A Novel Electrochemical Sensor Based on r-GO@SiC Nanocomposite Materials for the Highly Sensitive Detection of Metronidazole

In this study, a novel SiC/rGO nanocomposite-modified glassy carbon electrode (SiC/rGO/GCE) was developed as a simple, cost-effective, and efficient electrochemical platform for metronidazole (MTZ) detection. The combination of silicon carbide (SiC) and reduced graphene oxide (rGO) provides a favorable interface with a high electroactive surface area, efficient electron transfer, and enhanced electrocatalytic activity. The mor-phology and surface characteristics of the modified electrode were investigated by scan-ning electron microscopy (SEM), while its electrochemical properties were evaluated by cyclic voltammetry and electrochemical impedance spectroscopy. The results confirmed successful electrode modification and improved electron-transfer kinetics compared with the bare GCE. The main experimental parameters were systematically optimized, with the optimum conditions established at pH 10, an accumulation time of 300 s, and an accu-mulation potential of 0.5 V. Under these conditions, the SiC/rGO/GCE exhibited a broad linear response to MTZ over the concentration range of 5–5000 µmol/dm3, with a detection limit of 0.5 µmol/dm3 (S/N ≥ 3). The enhanced analytical performance is attributed to the synergistic contribution of rGO and SiC, where rGO promotes rapid electron transport and provides a large electroactive surface, while SiC contributes additional active sites and structural stability. The sensor was successfully applied to pharmaceutical samples, providing recoveries of 99.85–102.29% with RSD values below 2%. These results demon-strate the practical potential of the proposed sensor for reliable MTZ determination. Fur-ther validation in food and biological matrices and comparison with reference chromato-graphic methods will be necessary to establish its broader analytical applicability.