Helical TiO2 Nanotube Arrays Modified by Cu鈥揅u2O with Ultrahigh Sensitivity for the Nonenzymatic Electro-oxidation of Glucose

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• 作者：Qian Yang ; Mei Long ; Lin Tan ; Yi Zhang ; Jin Ouyang ; Ping Liu ; Aidong Tang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：June 17, 2015
• 年：2015
• 卷：7
• 期：23
• 页码：12719-12730
• 全文大小：568K
• ISSN：1944-8252

文摘

A novel Cu鈥揅u₂O/TiO₂/Ti electrode for the nonenzymatic electro-oxidation of glucose has been fabricated by secondary anodic oxidation combined with the electrodeposition method. It represents a new type of copper oxide鈥揟iO₂ complex nanostructure that demonstrates a new application. At the potential range from 鈭?.0 to 鈭?.6 V, Cu²⁺ was electrochemically reduced to Cu₂O, accompanied by the simultaneous formation of Cu covering the top surface of the TiO₂ nanotubes. The highest response current was obtained at the optimized fabrication conditions with a deposition charge of 1.5 C, a pH of 12, 4 mM CuSO₄, and a deposition potential of 鈭?.4 V. The results indicate that Cu₂O helps to keep a broad linear range, and the incorporation of Cu nanoparticles improves the response current and sensitivity. The linearity between the response current and the glucose concentration was obtained in the range from 0.1 to 2.5 mM with a sensitivity of 4895 渭A cm^鈥? mM^鈥?. Such high sensitivity was attributed to the synergistic effect of the small Cu鈥揅u₂O grain size and the large surface area of the helical TiO₂ nanotube arrays as well as the fast electron transfer. Electrochemical impedance spectroscopy has been successfully applied to explain the differences among different electrode interfaces and the change rule of nonenzymatic electro-oxidation properties.