Scientists develop artificial nose to sniff out bombs

April 2nd, 2008 - 6:21 pm ICT by admin  

Washington, Apr 2 (ANI): Military and police sniffer dogs may soon be out of job, for scientists have now developed an artificial nose, called eNose, that sniffs out the explosive TNT with genetically engineered viruses.

The discovery of the eNose will be the first advancement used for protecting soldiers and identify terrorists.

It is based on a technology, which has a number of uses not only in defence but also in the consumer section, where it 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,” Discovery News quoted Seung-Wuk Lee, a professor of bioengineering at the University of California , Berkeley , as saying.

The eNose was created by coating a virus with billions of specialized proteins, in different combinations. All these proteins when exposed, recognise and respond to a different substance, just like the antibodies produced by the human immune system.

Out of all the modified viruses, a few were found that recognise TNT and were injected into bacteria. Later, the viruses replicated inside their hosts and resulted in millions of TNT-sensitive clones. Then, these viral sentries were taken and embedded into a Jello-like hydrogel, which can be used to test for TNT.

The researchers observed that the virus could only infect bacteria and was completely harmless to humans. In fact, Lee mentioned that recently the Food and Drug Administration supported the use of similar viruses for destroying deadly bacteria, like e.coli, in food.

We know that other available sensors identify a range of chemicals, from explosives to bad food, but almost all experience high numbers of false positives, leading to an alarm when there is no problem and their use limited.

Lee said that the key to the eNose, is its high selectivity making it more accurate and triggers fewer false alarms. It was also pointed out that the eNose could be used for many everyday tasks, like matching food with wine or detecting peanuts in food for children who could die from a peanut allergy.

All these substanceswine, explosives, peanutsall contain volatile organic compounds, or VOCs, and they are constantly released into the air. And it is possible for our noses, as well as the eNose, to detect them.

In fact, anything that releases VOCs, or anything with an odour, theoretically the eNose could be designed to detect it. However, according to the developers of eNose, it is the national security that comes first.

“Achieving chemical selectivity has been a major challenge, especially for detection of small molecules such as TNT in vapor,” said Thomas Thundat, a scientist at the Oak Ridge National Laboratory who develops miniature sensors that detect explosives.

However, according to him, it will take almost two to three years before the technology is widely used.

“Introducing inexpensive sensors that can be mass produced will cut down the terrorist threats. Right now terrorists have a huge economic advantage,” said Thundat.

The recent paper describing the technology appeared in the journal Langmuir. (ANI)

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