Single-molecule DNA conductance in water solutions: Role of explicit water-counterion sheath and chemical modification of nucleobases

Abstract

Dependence of charge transmission through several conventional and extended DNA duplexes on the explicit presence of their water-counterion surrounding has been theoretically studied. We show here that: (a) the latter does not form specific charge transmission channels in addition to those available in DNA duplexes themselves; (b) chemically modifying DNA bases to extend their π-electronic systems does not significantly alter time-averaged charge transmission probability through DNA duplexes. ？ 2009 World Scientific Publishing Company.