title: Selective detection of parathion-methyl based on near-infrared CuInS2 quantum dots.
abstract: A novel and sensitive fluorescence probe based on near-infrared CuInS2 quantum dots (QDs) for parathion-methyl (PM) detection was developed. Water-soluble CuInS2 QDs were directly synthesised in aqueous solution with mercaptopropionic acid as stabilizers. The fluorescence intensity of CuInS2 QDs was quenched in the presence of Pb(2+) due to the competitive binding of Pb(2+) and mercaptopropionic acid with QDs. PM could be hydrolysed by organophosphorus hydrolase to form di-methylthiophosphoricacid. Subsequently, di-methylthiophosphoricacid moiety with a PS bond could capture Pb(2+) on the surface of the CuInS2 QDs, which would lead the fluorescence of the CuInS2 QDs-Pb(2+) system recovery. The fluorescence intensity of the CuInS2 QD-Pb(2+) system was proportional to the PM concentration in the range of 0.10-38.00 μmol/L, with a detection limit of 0.06 μmol/L. The proposed method had been used for PM detection in environmental and agricultural samples with satisfactory results.
authors.affiliation: Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Yan
authors.affiliation: School of Pharmacy, Jilin University, Changchun 130021, China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China. Electronic address: suxg@jlu.edu.cn.
authors.forename: Xingguang
authors.initials: X
authors.lastname: Su
mesh_terms: D003300:Copper / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D007306:Insecticides / Q000032:analysis*; D008743:Methyl Parathion / Q000032:analysis*; D045663:Quantum Dots / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D005456:Fluorescent Dyes; D007306:Insecticides; D008743:Methyl Parathion; D003300:Copper
keywords: CuInS(2) QDs; Near-infrared fluorescent probe; Organophosphorus hydrolase; Parathion-methyl; Pb(2+)