Ultra-sensitive platform for the detection of a psychostimulant drug using a nanostructured titanium carbide/carbon matrix: Insights into electrochemical sensing mechanism

Abstract

Mefexamide hydrochloride (MAH), a psychostimulant substance, was detected using an electrochemical sensor using a nanostructured titanium carbide/carbon matrix. Techniques like Cyclic voltammetry (CV), square wave voltammetry (SWV), electrochemical impedance spectroscopy (EIS) and surface characterisation was employed to develop insights on the electrocatalytic activity of the sensing surface. The modified sensing electrode demonstrated a selective and sensitive response to MAH in a phosphate buffer solution at pH 7.0, showing significantly enhanced electro-catalytic activity compared to the bare carbon paste electrode. The electron transfer reaction produced a diffusion controlled mechanism with two oxidation and a reduction peak. The linearity for the detection of MAH was studied at SWV under optimum conditions and the range was found to be at 200.0 μM–8.0 μM with the LOD and LOQ values of 3.6 × 10⁻⁷ M and 11.9 × 10⁻⁷ M. The study utilized various excipients to examine their potential interference in the analytical process, and the results demonstrated the simplicity of the method, with its high sensitivity and selectivity, in the detection of MAH in real samples like biofluids and water samples.