Utilization of a Simple and Fast Electroanalytical Method with an Unmodified Boron-Doped Diamond Electrode for Taxifolin Sensing in Food Supplement Samples

Abstract

Using an unmodified boron-doped diamond electrode, an electrochemical sensor was established for the determination of taxifolin through square-wave voltammetry. Cyclic voltammetry measurements conducted in a 0.1 M HClO<inf>4</inf> solution showed that taxifolin exhibits irreversible behavior with diffusion control, marked by distinct oxidation peaks at approximately + 1.04 V (P<inf>A1</inf>) and + 1.44 V (P<inf>A2</inf>) versus Ag/AgCl. Furthermore, the pH as well as the supporting electrolyte had an effect on the oxidation process. The quantification of taxifolin was based on its two anodic peaks. The optimized method yielded a current response that was linearly proportional to taxifolin concentration, ranging from 2.5 to 50.0 μg mL−1 (8.2 × 10–6 to 1.6 × 10–4 M), with detection limits of 0.72 μg mL−1 (2.4 × 10–6 M) for P<inf>A1</inf> and 0.63 μg mL−1 (2.1 × 10–6 M) for P<inf>A2</inf> in HClO<inf>4</inf>. The method was successfully applied for the evaluation of taxifolin in a food supplement, thereby demonstrating its practical applicability. This study is among the first to utilize both oxidation peaks of taxifolin in electroanalytical measurements. Comparisons between the results obtained using this technique and those from the UV–Vis spectrometry method confirmed the accuracy of the approach. © 2025 Elsevier B.V., All rights reserved.