title: Fe3O4 magnetic nanoparticle peroxidase mimetic-based colorimetric assay for the rapid detection of organophosphorus pesticide and nerve agent.
abstract: Rapid and sensitive detection methods are in urgent demand for the screening of extensively used organophosphorus pesticides and highly toxic nerve agents for their neurotoxicity. In this study, we developed a novel Fe(3)O(4) magnetic nanoparticle (MNP) peroxidase mimetic-based colorimetric method for the rapid detection of organophosphorus pesticides and nerve agents. The detection assay is composed of MNPs, acetylcholinesterase (AChE), and choline oxidase (CHO). The enzymes AChE and CHO catalyze the formation of H(2)O(2) in the presence of acetylcholine, which then activates MNPs to catalyze the oxidation of colorimetric substrates to produce a color reaction. After incubation with the organophosphorus neurotoxins, the enzymatic activity of AChE was inhibited and produced less H(2)O(2), resulting in a decreased catalytic oxidation of colorimetric substrates over MNP peroxidase mimetics, accompanied by a drop in color intensity. Three organophosphorus compounds were tested on the assay: acephate and methyl-paraoxon as representative organophosphorus pesticides and the nerve agent Sarin. The novel assay displayed substantial color change after incubation in organophosphorus neurotoxins in a concentration-dependent manner. As low as 1 nM Sarin, 10 nM methyl-paraoxon, and 5 μM acephate are easily detected by the novel assay. In conclusion, by employing the peroxidase-mimicking activity of MNPs, the developed colorimetric assay has the potential of becoming a screening tool for the rapid and sensitive assessment of the neurotoxicity of an overwhelming number of organophosphate compounds.
authors.affiliation: Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Minmin
authors.initials: M
authors.lastname: Liang
authors.forename: Kelong
authors.initials: K
authors.lastname: Fan
authors.forename: Yong
authors.initials: Y
authors.lastname: Pan
authors.forename: Hui
authors.initials: H
authors.lastname: Jiang
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.forename: Dongling
authors.initials: D
authors.lastname: Yang
authors.forename: Di
authors.initials: D
authors.lastname: Lu
authors.forename: Jing
authors.initials: J
authors.lastname: Feng
authors.forename: Jianjun
authors.initials: J
authors.lastname: Zhao
authors.forename: Liu
authors.initials: L
authors.lastname: Yang
authors.forename: Xiyun
authors.initials: X
authors.lastname: Yan
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000429:Alcohol Oxidoreductases / Q000378:metabolism; D040761:Biomimetic Materials / Q000737:chemistry / Q000378:metabolism*; D002384:Catalysis; D002619:Chemical Warfare Agents / Q000032:analysis*; D003124:Colorimetry; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000032:analysis*; D009946:Organothiophosphorus Compounds / Q000032:analysis; D010084:Oxidation-Reduction; D010261:Paraoxon / Q000031:analogs & derivatives / Q000032:analysis; D010575:Pesticides / Q000032:analysis*; D063088:Phosphoramides; D012524:Sarin / Q000032:analysis
chemical_list: D002619:Chemical Warfare Agents; D058185:Magnetite Nanoparticles; D009943:Organophosphorus Compounds; D009946:Organothiophosphorus Compounds; D010575:Pesticides; D063088:Phosphoramides; C001969:acephate; D012524:Sarin; D006861:Hydrogen Peroxide; D000429:Alcohol Oxidoreductases; C019888:choline oxidase; D000110:Acetylcholinesterase; D010261:Paraoxon; C008480:methylparaoxon; D052203:Ferrosoferric Oxide