Electrochemical Nonenzymatic Glucose Detection Based on the Nanostructures of NiCo₂O₄ Nanosheets Wrapped CuO Nanowires

Abstract

A type of NiCo2O4-based hierarchically-nanostructured composite has been synthesized for electrooxidation of glucose. The Cu(OH)2 nanowires were initially growth in-situ on the surface of Cu foam (CF) and wrapped with Ni-Co precursor (Ni-Co Pre) to prepare nanocomposites (Ni-Co Pre@Cu(OH)2 NWs/CF). Then, the obtained composites were annealed in air to form the NiCo2O4 nanosheets wrapped CuO nanowires nanostructures which were supported on the Cu foam (NiCo2O4@CuO NWs/CF). Because of the synergism of Ni, Co, and Cu, as well as the enhanced surface area by hierarchical nanostructure, the as-prepared NiCo2O4@CuO NWs/CF sensor exhibits outstanding electrooxidation activity for glucose detection, including high sensitivity (7.98 μA/μM/cm2), wide linear range (1.0×10-3-2.0 mM), low detection limit (0.68 μM), and fast response/recovery times (1.3/2.0 s). Meanwhile, the as-fabricated sensor also possesses good reproducibility, flexibility, selectivity, and long-term stability, which is a promising platform for glucose electrooxidation and determination in serum sample.