Fabrication composite of copper sulfide nanoparticles/multiwall carbon nanotubes stabilized by chitosan modified screen-printed carbon electrode: Sensitive analysis of the paraoxon ethyl

A nanocomposite ink-based pesticide sensor has been developed to detect a paraoxon ethyl pesticide using enzyme-less electrochemical processes. Paraoxon ethyl contamination on agricultural produce, e.g., grains, vegetables, and fruit, has adverse health effects on humans. Nanocomposite ink was synthesized using copper sulfide nanoparticles composited with multiwall carbon nanotube and using chitosan as a binder to modify the screen print carbon electrode for the paraoxon ethyl sensor. The performance of the proposed imprinted working electrode Nanocomposite ink was investigated using cyclic voltammetry, electrical impedance spectroscopy, and differential pulse voltammetry techniques. The nanocomposite (1:1:1) modified electrode illustrated good electrochemical performance, high active surface area (2.15 cm²), low charge transfer resistance (355.59 Ω), and excellent electro-catalytic activity. This sensor is rapid and highly sensitive for small amounts of paraoxon ethyl pesticide detection in the 0.001–0.1 mM range. The DPV techniques demonstrated two linear reactions ranging between 0.001 and 0.02 mM (R² = 0.981) and 0.025 to 0.1 mM (R² = 0.935) with a limit of detection of 0.0018 mM and a limit of quantitation of 0.005 mM, respectively.