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Journal Cover Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
  [SJR: 0.717]   [H-I: 80]   [17 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1386-1425
   Published by Elsevier Homepage  [3043 journals]
  • Quantification of minerals from ATR-FTIR spectra with spectral
           interferences using the MRC method
    • Authors: Francisco Bosch-Reig; José Vicente Gimeno-Adelantado; Francisco Bosch-Mossi; Antonio Doménech-Carbó
      Pages: 7 - 12
      Abstract: Publication date: 15 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 181
      Author(s): Francisco Bosch-Reig, José Vicente Gimeno-Adelantado, Francisco Bosch-Mossi, Antonio Doménech-Carbó
      A method for quantifying the individual components of mineral samples based on attenuated total reflectance – Fourier transform infrared spectroscopy (ATR-FTIR) is described, extending the constant ratio (CR) method to analytes absorbing in a common range of wavenumbers. Absorbance values in the spectral region where the analytes absorb relative to the absorbance of an internal standard absorbing at a wavenumber where the analytes do not absorb, permits the quantification of N analytes using measurements at N fixed wavenumbers. The method was tested for mixtures of albite, orthoclase, kaolin and quartz.
      Graphical abstract image

      PubDate: 2017-03-17T16:11:37Z
      DOI: 10.1016/j.saa.2017.02.012
      Issue No: Vol. 181 (2017)
       
  • Stability, speciation and spectral properties of NpO2+ complexes with
           pyridine monocarboxylates in aqueous solution
    • Authors: Rama Mohana Rao Dumpala; Neetika Rawat; B.S. Tomar
      Pages: 13 - 22
      Abstract: Publication date: 15 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 181
      Author(s): Rama Mohana Rao Dumpala, Neetika Rawat, B.S. Tomar
      Neptunyl ion as NpO2 + is the least reacting and most mobile radioactive species among all the actinides. The picolinic acid used for decontamination is co-disposed along with the radioactive waste. Thus, in long term storage of HLW, there is high possibility of interaction of actinides and long lived fission products with the picolinate and can cause migration. The complexation of NpO2 + with the three structural isomers of pyridine monocarboxylates provides an insight to explore the role of hetero atom (nitrogen) with respect to key binding moiety (carboxylate). In the present study, the log β values, speciation and spectral properties of NpO2 + complexes with pyridine monocarboxylates viz. picolinate, nicotinate and isonicotinate, have been studied at 298K in 0.1M NaClO4 medium using spectrophotometry. The complexation reactions involving protonated ligands are always accompanied by protonation/deprotonation process; thus, the protonation constants of all the three pyridine monocarboxylates under same conditions were also determined by potentiometry. The spectrophotometric data analysis for complexation of NpO2 + with pyridine monocarboxylates indicated the presence of ML and ML2 complexes with log β values of 2.96±0.04, 5.67±0.08 for picolinate, 1.34±0.09, 1.65±0.12 for nicotinate and 1.52±0.04, 2.39±0.06 for isonicotinate. The higher values of log β for picolinate were attributed to chelation while in other two isomers, the binding is through carboxylate group only. Density Functional Theory (DFT) calculations were carried out to get optimized geometries and electrostatic charges on various atoms of the complexes and free pyridine monocarboxylates to support the experimental data. The higher stability of NpO2 + nicotinate and isonicotinate complexes compared to simple carboxylates and the difference in log β between the two is due to the charge polarization from unbound nitrogen to the bound carboxylate oxygen atoms.
      Graphical abstract image

      PubDate: 2017-03-17T16:11:37Z
      DOI: 10.1016/j.saa.2017.03.013
      Issue No: Vol. 181 (2017)
       
  • Corrigendum to “Validated spectrofluorimetric methods for the
           determination of apixaban and tirofiban hydrochloride in pharmaceutical
           formulations” [Spectrochim. Acta A Mol. Biomol. Spectrosc. 174 (2017)
           326–330]
    • Authors: Ramzia I. El-Bagary; Ehab F. Elkady; Naira A. Farid; Nadia F. Youssef
      First page: 23
      Abstract: Publication date: 15 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 181
      Author(s): Ramzia I. El-Bagary, Ehab F. Elkady, Naira A. Farid, Nadia F. Youssef


      PubDate: 2017-03-17T16:11:37Z
      DOI: 10.1016/j.saa.2017.02.044
      Issue No: Vol. 181 (2017)
       
  • Theoretical study of thieno-thiophene based low band gap copolymers and
           substituent effect on the optoelectronic properties of them
    • Authors: Mehri Javan Khoshkholgh; Mohammad Reza Abolhassani; Farah Marsusi
      Pages: 24 - 29
      Abstract: Publication date: 15 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 181
      Author(s): Mehri Javan Khoshkholgh, Mohammad Reza Abolhassani, Farah Marsusi
      This paper studies donor-acceptor systems which incorporate benzodithiophene (BDT), benzodifuran (BDF) and benzodipyrrole (BDP) units as the electron-rich monomer with TT unit representing the electron-deficient monomer. This research is based on employing density functional theory (DFT) and time-dependent DFT (TD-DFT). The highest occupied molecular orbitals (HOMO) and the lowest unoccupied molecular orbitals (LUMO), HOMO-LUMO gaps and dihedral-angles of these copolymers were calculated using oligomer extrapolation technique and periodic boundary condition (PBC) method. The optical band gaps and UV–vis absorption spectra of aforementioned copolymers were obtained by TD-DFT at the same level of theory. Based on the fair agreement between PBC-DFT calculated results and experimental data, the substituent effects of Cl, Br, CCH, COH, NO2 , OH, SH and NH2 groups were investigated by PBC-DFT method. The difference between the ground and excited-states dipole moment (Δμge) of all derivatives were also calculated. Taking these results into account, a better understanding of the substituent effects on the photo-physical properties of the copolymers under study was achieved. Due to the shift of HOMO and LUMO energy levels, smaller band gaps and higher Δμge are observed in some derivatives. The calculation results demonstrate that the substitution of COH and NO2 by fluorine in BDF-TT and BDP-TT leads to higher maximum theoretical efficiencies (η).
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      PubDate: 2017-03-17T16:11:37Z
      DOI: 10.1016/j.saa.2017.03.018
      Issue No: Vol. 181 (2017)
       
  • Effects of stepwise nitrogen depletion on carotenoid content, fluorescence
           parameters and the cellular stoichiometry of Chlorella vulgaris
    • Authors: Ping Zhang; Zhe Li; Lunhui Lu; Yan Xiao; Jing Liu; Jinsong Guo; Fang Fang
      Pages: 30 - 38
      Abstract: Publication date: 15 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 181
      Author(s): Ping Zhang, Zhe Li, Lunhui Lu, Yan Xiao, Jing Liu, Jinsong Guo, Fang Fang
      Stressful conditions can stimulate the accumulation of carotenoids in some microalgae. To obtain more knowledge of the stress response, we studied the effects of different N concentrations on unicellular content of carotenoids using Raman spectroscopic technique; cellular stoichiometric changes and the fluorescence parameters of Chlorella vulgaris were concomitantly studied. Initially, we optimized the Raman scattering conditions and demonstrated the feasibility of unicellular carotenoid analysis by Raman spectroscopic technique. The results showed that an integration time of 10 s, laser power at 0.1mW and an accumulation time of 1 were the optimum conditions, and the peak height at 1523cm−1 scaled linearly with the carotenoid content in the range of 0.625–1440mg/L with a recovery rate of 97%~103%. In the experiment, seven different nitrogen levels ranging from 0 to 2.48×105 μg/L were imposed. Samples were taken at the start, exponential phase and end of the experiment. The results showed that nitrogen stress can facilitate the synthesis of carotenoids, while at the same time, excessive nitrogen stress led to lower proliferative and photosynthetic activity. Compared with carotenoids, chlorophylls were more sensitive to nitrogen stress; it declined dramatically as stress processed. There existed no significant differences for Fv/Fm among different nitrogen levels during the exponential phase, while in the end, it declined and a significant difference appeared between cells in 2.48×105 μg/L N and other experimental levels. Photosynthetic efficiency, namely the C/N mole ratio in algal cells, didnot significantly change during the exponential phase; however, apparent increases ultimately occurred, except for the stable C/N in BG11 medium. This increase matched well with the carotenoid decline, indicating that an increasing cellular C/N mole ratio can be used as an indicator of excessive stress in carotenoid production. Besides, there also existed an inverse correlation with ETRmax.
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      PubDate: 2017-03-17T16:11:37Z
      DOI: 10.1016/j.saa.2017.03.022
      Issue No: Vol. 181 (2017)
       
  • Non-enolisable Knoevenagel condensate appended Schiff bases-metal (II)
           complexes: Spectral characteristics, DNA-binding and nuclease activities
    • Authors: Ammavasi Gubendran; Mookkandi Palsamy Kesavan; Srinivasan Ayyanaar; Liviu Mitu; Periyakaruppan Athappan; Jegathalaprathaban Rajesh
      Pages: 39 - 46
      Abstract: Publication date: 15 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 181
      Author(s): Ammavasi Gubendran, Mookkandi Palsamy Kesavan, Srinivasan Ayyanaar, Liviu Mitu, Periyakaruppan Athappan, Jegathalaprathaban Rajesh
      New Schiff base complexes [Cu(L 1 )Cl] (1), [Ni(L 1 )Cl] (2), [Zn(L 1 )Cl] (3), and [Fe(L 2 )H2OCl] (4) {L 1 =(4E)-3-(2-hydroxybenzylidene)-4-(2-hydroxyphenylimino)pentan-2-one, L 2 =2,2′-(1E,1′E)-(3-(2-hydroxybenzylidene)-pentane-2,4-diylidene)bis(azan-1-yl-1 idene)diphenol} have been synthesized and characterized by elemental analysis, UV–Vis, IR, FAB-mass, EPR, spectral studies and electrochemical studies, the ligands L 1 & L 2 were characterized by 1H and 13C NMR spectra. Complex 1 show a visible spectral d-d band near 600nm and display cyclic voltammetric quasireversible response for the Cu(II)/Cu(I) couple vs Ag/AgCl in DMSO. The EPR spectrum of 1 show g‖ >g⊥ suggesting a square planar geometry around copper with dx 2 − y 2 as the ground state. The mass spectral results have confirmed the proposed structure for complexes 1–4. DNA binding properties of these complexes 1–4 have been investigated by absorption titrations, cyclic voltammetric studies and circular dichroism studies. On titration with DNA, the complexes 1–4 show hypochromism at the MLCT band (13–31%) with a red shift of 1–8nm in the electronic spectrum and positive shift of voltammetric E1/2 in the CV studies are in favour of intercalative binding. CD spectra of 1 showed an increase in molar ellipticity (θ278) of the positive band with a minor red shift indicating the transition of B-form of DNA to A like form. DNA cleavage studies of complexes 1 and 4 with pUC18 DNA were studied by gel electrophoresis and complex 4 cleaves supercoiled pUC18 DNA in an oxidative manner in the presence of H2O2 and on photo irradiation at 312nm.
      Graphical abstract image

