Selective graphene-based electrochemical sensing platform for enhanced sulfamethoxazole assay

Antibiotics are currently considered as a major source of pollution. Sulfamethoxazole (SFX), an antibacterial sulphonamide drug, commonly prescribed and employed in a variety of bacterial infections, was reported to have a multitude of adverse health reactions, therefore its quantification in pharmaceutical industry, medicine and environment is of great interest. This study reports a novel graphene-based electrochemical sensing platform for enhanced SFX detection. Graphene material was prepared by electrochemical exfoliation at 19 V applied bias, in 0.05 M boric acid/0.05 M sodium chloride mixed solution. The performances of the graphene-modified glassy carbon electrode (GR/GCE) were evaluated in terms of selectivity, sensitivity, accuracy, and reproducibility employing cyclic voltammetry, differential pulse voltammetry, and amperometry. Under optimized conditions, at pH 5, the developed sensor shows a remarkable enhancement of the sensing abilities compared to the bare electrode, with a linear response in the 0.009 - 28.8 mu M SFX concentration range, and a low limit of detection: 0.00272 mu M. Furthermore, the analytical applicability of the modified electrode in real sample analysis was performed on two commercially available pharmaceutical formulations. The results of the study demonstrate that the developed sensing platform is able to achieve high selectivity and sensitivity for SFX detection, thus providing a reliable and cost-effective solution for SFX assay.