Bomb detection: Fruit flies can sniff out explosives with their acute sense of smell

Sarah Spickernell
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Fruit flies are normally thought of as a nuisance (Source: Getty)
The detection of explosives is a heavy burden to place on the small wings of a fruit fly, but scientists at the University of Sussex believe the creature's acute sense of smell could more than make up for the many times it has been nothing but a nuisance.
The small insect has a nose so powerful it can accurately sniff out illicit drugs and explosive substances, according to paper published today in the journal Bioinspiration and Biomimetics.
Thomas Nowotny, brain scientist and lead researcher of a study, says this offers great possibilities in terms of “recreating” the flies' noses in electronic format for a wide range of detection technologies.
Nowotny and his team came to this conclusion by recording how 20 different receptor neurones in fruit flies responded to a variety of chemicals related to wine, and compared the results with how they responded to chemicals from hazarduous materials such as drugs and explosive combustion products.
By monitoring how quickly each neurone fired, the researchers were able to assess which smells elicited the strongest reactions from the flies. They then used a computer program to simulate the part of the fly's brain used for recognition to show that the receptor responses contained enough information to recognise odours.
"In looking at fruit flies, we have found that, contrary to our expectation, unfamiliar odours, such as from explosives, were not only recognised but broadly recognised with the same accuracy as odours more relevant to a fly's behaviour,” Nowotny said.
Scientists are still a way off developing effective electronic noses, or e-noses, which are typically based on metal-oxide sensors and are very slow compared to biological noses.
But this latest discovery brings scientists a step closer to accurately replicating the sensitive olfactory sense of animals.
“The long-term goal of this research direction is to 'recreate' animals' noses for technical applications. As well as the detection of explosives, chemical weapons and drugs, there is a broad array of other possible applications, such as measuring food quality, health, environmental monitoring, and even geological monitoring and agriculture,” Nowonty explained.
There are still questions to be answered before advanced e-noses can be developed, however.
“It would be quite difficult to recreate the entire nose; even adopting all sensors would be too difficult. One may be able to do five or maybe 10, out of 43 in the fruit fly. So the question is, which 10 should we use and would it work?
“In this paper we show that it could work with as little as 10 fruit fly receptors and we identify the most likely candidates to use."