Metal-organic framework derived nanoporous carbon/Co₃O₄ composite electrode as a sensing platform for the determination of glucose and high-performance supercapacitor

Here, we demonstrate the controlled synthesis of nanoporous carbon and cobalt oxide (NPC[sbnd]Co₃O₄) composite from a single precursor source zeolitic imidazolate framework-67, which leads to some new interesting electrochemical properties. The composite shows an outstanding electrochemical performance for measuring the oxidation of glucose in alkaline solution. The differential pulse voltammetric response of the NPC–Co₃O₄ composite electrode for the sensing of glucose exhibits a linear relation with the concentration range of 5 × 10⁻¹²–2.05 × 10⁻¹⁰ M and a low detection limit of 2 × 10⁻¹² M. The fabricated sensor shows high sensitivity, reliable reproducibility, and good selectivity. The sensor, when used for the direct determination of glucose in blood serum samples, shows good recovery (98.5–101.0%), suggesting its feasibility for biomedical applications. In addition, in a given potential range of 0–1 V, the composite exhibits a high capacitance (885 F g⁻¹ at a current density of 2.5 A g⁻¹) and long cycle life (∼94% capacitance retention after 10,000 cycles).