U.S. Water News Online
ATLANTA, Ga. -- These days, Americans want to know
instantly if the dust on the lip of a mailbox is only dust, if the
water in U.S. reservoirs is safe, or if food is free from
Scientists at the Georgia Tech Research Institute's Center for
Emergency Response Technology, Instruction, and Policy (CERTIP) in
Atlanta have developed a low-cost portable toxin detector that could
help put a jittery nation more at ease.
"Americans tend to turn toward technology to solve their
problems," Georgia Tech researcher Dr. Tom Bevan said. "It helped us
in the Cold War. It has helped us in a lot of places."
Amid rising fears of bioterror, Americans may soon find themselves
turning to a handheld biological and chemical threat detector
developed by Bevan and his colleagues. The device is designed to
sniff out even the tiniest trace of harmful agents, whether they are
proteins, toxins, DNA, or an entire organism.
Known as an opto-electronic interferometer, the device uses simple
chemistry and light to identify the offending particles. Basically,
the device is an optical sensor housed on a 1-by-2-centimeter chip.
One layer on the chip is a glass wave guide that transmits light.
Another layer consists of thin chemical coatings that act as sensors.
When they come into contact with different biological or chemical
agents, the coatings are transformed in unique and measurable ways.
Right now, the device is equipped with 12 different sensors, but
the researchers say there is room to incorporate dozens more. To test
a suspect substance, a laser like the one used in a CD player shines
through the wave guide and the chemical coatings. The coatings, or
sensors, change the direction the light travels. Signal-processing
software incorporated into the chip analyzes this light interference
in seconds to identify the contaminant and determine how much of it
Though the process may sound complicated, GTRI researcher Daniel
Campbell said reading the results is a relatively simple process.
"It shouldn't take a Ph.D. to be able to use the sensor and
analyze the results," Campbell said.
In fact, the inventors say their toxin detector is so easy to use
that they plan to market the device as a PDA plug-in. That would
allow a police officer or firefighter armed with a handheld to enter
a suspected "hot zone," plug in the detector, take a sample, and get
an immediate readout.
The GTRI researchers say it would cost between $200 and $300 per
unit to produce the detectors commercially. At that price, the
detectors might also find a market among ordinary citizens seeking a
little peace of mind.
"[This would] let people be able to decide whether there is a
threat present or not before letting hysteria take over," Campbell
The opto-electronic interferometer also could have other, more
mundane uses, such as measuring smog or the quality of drinking
Even before the current bioterrorism threat, the device was
already headed for market, with a launch possible by late next year.
But given the need to build public confidence, the researchers say
their invention could become commercially available much sooner.
"We've been approached by both governmental and non-governmental
people to figure out how to accelerate it," Bevan said. "At this
point, it just takes money."
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