Nickel foam-decorated hollow-Co3O4/GO nanocomposites: A highly sensitive non-enzymatic electrochemical sensor for glucose detection

Cobalt-based nanomaterials, characterized by multiple oxidation states and high stability in alkaline environments, have been found extensive applications in glucose detection. In this study, a cobalt-based zeolitic imidazolate framework (ZIF-67) was employed as a precursor, where Co2+ was coordinated with carboxyl groups of oxidized graphene oxide (GO), resulting in the formation of cobalt-based nanoparticles. The integration of Co2+ with GO established a novel cobalt-based nanomaterial with potential implications for glucose detection. At a calcination temperature of 260 °C, the calcination process extended for 4 h, fulfilling the synthesis of Hollow-Co3O4/GO nanocomposites. These nanocomposites were subsequently engaged as electrochemical electrodes for glucose detection through the impregnation method. The distinctive structure of Hollow-Co3O4/GO has spurred mutual promotion of the reoxidation reactions at the interface, culminating in a substantial augmentation of the specific surface area and a consequent considerable surge in the glucose oxidation current. In addition, due to the retention of the structure of MOFs, the pores can be used to adsorb glucose molecules, which is conducive to the accurate detection of the reaction. Under optimal conditions, the sensitivity of the Hollow-Co3O4/GO modified electrode hits 1625.336 μA mmol−1 cm−2, with a detection limit of 0.43 μmol/L (S/N=3) and a response time of approximately 2 s. These achievements have emphasized the promising applicability of Hollow-Co3O4/GO nanocomposites as an active material for practical electrochemical biosensors.