Efficient nonenzymatic H2O2 biosensor based on ZIF-67 MOF derived Co nanoparticles embedded N-doped mesoporous carbon composites

Co nanoparticles embedded nitrogen-doped mesoporous carbon composites with rhombic dodecahedral morphology (Co-NC RDCs) are prepared by the carbonization of cobalt containing metal-organic framework (ZIF-67). A novel nonenzymatic H2O2 electrochemical biosensor is developed based on Co-NC RDCs that drop-casted on rotating-disk electrode. The effects of carbonization temperatures and times to the sensing properties of Co-NC RDCs are systematically investigated. Among the studied composites, Co-NC-600-5 gives the largest surface area and the highest content of residual N-doped carbon, results in the best electrocatalytic activity for H2O2 reduction in 0.1 M phosphate buffer solution (PBS, pH 7.4). The Co-NC-600-5 based H2O2 biosensor exhibits fast amperometric response within 6 s, low detection limit of 0.143 μM (S/N = 3) and wide linear range of 0.001–30 mM with a high sensitivity of 234.913 μA mM−1 cm−2, which is comparable to the reported high-performance H2O2 biosensors. In addition, this nonenzymatic biosensor displays good selectivity, high reproducibility and long-term stability. Further study proves that the synergetic effect between nitrogen and cobalt in the composite is critical to the attractive performance. The present study proves that cobalt nanoparticles embedded nitrogen-doped porous carbon material could be a class of promising sensing platform for the electrochemical detection of H2O2.