      PubDate: 2017-03-21T16:27:41Z
      DOI: 10.1016/j.saa.2017.03.031
      Issue No: Vol. 181 (2017)
       
  • Antibacterial properties of amino acid functionalized silver nanoparticles
           decorated on graphene oxide sheets
    • Authors: Kumudini Chandraker; Rekha Nagwanshi; S.K. Jadhav; Kallol K. Ghosh; Manmohan L. Satnami
      Pages: 47 - 54
      Abstract: Publication date: 15 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 181
      Author(s): Kumudini Chandraker, Rekha Nagwanshi, S.K. Jadhav, Kallol K. Ghosh, Manmohan L. Satnami
      Graphene oxide (GO) sheets decorated with amino acid L-cysteine (L-cys) functionalized silver nanoparticles (GO-L-cys-Ag) was synthesized by AgNO3, trisodium citrate, and NaBH4. GO-L-cys-Ag nanocomposite was characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectra, ultraviolet–visible (UV–vis) absorption spectra, which demonstrated that a diameter of L-cys-AgNPs compactly deposited on GO. Antibacterial activity tests of GO-L-cys-Ag nanocomposite were carried out using Escherichia coli MTCC 1687 and Staphylococcus aureus MTCC 3160 as model strains of Gram-negative and Gram-positive bacteria, respectively. The effect of bactericide dosage on antibacterial activity of GO-L-cys-Ag nanocomposite was examined by plate count, well diffusion and broth dilution methods. Morphological observation of bacterial cells by scanning electron microscope (SEM) showed that GO-L-cys-Ag nanocomposite was more destructive to cell membrane of Escherichia coli than that of Staphylococcus aureus. The above technique establish that the bactericidal property of GO-L-cys-Ag nanocomposite with wide range of applications in biomedical science.
      Graphical abstract image

      PubDate: 2017-03-21T16:27:41Z
      DOI: 10.1016/j.saa.2017.03.032
      Issue No: Vol. 181 (2017)
       
  • A quint-wavelength UV spectroscopy for simultaneous determination of
           dichlorobenzene, chlorobenzene, and benzene in simulated water reduced by
           nanoscale zero-valent Fe/Ni bimetal
    • Authors: Xiaofang Wan; Yu Liu; Xin-Sheng Chai; Youming Li; Congbao Guo
      Pages: 55 - 59
      Abstract: Publication date: 15 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 181
      Author(s): Xiaofang Wan, Yu Liu, Xin-Sheng Chai, Youming Li, Congbao Guo
      A quint-wavelength UV spectroscopy for rapid determination of dichlorobenzene (DCB), chlorobenzene (CB) and benzene (B) was developed for the dechlorination process of DCB reduced by nanoscale zero-valent Fe/Ni bimetal. Based on the absorbance measurements at 260, 269, 277, 290 and 300nm, the equations for calculating the concentration of DCB and CB and B were established, in which the spectral interference from the nanoparticles could be effectively minimized. The results show that the present method has a good measurement precision (the relative standard deviations are within 2.0%) and accuracy (the recoveries are between 89 and 111%) in the DCB, CB and B's quantification. The present method is simple, rapid, and such a methodology is very suitable to be used for evaluating the dechlorination performance of chlorinated aromatic compounds in the presence of bimetal nanoparticle.
      Graphical abstract image

      PubDate: 2017-03-21T16:27:41Z
      DOI: 10.1016/j.saa.2017.03.037
      Issue No: Vol. 181 (2017)
       
  • Spectral studies on anthracene based dual sensor for Hg2+ and Al3+ ions
           with two distinct output modes of detection
    • Authors: Navneet Kaur; Baljeet Kaur
      Pages: 60 - 64
      Abstract: Publication date: 15 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 181
      Author(s): Navneet Kaur, Baljeet Kaur
      A simple and easily synthesized colorimetric and fluorescent chemosensor 1, based on aromatic OH and imine moieties as a binding and anthracene as signaling unit, has been synthesized in a one-step procedure. The chemosensor 1 is developed as a dual chemosensor for detection of Hg2+ and Al3+ ions in CH3OH, which exhibited a color change from light yellow to dark yellow with Hg2+ ions, enabling 1 a suitable “bare eye” indicator for Hg2+ ions. On the other hand, fluorescent enhancement with blue shift along with brilliant cyan fluorescence was observed upon binding with Al3+ ions. A possible sensing mechanism has been proposed by means of Job's plot and 1H NMR titration.
      Graphical abstract image

      PubDate: 2017-03-21T16:27:41Z
      DOI: 10.1016/j.saa.2017.03.029
      Issue No: Vol. 181 (2017)
       
  • In-line monitoring of cocrystallization process and quantification of
           carbamazepine-nicotinamide cocrystal using Raman spectroscopy and
           chemometric tools
    • Authors: Frederico L.F. Soares; Renato L. Carneiro
      Pages: 1 - 8
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Frederico L.F. Soares, Renato L. Carneiro
      A cocrystallization process may involve several molecular species, which are generally solid under ambient conditions. Thus, accurate monitoring of different components that might appear during the reaction is necessary, as well as quantification of the final product. This work reports for the first time the synthesis of carbamazepine-nicotinamide cocrystal in aqueous media with a full conversion. The reactions were monitored by Raman spectroscopy coupled with Multivariate Curve Resolution - Alternating Least Squares, and the quantification of the final product among its coformers was performed using Raman spectroscopy and Partial Least Squares regression. The slurry reaction was made in four different conditions: room temperature, 40°C, 60°C and 80°C. The slurry reaction at 80°C enabled a full conversion of initial substrates into the cocrystal form, using water as solvent for a greener method. The employment of MCR-ALS coupled with Raman spectroscopy enabled to observe the main steps of the reactions, such as drug dissolution, nucleation and crystallization of the cocrystal. The PLS models gave mean errors of cross validation around 2.0 (% wt/wt), and errors of validation between 2.5 and 8.2 (% wt/wt) for all components. These were good results since the spectra of cocrystals and the physical mixture of the coformers present some similar peaks.
      Graphical abstract image

      PubDate: 2017-03-04T14:11:05Z
      DOI: 10.1016/j.saa.2017.02.045
      Issue No: Vol. 180 (2017)
       
  • Temperature dependence of the Raman spectrum of
           1-(4-chlorophenyl)-3-(2-thienyl)prop-2-en-1-one
    • Authors: T.A. de Toledo; R.C. da Costa; H.M. Al-Maqtari; J. Jamalis; P.S. Pizani
      Pages: 9 - 17
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): T.A. de Toledo, R.C. da Costa, H.M. Al-Maqtari, J. Jamalis, P.S. Pizani
      The heterocyclic chalcone containing thiophene ring 1-(4-chlorophenyl)-3-(2-thienyl)prop-2-en-1-one, C13H9ClOS was synthesized and investigated using experimental techniques such as nuclear magnetic resonance (1H and 13C NMR), Fourier transform infrared spectroscopy (FTIR) at room temperature, differential scanning calorimeter (DSC) from room temperature to 500K and Raman scattering at the temperature range 10–413K in order to study its structure and vibrational properties as well as stability and possible phase transition. Density functional theory (DFT) calculations were performed to determine the vibrational spectrum viewing to improve the knowledge of the material properties. A reasonable agreement was observed between theoretical and experimental Raman spectrum taken at 10K since anharmonic effects of the molecular motion is reduced at low temperatures, leading to a more comprehensive assignment of the vibrational modes. Increasing the temperature up to 393K, was observed the typical phonon anharmonicity behavior associated to changes in the Raman line intensities, line-widths and red-shift, in special in the external mode region, whereas the internal modes region remains almost unchanged due its strong chemical bonds. Furthermore, C13H9ClOS goes to melting phase transition in the temperature range 393–403K and then sublimates in the temperature range 403–413K. This is denounced by the disappearance of the external modes and the absence of internal modes in the Raman spectra, in accordance with DSC curve. The enthalpy (ΔH) obtained from the integration of the endothermic peak in DSC curve centered at 397K is founded to be 121.5J/g.
      Graphical abstract image

      PubDate: 2017-03-04T14:11:05Z
      DOI: 10.1016/j.saa.2017.02.051
      Issue No: Vol. 180 (2017)
       
  • Corrigendum to “Highly selective colorimetric detection and estimation
           of Hg2+ at nano-molar concentration by silver nanoparticles in the
           presence of glutathione” [Spectrochim. Acta A Mol. Biomol. Spectrosc.
           137 (2015) 503–508]
    • Authors: Ayesha Alam; Aswathy Ravindran; Preethy Chandran; S. Sudheer Khan
      First page: 18
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Ayesha Alam, Aswathy Ravindran, Preethy Chandran, S. Sudheer Khan


