title: Visual detection of organophosphorus pesticides represented by mathamidophos using Au nanoparticles as colorimetric probe.
abstract: With citrate-coated Au nanoparticles as colorimetric probe, a novel visual method for rapid assay of organophosphorus pesticides has been developed. The assay principle is based on catalytic hydrolysis of acetylthiocholine into thiocholine by acetylcholinesterase, which induces the aggregation of Au nanoparticles and the color change from claret-red to purple or even grey. The original plasmon absorption of Au nanoparticles at 522 nm decreases, and simultaneously, a new absorption band appears at 675 nm. The irreversible inhibition of organophosphorus pesticides on acetylcholinesterase prevents aggregation of Au nanoparticles. Under optimum conditions, the absorbance at 522 nm of Au nanoparticles is related linearly to the concentration of mathamidophos in the range of 0.02-1.42 μg/mL with a detection limit of 1.40 ng/mL. This colorimetric method has been successfully utilized to detect mathamidophos in vegetables with satisfactory results. The proposed colorimetric assay exhibits good reproducibility and accuracy, providing a simple and rapid method for the analysis of organophosphorus pesticides.
authors.affiliation: Department of Food Quality and Safety, College of Quartermaster Technology, Jilin University, Changchun 130062, PR China.
authors.forename: Hongkun
authors.initials: H
authors.lastname: Li
authors.forename: Jiajia
authors.initials: J
authors.lastname: Guo
authors.forename: Hong
authors.initials: H
authors.lastname: Ping
authors.forename: Lurui
authors.initials: L
authors.lastname: Liu
authors.forename: Minwei
authors.initials: M
authors.lastname: Zhang
authors.forename: Fengrui
authors.initials: F
authors.lastname: Guan
authors.forename: Chunyan
authors.initials: C
authors.lastname: Sun
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000122:Acetylthiocholine / Q000378:metabolism; D000818:Animals; D001937:Brassica / Q000737:chemistry; D003124:Colorimetry / Q000191:economics / Q000379:methods*; D004593:Electrophorus; D006046:Gold / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009946:Organothiophosphorus Compounds / Q000032:analysis*; D010575:Pesticides / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013860:Thiocholine / Q000378:metabolism; D013997:Time Factors
chemical_list: D009946:Organothiophosphorus Compounds; D010575:Pesticides; D000122:Acetylthiocholine; D013860:Thiocholine; D006046:Gold; C014655:methamidophos; D000110:Acetylcholinesterase