Nanotech device mimics nose functions to detect explosives

Researchers at University of California, Santa Barbara have designed a microfluidic nanotech detector that mimics the biological mechanism of canine scent receptors. The device is both highly sensitive to trace amounts of certain vapor molecules, and able to differentiate a specific substance from similar ones. The results are published in this month’s Analytical Chemistry.

“Dogs are still the gold standard for scent detection of explosives. But like a person, a dog can have a good day or a bad day, get tired or distracted,” said Carl Meinhart, professor of mechanical engineering at UCSB, and co-leader of the research, along with chemistry professor Martin Moskovits. “We have developed a device with the same or better sensitivity as a dog’s nose that feeds into a computer to report exactly what kind of molecule it’s detecting.”

The device can detect airborne molecules of 2,4-dinitrotoluene, the primary vapor that emanates from TNT-based explosives. It is packaged on a silicon microchip where a microscale channel of liquid absorbs and concentrates the molecules by up to six orders of magnitude. These vapor molecules interact with nanoparticles that amplify their spectral signature when excited by laser light. A computer database then identifies what kind of molecule has been captured.