Non-enzymatic glucose sensor based on micro-/nanostructured Cu/Ni deposited on graphene sheets

The response performance of enzyme-free glucose sensors can be improved by using high conductivity and by loading redox probes with high electrochemical activity onto a graphene skeleton with a large surface area and by employing a design involving a binderless sensor structure. We prepared a Cu/Ni/graphene electrode containing neither a polymeric binder nor biofilm. Instead, graphene was grown vertically on the surface of the current collector by direct current (DC) arc plasma jet chemical vapor deposition (CVD) to form a structure consisting of a high-conductivity three-dimensional network. A large number of Ni and Cu micro-/nanostructured redox probes, which were prepared by square wave pulsed electrodeposition, was loaded onto the graphene skeleton. The reasons for the advantageous effect of these Cu/Ni/graphene electrodes on the performance were investigated by characterizing the morphology, structure, and composition of the sensitive films, and by combining the impedance characteristics of each component and the response characteristics to glucose. The results showed that the fabrication of Cu/Ni/graphene as the sensitive layer combined the performance characteristics of Ni, Cu, and graphene nanomaterials to exhibit excellent electrocatalytic activity toward glucose oxidation; three linear working curves were obtained in a wide concentration range of 0.005-2174 mu M, with an ultra-low detection limit of 0.0027 mu M (S/N = 3). The glucose sensor exhibited high anti-interference properties against sucrose, fructose, xylose, maltose, lactose, ascorbic acid, dopamine, and uric acid.