      PubDate: 2017-03-04T14:11:05Z
      DOI: 10.1016/j.saa.2017.02.033
      Issue No: Vol. 180 (2017)
       
  • Visible and near-infrared spectroscopic comparison of five phyllosilicate
           mineral samples
    • Authors: Hongfei Cheng; Riwa Hao; Yi Zhou; Ray L. Frost
      Pages: 19 - 22
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Hongfei Cheng, Riwa Hao, Yi Zhou, Ray L. Frost
      Portable visible and near-infrared (vis/NIR) spectroscopy was used to characterize and differentiate the five phyllosilicate minerals and relate the bands to the mineral structure. The feature band at 2160–2170nm (4600–4630cm−1) has been assigned to the high presence of Al-OH and is described as typical of dioctahedral phyllosilicate with OH groups coordinated around Al, and the feature occurred near 2322nm is considered to be due to a combination of the OH stretch with the MgOH deformation mode, which is a typical of trioctahedral phyllosilicates. The presence of the bands 1400 and 1900nm in vis/NIR spectrum indicated that some water is present in this sample. The absence of a 1900nm band but the presence of a 1400nm band indicates that only OH is present. Moreover, the significant differences between these five minerals were observed by the portable vis/NIR spectroscopy. The results show a potential for the application of vis/NIR spectroscopy in the identification and quantification of these minerals in the field. Further, such analysis can also provide important constraints on the nature of putative global and local-scale mineralogical transitions on Mars.
      Graphical abstract image

      PubDate: 2017-03-04T14:11:05Z
      DOI: 10.1016/j.saa.2017.02.043
      Issue No: Vol. 180 (2017)
       
  • Self-assembly of silver nanoparticles as high active surface-enhanced
           Raman scattering substrate for rapid and trace analysis of uranyl(VI) ions
           
    • Authors: Shaofei Wang; Jiaolai Jiang; Haoxi Wu; Jianping Jia; Lang Shao; Hao Tang; Yiming Ren; Mingfu Chu; Xiaolin Wang
      Pages: 23 - 28
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Shaofei Wang, Jiaolai Jiang, Haoxi Wu, Jianping Jia, Lang Shao, Hao Tang, Yiming Ren, Mingfu Chu, Xiaolin Wang
      A facile surface-enhanced Raman scattering (SERS) substrate based on the self-assembly of silver nanoparticles on the modified silicon wafer was obtained, and for the first time, an advanced SERS analysis method basing on this as-prepared substrate was established for high sensitive and rapid detection of uranyl ions. Due to the weakened bond strength of OUO resulting from two kinds of adsorption of uranyl species (“strong” and “weak” adsorption) on the substrate, the ν 1 symmetric stretch vibration frequency of OUO shifted from 871cm−1 (normal Raman) to 720cm−1 and 826cm−1 (SERS) along with significant Raman enhancement. Effects of the hydrolysis of uranyl ions on SERS were also investigated, and the SERS band at ~826cm−1 was first used to approximately define the constitution of uranyl species at trace quantity level. Besides, the SERS intensity was proportional to the variable concentrations of uranyl nitrate ranging from 10−7 to 10−3 molL−1 with an excellent linear relation (R2 =0.998), and the detection limit was ~10−7 molL−1. Furthermore, the related SERS approach involves low-cost substrate fabrication, rapid and trace analysis simultaneously, and shows great potential applications for the field assays of uranyl ions in the nuclear fuel cycle and environmental monitoring.
      Graphical abstract image

      PubDate: 2017-03-04T14:11:05Z
      DOI: 10.1016/j.saa.2017.02.042
      Issue No: Vol. 180 (2017)
       
  • Configuration interaction study on the low-lying electronic states of
           strontium hydride cation including spin-orbit coupling
    • Authors: Dandan Shi; Xiaoting Liu; Shimin Shan; Haifeng Xu; Bing Yan
      Pages: 29 - 36
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Dandan Shi, Xiaoting Liu, Shimin Shan, Haifeng Xu, Bing Yan
      Ab initio calculations on low-lying electronic states of strontium hydride cations, SrH+, have been performed using the internally contracted multi-reference configuration interaction (icMRCI) method with Davidson correction (+Q). Spin-orbit coupling (SOC) effect between the singlet and triplet states of SrH+ has been investigated for the first time. The potential energy curves (PECs) of a total of 12 Λ-S states, as well as the 23 Ω states generated from the Λ-S states after considering the SOC effect, have been calculated. The spectroscopic constants and transition properties, including the transition dipole moments, the Franck–Condon factors, and the radiative lifetimes, have been obtained based on the calculated PECs. It indicates that the SOC effect plays a non-negligible role in electronic states of SrH+. Our study should shed light on the structure and behavior of low-lying electronic states and should pave further experimental studies on the spectroscopy of strontium hydride cations.
      Graphical abstract image

      PubDate: 2017-03-21T16:27:41Z
      DOI: 10.1016/j.saa.2017.02.054
      Issue No: Vol. 180 (2017)
       
  • A fluorescent probe based on nitrogen doped graphene quantum dots for turn
           off sensing of explosive and detrimental water pollutant, TNP in aqueous
           medium
    • Authors: Manjot Kaur; Surinder K Mehta; Sushil Kumar Kansal
      Pages: 37 - 43
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Manjot Kaur, Surinder K Mehta, Sushil Kumar Kansal
      This paper reports the carbonization assisted green approach for the fabrication of nitrogen doped graphene quantum dots (N-GQDs). The obtained N-GQDs displayed good water dispersibility and stability in the wide pH range. The as synthesized N-GQDs were used as a fluorescent probe for the sensing of explosive 2,4,6-trinitrophenol (TNP) in aqueous medium based on fluorescence resonance energy transfer (FRET), molecular interactions and charge transfer mechanism. The quenching efficiency was found to be linear in proportion to the TNP concentration within the range of 0–16μM with detection limit (LOD) of 0.92μM. The presented method was successfully applied to the sensing of TNP in tap and lake water samples with satisfactory results. Thus, N-GQDs were used as a selective, sensitive and turn off fluorescent sensor for the detection of perilous water contaminant i.e. TNP.
      Graphical abstract image

      PubDate: 2017-03-09T14:24:55Z
      DOI: 10.1016/j.saa.2017.02.035
      Issue No: Vol. 180 (2017)
       
  • Optical sensing of hydrogen sulphate using rhodamine 6G hydrazide from
           aqueous medium
    • Authors: Yachana Upadhyay; Shilpa Bothra; Rajender Kumar; Heung-Jin Choi; Suban K Sahoo
      Pages: 44 - 50
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Yachana Upadhyay, Shilpa Bothra, Rajender Kumar, Heung-Jin Choi, Suban K Sahoo
      This communication reports the application of rhodamine 6G hydrazide (L) for the selective colorimetric and turn-on fluorescent sensing of hydrogen sulphate ions from aqueous medium. The ring opening of the colourless spirocyclic form of L was selectively triggered in the presence of HSO4 − among the other tested anions (F−, Cl−, Br−, I−, AcO−, H2PO4 −, NO3 −, ClO4 −, CN−, HO−, AsO3 3− and SO4 2−), which gives rise to a pink colour and strong fluorescence in the visible region. Sensor L showed a detection limit down to micromolar range without any interference from the other tested competitive anions. Sensor L was applied for the construction of two inputs (HO– and HSO4 −) INHIBIT type molecular logic gate and naked-eye detection of HSO4 − using test paper strips.
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      PubDate: 2017-03-04T14:11:05Z
      DOI: 10.1016/j.saa.2017.02.057
      Issue No: Vol. 180 (2017)
       
  • Molecular structure, FT IR, NMR, UV, NBO and HOMO–LUMO of
           1-(3-(dimethylamino)propyl)-1-(4-fluorophenyl)-1,3-dihydroisobenzofuran-5-carbonitrile
           by DFT/B3LYP and PBEPBE methods with LanL2DZ and 6-311++G(d,2p) basis sets
           
    • Authors: Mostafa Khajehzadeh; Majid Moghadam
      Pages: 51 - 66
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Mostafa Khajehzadeh, Majid Moghadam
      Structural and molecular properties of antidepressants 1-(3-(dimethylamino)propyl)-1-(4-fluorophenyl)-1,3-dihydroisobenzofuran-5-carbonitrile were examined using quantum mechanics of Density Functional Theory (DFT)/B3LYP and PBEPBE methods with 6-311++G(d,2p) and LanL2DZ basis sets to study the therapeutic properties of the drug. For this, the structure of desired material was optimized by the computer calculation method and with the use of powerful Gaussian 09 software. Then the lowest energy value and the bond length, bond angle and dihedral angle between its constituent atoms in the crystal structure of the desired material were measured from the optimized values. Then the amount of positive and negative charges, polarizability and dipole moment of its atoms using Mulliken charge and Natural atomic charges, DFT/B3LYP and PBEPBE methods with 6-311++G(d,2p) and LanL2DZ basis sets were determined and the results were compared with each other for individual atoms and by mentioned methods. Also the type of stretching vibrations and bending vibrations between the constituent atoms of the molecule were specified using mentioned computational methods and FT IR vibrational spectra. The experimental spectrum of this material was taken to determine the functional groups and the computational and experimental values were compared to each other and Nuclear Magnetic Resonance (NMR) was used to specify the isomer shift between the carbons and protons in the presence of polar and nonpolar solvents. Also Natural Bond Orbital (NBO) was used to determine the type of electron transfers in σ→σ∗ and π→π∗ and LP(1)→σ∗ and LP(2)→σ∗ and the amount of hardness and softness in molecule was determined using the difference between ionization energy and electron affinity energy in constituent atoms of that molecule in the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and in the presence of solvents H2O, CH3CN and C6H12. UV–Vis spectrum of the drug was taken using DFT/B3LYP and PBEPBE methods with 6-311++G(d,2p) and LanL2DZ basis sets as well as solvents H2O, CH3CN and C6H12 and the associated transmissions were examined.
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      PubDate: 2017-03-21T16:27:41Z
      DOI: 10.1016/j.saa.2017.02.055
      Issue No: Vol. 180 (2017)
       
