Theoretical Study on Excess-Electron Transfer in DNA Based on the Marcus Theory

Abstract

DNAs, which have charge transport abilities, are expected to apply to advanced materials in nanotechnology as conducting nano-wires. while the hole-transfer in DNA has been extensively investigated in many experimental and theoretical studies, the knowledge on the transfer of a negative charge, i.e., the excess-electron transfer (EET), is limited so far. In the present study, we evaluated the rate constants of EET in DNA, using the Marcus theory with den- sity functional theory (DFT) calculations. The computed rate constant of EET between thymine bases, 2.31 − 3.49 × 1010 s−1, showed good agreement with the experimental value, 4.4 ± 0.3 × 1010 s−1. Furthermore, the mechanism of the decrease of EET rates due to miss-match base pairs was elucidated.