title: A novel fluorescence probing strategy for the determination of parathion-methyl.
abstract: A sensitive fluorescence probing strategy for parathion-methyl (PM) detection was developed based on electron transfer (ET) between p-nitrophenol (the hydrolysate of PM) and CdTe quantum dots (QDs) in cetyltrimethylammonium bromide (CTAB). PM was hydrolyzed by organophosphorus hydrolase (OPH) to form p-nitrophenol. P-nitrophenol is a typically electron-deficient compound due to the strong electron-withdrawing effect of the nitro groups. The positive charge of CTAB which make it assemble with electronegative mercaptopropionic acid-capped QDs, could be used as an absorbent for p-nitrophenol due to the strong hydrophobic interaction between the long alkyl chain of CTAB and aromatic ring of p-nitrophenol. Thus, the fluorescence intensity of CdTe QDs/CTAB probe could be quenched by p-nitrophenol due to the ET mechanism. The fluorescence intensity of the QD/CTAB system was proportional to PM concentration in the range of 25-3000 ng mL(-1), with a detection limit of 18 ng mL(-1). Furthermore, the proposed method was simple in design and fast in operation, and has been successfully used for PM detection in environmental and agricultural samples with satisfactory recovery.
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: Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
authors.forename: Xinyan
authors.initials: X
authors.lastname: Wang
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: D019187:Cadmium Compounds / Q000737:chemistry*; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D057230:Limit of Detection; D008743:Methyl Parathion / Q000032:analysis*; D009596:Nitrophenols / Q000737:chemistry*; D012275:Oryza / Q000737:chemistry; D045663:Quantum Dots; D013050:Spectrometry, Fluorescence; D013691:Tellurium / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D002593:Cetrimonium Compounds; D005456:Fluorescent Dyes; D009596:Nitrophenols; D014867:Water; D008743:Methyl Parathion; D013691:Tellurium; C028337:cadmium telluride; C024836:4-nitrophenol; D000077286:Cetrimonium
keywords: Agricultural samples; Electron transfer; Organophosphorus hydrolase; Parathion-methyl; Quantum dots