  • Dispersion analysis of arbitrarily cut orthorhombic crystals
    • Authors: Sonja Höfer; Vladimir Ivanovski; Reinhard Uecker; Albert Kwasniewski; Jürgen Popp; Thomas G. Mayerhöfer
      Pages: 67 - 78
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Sonja Höfer, Vladimir Ivanovski, Reinhard Uecker, Albert Kwasniewski, Jürgen Popp, Thomas G. Mayerhöfer
      We developed a measurement and evaluation scheme to perform dispersion analysis on arbitrarily cut orthorhombic crystals based on the schemes developed for triclinic and uniaxial crystals. As byproduct of dispersion analysis the orientations of the crystal axes are found. In contrast to the spectra of arbitrarily cut uniaxial crystals, where the fit routine has to separate two independent principal spectra, the spectra of arbitrarily cut orthorhombic crystals are a combination of three independent spectra and the evaluation scheme gets more complex. Dispersion analysis is exemplary performed on two different crystals, which show different spectral features and different levels of difficulties to evaluate. Neodymium gallate (NdGaO3) has broad overlapping reflections bands while topaz (Al2SiO4 [F, OH]2) has a quite high total number of infrared active bands.

      PubDate: 2017-03-09T14:24:55Z
      DOI: 10.1016/j.saa.2017.03.006
      Issue No: Vol. 180 (2017)
       
  • Vibrational and spectroscopic analysis of white light emitting Bi2SiO5
           nanophosphor
    • Authors: Pushpa Kumari; Y. Dwivedi
      Pages: 79 - 84
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Pushpa Kumari, Y. Dwivedi
      A series of Dy3+ ion activated Bi2SiO5 nanophosphors were synthesized by the hydrothermal and coprecipitation methods. Various structural and optical characterizations were made using X-ray diffraction, Scanning and Transmission electron microscopy, UV–Visible-Infrared absorption, Raman Spectroscopy, Photoluminescence, Time resolved luminescence techniques etc. Dy3+ ion doped samples yields characteristic bright yellow and blue emissions, on resonant excitation with 349nm and 386nm. The intensity ratio of the yellow/blue peaks was found to be function of Dy ion concentration and synthesis method. We have achieved white colour emission at 1.5mol% Dy concentration, CIE coordinate (0.36, 0.4) of which fall well within gamut of white light. The time-resolved fluorescence reveals decrease in radiative lifetime values with increasing Dy3+ ions concentration. A comparison between the samples synthesized by different methods, and Dy ion concentrations has been made and detail photo-physics involved is presented in the article.
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      PubDate: 2017-03-09T14:24:55Z
      DOI: 10.1016/j.saa.2017.03.005
      Issue No: Vol. 180 (2017)
       
  • Luminescence sensitization of Tb3+-DNA complexes by Ag+
    • Authors: Lijun Xu; Lu Zhou; Xing Chen; Xiaoqiang Shen; Jine Wang; Jianye Zhang; Renjun Pei
      Pages: 85 - 90
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Lijun Xu, Lu Zhou, Xing Chen, Xiaoqiang Shen, Jine Wang, Jianye Zhang, Renjun Pei
      Terbium ions (Tb3+) with unique photophysical properties have been utilized to develop biosensors with low background and high sensitivity. In this study, the Ag+-sensitized luminescence of Tb3+-DNA complexes was uncovered. The luminescence of Tb3+-DNA complexes could be enhanced by more than 30 times in the presence of Ag+, when Tb3+ was bound with poly(G) and poly(T) whereas not with other homopolymers. This research confirmed that the sensitization resulted from the interaction of Ag+ with certain bases involved in DNA, not just with the reported certain G-quadruplex sequence. The coordination of Ag+ to guanine and thymine bases was expected to increase their rigidities, form Tb3+-DNA-Ag+ ternary structures, and thus enhance energy transfer from guanine and thymine to Tb3+. These findings benefit the development of sensitive luminescence probes for various nucleic acids-related targets.
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      PubDate: 2017-03-09T14:24:55Z
      DOI: 10.1016/j.saa.2017.03.001
      Issue No: Vol. 180 (2017)
       
  • Intelligent evaluation of color sensory quality of black tea by
           visible-near infrared spectroscopy technology: A comparison of spectra and
           color data information
    • Authors: Qin Ouyang; Yan Liu; Quansheng Chen; Zhengzhu Zhang; Jiewen Zhao; Zhiming Guo; Hang Gu
      Pages: 91 - 96
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Qin Ouyang, Yan Liu, Quansheng Chen, Zhengzhu Zhang, Jiewen Zhao, Zhiming Guo, Hang Gu
      Instrumental test of black tea samples instead of human panel test is attracting massive attention recently. This study focused on an investigation of the feasibility for estimation of the color sensory quality of black tea samples using the VIS-NIR spectroscopy technique, comparing the performances of models based on the spectra and color information. In model calibration, the variables were first selected by genetic algorithm (GA); then the nonlinear back propagation-artificial neural network (BPANN) models were established based on the optimal variables. In comparison with the other models, GA-BPANN models from spectra data information showed the best performance, with the correlation coefficient of 0.8935, and the root mean square error of 0.392 in the prediction set. In addition, models based on the spectra information provided better performance than that based on the color parameters. Therefore, the VIS-NIR spectroscopy technique is a promising tool for rapid and accurate evaluation of the sensory quality of black tea samples.
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      PubDate: 2017-03-09T14:24:55Z
      DOI: 10.1016/j.saa.2017.03.009
      Issue No: Vol. 180 (2017)
       
  • Synthesis, characterization and biological evaluation of ruthenium
           flavanol complexes against breast cancer
    • Authors: Ashok Kumar Singh; Gunjan Saxena; Sahabjada; M. Arshad
      Pages: 97 - 104
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Ashok Kumar Singh, Gunjan Saxena, Sahabjada, M. Arshad
      Four Ru(II) DMSO complexes (M1R-M4R) having substituted flavones viz. 3-Hydroxy-2-(4-methoxyphenyl)-4H-chromen-4-one (HL1), 3-Hydroxy-2-(4-nitrophenyl)-4H-chromen-4-one (HL2), 3-Hydroxy-2-(4-dimethylaminophenyl)-4H–chromen-4-one (HL3) and 3-Hydroxy-2-(4-chlorophenyl)-4H-chromen-4-one (HL4) were synthesized and characterized by elemental analysis, IR, UV–Vis, 1H NMR spectroscopies and ESI-MS. The molecular structures of the complexes were investigated by integrated spectroscopic and computational techniques (DFT). Both ligands as well as their complexes were screened for anticancer activities against breast cancer cell lines MCF-7. Cytotoxicity was assayed by MTT [3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] assay. All ligands and their complexes exhibited significant cytotoxic potential of 5–40μM concentration at incubation period of 24h. The cell cytotoxicity increased significantly in a concentration-dependent manner. In this series of compounds, HL2 (IC50 17.2μM) and its complex M2R (IC50 16μM) induced the highest cytotoxicity.
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      PubDate: 2017-03-21T16:27:41Z
      DOI: 10.1016/j.saa.2017.02.056
      Issue No: Vol. 180 (2017)
       
  • Nd3+, Ho3+-codoped garnet-related Li7La3Hf2O12 phosphor with NIR
           luminescence
    • Authors: Yana V. Baklanova; Olga A. Lipina; Lidiya G. Maksimova; Alexander P. Tyutyunnik; Ivan I. Leonidov; Tatyana A. Denisova; Vladimir G. Zubkov
      Pages: 105 - 109
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Yana V. Baklanova, Olga A. Lipina, Lidiya G. Maksimova, Alexander P. Tyutyunnik, Ivan I. Leonidov, Tatyana A. Denisova, Vladimir G. Zubkov
      Simultaneous emission lines around 1.05μm, 1.3μm, 1.8μm, 2.1μm and 2.7μm have been observed in Li7La3− x Nd x Hf2O12:Ho3+ (x =0.00–0.15) under 808nm laser diode excitation. Near-infrared luminescence due to holmium ions with residual concentration in the Li7La3Hf2O12 host has been studied. The intensity of 2.1 and 2.7μm lines associated with 5I7 → 5I8 and 5I6 → 5I7 transitions in Ho3+ depends on the neodymium codopant concentration. This result indicates that Nd3+ ions can be potentially used as sensitizers for Ho3+ ions to stimulate the intense near-infrared emission in this system. Possible energy transfer mechanisms between lanthanide ions have been briefly discussed.
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      PubDate: 2017-03-09T14:24:55Z
      DOI: 10.1016/j.saa.2017.03.007
      Issue No: Vol. 180 (2017)
       
  • Composite CuFe1−xSnxO2/p-type silicon photodiodes
    • Authors: Abdullah G. Al-Sehemi; K. Mensah-Darkwa; Ahmed A. Al-Ghamdi; M. Soylu; R.K. Gupta; F. Yakuphanoglu
      Pages: 110 - 118
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Abdullah G. Al-Sehemi, K. Mensah-Darkwa, Ahmed A. Al-Ghamdi, M. Soylu, R.K. Gupta, F. Yakuphanoglu
      CuFe1− x Sn x O2 composite thin film/p-type silicon diodes were prepared on substrate by sol-gel method (x =0.00, 0.01, 0.03, 0.05, 0.07). The structure of CuFe1− x Sn x O2 composite thin films was studied using XRD analysis and films exhibited amorphous behavior. The elemental compositions and surface morphology of the films were characterized using SEM and EDX. EDX results confirmed the presence of the compositional elements. The optical band gap of CuFe1− x Sn x O2 composite thin films was determined using the optic spectra. The optical band gaps of the CuFe1− x Sn x O2 composite thin films were calculated using optical data and were found to be 3.75, 3.78, 3.80, 3.85 and 3.83eV for x =0.00, 0.01, 0.03, 0.05 and 0.07, respectively. The photoresponse and electrical properties of the Al/CuFe1− x Sn x O2/p-Si/Al diode were studied. The barrier height and ideality factor were determined to be averagely 0.67eV and 2.6, respectively. The electrical and photoresponse characteristics of the diodes have been investigated under dark and solar light illuminations, respectively. The interface states were used to explain the results obtained in present study. CuFe1− x Sn x O2 photodiodes exhibited a high photoresponsivity to be used in optoelectronic applications.
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      PubDate: 2017-03-09T14:24:55Z
      DOI: 10.1016/j.saa.2017.03.004
      Issue No: Vol. 180 (2017)
       
