Electrochemical Simultaneous Determination of Levodopa and Benserazide in Aniline and Multi–Walled Carbon Nanotube Modified Sensor

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ABSTRACT

The present study reports the development of a highly sensitive electrochemical sensor for the simultaneous determination of levodopa and benserazide, two pharmacologically active substances used in the treatment of Parkinson’s disease. The sensor was fabricated by electropolymerization of aniline on a glassy carbon electrode (GCE) in a nonaqueous medium, followed by modification with multi-walled carbon nanotubes (MWCNTs). The synergistic effect of polyaniline and MWCNTs resulted in enhanced electrochemical performance, providing high selectivity and sensitivity toward the target analytes. The modified electrode exhibited well-defined differential pulse voltammetry (DPV) responses, allowing for quantitative determination of levodopa in the linear range of 500-1000 µM and benserazide in the range of 100-500 µM, with detection limits of 67.01 µM and 163.60 µM, respectively. The electrochemical behavior of the sensor was evaluated under various conditions, including film thickness, supporting electrolyte type, and pH variations, to optimize its performance. The sensor demonstrated excellent repeatability, stability, and resistance to interference from ascorbic acid, a common interfering species. Additionally, the method was successfully applied to the determination of levodopa and benserazide in real urine samples and pharmaceutical formulations, achieving satisfactory recovery rates. These findings highlight the potential of the developed sensor as a reliable and cost-effective tool for clinical and pharmaceutical applications.

Significance of the Study:

This study focuses on developing a modified electrode using aniline monomer and multi-walled carbon nanotubes (MWCNTs) for electrochemical sensing. The sensor effectively determines active drug substances like levodopa and benserazide, even in the presence of common interfering species such as ascorbic acid and uric acid. Additionally, it enables the selective detection of these compounds in complex biological fluids, including pharmaceutical samples, blood serum, and urine, demonstrating its potential for clinical diagnostics and pharmaceutical quality control.

Summary of the Study:

An electrochemical sensor was developed by electropolymerizing aniline on a glassy carbon electrode in a nonaqueous medium and modifying it with multi-walled carbon nanotubes (MWCNTs). This sensor enabled the quantitative determination of levodopa and benserazide, key drugs for Parkinson’s disease treatment. The optimized method demonstrated high selectivity and sensitivity, with detection limits of 67.01 µM for levodopa and 163.60 µM for benserazide. The sensor performed well in real urine samples and pharmaceutical formulations, even in the presence of interfering species.