Nanowires Built From DNA

Feb. 5, 2008 -- By stirring DNA into a chemical solution and exposing it to ultraviolet light, scientists have come up with a simple, cheap method to create nanowires that could be used to create tiny computers and medical devices.

"The process is very simple stuff," said Hong Liang of Texas A & M University, one of the authors of the paper, which appears in the current issue of Advanced Materials.

"Basically you put the solution and DNA into a beaker, stir it around, and expose it to light."

DNA, or deoxyribonucleic acid, contains the blueprints for all life. The Texas researchers used it as a scaffold, a structure that other molecules can bind to. Since DNA naturally forms long chains, the researchers started by creating wires, but making other shapes and structures from the solution are possible.

The researchers mixed the DNA with a solution containing cadmium, a metal, and stirred it around before exposing it to UV light.

"The UV light triggers a reaction, and the cadmium looks around for something to attach to," said Liang. "They find the DNA and grab it."

By controlling the concentration of the solution, the scientists can control the thickness of the wire. The wires form along the length of the DNA molecule, so cutting the DNA results in wires of different lengths.

As any beachgoer knows, UV light can degrade DNA, causing problems like cancer. To avoid damaging their DNA solution, the researchers used low-intensity UV light, much less intense levels that damage DNA.