Cu@C composite nanotube array and its application as an enzyme-free glucose sensor.

We report a novel hydrothermal method for the synthesis of a Cu@C nanotube array on a centimeter-scale substrate for the first time. In this hydrothermal reaction process, employing the carbon coated ZnO nanorod array as an inexpensive and partially sacrificial template, along with the ZnO dissolving in the alkaline atmosphere, the formed Cu particles deposit and grow on the carbon surface gradually. Importantly, the carbon shell of the template is not only essential to the preservation of the array configuration, but also makes a significant contribution to the final nanostructure. Such a method provides a morphology-reservation transformation when various shaped carbon-containing templates are adopted. Moreover, this designed Cu@C array has been demonstrated as an excellent electrode material for an enzyme-free glucose sensor in terms of sensitivity (1200 µA mM( - 1) cm( - 2)) and significantly lower applied potential (-0.2 V). Our results present the first preparation of the Cu@C composite nanotube array and may open up an opportunity for rational design of advanced electrode materials for enzyme-free glucose sensors.