Halonanoclay-carbon paste composite sustainable electrode for electrochemical oxidation and determination of tryptophan

This research aims to develop a sensitive electrochemical technique for detecting and quantifying Tryptophan (TRP), an amino acid, using a carbon paste electrode modified with halonanoclay. The morphology of the prepared electrode was characterized using XRD and SEM techniques. Tryptophan electro-oxidation was investigated primarily using cyclic voltammetry (CV). Systematic studies were conducted to explore the influence of various parameters, such as scan rate, pH, pre-concentration time, modifier quantity, and analyte concentration, on the peak current response of TRP. Tryptophan exhibited an irreversible, well-defined oxidation peak at 0.820 V. Cyclic voltammetry was used to evaluate the effect of scan rate, allowing for the determination of physicochemical parameters, including the heterogeneous rate constant (k⁰) and the number of electrons (n) involved in the electrochemical reaction. Additionally, differential pulse voltammetry was employed to quantitatively analyze pharmaceuticals and human biological fluids. Linearity in detection was observed between 2.0 × 10^-6 M and 50.0 × 10⁻⁶ M, with a limit of detection of 7.77 × 10^–9 M. As a result, the current electrocatalytic method provides a quick, accurate, and simple method to detect TRP in biological medium and pharmaceutical formulations. A sensor with excellent reproducibility, short response times, and outstanding stability has been described as the modified electrode.