Sequence-independent and rapid long-range charge transfer through DNA

Abstract

Interest in using DNA as a building block for nanoelectronic sensors and devices stems from its efficient hole-conducting properties and the relative ease with which it can be organized into predictable nanometre-sized two- and three-dimensional structures. However, because a hole migrates along DNA through the highest occupied molecular orbital of the guanine bases, its conductivity decreases as the adenine–thymine base-pair content increases. This means that there are limitations on what sequences can be used to construct functional nanoelectronic circuits, particularly those rich in adenine–thymine pairs. Here we show that the charge-transfer efficiency can be dramatically increased in a manner independent of guanine–cytosine content by adjusting the highest occupied molecular orbital level of the adenine–thymine base pair to be closer to that of the guanine–cytosine pair. This is achieved by substituting the N7 nitrogen atom of adenine with a C–H group to give 7-deazaadenine, which does not disturb the complementary base pairing observed in DNA. The presence of adenine–thymine base pairs in DNA duplexes significantly reduces their electrical conductivity. However, by replacing adenine with a closely related analogue that does not disturb the normal complementary base pairing, it is possible to make duplexes that can transfer charge efficiently without having to use only guanine–cytosine base pairs.

Cite this article

Kawai, K., Kodera, H., Osakada, Y. et al. Sequence-independent and rapid long-range charge transfer through DNA. Nature Chem 1, 156–159 (2009). https://doi.org/10.1038/nchem.171

View full text

>> Full Text:   Sequence-independent and rapid long-range charge transfer through DNA