Boosting Electrochemical Fenton Process Via Cu, S-doped FeOOH sheet for hydrogen peroxide detection

The rational design of the efficient sensors with excellent selectivity, stability, and reproducibility has shown great potential for electrochemical detection of hydrogen peroxide. Herein, FeOOH sheets doped with Cu and S atoms (Cu-S/FeOOH) were prepared via a simple hydrothermal method and then uniformly modified on a glassy carbon electrode to assemble a novel non-enzymatic electrochemical sensor for H2O2 detection. The sensor showed an excellent electrocatalytic reduction ability of H2O2 at a potential of -0.4 V in a nearly neutral solution, demonstrating a lower detection limit (0.6 μM, S/N = 3), and a high sensitivity (321.4 μA mM−1cm−2) with 95% confidence interval in the potential range 0.002-9 mM. This super performance was attributed to the multiple effects of the typical sheet-like open structure, enhanced electrochemical conductivity, rich adsorbed oxygen content, and Fenton Cu+/Cu2+ and Fe2+/Fe3+ redox coupling. In addition, this sensor exhibited excellent stability and realized the rapid detection of trace H2O2 in fetal bovine serum, giving the sensor good potential in the testing of H2O2.