Sequence-Dependent Photocurrent Generation through Long-Distance Excess-Electron Transfer in DNA.

Given its well-ordered continuous π stacking of nucleobases, DNA has been considered as a biomaterial for charge transfer in biosensors. For cathodic photocurrent generation resulting from hole transfer in DNA, sensitivity to DNA structure and base-pair stacking has been confirmed. However, such information has not been provided for anodic photocurrent generation resulting from excess-electron transfer in DNA. In the present study, we measured the anodic photocurrent of a DNA-modified Au electrode. Our results demonstrate long-distance excess-electron transfer in DNA, which is dominated by a hopping mechanism, and the photocurrent generation is sequence dependent.