Electrochemical Determination of Tinidazole and Brucine Using Poly (l-Glutamic Acid) Modified Carbon Nanotube Paste Electrode

Abstract

This study developed an electrochemical method for the selective and sensitive detection of Tinidazole (TZ) by modifying a bare carbon nanotube paste electrode (BCNTPE) with electrochemically polymerized l-Glutamic acid (P(L-GA)/MCNTPE). The modified carbon nanotube paste electrode (MCNTPE) achieved optimal detection with an irreversible peak in a 0.2 M phosphate buffer solution (PBS) at pH 3.5. Characterization of both the P(L-GA)/MCNTPE and BCNTPE was carried out using techniques such as scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and linear sweep voltammetry (LSV). The sensor effectively identified possible interferences from different metals and organic compounds, with scan rate studies indicating that the reaction was controlled by diffusion. The effects of pH and concentration variations were also thoroughly investigated. The active surface area of the P(l-GA)/MCNTPE and BCNTPE were found to be 0.471 cm² and 0.217 cm² respectively. The P(l-GA)/MCNTPE displayed excellent electrochemical properties, with a limit of detection (LOD) of 0.06 µM and a limit of quantification (LOQ) of 0.2 µM, along with good reproducibility, repeatability, and stability. This study presents a P(l-GA) MCNTPE that significantly enhances the sensitivity and selectivity for simultaneous detection of TZ and bare carbon nanotube (BCN). The improved electroactive surface area and electron transfer dynamics demonstrate its potential for practical applications in pharmaceutical analysis.