The nanotechnology research field is pretty fertile these days. Researchers at Harvard recently showed a nanowire which could be the next big diagnostic tool for doctors. Meanwhile, University of Southern California scientists have developed a 'nanosensor' that only works when noise is added. And another Harvard team has developed nanoscale fibers that are thinner than the wavelengths of light they carry.

Here are some details about the next future diagnostic tool.

A tiny nanowire sensor -- smaller than the width of a human hair, 1,000 times more sensitive than conventional DNA tests, and capable of producing results in minutes rather than days or weeks -- could pave the way for faster, more accurate medical diagnostic tests for countless conditions and may ultimately save lives by allowing earlier disease detection and intervention, Harvard scientists say.

One of a growing number of promising diagnostic tools that are based on nanotechnology, the silicon sensor represents the first example of direct electrical detection of DNA using nanotechnology, according to the researchers. The sensor and the detection of the CF (cystic fibrosis) gene will be described in the Jan. 14 issue of the journal Nano Letters.

"What one could imagine," says study leader Charles M. Lieber, a professor of chemistry at Harvard, "is to go into your doctor's office, give a drop of blood from a pin prick on your finger, and within minutes, find out whether you have a particular virus, a genetic disease, or your risk for different diseases or drug interactions."

The basic idea of stochastic resonance detection, says Kosko, is to create devices with strict threshold effects, that only respond to signals of more than a certain amplitude -- and then set this threshold around, or even below the amplitude
of the signal expected.

In the sub threshold form, "In a quiet, noise-free environment," said the scientist, "the detectors will not receive a signal." But if a moderate amount of noise is present, the signal will, as it were, float on top of the noise, triggering the detectors."