The electrical conductivity of an individual DNA molecule can be measured by wiring it into a nanoscale circuit, reports a study published online in Nature Nanotechnology. This work suggests that the electronic properties of a fully base-paired double helix are comparable to those of a similarly sized stack of graphite.
A team led by Colin Nuckolls and Jacqueline Barton made a tiny electronic device in which part of the circuit is formed by a single-walled carbon nanotube. Cutting a very small gap in the nanotube opened the circuit and current stopped flowing through the device. When this gap was bridged with a DNA molecule, however, the conductive path was restored and the electrical properties of the DNA could be measured. It was shown that even a single base-pair mismatch in a double helix led to a significant decrease in conductivity.
The flow of current could be stopped by cutting the bridging DNA with an enzyme. This suggests that the DNA adopts its usual shape, rather than being distorted by the device, and therefore that the conductivity is not simply an artifact of the measuring technique.
Colin Nuckolls (Columbia University, New York, NY, USA)
Jacqueline Barton (California Institute of Technology, Pasadena, CA, USA)
Abstract available online.
(C) Nature Nanotechnology press release.
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