SSS 2008-03-06（在线收听）

This is scientific American’s 60 Second Science. I'm Steve Mirskey. Got a minute?

The lure of gold can be electric to some people even though the element is chemically inert on the large scale. But the researchers from Georgia Tech report that down at the level of atoms, gold can conduct electricity and act as an insulator as well. When an oxygen molecule was embedded into six-atom-long gold wire, the wire can conduct electricity. But when the wire is longer than six atoms, the oxygenated gold becomes an insulator. The scientists reported their discovery in the journal Physical Review Letters. The researchers say these properties mean that gold nano-wires might be used as sensors to detect motion in nano-scale situations, such as neurons or nanomachines--futuristic devices built from individual atoms that might enter cells and fight disease. The wire could be a sensor because when it’s extended even slightly it would switch from a conductor to an insulator. Using gold as a sensor in this way could never have been predicted from what has known about gold in bulk but being very small can lead to some very big changes.

Thanks for the minute for a Scientific American's 60-Second Science. I'm Steve Mirsky