title: Functionalized ZnS quantum dots as luminescent probes for detection of amino acids.
abstract: In this work, L-cysteine capped-ZnS quantum dots were synthesized in aqueous medium, and their interaction with some of the amino acids was studied with fluorescence spectra. The results demonstrated that histidine could effectively quench the Quantum dots emission more than other amino acids. Electron transfer process between the capping ligands and histidine was mainly responsible for the remarkable quenching effect of histidine, because according to the structure of histidine, it is the strongest acceptor among essential amino acids. Under optimum conditions, the quenched fluorescence intensity increased linearly with the concentration of histidine ranging from 1.33×10(-6) to 1.49×10(-4) mol L(-1). The limit of detection for histidine was 0.05×10(-7) mol L(-1).
authors.affiliation: Center of Excellence in Electrochemistry, University of Tehran, Tehran, Iran. mahsa_mobarrez@yahoo.com
authors.forename: Mahsa
authors.initials: M
authors.lastname: Mobarraz
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Ganjali
authors.forename: Mohammad Javad
authors.initials: MJ
authors.lastname: Chaichi
authors.forename: Parviz
authors.initials: P
authors.lastname: Norouzi
mesh_terms: D000042:Absorption; D000596:Amino Acids / Q000032:analysis*; D003545:Cysteine / Q000032:analysis; D006639:Histidine / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D049449:Luminescence; D015335:Molecular Probes / Q000737:chemistry*; D045663:Quantum Dots; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D013440:Sulfides / Q000737:chemistry*; D017967:Zinc Compounds / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D015335:Molecular Probes; D013440:Sulfides; D017967:Zinc Compounds; D006639:Histidine; D003545:Cysteine; C031238:zinc sulfide