title: Characterization of the tunneling conductance across DNA bases.
abstract: Characterization of the electrical properties of the DNA bases (adenine, cytosine, guanine, and thymine), in addition to building the basic knowledge on these fundamental constituents of a DNA, is a crucial step in developing a DNA sequencing technology. We present a first-principles study of the current-voltage characteristics of nucleotidelike molecules of the DNA bases, placed in a 1.5 nm gap formed between gold nanoelectrodes. The quantum transport calculations in the tunneling regime are shown to vary strongly with the electrode-molecule geometry and the choice of the density-functional theory exchange-correlation functionals. Analysis of the results in the zero-bias limit indicates that distinguishable current-voltage characteristics of different DNA bases are dominated by the geometrical conformations of the bases and nanoelectrodes.
authors.affiliation: Physics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831, USA.
authors.forename: Radomir
authors.initials: R
authors.lastname: Zikic
authors.forename: Predrag S
authors.initials: PS
authors.lastname: Krstić
authors.forename: X-G
authors.initials: XG
authors.lastname: Zhang
authors.forename: Miguel
authors.initials: M
authors.lastname: Fuentes-Cabrera
authors.forename: Jack
authors.initials: J
authors.lastname: Wells
authors.forename: Xiongce
authors.initials: X
authors.lastname: Zhao
mesh_terms: D003198:Computer Simulation; D004247:DNA / Q000737:chemistry*; D004553:Electric Conductivity; D004563:Electrochemistry / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D009711:Nucleotides / Q000737:chemistry*; D012666:Semiconductors
chemical_list: D009711:Nucleotides; D004247:DNA