Federal funding spurs R&D for sensors to detect bioagents, war chemicals, explosives, and radiation.

The Free World knew terrorists planned biological attacks even before those unsettling days last September, when everyday mail carriers delivered letters containing anthrax to U.S. Senate and New York news media offices.

And although investigators appear convinced a U.S. citizen not involved with the 11 Sept. terrorist attacks mailed the anthrax, the letters triggered a torrent of new government money to develop advanced sensor-based instrumentation to guard the precious air we breathe and the water we drink.

Considering the possibilities, it's easy to understand why improved guardian instruments are urgently needed to assure utilities, government and business offices, industrial plants, and society in general are safer. For sensor and analytical instrument makers, it also means a rapidly growing business opportunity.

Besides anthrax, previously developed by Iraqi and USSR bioweapon programs, there are 27 other bacterial agents the U.S. Department of Justice lists that can kill humans—some in holocaust proportions.

"High-ranked" potentials include bubonic and pneumonic plague, which terrorists could distribute via fleas or aerosols, and Marburg virus, which can lead to internal and external bleeding in five days. A former Soviet Union biological program turned that virus into a weapon in aerosol form.

Venezuelan equine encephalitis brings on sudden illness, with spiking fevers. The U.S. and USSR turned it into a weapon in liquid and dry aerosol forms. Yellow fever, distributed by mosquitoes, kills up to 20% of those infected.

Saxitoxin, contaminated shellfish, is highly toxic in aerosol form. Yet another, Q fever, is not the most deadly agent but could be one of the most effective because of its ability to spread easily through the air and cause widespread, debilitating illness.

in low doses, so detection systems must be highly sensitive. They must also discriminate between biological agents and normal particulates in air or water, such as dust, dirt, and pollen. Finally, speed is of the essence. They must report danger fast—in time to save lives.

Biodetection systems typically consist of four components: a trigger/cue, which first determines whether there's a change in the sensor's particulate background; a collector, which separates the new particle from normal particulates; a detector, which determines whether the foreign particle is biological in origin; and an identifier, which reports the specific type of biological agent collected.

While some biodetection systems are commercially available, most are costly and respond to only a small number of agents. Improved versions are in the research and early development stages. Because bioagents involve complex molecules, biodetection systems are much more complex than systems designed to detect chemical agents.

"In fact, the need for high-efficiency collection and concentration of the sample, high sensitivities, and high selectivities make all chemical detectors in their current form unusable for biological agent detection," said a December 2001 U.S. Department of Justice report.

Fueled by federal funding, detection technology today marches at a quick-time pace. In February, the U.S. Army Robert Morris Acquisition Center in Edgewood, Md., awarded Advanced Technology Products Inc.'s Intellitec division $23.4 million in initial funding to begin producing joint biological point detection systems (JBPDS).

Two plants will perform the work. One will be at Intellitec's DeLand, Fla., plant and the other at the Columbus, Ohio, facilities of team partner Battelle, a nonprofit laboratory advancing technologies. MIT's Lincoln Laboratory largely developed the JBPDS software.

JBPDS automatically detects and identifies very low levels of biowarfare agents in the air, triggers local and remote warning systems, then reports threat information over standard communications systems. It detects up to 10 agents at once while operating on land, light-armored vehicles, and ships.

According to an Intellitec/Battelle spec sheet, the trigger/detector uses laser-induced fluorescence to evaluate the atmospheric aerosol background. Florescence technology uses light, typically in the ultraviolet region, to excite molecular components. When an excited component spontaneously reverts to an unexcited state, it emits a light pattern that specifically identifies it.

When the algorithm detects something suspicious, the collector/concentrator automatically samples hundreds of liters per minute and provides a few milliliters of liquid sample containing the suspected bioagent.

Using handheld assays, similar to pregnancy tests, JBPDS then tests the sample for specific biowarfare agents. Positive tests trigger alarms.

Separately, MesoSystems Technology Inc. developed a handheld biosampling device, the Biocapture BT-500 Air Sampler. It uses that company's BioVIC aerosol collector, a front-end air sampler that captures large numbers of microbes in an aqueous sample. A whole cell rapid detection, nucleic acid, or other liquid-based sensor system analyzes the sample.

Researchers are also developing sensors that would use live cells to detect biological agents. For example, when a heart or liver cell is under invasion, it might release protein or change in some other way sensors can detect. One of the live-cell sensors' many challenges, however, is to keep the cells alive.

Also under development are "standoff" technologies that detect and identify biological agents at a distance, far away from a detection sensor's location. Typically, they use a bright light source, usually laser light detecting and ranging (Lidar) technology.

Lidar systems transmit a short laser pulse through the atmosphere, then a portion reflects back from particles such as molecules, aerosols, clouds, or dust. Some Lidars can "see" bioagent particles up to 30 miles away.

According to sources, another remote sensing technology, called a "DNA sequencer," is under development to specifically identify bacteria types in the air. The California National Guard, which like all guard units has a rapid response team to defend against biological or chemical warfare acts, is reportedly testing the technology.

Last March, the U.S. Environmental Protection Agency launched a nearly $90 million national effort to protect drinking water and wastewater utilities as quickly as possible.

The largest drinking water systems, those regularly serving more than 100,000 people, will be eligible to apply for grants of up to $115,000 to help complete vulnerability assessments and other security planning.

The assessments will identify potential vulnerabilities and suggest security upgrades. ST