Ni–rGO NANO-SENSOR FOR PESTICIDE DETECTION IN FOOD SAMPLES

The development of reliable strategies for the concurrent identification of structurally analogous pesticides remains a significant challenge in electrochemical sensing. This study presents a nickel nanoparticle-decorated reduced graphene oxide (Ni–rGO) laser-scribed electrode designed for the simultaneous determination of neonicotinoids, particularly imidacloprid (IMI) and thiamethoxam (THMX).The Ni–rGO composite demonstrated enhanced electrochemical performance through synergistic effects, leading to improved electron-transfer kinetics and elevated electrochemically performance, as confirmed by cyclic voltammetry and electrochemical impedance spectroscopy. Under optimized conditions, differential pulse voltammetry facilitated sensitive detection of the IMI–THMX mixture, showing a linear response with a sensitivity of 0.17 µA ppm-1 and a coefficient of determination(R2) of 0.9925. The sensor exhibited a limit of detection (LoD) of 0.39 ppm and a limit of quantification (LoQ) of 1.18 ppm. High selectivity was confirmed in the presence of common inorganic ions and structurally similar compounds, with minimal signal variation (95–104%). Additionally, the sensor demonstrated good repeatability and reproducibility (RSD ≤ 6.7%) and retained stable performance over time. The applicability of the method was validated in real food samples, yielding satisfactory recovery and reliable detection in complex matrices. This work introduces an efficient electrochemical approach for the simultaneous determination of pesticides using a Ni–rGO platform, offering a simple, cost-effective and portable solution for rapid screening of neonicotinoid residues in food safety applications.