Nanosensor Detects Virus-Sized Particles
5 January 2008, 13:54
Categories: sensors optics--photonics
Scientists at the University of Rochester, in New York State, have created a nanoscale device that is capable of detecting one-quadrillionth of a gram of biological matter, which is about the size of certain viruses. In the future, the sensor may be able to detect influenza, severe acute respiratory syndrome (SARS), bird flu, and other viruses.
The sensor is a hexagonal array of tiny cavities, each 240 nanometers in diameter, carved into a very thin slab of silicon using a beam of electrons. When a laser beam is directed into the silicon, it interacts with the crystal such that only a particular part of the light’s spectrum is transmitted. But when a particle is trapped in one of the nanocavities, the transmitted spectrum changes slightly. A detector measures the altered spectrum.
“When a virus within a certain size range is caught in one of the nanocavities, the sensor transmits a light spectrum that is slightly different than the spectrum it transmits when no particles are present,” said Philippe Fauchet. “We can then compare the two spectra to determine whether the target particle was captured, which forms the basis for a very simple yet powerful biosensor that could be used by untrained personnel, such as front-line health care providers.”
Posted by: The Editors
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