Sensitive Simultaneous Detection of Methyldopa and Hydrochlorothiazide on Ce^3+-NiO Hexagonal Nanoparticles-Modified Electrode

We applied GCE modified with Ce^3+-NiO hexagonal nanoparticles (Ce^3+-NiO HNPs) for preparing methyldopa electrochemical sensor. Electrochemical study of the modified electrode showed that within the optimal conditions of phosphate buffer solution (PBS) at a pH of 7.0 in CV, oxidation potency of methyldopa decline to ~100 mV at the modified electrode in comparison with an unmodified GCE. The sensor exhibits a sensitive response to methyldopa in range between 0.1 and 80.0 μM with a limit of detection (LOD) equal to 0.03 μM. In addition, as sensing materials for simultaneously determine hydro-chlorothiazide and methyldopa, Ce^3+-NiO HNPs/GCE, exhibited high sensitivity. The defined and separated oxidation peaks of a mixture of methyldopa and hydrochlorothiazide were obtained with significant peak potential differences of 390 V. The proposed electrochemical sensor was employed in analysis of both drugs in the real specimens.