New approach to biological threat detection promises savings for defense, homeland security.

• Author: Magnuson, Stew
• Position: Homeland Security News

Detecting biological agents in the field has been a tough technological challenge in the military and homeland security realms.

It's a "needle-in-a-haystack" problem to find potentially deadly airborne microbes, but not impossible to solve. Biological threats, for example, can be detected onsite, but the machines are as large as refrigerators, and obtaining results may take hours or days depending on whether samples can be processed automatically inside the equipment or must be taken back to a laboratory.

The nonprofit lab Battelle recently introduced an all-inclusive chemical-biological-explosive detector the size of a microwave oven that can detect airborne pathogens in minutes with recurring costs of about $1 per day as opposed to other lab-in-a-box systems that cost hundreds or thousands of dollars per day to operate.

It made the breakthrough by taking a different approach to the problem, said Matt Shaw, vice president and general manager of chemical, biological, radiological, nuclear and explosive programs at Battelle.

The new Resource Effective Bioidentifi-cation System, REBS, uses rarnan spectroscopy rather than fluidics and reagents to find potentially harmful bioweapons or diseases. "Biological materials, be they bacteria, viruses or toxins, have distinct chemical signatures that raman spectroscopy is able to pick out from the vast array of other signatures that are out there," he said.

Raman uses a laser to shoot energy at particles to "interrogate" them. The particles give off a light signature that is picked up by a raman camera. It creates a spectrograph of the particle and compares it to a library of dozens of dangerous pathogens.

Before that happens, air samples are collected on a dime-sized piece of tape. Every 15 minutes or so, the sample is placed under the laser, which begins looking at the particles spending only microseconds on each one. If there is no match, the laser moves on to the next particle. Once a swath is investigated, the reel-to-reel tape moves the next air sample in, he said.

Biological agents, chemicals that comprise poison gas and the materials found in explosives all give off a chemical signature, he noted. 'We settled on raman largely because of its great ability to exploit chemical signatures of materials such as explosives," he said.

Battelle has been in the chem-bio detecting business for decades. It produced the first-generation detectors, the biological integrated detection system that was fielded...