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

Herein, we present an efficient non‐enzymatic electrochemical sensor for H2O2 detection based on the catalytic‐reduction of H2O2 on ZnMn0.5Co1.5O4. The ZnMn0.5Co1.5O4 derived from ZnCo2O4 by the partial substitution of Co with Mn was synthesized via sol‐gel combustion method. The catalytic performance of ZnMn0.5Co1.5O4 for the reduction of H2O2 is better than that of ZnCo2O4, attributing to the synergetic effects of electronic structure, lattice distortion, and multivalent state of Mn. Specifically, as‐fabricated ZnMn0.5Co1.5O4‐based electrochemical sensor shows an excellent quantitative detection capability toward H2O2 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 H2O2 sensing was also verified. The excellent recoveries from 94.4 to 103.2 % were obtained for H2O2‐spiked orange juice and beer. More importantly, the sensor exhibits desirable performance in the real‐time monitoring of H2O2 released from living human colon cancer cell (HCT116 cells). The results indicate that the as‐presented sensor is a promising candidate for the H2O2 determination in food safety and clinical diagnose. [ABSTRACT FROM AUTHOR]