Science may be one step closer to nanoscale computer circuits that can assemble themselves. Self-assembly is almost essential for nanotechnology devices--because the components are so tiny. In nature, self-assembly happens all the time. The DNA in living cells acts like an old-fashioned switchboard: Certain DNA strands plug into matching DNA holes. So researchers at Pennsylvania State University decided to see if DNA could help hook up ultrasmall gold wires.
Materials scientists Thomas Mallouk and Christine Keating attached different DNA tags to wires that were a mere 6,000 nanometers (Nm) long and 200 Nm wide: By contrast, a human hair is 100,000 Nm wide. When the wires were put in solution with a gold film covered with complementary DNA strands, the wires were drawn to their DNA counterparts on the film and attached themselves.
The process wasn't perfect, however. Some mismatches occurred, and some untagged wires even stuck to the surface. Still, the researchers remain optimistic. In the next phase, they'll plant DNA tags on just the tips of the wires to see if the wires will then link together, end-to-end. If that works, it might eventually lead to a family of DNA-based recipes for various types of electronic-circuit modules. Think of nano-processors, or even nano-memory chips, all assembled spontaneously from the stuff of life.
By Mitch Nelin
Edited by Adam Aston