Monday, September 14, 2009

"NANOTECH: Electronic nose knows, warning with color-changing badge"

Nanoscale sensors not only permit many different tests to be performed simultaneously, but also speeds up recognition tasks by virtue of the smaller chemical reactions necessary to trigger alarms. Look for hazardous materials badges that detect exposure to toxic chemicals within three years. R.C.J.

A sensor akin to an electronic nose could be used to detect toxic industrial chemicals and be as commonplace as radiation badges around nuclear facilities, according to the the National Institute of Environmental Health Sciences. NIEHS funded research at the University of Illinois at Urbana-Champaign, where investigators created disposable badges using optoelectronics technology to create an artificial nose that detects a range of known toxic industrial chemicals. The sensor works by glowing a different color when detecting specific toxins. The 36-color sensor array also will display a unique pattern of color change for a mix of toxins, permitting a library of color fingerprints to be cataloged. These can be used to identify both common and uncommon exposure. A postage stamp-sized optical sensor array for detecting industrial toxins is said to be able to identify toxins and displaying color changes associated with representative poison gases. The colorimetric sensor array detects a wide range of volatile analytes using a disposable array of cross-responsive nanoporous pigments. Colors change in response to complex sets of chemical reactions, revealing the fingerprint of the toxic substance detected.