Hybridization of Co3O4 and α-MnO2 Nanostructures for High-Performance Nonenzymatic Glucose Sensing

This work reports a highly sensitive and selective nonenzymatic detection of glucose that has been achieved by hybridization of 1D α-MnO2 nanorods modified with surface decoration of Co3O4 nanoparticles. The rational design and controlled synthesis of the hybrid nanostructures are of great importance in enabling the fine tuning of their properties and functions. First-principles-based periodic hybrid unrestricted HSE06 DFT with Grimme's long-range dispersion corrections are employed to compute the equilibrium crystal structures and electronic properties (i.e., band structure, Fermi energy level, and density of states) of both materials. These calculations reveal that both the α-MnO2 and the Co3O4 materials are indirect band gap semiconductor, and the band gap is about 2.89 and 3.18 eV, respectively. The α-MnO2/Co3O4 hybrid nanostructure has been synthesized by a simple and economical hydrothermal method. Compared with the performances of pure components MnO2 nanorods and Co3O4 nanoparticles, these hybrid nanostructures demonstrated a maximum electrooxidation toward glucose. The glucose-sensing performances of fabricated hybrid structures were measured by cyclic voltammetry (CV) and chronoamperometry. The synthesized α-MnO2/Co3O4 electrode exhibited a high sensitivity of 127 μA mM–1 cm–2 (S/N = 3) with a detection limit of 0.03 μM, wide linear range from 60 μM to 7 mM of glucose, with a short response time of less than 5 s. The favorable properties of the nanostructure fortify its potential utilization in the clinical detection of diabetes.