Dr. Raj Mutharasan (a professor of chemical engineering at Drexel University) is optimizing a sensor that...can provide a result within 10 minutes and can detect pathogens or bacteria, like E. coli, with a sensitivity of four cells per milliliter.
Mutharasan’s sensor can be placed into a palm-sized device that can be placed in the hands of food inspectors and growers, and is even cheap enough to one day enter the home.
The sensor uses E. coli antibodies to detect the bacteria in much the way that our bodies work. These antibodies are affixed to a narrow sliver of glass. Attached to the other end of the glass is a ceramic layer that generates voltage in response to applied mechanical stress.
A voltage is applied to the ceramic layer, making it expand and contract, causing the glass sliver to vibrate. The sensor detects changes in the glass sliver’s resonate frequency (the point where vibration is the greatest) and uses this to determine both the presence and concentration of E. coli bacteria.
Mutharasan is working with a company to commercialize the device and expects it to be in the hands of food safety experts soon.
press release | Newswise
~"With a sensitivity of four cells per milliliter", no one's eating spinach factory-sealed in plastic ever again?
Posted by Stubbornson at September 25, 2006 06:45 AM