Chemical "Nose" Could Sniff Out Landmines

November 13, 1998

Newly designed polymers may soon rival dogs as the most advanced landmine detection device. Mimicking dogs' acute biochemical mechanisms of smell, the polymers are engineered to notice trace vapors of TNT and its derivatives, which are commonly used in landmines.

The latest generation of these polymers is described in the November 10 Web edition of the Journal of the American Chemical Society, published by the American Chemical Society, the world's largest scientific society. It is scheduled to appear in the print version of the peer-reviewed journal on November 25.

Currently man's best friend is also the best tool for finding the estimated 120 million unexploded landmines hidden around the world. The chemicals that may relieve dogs of this dangerous duty are being developed by a team of scientists at the Massachusetts Institute of Technology, in Cambridge.

"We've come up with a very specific, sophisticated polymeric material," says team leader Timothy M. Swager, Ph.D.

The new sensors are fluorescent polymers, activated by light to have high energy electrons. The polymers look like 3-dimensional X's, attached through their center to parallel rows of chemical backbones. This structure keeps individual sensor polymers separated. When TNT floats in between the spaces it momentarily steals an electron, decreasing the fluorescence and sending a signal to the detector's "brain."

The system is expected to be very sensitive because "one TNT molecule can deactivate many of these electrons," according to Swager.

Swager says this chemistry could enable development of a simple, low cost, rugged and portable instrument to complement existing technologies for finding unexploded land mines. Current methods have drawbacks ranging from frequent false alarms to fragility to complex operation. A device based on Swager's polymers is currently being tested.

The invention might have other applications as well. For example, Swager envisions a system that would replace security spot checks: "Everyone walks through a little air shower and it would look at you" for substances ranging from drugs to explosives.
-end-
A nonprofit organization with a membership of more than 155,000 chemists and chemical engineers, the American Chemical Society publishes scientific journals and databases, convenes major research conferences, and provides educational, science policy and career programs in chemistry. Its main offices are in Washington, D.C., and Columbus, Ohio.



American Chemical Society

Related Electrons Articles from Brightsurf:

One-way street for electrons
An international team of physicists, led by researchers of the Universities of Oldenburg and Bremen, Germany, has recorded an ultrafast film of the directed energy transport between neighbouring molecules in a nanomaterial.

Mystery solved: a 'New Kind of Electrons'
Why do certain materials emit electrons with a very specific energy?

Sticky electrons: When repulsion turns into attraction
Scientists in Vienna explain what happens at a strange 'border line' in materials science: Under certain conditions, materials change from well-known behaviour to different, partly unexplained phenomena.

Self-imaging of a molecule by its own electrons
Researchers at the Max Born Institute (MBI) have shown that high-resolution movies of molecular dynamics can be recorded using electrons ejected from the molecule by an intense laser field.

Electrons in the fast lane
Microscopic structures could further improve perovskite solar cells

Laser takes pictures of electrons in crystals
Microscopes of visible light allow to see tiny objects as living cells and their interior.

Plasma electrons can be used to produce metallic films
Computers, mobile phones and all other electronic devices contain thousands of transistors, linked together by thin films of metal.

Flatter graphene, faster electrons
Scientists from the Swiss Nanoscience Institute and the Department of Physics at the University of Basel developed a technique to flatten corrugations in graphene layers.

Researchers develop one-way street for electrons
The work has shown that these electron ratchets create geometric diodes that operate at room temperature and may unlock unprecedented abilities in the illusive terahertz regime.

Photons and electrons one on one
The dynamics of electrons changes ever so slightly on each interaction with a photon.

Read More: Electrons News and Electrons Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.