Charge Transfer through Single and Double-strand DNAs : Theoretical Analysis Based on Molecular Orbital Calculations

Abstract

We investigated the charge transfer through single- and double-strand DNAs by molecular dynamics (MD) and molecular orbital (MO) methods. The stable structures of DNAs in water solvent were obtained by MD calculations. The energy levels and distributions of frontier molecular orbitals related to charge transfer were analyzed in detail by the semiemprical MO method. Furthermore, from the energy levels, the transfer integrals for a hole and an electron between DNA bases were estimated. Finally, we obtained the current-voltage characteristics in single- and double-strand DNAs based on these results. The calculated results are qualitatively in agreement with the experimental results.