A theoretical study on the charge transport properties of DNA

摘要

The charge transport properties of DNA are studied by the first-principle simulation to discuss the possibility of applying DNA to molecular wire. Both the hopping model and band-like model are introduced. By using hopping model, the theoretical hole mobilities calculated by Marcus theory between the same bases in DNA are 5.6 × 10~(-3),4.1 × 10~(-2),2.0 × 10~(-2) and 1.2 × 10~(-4) cm~2V~(-1)s~(-1)forT-T, A-A, C-C and G-G; and the calculated electron mobilities are 5.3 × 10~(-8), 1.5 × 10~(-4), 8.1 × 10~(-7) and 7.5 × 10~(10) cm~2V~(-1)s~(-1) for T-T, A-A, C-C and G-G, respectively. And the charge transport for both holes and electrons between different bases exhibits directivity. By using band-like model, we calculated the band width of DNA with double helix structure and bilinear structure to investigate which structure will facilitate to the charge transport. We found that the band width of DNA increased when DNA transforming from the double helix structure to the bilinear structure, which means DNA with the bilinear structure possesses better charge transport properties. This research sheds a light on the molecular design for the molecule serving as the molecular wire.