First-Principles Investigation of Nucleobase Detection by Tetranitrogen Coordinated Transition Metal Doped Graphene...

Detection of nucleobases is of great significance in DNA sequencing, which is one of the main goals of the Human Genome Project. By employing the nonequilibrium Green function method combined with density functional theory, we proposed a biosensor based on the TMN₄ (TM = Ni, Cu) embedded graphene nanoribbons for nucleobase detection. The adsorption energy calculations show that all five nucleobases are physisorbed on the TMN₄-doped graphene nanoribbons. Utilizing the distinction of current, the bases T, C, and U can be gradually detected at the biases of 0.4, 0.6, and 0.8 V by NiN₄-doped graphene nanoribbons, respectively. The bases A and G can be finally distinguished by CuN₄-doped graphene nanoribbons under an external bias of not less than 0.8 V. The identification of individual nucleobases at specific biases could provide a novel mechanism for the further development of biosensors in rapid genome sequencing applications.