title: Tyrosine-functionalized CuInS2 quantum dots as a fluorescence probe for the determination of biothiols, histidine and threonine.
abstract: A novel, rapid and highly sensitive fluorescence turn-on assay for the detection of biothiols (glutathione, and L-cysteine), histidine and threonine was developed. Water-soluble CuInS2 ternary quantum dots (QDs) capped by mercaptopropionic acid (MPA) were directly synthesized in aqueous solution, and then functionalized using tyrosine molecules to form tyrosine-functionalized CuInS2 QDs (T-CuInS2 QDs). The fluorescence of T-CuInS2 QDs would decrease in the presence of Cu(2+) due to the coordination effect of phenolic hydroxyls of the tyrosine molecules. Subsequently, the addition of biothiols (glutathione and L-cysteine), histidine or threonine could turn on the fluorescence of the T-CuInS2 QDs-Cu(2+) system due to their strong affinity for Cu(2+). The proposed method was simple in design and fast in operation, and it was applied for the detection of glutathione, L-cysteine, histidine, and threonine in human serum samples with satisfactory results.
authors.affiliation: Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China. suxg@jlu.edu.cn.
authors.forename: Siyu
authors.initials: S
authors.lastname: Liu
authors.forename: Fanping
authors.initials: F
authors.lastname: Shi
authors.forename: Lu
authors.initials: L
authors.lastname: Chen
authors.forename: Xingguang
authors.initials: X
authors.lastname: Su
mesh_terms: D003300:Copper / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D006639:Histidine / Q000032:analysis*; D006801:Humans; D007328:Insulin / Q000737:chemistry; D045663:Quantum Dots / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods; D013438:Sulfhydryl Compounds / Q000032:analysis; D013912:Threonine / Q000032:analysis*; D014443:Tyrosine / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D007328:Insulin; D013438:Sulfhydryl Compounds; D013912:Threonine; D014443:Tyrosine; D006639:Histidine; D003300:Copper