Novel DNA-based nanowires may power gen-next computers

Scientists have successfully created gold-plated nanowires assembled from single DNA strands that can conduct current, an advance that may pave the way for tiny electonic devices made from genetic material.
Currently the circumference of the smallest transistors are tinier than the AIDS virus. The industry has shrunk the central elements of their computer chips to fourteen nanometers in the last sixty years.
Conventional methods, however, are hitting physical boundaries. Researchers around the world are looking for alternatives. One method could be the self-organisation of complex components from molecules and atoms.
Researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and Paderborn University in Germany 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.
"Our measurements have shown that an electrical current is conducted through these tiny wires," said Artur Erbe from HZDR's Institute of Ion Beam Physics and Materials Research.

"With the help of this approach, which resembles the Japanese paper folding technique origami and is therefore referred to as DNA-origami, we can create tiny patterns," said Erbe.
"Extremely small circuits made of molecules and atoms are also conceivable here," he said.
This strategy, which scientists call the "bottom-up" method, aims to turn conventional production of electronic components on its head.
"The industry has thus far been using what is known as the 'top-down' method. Large portions are cut away from the base material until the desired structure is achieved. Soon this will no longer be possible due to continual miniaturisation," Erbe said.

The new approach is instead oriented on nature - molecules that develop complex structures through self-assembling processes.
The elements that thereby develop would be substantially smaller than today's tiniest computer chip components.
"Genetic matter doesn't conduct a current particularly well," said Erbe.
Researchers have therefore placed gold-plated nanoparticles on the DNA wires using chemical bonds.
Using electron beam lithography they subsequently make contact with the individual wires electronically.
"We could demonstrate that the gold-plated DNA wires conduct energy. We are actually still in the basic research phase, which is why we are using gold rather than a more cost-efficient metal," said Erbe.

"We have, nevertheless, made an important stride, which could make electronic devices based on DNA possible in the future," he said.
The study was published in the journal Langmuir.