The nano molecular sensor could help with early diagnosis of genetic diseases, and have numerous other applications for medicine, biotechnology and other fields, said Giovanni Zocchi, assistant professor of physics at UCLA, member of the California NanoSystems Institute and leader of the research team.

"This nanoscale single-molecule method could lead to significant improvements in early diagnosis of genetic diseases, including the growing number of cancer forms for which genetic markers are known," Zocchi said. "The largest potential applications for this sensor may be in the drug discovery process, where the possibility of quickly gauging the gene expression response of cells to prospective drugs is crucial."

The research is federally funded by the National Science Foundation.

Zocchi's nanoscale sensor uses a single molecule to recognize the presence of a specific short sequence in a mixture of DNA or RNA molecules -- which he equates to finding a needle in a haystack.

"Traditional assays use an averaged procedure that detects a minimum amount of molecules, but our method can detect a single one," Zocchi said. "When a target molecule binds to the probe in the sensor, the probe molecule changes shape, and in its new conformation, pulls on the sensor. It is remarkable that a single molecule can actually move the sensor, because the relative sizes are comparable to one person trying to move a mountain, but mass is of no consequence at these miniscule scales."

The motion of the sensor is detected by an optical technique called "evanescent wave scattering," which analyzes light that leaks out behind a reflecting mirror. This evanescent wave ca
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Contact: Stuart Wolpert
stuartw@college.ucla.edu
310-206-0511
University of California - Los Angeles
19-Jun-2003