modified 3d graphene-au as a novel sensing layer for direct and sensitive electrochemical determination of carbaryl pesticide in fruit, vegetable, and water samples

A novel, sensitive, and selective electrochemical sensor has been fabricated for the determination of 1-naphthyl methylcarbamate (carbaryl) as an important pesticide. three-dimensional graphene (3dg) was synthesized by using thiourea as the crosslinking agent that simultaneously caused impregnation of sulfur and nitrogen functional groups onto the graphene. graphene doped with s and n atoms was modified by gold nanoparticles. the obtained 3dg-au nanocomposite was used for the determination of carbaryl by differential pulse voltammetry. different experimental parameters such as ph, type of electrolyte, accumulation time, and accumulation potential were optimized. under optimal conditions, a linear response was achieved in the range of 0.004–0.3 μm of carbaryl with a detection limit of 0.0012 μm (s/n = 3). the sensor demonstrated suitable selectivity, stability, and reproducibility through its successful application for the determination of carbaryl in fruit, vegetable, and water samples with good recoveries.