Flowerlike CuO/Au Nanoparticle Heterostructures for Nonenzymatic Glucose Detection

The controlled preparation of two-dimensional (2D) nanomaterials exhibiting heterojunction structures based on nontoxic and economical transition metal oxides represents breakthroughs in the electrochemistry field. Herein, flowerlike CuO/Au nanoparticles that have 2D nanomaterial characteristics and excellent glucose sensing performance were prepared by microwave hydrothermal synthesis of sea urchinlike CuO and subsequent self-generated acid etching of the sea urchinlike CuO in the presence of HAuCl4 and NaBH4. HAuCl4 was not only the reactant for the authigenic acid etching, but also the raw material for the heterojunction structure. Upon the acid etching, Au nanoparticles with an average size of 15 nm were uniformly distributed on the surface of CuO nanoflakes. Benefiting from a large specific surface area and low electron transfer resistance, the flowerlike CuO/Au nanoparticles were excellent electrode modification materials: glucose sensors based on the glassy carbon electrodes modified by the flowerlike CuO/Au nanoparticles demonstrated high sensitivity (2455 μA·mM–1·cm–2), wide detection range (0.01–12 mM), low detection limit (0.53 μM), good stability, good reproducibility, and good selectivity. The green and economical authigenic acid etching method presented in this study exemplifies the controlled preparation of 2D nanomaterials with specific properties.