Electro-sensing base for mefenamic acid on a 5% barium-doped zinc oxide nanoparticle modified electrode and its analytical application

Abstract

In the present work, surface enhanced electro-oxidation of mefenamic acid (MFA) at a glassy carbon electrode modified with 5% barium doped ZnO nanoparticles was studied. Cyclic voltammograms with a maximum peak current at pH 5 in the pH range of 3.0–11.0 were recorded at a scan rate of 50 mV s⁻¹, with a distinct oxidation peak in the range of 0.2–1.0 V (versus Ag/AgCl). Two protons and electrons accompanied the electrode reaction. Based on the experimental results, a possible electro-oxidation mechanism for MFA was proposed. Quantitative analysis of MFA was carried out using a differential-pulse voltammetric method (DPV). Linearity was observed in the range of 500 nM to 10.0 × 10³ nM. LOD and LOQ were calculated to be 6.02 nM and 20 nM, respectively. In addition, the developed method was used in the in vitro analysis of MFA in pharmaceutical formulations and spiked human urine samples.