In order to produce the nanowires, the researchers combined a long single strand of genetic material with shorter DNA segments through the base pairs to form a stable double strand. Using this method, the structures independently take on the desired form.
The strategy, which scientists call the 'bottom-up' method, aims to turn conventional production of electronic components on its head. The new approach is oriented on nature: molecules that develop complex structures through self-assembling processes.
There is, however, a problem. “Genetic matter doesn’t conduct a current particularly well,” points out Dr Artur Erbe.
He and his colleagues therefore placed gold-plated nanoparticles on the DNA wires using chemical bonds. Using electron beam lithography, the nanoparticules make contact with the individual wires electronically.
“This connection between the substantially larger electrodes and the individual DNA structures has come up against technical difficulties until now. By combining the two methods, we can resolve this issue. We could thus precisely determine the charge transport through individual wires for the first time,” adds Dr Erbe.
As the tests of the Dresden researchers have shown, a current is conducted through the gold-plated wires – it is, however, dependent on the ambient temperature.
“The charge transport is simultaneously reduced as the temperature decreases,” describes Erbe. “At normal room temperature, the wires function well, even if the electrons must partially jump from one gold particle to the next because they haven't completely melded together.”
In order to improve the conduction, Artur Erbe’s team aims to incorporate conductive polymers between the gold particles.
“We have made an important stride, which could make electronic devices based on DNA possible in the future,” says Dr Erbe.