Highly selective and stable electrochemical sensor for hydrogen peroxide – application in cosmetics quality control

Abstract Nowadays, electrochemical sensors have become a popular topic in cosmetics quality control. A simple and stable electrochemical sensor for hydrogen peroxide (H2O2) was developed on the basis of rhodium-modified glassy carbon electrode (Rh/GCE). A quick, one-step, reproducible and cost-effective electrodeposition procedure was applied to modify GCE with Rh nanoparticles. The sensor shows high selectivity for H2O2 at a low applied potential of –0.1 V (vs. Ag/AgCl, 3 M KCl), with excellent stability and good repeatability (RSD = 3.2%; n = 5). The modified electrode Rh/GCE demonstrates a high sensitivity of 760.11 ± 8.59 μA mM–1 cm–2 (n = 3), a linear response to H2O2 between 5 and 1000 µM and a detection limit estimated to be 1.2 µM. Furthermore, Rh/GCE has been successfully used to measure H2O2 concentration in hair dye and antiseptic solution, yielding satisfactory recovery rates. These findings highlight the potential of the Rh/GCE electrode for reliable quantitative detection of H2O2 in complex cosmetics matrices.