A sensitive and selective electrochemical determination of Diazinon based on Au–Pd/rGO–MWCNTs composite: analytical application in water, fruit and vegetable samples

Abstract

In this research, a sensitive and selective electrochemical sensor based on bimetallic gold (Au) and palladium (Pd) nanoparticles coated on mixture of reduced graphene oxide (rGO) and multiwall carbon nanotube (MWCNTs) nanocomposite was constructed by using glassy carbon electrode which has been developed for determination of an organophosphorus (OPs) insecticide, Diazinon. Au–Pd/rGO–MWCNTs was synthesized by chemical reduction method, and the final product was investigated by transmission electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy and energy-dispersive X-ray spectroscopy. Under optimized conditions, the proposed sensor showed that the stripping oxidation peak current of Diazinon was linearly proportional to its concentrations in an appropriate range of 0.009 to 11.3 µM with a limit of detection and limit of quantification of 0.002 and 0.009 µM, respectively. The selectivity and reproducibility of the proposed sensor were checked, and the results showed that these factors of the sensor were in high level. Finally, the Au–Pd/rGO–MWCNTs/GCE was successfully used for measurement of target analyte in water, apple and cucumber samples recoveries ranging from 96 to 105%.