  • Calibration sets selection strategy for the construction of robust PLS
           models for prediction of biodiesel/diesel blends physico-chemical
           properties using NIR spectroscopy
    • Authors: Anna Palou; Aira Miró; Marcelo Blanco; Rafael Larraz; José Francisco Gómez; Teresa Martínez; Josep Maria González; Manel Alcalà
      Pages: 119 - 126
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Anna Palou, Aira Miró, Marcelo Blanco, Rafael Larraz, José Francisco Gómez, Teresa Martínez, Josep Maria González, Manel Alcalà
      Even when the feasibility of using near infrared (NIR) spectroscopy combined with partial least squares (PLS) regression for prediction of physico-chemical properties of biodiesel/diesel blends has been widely demonstrated, inclusion in the calibration sets of the whole variability of diesel samples from diverse production origins still remains as an important challenge when constructing the models. This work presents a useful strategy for the systematic selection of calibration sets of samples of biodiesel/diesel blends from diverse origins, based on a binary code, principal components analysis (PCA) and the Kennard-Stones algorithm. Results show that using this methodology the models can keep their robustness over time. PLS calculations have been done using a specialized chemometric software as well as the software of the NIR instrument installed in plant, and both produced RMSEP under reproducibility values of the reference methods. The models have been proved for on-line simultaneous determination of seven properties: density, cetane index, fatty acid methyl esters (FAME) content, cloud point, boiling point at 95% of recovery, flash point and sulphur.
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      PubDate: 2017-03-09T14:24:55Z
      DOI: 10.1016/j.saa.2017.03.008
      Issue No: Vol. 180 (2017)
       
  • Synthesis, spectroscopic, DFT and in vitro biological studies of
           vanadium(III) complexes of aryldithiocarbonates
    • Authors: Savit Andotra; Sandeep Kumar; Mandeep Kour; Vikas; Chayawan; Vishal Sharma; Sundeep Jaglan; Sushil. K. Pandey
      Pages: 127 - 137
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Savit Andotra, Sandeep Kumar, Mandeep Kour, Vikas, Chayawan, Vishal Sharma, Sundeep Jaglan, Sushil. K. Pandey
      Vanadium(III) tris(dithiocarbonates), [(ROCS2)3V] (R= o-, m-, p-CH3C6H4 and 4-Cl-3-CH3C6H3) and donor stabilized addition complexes [(ROCS2)2V(Cl)·L] [L=NC5H5 or P(C6H5)3] were synthesized and characterized by elemental analyses, IR, mass, TGA/DTA, SEM magnetic susceptibility and heteronuclear NMR (1H, 13C and 31P) spectroscopic studies. The cytotoxicity of the complexes was measured in vitro using the cultivated human cell lines. In addition, the antioxidant activities of the ligands and its vanadium complexes were also investigated through their scavenging effect on DPPH radicals. The antimicrobial activity of ligands and some complexes has been conducted against three bacterial strains and fungus. The density functional theory (DFT) calculations of ligands and vanadium complexes were performed by the DFT/B3LYP/LANL2DZ method to obtain the optimized molecular geometry, vibrational frequencies, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), thermodynamic properties and various other quantum-mechanical parameters.
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      PubDate: 2017-03-09T14:24:55Z
      DOI: 10.1016/j.saa.2017.03.003
      Issue No: Vol. 180 (2017)
       
  • Portable Raman spectroscopy for an in-situ monitoring the ripening of
           tomato (Solanum lycopersicum) fruits
    • Authors: Josu Trebolazabala; Maite Maguregui; Héctor Morillas; Alberto de Diego; Juan Manuel Madariaga
      Pages: 138 - 143
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Josu Trebolazabala, Maite Maguregui, Héctor Morillas, Alberto de Diego, Juan Manuel Madariaga
      Ripening is one of the most important transformations that fruits and vegetables suffer, from an unripe to a ripe stage. In this study, it was followed up and analyzed the variations in the composition of tomato fruits at different ripening stages (green or unripe, orange or middle ripe, red or ripe and brown or overripe). The results obtained from the Raman measurements carried out showed a change in the composition of tomato fruits in the transit from green to brown. The analysis confirmed an increase of carotenoids from an unripe to a ripe stage of these fruits, being lycopene the characteristic carotenoid of the optimum ripe stage. The presence of chlorophyll and cuticular waxes decrease from the unripe to the ripe stage. Moreover, the relative intensity of phytofluene, a transition compound in the carotenoid biosynthetic pathway, is higher in the orange or middle ripening stage. The results obtained in-situ, without cutting and handling the tomato fruits, by means of a portable Raman spectrometer offered the same information that can be achieved using a more expensive and sophisticated confocal Raman microscope.
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      PubDate: 2017-03-09T14:24:55Z
      DOI: 10.1016/j.saa.2017.03.024
      Issue No: Vol. 180 (2017)
       
  • An experimental and theoretical study on the interaction of DNA and BSA
           with novel Ni2+, Cu2+ and VO2+ complexes derived from vanillin bidentate
           Schiff base ligand
    • Authors: Morteza Dostani; Ali Hossein Kianfar; Wan Ahmad Kamil Mahmood; Mohammad Dinari; Hossein Farrokhpour; Mohammad R. Sabzalian; Fatemeh Abyar; Mohammad Hossein Azarian
      Pages: 144 - 153
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Morteza Dostani, Ali Hossein Kianfar, Wan Ahmad Kamil Mahmood, Mohammad Dinari, Hossein Farrokhpour, Mohammad R. Sabzalian, Fatemeh Abyar, Mohammad Hossein Azarian
      In this investigation, the structure of bidentate N,N-Schiff base ligand of vanillin, (E)-4-(((2-amino-5-nitrophenyl)imino)methyl)-2-methoxyphenol (HL) was determined by single crystal X-ray diffraction. The interaction of new [CuL2], [NiL2] and [VOL2] complexes with DNA and BSA was explored through UV–Vis and fluorescence spectroscopy. The electronic spectra changes displayed an isosbestic point for the complexes upon titration with DNA. The Kb values for the complexes [CuL2], [NiL2] and [VOL2] were 2.4×105, 1.9×105 and 4.2×104, respectively. [CuL2] complex was bound more toughly than [NiL2] and [VOL2] complexes. These complexes had a significant interaction with Bovine Serum Albumin (BSA) and the results demonstrated that the quenching mechanism was a static procedure. Also, the complexes interacted with BSA by more than one binding site (n>1). Finally, the theoretical studies were performed using the docking method to calculate the binding constants and recognize the binding site of the DNA and BSA with the complexes. The ligand and complexes including Ni2+, Cu2+ and VO2+ ions were colonized by fungal growth.
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      PubDate: 2017-03-09T14:24:55Z
      DOI: 10.1016/j.saa.2017.02.047
      Issue No: Vol. 180 (2017)
       
  • Identification of trace additives in polymer materials by attenuated total
           reflection Fourier transform infrared mapping coupled with multivariate
           curve resolution
    • Authors: Qian Li; Yongjiao Tang; Zhiwei Yan; Pudun Zhang
      Pages: 154 - 160
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Qian Li, Yongjiao Tang, Zhiwei Yan, Pudun Zhang
      Although multivariate curve resolution (MCR) has been applied to the analysis of Fourier transform infrared (FTIR) imaging, it is still problematic to determine the number of components. The reported methods at present tend to cause the components of low concentration missed. In this paper a new idea was proposed to resolve this problem. First, MCR calculation was repeated by increasing the number of components sequentially, then each retrieved pure spectrum of as-resulted MCR component was directly compared with a real-world pixel spectrum of the local high concentration in the corresponding MCR map. One component was affirmed only if the characteristic bands of the MCR component had been included in its pixel spectrum. This idea was applied to attenuated total reflection (ATR)/FTIR mapping for identifying the trace additives in blind polymer materials and satisfactory results were acquired. The successful demonstration of this novel approach opens up new possibilities for analyzing additives in polymer materials.
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      PubDate: 2017-03-09T14:24:55Z
      DOI: 10.1016/j.saa.2017.03.019
      Issue No: Vol. 180 (2017)
       
  • SERS substrates fabricated using ceramic filters for the detection of
           bacteria: Eliminating the citrate interference
    • Authors: P.A. Mosier-Boss; K.C. Sorensen; R.D. George; P.C. Sims; A. O'braztsova
      Pages: 161 - 167
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): P.A. Mosier-Boss, K.C. Sorensen, R.D. George, P.C. Sims, A. O'braztsova
      It was found that spectra obtained for bacteria on SERS substrates fabricated by filtering citrate-generated Ag nanoparticles (NPs) onto rigid, ceramic filters exhibited peaks due to citrate as well as the bacteria. In many cases the citrate spectrum overwhelmed that of the bacteria. Given the simplicity of the method to prepare these substrates, means of eliminating this citrate interference were explored. It was found that allowing a mixture of bacteria suspension and citrate-generated Ag NPs to incubate prior to filtering onto the ceramic filter eliminated this interference.
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      PubDate: 2017-03-09T14:24:55Z
      DOI: 10.1016/j.saa.2017.03.021
      Issue No: Vol. 180 (2017)
       
