by John Harlow

Law enforcement agencies are seeking scientists to develop an artificial nose that can detect the smell of fear as terrorists pass through security at airports.

The US Department of Homeland Security is advertising for specialists to devise airport scanners that will sniff out “deceptive individuals”.

The technology builds on recent breakthroughs in finding human scent-prints which, many researchers believe, may be as unique to individuals as fingerprints.

Body odours also change perceptibly according to mood. Researchers at the Massachusetts Institute of Technology have already produced a gel that acts like the smell receptors in the human nose. Now they are trying to create a version that can isolate the tangy smell of adrenaline, the stress hormone, so that nervous passengers or those with a guilty conscience can be singled out.

Homeland Security wants a device that automatically compares odours with scents collected from crime scenes and held in a “smell bank” which, like DNA or fingerprints, could be used in court.

Last week officials said they only wanted to explore the possibilities but scientists are already predicting that it is only a matter of time before police will be able to sniff out crime artificially.

Professor Kenneth Furton, who is assembling a smell bank at Florida International University in Miami, said the technology could identify bank robbers by matching scent molecules collected from crime scenes on swabs.

He said chemists could already identify human smells by race, age and environment. Scientists will be able to tell police whether a thief is white, black or Asian, whether they are a teenager or older, and maybe even their last meal.

Furton, who taught chemistry at the University of Wales, Swansea, before moving to Miami, is also seeking body odours which mark people out as depressed. Other chemists are looking for the signature smells of cancers, asthma and other diseases.

Such advances could also be an additional tool in paternity cases, as family members give off a similar scent. Twins can smell as identical as they look.

One barrier to better security through sniffing is perfume. Detectors will have to be adapted to screen out more complicated molecules in bestselling scents such as Jennifer Lopez’s Glow range and Chanel No 5 which mask natural smells and confuse detector dogs.

Natural scents can be boosted by stress, which releases hormones from armpits and hands. The odour can then spread in 20ft clouds to cling to clothes, furniture and walls.