N-doped graphene sheets induced high electrochemical activity in carbon film

In this study, we prepared a carbon film with clearly shaped N-doped graphene sheets by electron cyclotron resonance (ECR) plasma sputtering under low-energy electron irradiation. We found the N-doped graphene sheets remarkably improved the electrochemical activity of carbon film. The charge-transfer resistance was decreased from 21.62 Omega cm(2) to 1.37 Omega cm(2), and the redox peak separation was reduced to a low value of 65.4 mV in Fe(CN)(6)(4-/3-) redox system. The high electrochemical activity of N-doped graphene sheets embedded carbon (N-GSEC) films was ascribed to the formation of smaller sized N-doped graphene sheets. The smaller sized N-doped graphene sheets with high electronic density of states produced abundant edge defects, which served as active sites, facilitated the adsorption of Fe(CN)(6)(4-/3-) on film surface and enhanced the electron transfer. In detecting DNA base of adenine, the N-GSEC film showed a low oxidation potential and high sensitivity. These results demonstrate the N-GSEC film is a promising candidate material for construction sensitivity electrochemical biosensor.