  • Designing of an artificial light energy converter in the form of
           
    • Authors: Gopa Dutta (Pal); Somnath Paul; Munmun Bardhan; Asish De; Tapan Ganguly
      Pages: 168 - 174
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Gopa Dutta (Pal), Somnath Paul, Munmun Bardhan, Asish De, Tapan Ganguly
      UV–vis absorption, steady state and time resolved fluorescence and absorption spectroscopic investigations demonstrate that the short chain dyad MNTMA when combined with gold-silver core-shell (Au@Ag) nanocomposite , forms elongated conformers in the excited state whereas for the dyad – Ag (spherical) system the majority of dyads remains in a folded conformation. In the dyad-core-shell nanocomposite system, energy wasting charge recombination rate slows down primarily due to elongated conformation and thus it may be anticipated that this hybrid nanocomposite system may serve as a better light energy conversion device.
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      PubDate: 2017-03-09T14:24:55Z
      DOI: 10.1016/j.saa.2017.03.015
      Issue No: Vol. 180 (2017)
       
  • Multi-signaling thiocarbohydrazide based colorimetric sensors for the
           selective recognition of heavy metal ions in an aqueous medium
    • Authors: Bharath Kumar Momidi; Venkatadri Tekuri; Darshak R. Trivedi
      Pages: 175 - 182
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Bharath Kumar Momidi, Venkatadri Tekuri, Darshak R. Trivedi
      A series of colorimetric chemosensors R1–R6 have been developed from thiocarbohydrazide derivatives, for the selective detection of heavy metal ions. The structures of the receptors R1–R6 were well characterized by standard spectroscopic techniques like FT-IR, 1H NMR, and ESI-MS. The solid structure of receptor R1 and R2 were derived by single crystal X-ray diffraction (SC-XRD). The cation reorganization abilities of receptors R1–R6 were studied by UV–Vis spectroscopy. The receptors R1, R3 and R4 acts as a tremendous sensitive probe for heavy metal ions (Hg2+, Cd2+ and Pb2+) with the μM detection (R1 for Hg2+, 2.72, R3 for Cd2+, 3.22, R4 for Hg2+, Cd2+ & Pb2+, 0.70, 0.20 & 0.30μM) and the receptors R2, R5 & R6 are sensitive towards Cu 2+ ions with the μM detection (3.34, 0.90 & 1.20μM) in an aqueous medium among all other tested cations. The receptor R4 shows a multi-color response towards Hg2+, Cu2+, Cd2+ and Pb2+ ions. The recognition mechanism, stoichiometric binding ratio and detection limit (DL) have been examined by UV–Visible spectroscopic titration experiments and Benesi-Hildebrand (B-H) plot, receptor R1–R6 sowed 1:1 binding ratio with good binding constant range of 103 to 105 M−1 with Hg2+, Cu2+, Cd2+ and Pb2+ ions metal ions.
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      PubDate: 2017-03-09T14:24:55Z
      DOI: 10.1016/j.saa.2017.03.010
      Issue No: Vol. 180 (2017)
       
  • Electronic structure determination using an assembly of conventional and
           synchrotron techniques: The case of a xanthate complex
    • Authors: Luciana C. Juncal; José Avila; Maria Carmen Asensio; Carlos O. Della Védova; Rosana M. Romano
      Pages: 183 - 192
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Luciana C. Juncal, José Avila, Maria Carmen Asensio, Carlos O. Della Védova, Rosana M. Romano
      The electronic properties of the coordination complex nickel (II) bis-n-propylxanthate, Ni(CH3(CH2)2OC(S)S)2, were studied by a combination of complementary experimental (both laboratory and synchrotron based techniques) and theoretical methods. Energy differences between HOMOs and LUMOs were determined from UV–visible spectroscopy. The assignment of the transitions were performed with the aid of TD-DFT calculations and based in symmetry considerations. The analysis of the Raman excitation profiles of selected vibrational modes of the complex, taken in resonance with a particular electronic transition, was found to reinforce the electronic assignment. Experimental binding energies of inner and core electrons were determined by PES measurements. Ni K-edge, S K-edge, Ni L-edge, O K-edge and C K-edge XANES spectra were interpreted in terms of the promotion of core electrons to unoccupied electronic levels. An experimental quantitative molecular orbital diagram was constructed using the information extracted from the different techniques.
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      PubDate: 2017-03-17T16:11:37Z
      DOI: 10.1016/j.saa.2017.03.002
      Issue No: Vol. 180 (2017)
       
  • Optical spectroscopy, 1.06μm emission properties of Nd3+-doped
           phosphate based glasses
    • Authors: Rasool Sk. Nayab; Sasikala T.; Mohan Babu A.; Rama Moorthy L.; Jayasankar C.K.
      Pages: 193 - 197
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Rasool Sk. Nayab, Sasikala T., Mohan Babu A., Rama Moorthy L., Jayasankar C.K.
      Neodymium doped phosphate based glasses with composition of (P2O5 +K2O+Al2O3 +CaF2) were prepared. The samples were analysed through differential thermal analysis (DTA), Fourier transform infrared (FTIR), absorption, emission and decay measurements. Judd-Ofelt parameters (Ωλ) have been determined from the spectral intensities of absorption bands in order to calculate the radiative parameters like radiative transition probabilities (AR), radiative lifetime (τR) and branching ratios (βR) for the 4F3/2 → 4I11/2 laser transition of Nd3+ ion. The effective emission bandwidths (Δλeff), experimental branching ratios (βexp) and stimulated emission cross-sections (σe) have been determined from the emission spectrum. The decay curves of the 4F3/2 level exhibited almost single exponential nature for all the Nd3+ ion concentrations.
      Graphical abstract image

      PubDate: 2017-03-17T16:11:37Z
      DOI: 10.1016/j.saa.2017.03.012
      Issue No: Vol. 180 (2017)
       
  • Corrigendum to “Optical Transitions of Tm3+ in Oxyfluoride Glasses and
           Compositional and Thermal Effect on Upconversion Luminescence of Tm3+/Yb3+
           -codoped Oxyfluoride Glasses” [Spectrochim. Acta A 118 (2014) 192–198]
           
    • Authors: Li Feng; Yinsu Wu; Zhuo Liu; Tao Guo
      First page: 198
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Li Feng, Yinsu Wu, Zhuo Liu, Tao Guo


      PubDate: 2017-03-17T16:11:37Z
      DOI: 10.1016/j.saa.2017.03.011
      Issue No: Vol. 180 (2017)
       
  • A simple ratiometric fluorescent sensor for fructose based on complexation
           of 10-hydroxybenzo[h]quinoline with boronic acid
    • Authors: Huihui Li; Cailing Yang; Xinyue Zhu; Haixia Zhang
      Pages: 199 - 203
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Huihui Li, Cailing Yang, Xinyue Zhu, Haixia Zhang
      A simple ratiometric fluorescent sensor for fructose was presented. It consisted of 10-hydroxybenzo[h]quinoline (HBQ) which showed emission at 572nm and 3-pyridylboronic acid (PDBA) whose complex with HBQ gave emission at 500nm. The reaction of fructose with PDBA inhibited the complexation of HBQ with PDBA, resulting in the change of dual-emission intensity ratio. The sensor well quantified fructose in the range of 0.015–2.5mM with detection limit of 0.005mM. Besides, this sensor exhibited excellent selectivity and was successfully applied to fructose detection in food. This work provides a simple ratiometric sensing platform for sensitive and selective detection of fructose.
      Graphical abstract image

      PubDate: 2017-03-17T16:11:37Z
      DOI: 10.1016/j.saa.2017.03.017
      Issue No: Vol. 180 (2017)
       
  • Seed-mediated grown silver nanoparticles as a colorimetric sensor for
           detection of ascorbic acid
    • Authors: Simindokht Rostami; Ali Mehdinia; Ali Jabbari
      Pages: 204 - 210
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Simindokht Rostami, Ali Mehdinia, Ali Jabbari
      A simple and sensitive approach was demonstrated for detection of ascorbic acid (AA) based on seed-mediated growth of silver nanoparticles (Ag NPs). According to the seeding strategy, silver ions existing in the growth solution were reduced to silver atoms on the surface of silver seeds via redox reaction between silver ions and AA. This process -led to appear an absorption band in near 420nm owing to the localized surface plasmon resonance peak of the generated Ag NPs. This change in absorption spectra of Ag NPs caused a change in color of the mixture from colorless to yellow. It was found that the changes in absorption intensity at 420nm have a good relationship with the concentration of AA. Also, detection of AA was achieved through the established colorimetric sensor in the range of 0.25–25μM with detection limit of 0.054μM. Moreover, the selectivity of the method was evaluated with considering potential interferences. The method showed high selectivity toward AA rather than potential interferences and coexisted molecules with AA. It was successfully applied for detection and determination of AA in pharmaceutical tablets and commercial lemonade.
      Graphical abstract image

      PubDate: 2017-03-17T16:11:37Z
      DOI: 10.1016/j.saa.2017.03.020
      Issue No: Vol. 180 (2017)
       
  • “Turn-on” fluorescent probe detection of Ca2+ ions and
           applications to bioimaging
    • Authors: Huifang Zhang; Caixia Yin; Tao Liu; Yongbin Zhang; Fangjun Huo
      Pages: 211 - 216
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Huifang Zhang, Caixia Yin, Tao Liu, Yongbin Zhang, Fangjun Huo
      Ca2+ is intracellular divalent cation with the largest concentration variations and involved in many biological phenomena and often acted as a second messenger in signaling pathway. Therefore, the development of probes for specific Ca2+ detection is of great importance. Herein, a novel turn-on fluorescent probe for the detection of Ca2+ in MeCN-aqueous medium was designed and synthesized. The probe displayed responses to Ca2+ with a fluorescence enhancement at 525nm, accompanying with a distinct fluorescence change from nearly colorless to bright yellow-green. Besides, the probe exhibited a rapid signal response time (within 25s), a good linearity range and a lower detection limit (2.70×10−7 M). In addition, the ability of the probe to detect Ca2+ in living cells (HeLa cells) via an enhancement of the fluorescence has also been demonstrated.
      Graphical abstract image

