New laser may foil Afghan bombers

The physicists in St Andrews University, Fife, made a laser which can detect vapours emitted by explosives such as TNT.

The scientists said the device could work like "an artificial nose for a robot dog", sniffing out extremely low concentrations of vapours.

The technology could not only improve airport security but may help detect landmines and roadside bombs.

Dr Graham Turnbull, of the research team, said: "Floating above a landmine in Iraq or Afghanistan, there's a very weak, dilute cloud of vapours of explosive molecules that the bomb is made from.

"We have shown that our lasers can rapidly sense these TNT-like molecules, frequently used in explosives, at extremely low concentrations."

Using a thin film of a light-emitting plastic they have created a laser beam which dims when the plastic comes into contact with vapour. The plastic is widely used in electronics, making the device relatively cheap.

Dr Turnbull added: "Essentially it's making an artificial nose for a robot sniffer dog."

The research is published in Advanced Functional Materials.