Sniff This: Artificial 'Nose' Scouts for Bombs

April 1, 2008 -- The job market for military working dogs is about to shrink: Scientists have created an artificial "nose" that sniffs out the explosive TNT with genetically engineered viruses.

The eNose, which will probably first be used to protect soldiers and identify terrorists, is based on a technology that has a whole host of potential uses. In the consumer landscape, the eNose could offer sniff tests against allergens or help foodies match a meal with the perfect wine.

"We use the similar approach and materials that nature uses for smell sensing," said Seung-Wuk Lee, a professor of bioengineering at the University of California, Berkeley, and an author of a recent paper describing the technology, which appeared in the journal Langmuir.

The scientists created the eNose by coating a virus with billions of specialized proteins, in different combinations. Each of the proteins, much like the antibodies produced by the human immune system, recognizes and responds to a different substance upon exposure.

Among the multitude of modified viruses, the scientists found a few that recognize TNT and injected them into bacteria. Inside their hosts, the viruses replicated, creating millions of TNT-sensitive clones. The researchers then took those viral sentries and embedded them into a Jello-like hydrogel, which can be used to test for TNT.

The virus can only infect bacteria and is harmless to humans. Lee notes that the Food and Drug Administration recently approved the use of similar viruses to kill deadly bacteria, such as e.coli, in food.