Able to detect smells ten thousand times as faint as humans can, a dog's nose is an invaluable asset to police forces around the globe. So, when UCSB researchers set out to build an effective electronic nose that could assist homeland security, they already knew where they could find the perfect design.
By modeling the way in which a dog's nose efficiently absorbs and then concentrates airborne molecules, the researchers were able to produce a device with remarkable performance, capable of capturing and identifying molecules in concentrations as low as one part per billion – as well, or better, than their furry counterparts.
Within the paperclip-sized chip, a network of microscale channels twenty times thinner than a human hair picks up the molecules and increases their concentration by a factor of up to a million. The molecules then interact with nanoparticles that amplify their spectral signature, and a miniature spectrometer detects their composition. The results from this analysis are then compared to a comprehensive database to find the closest match, identifying the molecule with a high degree of accuracy.
Even though it was first intended for use in explosives detection (the design will soon be commercialized for homeland security applications) this technology has much more far-reaching applications. Because it can be used to identify a very wide variety of molecules, the researchers say it could be easily adapted to detect narcotic substances, food that has spoiled, or even as a diagnostic tool that can identify disease, including certain forms of cancer.
A paper detailing the results was published this month in the journal Analytical Chemistry.
In the video below, UCSB researchers Carl Meinhart and Martin Moskovits discuss their device and some of its possible uses.
Source: UC Santa Barbara