Abstract
In this study, we report the fabrication of a novel impedimetric electrochemical sensor for the sensitive and reliable detection of the organophosphorus pesticide Dichlorvos (DDVP).The sensor is based on a glassy carbon electrode (GCE) modified with multi-walled carbon nanotubes (MWCNTs) and gold nanoparticles (AuNPs).MWCNTs provide a large surface area, high conductivity, and mechanical stability, while AuNPs enhance electron transfer and adsorption capability.The synergistic combination of these nanomaterials significantly improves the electrode's sensitivity and selectivity.The detection mechanism is based on the inhibition of interfacial electron transfer resulting from the strong interaction between DDVP and the modified electrode surface.This interaction produces measurable impedance changes, allowing indirect quantification of DDVP.The sensor achieved a low detection limit of 18.8 nM and a wide linear range of 0.36-1.8µM (R 2 = 0.99), demonstrating excellent reproducibility and reliability.The developed sensor is label-free, costeffective, and easy to fabricate, making it suitable for large-scale monitoring.Owing to its simplicity and high performance, this system holds great potential for environmental water analysis, agricultural product testing, and food safety assessment, offering an efficient tool for pesticide monitoring and public health protection.