Yang Qian, Long Mei, Tan Lin, Zhang Yi, Ouyang Jin, Liu Ping, Tang Aidong
†School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
‡Department of Neuroscience, Physiology, and Pharmacology, University College London, Gower Street, London WC1E 6BT, U.K.
ACS Appl Mater Interfaces. 2015 Jun 17;7(23):12719-30. doi: 10.1021/acsami.5b03401. Epub 2015 Jun 8.
A novel Cu-Cu2O/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-TiO2 complex nanostructure that demonstrates a new application. At the potential range from -1.0 to -1.6 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 -1.4 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 μA cm(-2) mM(-1). Such high sensitivity was attributed to the synergistic effect of the small Cu-Cu2O 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.
通过二次阳极氧化结合电沉积法制备了一种用于葡萄糖非酶电氧化的新型Cu-Cu2O/TiO2/Ti电极。它代表了一种新型的氧化铜-TiO2复合纳米结构，展示了一种新的应用。在-1.0至-1.6 V的电位范围内，Cu2+被电化学还原为Cu2O，同时在TiO2纳米管的顶表面形成覆盖的Cu。在沉积电荷为1.5 C、pH为12、CuSO4为4 mM以及沉积电位为-1.4 V的优化制备条件下获得了最高响应电流。结果表明，Cu2O有助于保持较宽的线性范围，并且Cu纳米颗粒的掺入提高了响应电流和灵敏度。响应电流与葡萄糖浓度之间的线性关系在0.1至2.5 mM范围内获得，灵敏度为4895 μA cm(-2) mM(-1)。如此高的灵敏度归因于小的Cu-Cu2O晶粒尺寸、螺旋TiO2纳米管阵列的大表面积以及快速电子转移的协同效应。电化学阻抗谱已成功应用于解释不同电极界面之间的差异以及非酶电氧化性质的变化规律。
