A novel self-powered bioelectrochemical sensor based on CoMn^sub 2^O^sub 4^ nanoparticle modified cathode for sensitive and rapid detection of hydrogen peroxide

The traditional (bio)electrochemical sensors for hydrogen peroxide (H2O2) detection require expensive external power sources which restricts their practicability. In this research, a novel self-powered bioelectrochemical sensor using bioanode as the electrical supplier and CoMn2O4 nanoparticle modified graphite cathode (CoMn2O4@GE) as the sensing element was developed for H2O2 determination. Electrochemical tests revealed that the CoMn2O4@GE exhibited attractive electrocatalytic activity towards H2O2 reduction, due to the large catalyst surface area and abundant Mn3+/Mn2+ and Co3+/CO2+ electroactive sites. Under the optimized conditions (flow rate 5 mL min−1, pH 7.0) and external load of 300 Ω, the proposed sensor demonstrated a wide linear detection range between 1 and 1000 mM with a high sensitivity of 13.2 μA mM−1, a detection limit of 40.2 μM (S/N = 3) and a fast response time within 5 s. Furthermore, the sensor presented good reproducibility, acceptable selectivity and excellent long-time stability. This study will provide a new approach for sensitive, rapid, in situ, and real-time monitoring of H2O2 for wide range applications.