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SUMMARY: UCSD researchers have developed a simple,
fast, and inexpensive sensor to detect trace amounts
of explosives. A silicon polymer has been made into
a "nanowire," 2000 times thinner than a human
hair, that detects compounds such as picric acid, nitrobenzene
(NB), dinitrotoluene (DNT) and trinitrotoluene (TNT)
in air or seawater, or on surfaces.
The sensor uses a thin film of photoluminescent polysilole
that can also be sprayed on solid surfaces such as filter
paper. Wherever the polymer comes into contact with
molecules of explosive material, the fluorescent signal
is quenched. This polysilole is stable in air, water,
acids, common organic solvents and seawater-containing
bioorganisms.
TNT vapor in air is detected to 4 ppb (parts per billion)
within 10 minutes; in sea water 50 ppb TNT and 6 ppb
Picric Acid can be detected. Picric Acid is a substance
commonly used in letter bombs.
A hand or object that has been in contact with even
tiny amounts of TNT may be readily imaged by pressing
it to a piece of paper, spraying the paper with a 0.1
M toluene solution of the polymer, and observing the
paper with the naked eye under a black light.
POTENTIAL COMMERCIAL APPLICATIONS: This technology
has myriad applications in forensic science, law enforcement
and the military. In addition, it could be used to map
pollution from munitions manufacturing and storage and
to locate unexploded land or sea mines to facilitate
their removal.
CASE NUMBER: SD2000-160 (see also SD2003-020, SD2003-020 and SD2005-268)
LabLinks: http://www-chem.ucsd.edu/Faculty/bios/trogler.html , http://chem-faculty.ucsd.edu/sailor/research/
INQUIRIES TO: invent@ucsd.edu
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