-Hydroxymethylfurfural Using Capture-SELEX

    • Authors: Xixia Liu, Yingyu Hou, Yanlin Qin, Jiaxin Cheng, Jianjun Hou, Qin Wu, Zhenmin Liu
      First page: 564
      Abstract: A capture systematic evolution of ligands by exponential enrichment (Capture-SELEX) was described to discover novel aptamers specific for 5-hydroxymethylfurfural (5-HMF), and a biosensor based on molecular beacon was constructed to detect 5-HMF. The ssDNA library was immobilized to streptavidin (SA) resin to select the specific aptamer. The selection progress was monitored using real-time quantitative PCR (Q-PCR), and the enriched library was sequenced by high-throughput sequencing (HTS). Candidate and mutant aptamers were selected and identified by Isothermal Titration Calorimetry (ITC). The FAM-aptamer and BHQ1-cDNA were designed as the quenching biosensor to detect 5-HMF in milk matrix. After the 18th round selection, the Ct value decreased from 9.09 to 8.79, indicating that the library was enriched. The HTS results indicated that the total sequence numbers for 9th, 13th, 16th, and 18th were 417054, 407987, 307666, and 259867, but the number of sequences for the top 300 sequences was gradually increased from 9th to 18th, and the ClustalX2 analysis showed that there were four families with high homology rate. ITC results indicated that the Kd values of H1 and its mutants H1-8, H1-12, H1-14, and H1-21 were 2.5 μM, 1.8 μM, 1.2 μM, 6.5 μM, and 4.7 μM. The linear range of the FRET biosensor was from 0 μM to 75 μM, and it had a similar linear range in the 0.1% milk matrix. This is the first report to select a novel aptamer specific for 5-HMF and develop quenching biosensor for the rapid detection of 5-HMF in milk matrix.
      Citation: Biosensors
      PubDate: 2023-05-22
      DOI: 10.3390/bios13050564
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 565: Highly Sensitive Detection of Urea Using
           Si Electrolyte-Gated Transistor with Low Power Consumption

    • Authors: Wonyeong Choi, Bo Jin, Seonghwan Shin, Jeonghyeon Do, Jongmin Son, Kihyun Kim, Jeong-Soo Lee
      First page: 565
      Abstract: We experimentally demonstrate Si-based electrolyte-gated transistors (EGTs) for detecting urea. The top-down-fabricated device exhibited excellent intrinsic characteristics, including a low subthreshold swing (SS) (~80 mV/dec) and a high on/off current ratio (~107). The sensitivity, which varied depending on the operation regime, was analyzed with the urea concentrations ranging from 0.1 to 316 mM. The current-related response could be enhanced by reducing the SS of the devices, whereas the voltage-related response remained relatively constant. The urea sensitivity in the subthreshold regime was as high as 1.9 dec/pUrea, four times higher than the reported value. The extracted power consumption of 0.3 nW was extremely low compared to other FET-type sensors.
      Citation: Biosensors
      PubDate: 2023-05-22
      DOI: 10.3390/bios13050565
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 566: Direct Electron Transfer of Glucose
           Oxidase on Pre-Anodized Paper/Carbon Electrodes Modified through
           Zero-Length Cross-Linkers for Glucose Biosensors

    • Authors: Gilberto Henao-Pabon, Ning Gao, K. Sudhakara Prasad, XiuJun Li
      First page: 566
      Abstract: A disposable paper-based glucose biosensor with direct electron transfer (DET) of glucose oxidase (GOX) was developed through simple covalent immobilization of GOX on a carbon electrode surface using zero-length cross-linkers. This glucose biosensor exhibited a high electron transfer rate (ks, 3.363 s−1) as well as good affinity (km, 0.03 mM) for GOX while keeping innate enzymatic activities. Furthermore, the DET-based glucose detection was accomplished by employing both square wave voltammetry and chronoamperometric techniques, and it achieved a glucose detection range from 5.4 mg/dL to 900 mg/dL, which is wider than most commercially available glucometers. This low-cost DET glucose biosensor showed remarkable selectivity, and the use of the negative operating potential avoided interference from other common electroactive compounds. It has great potential to monitor different stages of diabetes from hypoglycemic to hyperglycemic states, especially for self-monitoring of blood glucose.
      Citation: Biosensors
      PubDate: 2023-05-22
      DOI: 10.3390/bios13050566
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 567: Fe3O4@Au Core–Shell Magnetic
           Nanoparticles for the Rapid Analysis of E. coli O157:H7 in an
           Electrochemical Immunoassay

    • Authors: Shayesteh Bazsefidpar, Maria Freitas, Clara R. Pereira, Gemma Gutiérrez, Esther Serrano-Pertierra, Henri P. A. Nouws, María Matos, Cristina Delerue-Matos, María Carmen Blanco-López
      First page: 567
      Abstract: Escherichia coli (E. coli) O157:H7 is a pathogenic bacterium that causes serious toxic effects in the human gastrointestinal tract. In this paper, a method for its effective analytical control in a milk sample was developed. To perform rapid (1 h) and accurate analysis, monodisperse Fe3O4@Au magnetic nanoparticles were synthesized and used in an electrochemical sandwich-type magnetic immunoassay. Screen-printed carbon electrodes (SPCE) were used as transducers, and electrochemical detection was performed by chronoamperometry using a secondary horseradish peroxidase-labeled antibody and 3,3′,5,5′-tetramethylbenzidine. This magnetic assay was used to determine the E. coli O157:H7 strain in the linear range from 20 to 2 × 106 CFU/mL, with a limit of detection of 20 CFU/mL. The selectivity of the assay was tested using Listeria monocytogenes p60 protein, and the applicability of the assay was assessed by analyzing a commercial milk sample, demonstrating the usefulness of the synthesized nanoparticles in the developed magnetic immunoassay.
      Citation: Biosensors
      PubDate: 2023-05-22
      DOI: 10.3390/bios13050567
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 568: A Review on Photonic Sensing Technologies:
           Status and Outlook

