Nanomaterials, on the other hand, "offer the ability of incorporating multiple sensors capable of detecting numerous chemical threats simultaneously on a single miniature array platform."
The team built a prototype chip using clusters of nano-sized transistors that are extremely sensitive to chemicals -- causing changes in their electrical conductance upon surface contact.
The researchers tested the device's reaction to explosives like TNT, RCX and HMX used in commercial blasting and military applications, as well as peroxide-based ones like TATP and HMTD which are commonly used to build homemade bombs but are hard to detect with existing methods.
Some tests were done under "highly contaminated" conditions, like heavy cigarette smoke, to demonstrate the chip's accuracy. TATP particles could be detected five meters from the source, said the team, and TNT four meters. Only five seconds of air sample collection was required through a paper filter.
"These promising results demonstrate the potential capability of our sensing platform for the remote detection of explosive species," they write.