      PubDate: 2017-03-21T16:27:41Z
      DOI: 10.1016/j.saa.2017.03.023
      Issue No: Vol. 180 (2017)
       
  • Interaction of vasicine with calf thymus DNA: Molecular docking,
           spectroscopic and differential scanning calorimetric insights
    • Authors: Sai Murali R.S.; Sai Siddhardha R.S.; Rajesh Babu D.; Venketesh S.; Basavaraju R.; Nageswara Rao G.
      Pages: 217 - 223
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Sai Murali R.S., Sai Siddhardha R.S., Rajesh Babu D., Venketesh S., Basavaraju R., Nageswara Rao G.
      The present study brings out the interaction between vasicine, an alkaloid and Adhatoda vasica Nees with double stranded DNA. The physico-chemical interaction between small molecules and nucleic acids is a major area of focus in screening drugs against various cancers. Molecular probing in our study using Molecular Operating Environment (MOE) has revealed interaction of vasicine with DNA double helix. Here we report the interaction of vasicine with Calf thymus DNA. We present for the first time the results obtained from UV–visible, fluorescence spectroscopic and differential scanning calorimetric techniques that suggest a moderate to strong electrostatic, hydrophobic and van der Waals interactions mediating the DNA binding properties of vasicine, leading to disruption of DNA secondary structure.
      Graphical abstract image

      PubDate: 2017-03-21T16:27:41Z
      DOI: 10.1016/j.saa.2017.03.016
      Issue No: Vol. 180 (2017)
       
  • Proton conducting system (ImH2)2SeO4·2H2O investigated with
           vibrational spectroscopy
    • Authors: Sylwia Zięba; Adam Mizera; Katarzyna Pogorzelec-Glaser; Andrzej Łapiński
      Pages: 224 - 233
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Sylwia Zięba, Adam Mizera, Katarzyna Pogorzelec-Glaser, Andrzej Łapiński
      Imidazolium selenate dihydrate (ImH2)2SeO4·2H2O crystals have been investigated using Raman and IR spectroscopy. Experimental data were supported by the quantum-chemical calculations (DFT), Hirshfield surfaces and fingerprint plots analysis, and Bader theory calculations. The imidazolium selenate dihydrate crystal exhibits high proton conductivity of the order of ~10−1 S/m at T =333K. The spectra of this compound are dominated by bands related to the lattice modes, the internal vibrations of the protonated imidazole cation, selenate anion, water molecules, and hydrogen bonds network. For the imidazolium selenate dihydrate crystal, the formal classification of the fundamental modes has been carried out.
      Graphical abstract image

      PubDate: 2017-03-21T16:27:41Z
      DOI: 10.1016/j.saa.2017.02.049
      Issue No: Vol. 180 (2017)
       
  • 3-[(E)-(acridin-9′-ylmethylidene)amino]-1-substituted thioureas and
           their biological activity
    • Authors: Michal Bečka; Mária Vilková; Othman Salem; Jana Kašpárková; Viktor Brabec; Mária Kožurková
      Pages: 234 - 241
      Abstract: Publication date: 5 June 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 180
      Author(s): Michal Bečka, Mária Vilková, Othman Salem, Jana Kašpárková, Viktor Brabec, Mária Kožurková
      This paper describes the synthesis of a novel series of acridine thiosemicarbazones through a two-step reaction between various isothiocyanates and hydrazine followed by treatment with acridin-9-carbaldehyde. The properties of this series of seven new derivatives are studied using NMR and biochemical techniques, and the DNA-binding properties of the compounds are determined using spectrophotometric studies (UV–vis absorption, fluorescence, and circular/linear dichroism) and viscometry. The binding constants K are estimated as being in the range of 2.2 to 7.8×104 M−1 and the percentage of hypochromism was found to be 22.11–49.75% (from UV–vis spectral titration). Electrophoretic experiments prove that the novel compounds demonstrate moderate inhibitory effects against Topo I activity at a concentration of 60×10−6 M.
      Graphical abstract image

      PubDate: 2017-03-21T16:27:41Z
      DOI: 10.1016/j.saa.2017.03.014
      Issue No: Vol. 180 (2017)
       
  • A novel sensor for determination of naproxen based on change in localized
           surface plasmon peak of functionalized gold nanoparticles
    • Authors: Javad Khodaveisi; Ali Mohammad Haji Shabani; Shayessteh Dadfarnia; Dariush Saberi
      Pages: 11 - 16
      Abstract: Publication date: 15 May 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 179
      Author(s): Javad Khodaveisi, Ali Mohammad Haji Shabani, Shayessteh Dadfarnia, Dariush Saberi
      A highly selective and sensitive colorimetric sensor for the determination of naproxen (NAP) based on the aggregation of the thiolated β-cyclodextrin (Tβ-CD) functionalized gold nanoparticles (Tβ-CD-Au NPs) in the presence of NAP and Zn2+ is described. The hydrophobic end of NAP interacts with the immobilized Tβ-CD on the Au NPs and forms the complex of Tβ-CD:NAP while the Zn2+ ions form a 1:2 complex of (NAP)2Zn with the carboxyl groups of NAP resulting in the aggregation of functionalized gold nanoparticles. As a result of aggregation, the localized surface plasmon resonance (LSPR) band of functionalized gold nanoparticles around 520nm decreases and a new red shifted band at 650nm appears which increases gradually as the function of NAP concentration. The calibration graph derived from the intensity ratios of absorbance at 650nm to 520nm was linear in the concentration range of 4–180μgL−1of NAP. At the optimum conditions, the limit of detection (LOD) and quantification (LOQ) were found to be 0.6 and 2.1μgL−1, respectively and the relative standard deviation at 20μgL−1of NAP (n=5) was 2.5%. The selectivity and applicability of the method was verified through analyzes of the synthetic samples containing the major interference compounds reported in literature as well as tablets, wastewater and urine samples. The accuracy of the method was evaluated by recovery experiments and analysis of pharmaceutical tablets.
      Graphical abstract image

      PubDate: 2017-02-18T11:59:56Z
      DOI: 10.1016/j.saa.2017.02.008
      Issue No: Vol. 179 (2017)
       
  • Thermostability of photosystem I trimers and monomers from the
           cyanobacterium Thermosynechococcus elongatus
    • Authors: Vladimir V. Shubin; Irina V. Terekhova; Yulia V. Bolychevtseva; Eithar El-Mohsnawy; Matthias Rögner; Werner Mäntele; Marta J. Kopczak; Enela Džafić
      Pages: 17 - 22
      Abstract: Publication date: 15 May 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 179
      Author(s): Vladimir V. Shubin, Irina V. Terekhova, Yulia V. Bolychevtseva, Eithar El-Mohsnawy, Matthias Rögner, Werner Mäntele, Marta J. Kopczak, Enela Džafić
      The performance of solar energy conversion into alternative energy sources in artificial systems highly depends on the thermostability of photosystem I (PSI) complexes Terasaki et al. (2007), Iwuchukwu et al. (2010), Kothe et al. (2013) . To assess the thermostability of PSI complexes from the thermophilic cyanobacterium Thermosynechococcus elongatus heating induced perturbations on the level of secondary structure of the proteins were studied. Changes were monitored by Fourier transform infrared (FT-IR) spectra in the mid-IR region upon slow heating (1°C per minute) of samples in D2O phosphate buffer (pD 7.4) from 20°C to 100°C. These spectra showed distinct changes in the Amide I region of PSI complexes as a function of the rising temperature. Absorbance at the Amide I maximum of PSI monomers (centered around 1653cm−1), gradually dropped in two temperature intervals, i.e. 60–75 and 80–90°C. In contrast, absorbance at the Amide I maximum of PSI trimers (around 1656cm−1) dropped only in one temperature interval 80–95°C. The thermal profile of the spectral shift of α-helices bands in the region 1656–1642cm−1 confirms the same two temperature intervals for PSI monomers and only one interval for trimers. Apparently, the observed absorbance changes at the Amide I maximum during heating of PSI monomers and trimers are caused by deformation and unfolding of α-helices. The absence of absorbance changes in the interval of 20–65°C in PSI trimers is probably caused by a greater stability of protein secondary structure as compared to that in monomers. Upon heating above 80°C a large part of α-helices both in trimers and monomers converts to unordered and aggregated structures. Spectral changes of PSI trimers and monomers heated up to 100°C are irreversible due to protein denaturation and non-specific aggregation of complexes leading to new absorption bands at 1618–1620cm−1. We propose that monomers shield the denaturation sensitive sides at the monomer/monomer interface within a trimer, making the oligomeric structure more stable against thermal stress.
      Graphical abstract image

      PubDate: 2017-02-18T11:59:56Z
      DOI: 10.1016/j.saa.2017.02.010
      Issue No: Vol. 179 (2017)
       
