Selection of Anode Half‐Cells for Hydrogen Peroxide Self‐Powered Electrochemical Sensors Using Biomimetic Metal Complex Cathode Catalysts

A one‐compartment, self‐powered electrochemical sensor (SPES) can be created by selecting cathode and anode catalysts, so that the cathode and anode redox reactions do not interfere with each other. Biomimetic transition metal complexes are the most promising cathode catalysts for H 2 O 2 SPES and can be used in conjunction with nickel‐ or silver‐based anodes. However, many aspects of the operation mechanism of SPESs have not yet been explored. This article studies the mechanism and compares the properties of the H 2 O 2 SPESs with cathodes based on iron phthalocyanine (FePc) and Prussian blue (PB) on carbonaceous nanosupports, combined with Ni, Ag, and Ag/AgCl anodes. SPESs with an FePc‐based cathode performed best when combined with a Ni anode in the absence of Cl − anions, achieving a detection limit of 0.2 µM and a sensitivity of −0.197 A M −1 cm −2 at pH 7.4. SPESs with a PB‐based cathode exhibited a comparable performance when used with either a Ni or an Ag/AgCl anode, achieving a detection limit of 6 µM and a sensitivity of −0.101 A M −1 cm −2 at 7.4, when using the Ag/AgCl anode. It was established that the anode oxidation processes contributed to the sensor operation mechanism. The results of the study provide guidance for the selection of cathode and anode materials for the development of H 2 O 2 SPES and enzymatic SPBioES based on H 2 O 2 detection.