Development of an electrochemical sensor based on a cobalt oxide/tin oxide composite for determination of antibiotic drug ornidazole

Abstract

Simple chemical synthesis is highly efficient to develop metal oxide composites as active electrode materials for an electrochemical sensor displaying enhanced catalytic sites, fast kinetics, and easy accessibility to target molecules. In this work, a cobalt oxide/tin oxide (Co₃O₄/SnO₂) composite was prepared by a facile co-precipitation method and employed for the voltammetric determination of ornidazole (ODZ). The structural and morphological properties of the as-synthesized materials were studied through XRD, FT-IR, BET, FE-SEM, TEM, and XPS analyses. The electrochemical activity was investigated using cyclic voltammetric (CV) and linear sweep voltammetric (LSV) techniques. The electrochemical signal shows that the modified glassy carbon electrode (Co₃O₄/SnO₂/GCE) revealed superior sensing ability in rapid ODZ detection compared to a single component of Co₃O₄ or SnO₂. The performance was investigated over a wide linear range of 0.2 to 1185.8 μM with a low detection limit of 0.059 μM for ODZ, respectively, at a low-cost Co₃O₄/SnO₂ modified electrode. Good selectivity was observed in the presence of NFT, 2-NA, and Cd²⁺ by the ODZ sensor. Furthermore, the excellent stability, repeatability, and reproducibility suggest that the constructed electrode based on Co₃O₄/SnO₂/GCE is promising for real-time application in water samples.