A RAPID ELECTROCHEMICAL PLATFORM FORDETECTING THIAMETHOXAM USING A Ni-rGO CARBON PASTE COMPOSITE

Neonicotinoids, such as thiamethoxam (THMX), are widely used in agriculture, leading to water and environmental contamination. Hence, the main aim of this study is to develop an innovative and cost-effective sensing material for pesticide detection. To achieve this goal, an electrochemical sensor based on reduced graphene oxide functionalized with nickel was designed. The sensor was characterized via cyclic voltammetry (CV), differential pulse voltammetry (DPV), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS) and Fourier-transform infrared spectroscopy (FT-IR). The differential pulse voltammetry results indicate that the incorporation of nickel into reduced graphene oxide structure enhances the sensor’s performance compared to the unmodified carbon paste electrode. Under optimal conditions, the Ni-rGO/CPE sensor exhibited a sensitivity of 0.66 μA/ppm, with a detection limit of 3.96 ppm. A high correlation coefficient (R2 = 0.9993) suggests a strong linear relationship between thiamethoxam concentration and the sensor’s electrochemical response within a linear range of 6 -93 ppm, making the sensor suitable for rapid and portable detection applications. The sensor applied to river water samples in a recovery test showed a recovery of approximately 109.94%. These results highlight the potential of carbon-based nanomaterials for the efficient, cost-efficient and simple detection of neonicotinoids in complex water matrices.