In Situ Electrochemical Reduction of Imidacloprid involving a Nitroso-Intermediate-Trapped DWCNT and Its Biomimetic Cellular Oxidative Stress-Related Mediated Oxidation of Thiols.

Abstract

Imidacloprid (IMP) is a widely used pesticide and insecticide known for its effectiveness in controlling pests and increasing crop yields. Exposure of the compound to water bodies has led to environmental pollution and adverse effects on human health. One major concern is the generation of oxidative-stress in the cellular system, which is often a result of IMP exposure. Although the exact mechanism of toxicity is not fully understood, it is believed that the nitroso-intermediate of IMP (IMP-NO) binds to acetylcholine receptors, disrupting neural function. Thiol pools in the blood serum act as antioxidants to mitigate the toxicity. This study presents an in situ electrochemical conversion of IMP into its key intermediate, IMP-NO, and its subsequent entrapment on a double-walled carbon nanotube-modified glassy carbon electrode (GCE/DWCNT@IMP-NO) as a surface confined redox-peak in a physiological solution. It was characterized by SEM, FTIR, Raman, SECM, and LC-MS techniques. The system exhibited excellent mediated oxidation of the thiol group, using cysteine as a model. The findings presented in this work correlate with observations related to cellular oxidative-stress and its thiol-assisted mitigation. Employing a Michaelis-Menten-type enzyme-substrate reaction mechanism and estimated the kinetic parameters. Chronoamperometric techniques were used to demonstrate the oxidative detection of thiol.