Australian scientist using light to detect explosives

An Australian discovery has led to a portable new way to detect explosives using light-emitting molecules, offering an important tool to combat terrorism and remove land mines in war-torn countries.

University of Queensland Professor Paul Burn presented his work after he was admitted today as a new Fellow of the Australian Academy of Science, at the Academy’s annual ‘Science at the Shine Dome’ event in Canberra.

Professor Burn’s discovery of light-emitting polymers and tree-like macromolecules called dendrimers has led to worldwide interest across a broad range of applications including rapid detection of low levels of explosives.

“While there are many types of explosive materials, those that contain nitro groups such as TNT are very common and are key targets for detection,” says Professor Burn.

“Many detection systems used for identifying the presence of explosives are cumbersome or not portable.

“We have discovered that light-emitting dendrimers can be used for effective detection of explosives, by a decrease in their fluorescence.”

His talk introduced how nitrated explosives can be detected by fluorescence reduction with handheld detector devices. The devices contain a film that is excited using a light source. Air is passed over the sensing material; if the explosive is present, some of it gets absorbed into the film and decreases the fluorescence, which is measured using a photodiode.

Science at the Shine Dome will continue for the next two days. On 3 May the academy will present its highest awards to the country’s top scientists, and on 4 May the annual symposium will celebrate 100 years of Antarctic science.