Electrodeposition of Au@NiO Nanotube Arrays for Highly Sensitive Non-enzymatic Glucose Sensing.

Au@NiO nanotube arrays were prepared on carbon paper through orderly electrodeposition of ZnO nanorods, Au and NiO, followed by removing ZnO. The morphology and composition of the nanotubes were characterized using scanning electron microscopy, transmission electron microscopy, x-ray diffractometry and x-ray photoelectron spectroscopy. Cyclic voltammetry and amperometric detection were applied to analyze the electrochemical performance of the obtained materials. The Au@NiO nanotubes displayed highly improved electrocatalytic activity for glucose oxidation than that of NiO nanotubes. The optimized Au@NiO nanotube arrays demonstrated excellent glucose sensing performance with a high sensitivity of 5536.2 μA mM⁻¹ cm⁻², a wide linear range of 1–6000 μM and a lower detection limit of 0.25 μM. In addition, the Au@NiO nanotube sensors also revealed the good feasibility of glucose detection for real serum samples. The enhanced glucose sensing performance of Au@NiO nanotubes may be due to the bifunctional effect of Au (increasing the charge transfer and acting as direct electrocatalyst for glucose oxidation). The electrodeposition of the Au@NiO nanotube arrays may provide a promising strategy for preparing non-enzymatic glucose sensing materials. [ABSTRACT FROM AUTHOR]