A researcher working under an Office of Naval Research grant is just a couple of months away from completing a prototype detector designed to sound an alarm when airborne microbes such as anthrax are in the air.

Dr. Jeanne Small, a biophysicist and professor of chemistry and biochemistry at Eastern Washington University in (Cheney, WA), has come up with a detector that continuously samples the air, offering analysis in under a half-hour. "Our research showed that common substances such as road dust and soot behaved differently than bacteria," Small said.

Small has successfully tested biological particles ranging in size from 1 to 10 microns by using lasers and acoustic sensors to detect and identify microbes. In the research, laser pulses were used to excite light-absorbing substances that release energy as heat. Heat-induced solvent expansion generated sound waves, which were measured by an ultrasonic transducer.

Working with Small is InnovaTek, (Richland, WA), a company that makes the air sampler, and Quantum Northwest (Spokane, WA), which is building the sensor component.