    • Authors: Muhammad A. Butt, Nikolay L. Kazanskiy, Svetlana N. Khonina, Grigory S. Voronkov, Elizaveta P. Grakhova, Ruslan V. Kutluyarov
      First page: 568
      Abstract: In contemporary science and technology, photonic sensors are essential. They may be made to be extremely resistant to some physical parameters while also being extremely sensitive to other physical variables. Most photonic sensors may be incorporated on chips and operate with CMOS technology, making them suitable for use as extremely sensitive, compact, and affordable sensors. Photonic sensors can detect electromagnetic (EM) wave changes and convert them into an electric signal due to the photoelectric effect. Depending on the requirements, scientists have found ways to develop photonic sensors based on several interesting platforms. In this work, we extensively review the most generally utilized photonic sensors for detecting vital environmental parameters and personal health care. These sensing systems include optical waveguides, optical fibers, plasmonics, metasurfaces, and photonic crystals. Various aspects of light are used to investigate the transmission or reflection spectra of photonic sensors. In general, resonant cavity or grating-based sensor configurations that work on wavelength interrogation methods are preferred, so these sensor types are mostly presented. We believe that this paper will provide insight into the novel types of available photonic sensors.
      Citation: Biosensors
      PubDate: 2023-05-22
      DOI: 10.3390/bios13050568
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 569: Aptamer-Based Point-of-Care Devices:
           Emerging Technologies and Integration of Computational Methods

    • Authors: Yusuf Aslan, Maryam Atabay, Hussain Kawsar Chowdhury, Ilgım Göktürk, Yeşeren Saylan, Fatih Inci
      First page: 569
      Abstract: Recent innovations in point-of-care (POC) diagnostic technologies have paved a critical road for the improved application of biomedicine through the deployment of accurate and affordable programs into resource-scarce settings. The utilization of antibodies as a bio-recognition element in POC devices is currently limited due to obstacles associated with cost and production, impeding its widespread adoption. One promising alternative, on the other hand, is aptamer integration, i.e., short sequences of single-stranded DNA and RNA structures. The advantageous properties of these molecules are as follows: small molecular size, amenability to chemical modification, low- or nonimmunogenic characteristics, and their reproducibility within a short generation time. The utilization of these aforementioned features is critical in developing sensitive and portable POC systems. Furthermore, the deficiencies related to past experimental efforts to improve biosensor schematics, including the design of biorecognition elements, can be tackled with the integration of computational tools. These complementary tools enable the prediction of the reliability and functionality of the molecular structure of aptamers. In this review, we have overviewed the usage of aptamers in the development of novel and portable POC devices, in addition to highlighting the insights that simulations and other computational methods can provide into the use of aptamer modeling for POC integration.
      Citation: Biosensors
      PubDate: 2023-05-22
      DOI: 10.3390/bios13050569
      Issue No: Vol. 13, No. 5 (2023)
  • Biosensors, Vol. 13, Pages 570: On-Field Test of Tuberculosis Diagnosis
           through Exhaled Breath Analysis with a Gas Sensor Array

    • Authors: Yolande Christelle Ketchanji Mougang, Laurent-Mireille Endale Mangamba, Rosamaria Capuano, Fausto Ciccacci, Alexandro Catini, Roberto Paolesse, Hugo Bertrand Mbatchou Ngahane, Leonardo Palombi, Corrado Di Natale
      First page: 570
      Abstract: Tuberculosis (TB) is among the more frequent causes of death in many countries. For pulmonary TB, early diagnosis greatly increases the efficiency of therapies. Although highly sensitive tests based on nucleic acid amplification tests (NAATs) and loop-mediated isothermal amplification (TB-LAMP) are available, smear microscopy is still the most widespread diagnostics method in most low–middle-income countries, and the true positive rate of smear microscopy is lower than 65%. Thus, there is a need to increase the performance of low-cost diagnosis. For many years, the use of sensors to analyze the exhaled volatile organic compounds (VOCs) has been proposed as a promising alternative for the diagnosis of several diseases, including tuberculosis. In this paper, the diagnostic properties of an electronic nose (EN) based on sensor technology previously used to identify tuberculosis have been tested on-field in a Cameroon hospital. The EN analyzed the breath of a cohort of subjects including pulmonary TB patients (46), healthy controls (38), and TB suspects (16). Machine learning analysis of the sensor array data allows for the identification of the pulmonary TB group with respect to healthy controls with 88% accuracy, 90.8% sensitivity, 85.7% specificity, and 0.88 AUC. The model trained with TB and healthy controls maintains its performance when it is applied to symptomatic TB suspects with a negative TB-LAMP. These results encourage the investigation of electronic noses as an effective diagnostic method for future inclusion in clinical practice.
      Citation: Biosensors
      PubDate: 2023-05-22
      DOI: 10.3390/bios13050570
      Issue No: Vol. 13, No. 5 (2023)
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