ZIFs derived polyhedron with cobalt oxide nanoparticles as novel nanozyme for the biomimetic catalytic oxidation of glucose and non-enzymatic sensor

The global prevalence of diabetes makes it a significant work to develop flagship sensors in glucose monitoring technology. Particularly, exploring highly active nanocomposites as biomimetic catalysts for the enzymatic reaction of glucose is extremely attractive in non-enzymatic glucose sensing. Herein, nitrogen-doped hollow carbon nano-polyhedron implanted with Co3O4 nanoparticles (NHCN-Co3O4) was introduced as nanozyme for the catalytic oxidation of glucose. NHCN-Co3O4 was synthesized by a two-step redox carbonization of zeolitic imidazolate frameworks. Morphology and structure characterizations revealed that NHCN-Co3O4 was a rhombic nano-dodecahedron with hollow N-doped carbon frameworks. In the frameworks, well-defined Co3O4 nanoparticles were embedded. With highly porous N-doped graphitization structure and embedded Co3O4, NHCN-Co3O4 displayed a distinguished biomimetic catalysis towards the direct oxidation of glucose at a low onset potential of 0.30 V. The biomimetic catalysis of glucose oxidation at NHCN-Co3O4 was so efficient that a steady-state current signal could be established within 3 s. By using NHCN-Co3O4 as nanozyme, a brilliant non-enzymatic glucose sensor was developed with a very low detection limit of 0.2 μM and broad detection range from 1.0 μM to 32.0 mM. Besides, NHCN-Co3O4 sensor also displayed an effective anti-interference capability towards the simulated interfering species including small biomolecules, amino acids, and chloride ion. Furthermore, notable repeatability, reproducibility and long-term stability were also presented. Finally, the successful blood sugar detection in human serum strongly manifests the possible real application of NHCN-Co3O4 sensor.