Extended topological line defects in graphene for individual identification of DNA nucleobases†
Recently synthesized topological line defects in graphene containing octagonal and a pair of pentagonal structures open up new research directions for nano-sized electronic device applications. In this study, using consistent-exchange van der Waals density functional (vdW-DF-cx) calculations, we investigated an extended line defects (ELDs)-based graphene nano-device for individual identification of all four DNA nucleobases. The electronic transport properties of the ELDs in graphene and the conductance caused by adsorption of all four nucleobases on the ELDs in graphene were investigated to understand the capability for individual identification of all four DNA nucleobases using the non-equilibrium Green's function (NEGF) method. Our results show that the π–π interaction is very much responsible for the Fano resonance characteristics and such an ELDs graphene-based nano-device may detect the four nucleobases better than a graphene-based nano-device without line defects. Also, the results of the I–V characteristics indicate that a specific voltage window is required for individual identification of all four nucleobases. Thus, we believe that a one-dimensional ELDs graphene-based nano-device is promising for DNA sequencing.