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

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. [Figure not available: see fulltext.].