Copper-Nitrogen-Doped Graphene Hybrid as an Electrochemical Sensing Platform for Distinguishing DNA Bases

An electrochemical sensor using ultralight and porous copper nitrogen-doped graphene (CuNRGO) nanocomposite as the electrocatalyst has been constructed to simultaneously determine DNA bases such as guanine (G) and cytosine (C), adenine (A), and thymine (T). The nanocomposite is synthesized by thermally annealing an ice-templated structure of graphene oxide (GO) and Cu(phen)(2). Because of the unique structure and the presence of Cu2+-N active sites, the CuNRGO exhibits outstanding electrocatalytic activity toward the oxidation of free DNA bases. After optimizing the experimental conditions, the CuNRGO-based electrochemical sensor shows good linear responses for the G, A, T, and C bases in the concentration ranges of 0.132-6.62 mu M, 0.37-5.18 mu M, 198.2-5551 mu M, and 270.0-1575 mu M, respectively. The results demonstrate that CuNRGO is a promising electrocatalyst for electrochemical sensing devices.