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 mimeticbased 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.

Fabrication of Polymerized Crystalline Colloidal Array Thin Film Modified β-Cyclodextrin Polymer for Paraoxon-ethyl and Parathion-ethyl Detection

“…The PCCA thin film also shows a faster response time and this seems environmentally more relevant than previously reported based on enzyme modified sensors. 11,[38][39][40] However, the regeneration of modified PCCA thin film was not as good as expected. The diffraction peak was not fully recovered after several times of washing and cleaning.…”

Recent advances in biological detection with magnetic nanoparticles as a useful tool

“…The organophosphorus neurotoxins, can greatly inhibit the enzymatic activity of AChE, however, which leads to less H 2 O 2 . Taking advantage of this principle, they developed a novel Fe 3 O 4 magnetic nanoparticle (MNP) peroxidase mimetic-based colorimetric method to rapidly detect organophosphorus pesticides and nerve agents, which achieved a detection limit of as low as 1 nmol/L Sarin, 10 nmol/L methyl-paraoxon, and 5 μmol/L acephate [104]. With further development, this assay can be configured into an array format for the rapid, low-cost, and large-scale field screening of organophosphate neurotoxins.…”

From Nanotechnology to Nanoengineering

“…• Organo-phosphorus pesticides and nerve gases (Gan et al 2010;Liang et al 2012) • Pathogens and toxins, or total cholesterol and glucose, etc., in blood (Lahiff et al 2010;Kuila et al 2011) • Low concentration of toxic gases (Endo et al 2008;Asefa et al 2009). …”