Stepwise regulation of hole transport in DNA by control of triplex formation.

A functionality for regulating hole transport efficiency is a prerequisite for the utilization of DNA duplexes as nanodevices. Herein, we report the regulation of hole transport in anthraquinone-tethered DNA with dual triplex forming sites. Long-range photooxidation experiments showed that hole transport was effectively suppressed by the formation of triplex at low temperature, while it was recovered by dissociation to the duplex at higher temperature. Variation of temperature induced the formation and dissociation of the third strand at each triplex region individually, leading to the stepwise regulation of hole transport in DNA.