Electrochemical Determination of Rifampicin Based on Its Oxidation Using Multi-Walled Carbon Nanotube-Modified Glassy Carbon Electrodes

Objectives: The aim of the study was to investigate the electrochemical behavior of rifampicin (RIF) in the anodic direction using multi-walled carbon nanotube (MWCNT)-modified glassy carbon electrodes. Materials and Methods: The anodic investigation of RIF was carried out with cyclic, differential pulse, and square wave voltammetry. A three-electrode system consisting of a glassy carbon electrode with a modification by MWCNTs as the working electrode, a platinum wire as the counter electrode, and an Ag/AgCl electrode as reference was used for the experiments. Results: The anodic process of RIF was irreversible and diffusion controlled. Linear responses were obtained between 0.04 and 10 mu M for both techniques in acetate buffer (pH 3.5) as supporting electrolyte. The limit of detection values were 7.51 and 11.3 nM for differential pulse and square wave voltammetry, respectively. The repeatability, reproducibility, precision, and accuracy of the proposed methods were also investigated. Determination of RIF was carried out on its pharmaceutical dosage forms and the results were compared with those from other electrochemical sensors and the liquid chromatographic and spectrophotometric methods in the literature. Conclusion: These validated techniques provided selective, rapid, sensitive, precise, and cheap determination of RIF as alternative techniques to the liquid chromatographic and spectrophotometric methods in therapeutic drug monitoring.