  • Extraction, preparation and application of pigments from Cordyline
           fruticosa and Hylocereus polyrhizus as sensitizers for dye-sensitized
           solar cells
    • Authors: Mahmoud A.M. Al-Alwani; Norasikin A. Ludin; Abu Bakar Mohamad; Abd. Amir H. Kadhum; Kamaruzzaman Sopian
      Pages: 23 - 31
      Abstract: Publication date: 15 May 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 179
      Author(s): Mahmoud A.M. Al-Alwani, Norasikin A. Ludin, Abu Bakar Mohamad, Abd. Amir H. Kadhum, Kamaruzzaman Sopian
      Current study employs mixture of chlorophyll-anthocyanin dye extracted from leaves of Cordyline fruticosa as new sensitizers for dye-sensitized solar cell (DSSCs), as well as betalains dye obtained from fruit of Hylocereus polyrhizus. Among ten pigments solvents, the ethanol and methanol extracts revealed higher absorption spectra of pigments extracted from C. fruticosa and H. polyrhizus respectively. A major effect of temperature increase was studied to increase the extraction yield. The results indicated that extraction temperature between 70 and 80°C exhibited a high dye concentration of each plant than other temperatures. The optimal temperature was around 80°C and there was a sharp decrease of dye concentration at temperatures higher than this temperature. According to experimental results, the conversion efficiency of DSSC fabricated by mixture of chlorophyll and anthocyanin dyes from C. fruticosa leaves is 0.5% with short-circuit current (Isc) of 1.3mA/cm−2 , open-circuit voltage (Voc) of 0.62V and fill factor (FF) of 60.16%. The higher photoelectric conversion efficiency of the DSSC prepared from the extract of H. polyrhizus was 0.16%, with Voc of 0.5V, Isc of 0.4mA/cm−2 and FF of 79.16%. The DSSC based betalain dye extracted from fruit of H. polyrhizus shows higher maximum IPCE of 44% than that of the DSSCs sensitized with mixed chlorophyll-anthocyanin dye from C. fruticosa (42%).
      Graphical abstract image

      PubDate: 2017-02-18T11:59:56Z
      DOI: 10.1016/j.saa.2017.02.026
      Issue No: Vol. 179 (2017)
       
  • Selective detection of Cu2+ and Co2+ in aqueous media: Asymmetric
           chemosensors, crystal structure and spectroscopic studies
    • Authors: Samira Gholizadeh Dogaheh; Hamid Khanmohammadi; E. Carolina Sañudo
      Pages: 32 - 41
      Abstract: Publication date: 15 May 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 179
      Author(s): Samira Gholizadeh Dogaheh, Hamid Khanmohammadi, E. Carolina Sañudo
      Two new azo-azomethine receptors, H2L1 and H2L2, containing hydrazine, naphthalene and different electron withdrawing groups, Cl and NO2, have been designed and synthesized for qualitative and quantitative detection of Cu2+ and Co2+ in aqueous media. The crystal structure of H2L1is reported. The H2L1was used as a chemosensor for selective detection of trace amount of Cu2+ in aqueous media. H2L2 was also applied to naked-eye distinction of Cu2+ and Co2+ from other transition metal ions in aqueous media. Detection limit of Cu2+ is 1.13μM and 1.26μM, in water, for H2L1 and H2L2, respectively, which are lower than the World Health Organization (WHO) recommended level. The binuclear Cu2+ and Co2+ complexes of the receptors have been also prepared and characterized using spectroscopic methods and MALDI-TOF mass analysis. Furthermore, the binding stoichiometry between the receptors upon the addition Cu2+ and Co2+ has been investigated using Job's plot. Moreover, the fluorescence emission spectra of the receptors and their metal complexes are also reported.
      Graphical abstract image

      PubDate: 2017-02-18T11:59:56Z
      DOI: 10.1016/j.saa.2017.02.017
      Issue No: Vol. 179 (2017)
       
  • Intense 2.7μm emission in Er3+ doped zinc fluoride glass
    • Authors: Feifei Huang; Yanyan Guo; Ying Tian; Shiqing Xu; Junjie Zhang
      Pages: 42 - 45
      Abstract: Publication date: 15 May 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 179
      Author(s): Feifei Huang, Yanyan Guo, Ying Tian, Shiqing Xu, Junjie Zhang
      A novel erbium ion doped zinc fluoride glass was prepared. 2.7μm emission and transmittance properties together with thermal ability were investigated. An enhanced 2.7μm emission was observed by introducing ZnF2 in the ZrF4-based fluoride glass. Meanwhile, the J-O parameters and branching ratios (β) of Er3+-doped zinc fluoride glass were calculated and analyzed. The present Er3+-doped zinc fluoride glass with large emission cross-section (0.92×10−20 cm2) and long decay lifetime (2.05ms) at 2.7μm indicates that it have very promising applications for solid state lasers around 3μm.
      Graphical abstract image

      PubDate: 2017-02-18T11:59:56Z
      DOI: 10.1016/j.saa.2017.02.020
      Issue No: Vol. 179 (2017)
       
  • Chiral-aminoquinoline-based fluorescent pH probe with large stokes shift
           for bioimaging
    • Authors: Yong-Sheng Xie; Xin-Ling Zhang; Kun Xie; Yanmei Zhao; Huan Wu; Jidong Yang
      Pages: 51 - 57
      Abstract: Publication date: 15 May 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 179
      Author(s): Yong-Sheng Xie, Xin-Ling Zhang, Kun Xie, Yanmei Zhao, Huan Wu, Jidong Yang
      The aminoquinoline derivatives, (R)- and (S)-2-phenyl-2-(quinolin-6-ylamino)ethan-1-ol ( R-PEO and S-PEO), were synthesized by a tandem one-pot three-step CN coupling method where Smiles rearrangement was the key procedure. The selected compound R-PEO showed a significant fluorescence enhancement with a turn-on ratio over 98-fold and enabled the real time determination of proton concentration in acidic solution. The fluorescence intensity of R-PEO exhibited strong pH-dependent performance with a large Stokes shift (115nm) and responded linearly to minor pH change within the range of 3.8–6.0. With the help of 1H NMR spectrum, we also confirmed the protonation of the quinoline unit should be the proposed reaction. Compared with the conjugated acid of N-hexylquinolin-6-amine (NQA), the conjugated acid of R-PEO shows significant planar intramolecular charge transfer (PICT) character. Furthermore, biological imaging proved that R-PEO probe can be used to monitor the pH change of S. cerevisiae in vivo.
      Graphical abstract image

      PubDate: 2017-02-18T11:59:56Z
      DOI: 10.1016/j.saa.2017.02.025
      Issue No: Vol. 179 (2017)
       
  • Microwave dielectric relaxation spectroscopy study of propylene
           glycol/ethanol binary mixtures: Temperature dependence
    • Authors: T. Vishwam; Suriya Shihab; V.R K. Murthy; Ha Sie Tiong; S. Sreehari Sastry
      Pages: 74 - 82
      Abstract: Publication date: 15 May 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 179
      Author(s): T. Vishwam, Suriya Shihab, V.R K. Murthy, Ha Sie Tiong, S. Sreehari Sastry
      Complex dielectric permittivity measurements of propylene glycol (PG) in ethanol at various mole fractions were measured by using open-ended coaxial probe technique at different temperatures in the frequency range 0.02<ν/GHz<20. The dipole moment (μ), excess dipole moment (Δμ),excess permittivity (εE), excess inverse relaxation time(1/τ)E, Bruggeman parameter (f B ), excess Helmholtz energy (ΔF E ) are determined using experimental data. From the minimum energy based geometry optimization, dipole moments of individual monomers of propylene glycol and ethanol and their binary system have been evaluated theoretically at gaseous state as well as alcoholic medium by using PCM and IEFPCM solvation models from the Hatree-Fock (HF) and Density Functional Theory (DFT-B3LYP) methods with 6-311G* and 6-311G** basis sets. The obtained results have been interpreted in terms of the short and long range ordering of the dipoles, Kirkwood correlation factor (geff), thermodynamic parameters, mean molecular polarizability (αM) and interaction in the mixture through hydrogen bonding.
      Graphical abstract image

      PubDate: 2017-02-18T11:59:56Z
      DOI: 10.1016/j.saa.2017.02.023
      Issue No: Vol. 179 (2017)
       
  • Levofloxacin capped Ag-nanoparicles: A new highly selective sensor for
           cations under joint experimental and DFT investigation
    • Authors: Sutapa Mondal Roy; Debesh Ranjan Roy
      Pages: 178 - 187
      Abstract: Publication date: 15 May 2017
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 179
      Author(s): Sutapa Mondal Roy, Debesh Ranjan Roy
      A very new and alternate function of an antibiotic drug levofloxacin (Lv), as a highly selective, colorimetric turn-OFF/turn-ON chemosensor for metal-ions Hg2+ and Fe3+, has been reported in this study. An extremely easy, very less time consuming, economical one-pot method of synthesis has been developed for the production of silver nanoparticles (AgNPs). The AgNPs that are stabilized and surface functionalized by Lv. Functionalization of AgNPs by antibiotic drug Lv has been thoroughly confirmed using FTIR spectrophotometry. Two carbonyl oxygen moieties, one belongs to the pyridine oxygen group and another one from the carboxylate oxygen group of Lv together form the binding site over the nanoparticle surface. The Lv-AgNPs system has shown naked eye detectable colour change, as well as significant change via both UV–Vis and fluorescence spectroscopy. The limits of detection (LODs) are predicted to be 6.86×10−8 M for Hg2+ and 2.52×10−9 M for Fe3+ using UV–Vis spectroscopy and 2.35×10−9 M for Fe3+ using fluorescence spectroscopy. UV–Vis spectroscopy, fluorescence spectroscopy, FTIR, TEM, DLS etc. have been used for the physico-chemical characterization of Lv-AgNPs system and the nanoparticle mediated sensing process. Detailed experimental and theoretical studies employing FTIR spectrophotometry and density functional theory (DFT) studies have been used for the elucidation of drug-nanoparticle based sensing mechanism. It is also demonstrated that the Lv-AgNPs system can show real time application using Test-Paper Kit to establish the drug-nanoparticle assembly as a potential colorimetric turn-OFF/turn-ON sensing system for Hg2+ and Fe3+ respectively.
      Graphical abstract image

      PubDate: 2017-02-25T13:20:59Z
      DOI: 10.1016/j.saa.2017.02.030
      Issue No: Vol. 179 (2017)
       
 
 
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