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 density 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.