Electro-oxidation of pharmaceutical sulfonamide derivatives on carbon paste electrode modified by cerium oxide-reduced graphene oxide nano-composite

In this work, the electrochemical behaviors of some pharmaceutical sulfonamide derivatives including sulfadiazine (SDZ), sulfathiazole (STZ), sulfaquinoxaline (SQX), sulfacetamide (SAA), and sulfasalazine (SSZ) on carbon paste electrodes (CPEs) modified by carbon and lanthanide nano-materials were studied. Under the optimized conditions, the CPEs containing 5% of the reduced graphene oxide (RGO) decorated ceria (CeO2) nano-composite showed a significant increase in the response current toward sulfadiazine (SDZ) with respect to the other sulfonamide derivatives. A fast Fourier transform-square wave voltammetry (FFT-SWV) was applied in order to reveal the measurement applicability of the proposed electrode for the SDZ determination. The calibration curve result showed the linear range 3-1000 µM for the sulfadiazine redox. The LOD and LOQ quantities were calculated and compared with other reports in the literature. Furthermore, the SDZ measurement was carried out on some pharmaceutical tablets by the proposed sensor.