title: Colorimetric biosensor for the assay of paraoxon in environmental water samples based on the iodine-starch color reaction.
abstract: In this work, a new colorimetric biosensor for the assay of paraoxon was developed via the conventional iodine-starch color reaction and multi-enzyme cascade catalytic reactions. In the presence of acetylcholine chloride, acetylcholinesterase (AChE) and choline oxidase (ChO) catalyzed the formation of H2O2, which then activated horseradish peroxidase (HRP) to catalyze the oxidation of KI to produce an iodine-starch color reaction. Upon exposure to paraoxon, the catalytic activity of AChE was inhibited and less H2O2generated, resulting in a decrease in the production of I2and a drop in the intensity of solution color. This colorimetric biosensor showed high sensitivity for the assay of paraoxon with a limit of detection 4.7 ppb and was applied for the assay of paraoxon in spiked real samples. By employing the conventional iodine-starch color reaction, this biosensor has the potential of on-site assay of OPs residues in environmental samples.
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou 350116, China. Electronic address: lqguo@fzu.edu.cn.
authors.forename: Liangqia
authors.initials: L
authors.lastname: Guo
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou 350116, China.
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Li
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou 350116, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Chen
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou 350116, China.
authors.forename: Yarong
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou 350116, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou 350116, China.
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Song
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou 350116, China.
authors.forename: Tianran
authors.initials: T
authors.lastname: Lin
mesh_terms: D000109:Acetylcholine; D000110:Acetylcholinesterase; D000429:Alcohol Oxidoreductases; D015374:Biosensing Techniques; D003124:Colorimetry; D006861:Hydrogen Peroxide; D007455:Iodine; D010261:Paraoxon / Q000032:analysis*; D010575:Pesticides / Q000032:analysis; D013213:Starch; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D010575:Pesticides; D014874:Water Pollutants, Chemical; D013213:Starch; D007455:Iodine; D006861:Hydrogen Peroxide; D000429:Alcohol Oxidoreductases; C019888:choline oxidase; D000110:Acetylcholinesterase; D000109:Acetylcholine; D010261:Paraoxon
keywords: Acetylcholinesterase; Biosensor; Colorimetric method; Organophosphorus pesticides; Paraoxon