Mixed Co‐Mn Spinel Oxides Based Electrocatalysts for Amperometric Determination of Hydrogen Peroxide

Abstract Herein, we present an efficient non‐enzymatic electrochemical sensor for H 2 O 2 detection based on the catalytic‐reduction of H 2 O 2 on ZnMn 0.5 Co 1.5 O 4 . The ZnMn 0.5 Co 1.5 O 4 derived from ZnCo 2 O 4 by the partial substitution of Co with Mn was synthesized via sol‐gel combustion method. The catalytic performance of ZnMn 0.5 Co 1.5 O 4 for the reduction of H 2 O 2 is better than that of ZnCo 2 O 4 , attributing to the synergetic effects of electronic structure, lattice distortion, and multivalent state of Mn. Specifically, as‐fabricated ZnMn 0.5 Co 1.5 O 4 ‐based electrochemical sensor shows an excellent quantitative detection capability toward H 2 O 2 in a wide range of 5 to 7585 μM, with a theoretical detection limit of 0.12 μM (3S/N). Moreover, the excellent reproducibility and selectivity for H 2 O 2 sensing was also verified. The excellent recoveries from 94.4 to 103.2 % were obtained for H 2 O 2 ‐spiked orange juice and beer. More importantly, the sensor exhibits desirable performance in the real‐time monitoring of H 2 O 2 released from living human colon cancer cell (HCT116 cells). The results indicate that the as‐presented sensor is a promising candidate for the H 2 O 2 determination in food safety and clinical diagnose.