Ni(OH)^sub 2^/NiO nanosheet with opulent active sites for high-performance glucose biosensor

A novel non-enzymatic glucose sensor has been successfully fabricated based on Ni(OH)2/NiO nanosheet with unique defect-rich structure synthesized via a high-power, microwave-assisted hydrothermal method. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy were applied to characterize the composition and morphology of the materials. High-resolution transmission electron microscopy and Raman spectroscopy results verified that the Ni(OH)2/NiO nanosheets had abundant surface defects and additional active edge sites. Moreover, the glucose electrocatalytic properties of the defect-rich Ni(OH)2/NiO nanosheet were investigated through electrochemical methods, indicating that the fabricated biosensor had a high sensitivity of 2931.4 μA mM−1 cm−2, a wide linear range from 0.09 mM to 3.62 mM, and a low detection limit of 5.0 μM (S/N = 3). The excellent glucose-sensing properties can be attributed to the synergic effect of Ni(OH)2 and NiO, as well as the unique defect-rich structure of the active materials that produces opulent exposed active sites for glucose oxidation. The successful application of defect engineering to glucose sensing will pave a new way for the development of more efficacious catalyst.