Au Nanoparticles-Modified NiCo₂O₄ Nanowires-Supporting Co₃O₄ Dodecahedron as High-Performance Nonenzymatic Glucose Sensor

Abstract

A hierarchically nanostructured active material composed of nanoparticles, microsized dodecahedron, and nanowires (NWs) has been successfully fabricated and used for glucose oxidation, in which the NiCo2O4 NWs were grown in situ on the carbon paper (CP) and used for supporting the zeolitic imidazolate framework (ZIF-67)-derived Co3O4 dodecahedron, with the Au nanoparticles (Au-Np) being further electrodeposited on their surface (Au-Np/Co3O4/NiCo2O4 NWs/CP). The NWs effectively avoid the agglomeration of Co3O4, thus providing greater surface area for loading the Au nanoparticles. The introduction of Au can decrease the oxidation potential and enhance the catalytic current, which is beneficial for the electrocatalytic oxidation of glucose. The Au-Np/Co3O4/NiCo2O4 NWs/CP-based nonenzymatic glucose sensor exhibits good sensing performance, including high sensitivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$15.3~\mu \text{A}/\mu \text{M}$ </tex-math></inline-formula> /cm2, outstanding response/recovery times of 2.5/4.0 s (toward 180- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{M}$ </tex-math></inline-formula> glucose), good reproducibility, and excellent selectivity. Therefore, constructing a hierarchical nanocomposite is a promising strategy to develop a nonenzymatic electrochemical glucose sensor.