Uniform ordered mesoporous ZnCo2O4 nanospheres for super-sensitive enzyme-free H2O2 biosensing and glucose biofuel cell applications

Abstract

Uniform, ordered mesoporous ZnCo2O4 (meso-ZnCo2O4) nanospheres were successfully synthesized using a sacrificing template method. The meso-ZnCo2O4 nanospheres were used for the first time for H2O2 biosensing and in glucose biofuel cells (GBFCs) as an enzyme mimic. The meso-ZnCo2O4 nanospheres not only exhibited excellent catalytic performance in the H2O2 sensor, achieving a high sensitivity (658.92 μA·mM–1·cm–2) and low detection limit (0.3 nM at signal-to-noise ratio (S/N) = 3), but also performed as an excellent cathode material in GBFCs, resulting in an open circuit voltage of 0.83 V, maximum power density of 0.32 mW·cm–2, and limiting current density of 1.32 mA·cm–2. The preeminent catalytic abilities to H2O2 and glucose may be associated with the large specific surface area of the mesoporous structure in addition to the intrinsic catalytic activity of ZnCo2O4. These significant findings provide a successful basis for developing methods for the supersensitive detection of H2O2 and enriching catalytic materials for biofuel cells.