A facile nonenzymatic electrochemical sensor based on copper oxide nanoparticles deposited on activated carbon for the highly sensitive detection of methyl parathion

A facile and novel nonenzymatic electrochemical sensor for the detection of methyl parathion (MP) was developed using a glassy carbon electrode modified by copper oxide nanoparticle-deposited waste coffee grounds activated carbon (CuO-NPs/AC/GCE). Activated carbon from waste coffee grounds was prepared using chemical activation method by potassium hydroxide (KOH) and thermal activation with high power microwave-assisted hydrothermal technique from in-house microwave furnace. This method carried out at a lower temperature than which of physical process, providing a high surface area, porosity, and good conductivity. The CuO-NPs on CuO-NPs/AC/GCE can easily bind MP, owing to the high affinity between the Cu on electrode and the thionate sulfur (P=S) or oxon (P=O) groups of MP, resulting in an inhibited redox reaction of Cu and a decrease in the redox peak current of Cu. The nonenzymatic electrochemical sensor, CuO-NPs/AC/GCE, showed excellent electrochemical catalytic activity for the determination of MP compared to that of AC/GCE, CuO-NPs/GCE, and bare GCE by differential pulse voltammetry (DPV). The anodic (E-pa) and cathodic peak potentials (E-pc) of CuO-NPs on the modified electrode were 0.25 V and - 0.45 V, respectively. The linear ranges were 50-1500 mu g L-1, with a low detection limit of 2.42 mu g L-1. In addition to being environmentally friendly, the CuO-NPs/AC/GCE sensor demonstrated high selectivity and sensitivity, good stability, and low cost. Further, the proposed nonenzymatic electrochemical sensor has potential applicability for MP detection in soil samples and gave recoveries in the range of 80.18-105.48%. [GRAPHICS] .

Automated summary

A novel nonenzymatic electrochemical sensor for detecting methyl parathion was developed using copper oxide nanoparticle-deposited waste coffee grounds activated carbon. The sensor showed high selectivity, sensitivity, stability, and low cost, making it a promising tool for MP detection.