Electronic Enhancement Effect of Copper Modification of Base Pairs on the Conductivity of DNA

The effect of the new designed multicopper modification of base pairs on the conductivity of DNA was investigated by the nonequilibrium Green’s function method combined with density functional theory. Electronic transport calculations revealed that the equi-number H-by-Cu replacement can significantly enhance the conductivity of DNA from two aspects: transverse base-to-base communication along the hydrogen-bond direction and longitudinal transport along the DNA duplex. Furthermore, the enhancement effect on the longitudinal direction is more notable than that on the transverse. A tunneling mechanism is suggested for the short DNA segments. The decay factor of conductance in Cu-DNA decreases by half compared with the native DNA, thus making it more promising for constructing nanowires. In addition, Cu-DNA may prefer electron migration to hole transport with the lengthening of DNA segments. This work will shed some light on the design of promising DNA-based molecular wires.