Israeli scientists have developed an electronic chip with microscopic chemical sensors that can detect explosives in the air at concentrations as low as a few molecules per 1,000 trillion.
Developed by a Tel Aviv company called Tracense, the groundbreaking, nano-technology-based sensor was revealed in the journal Nature Communications on Tuesday.
The trace detector, which is still in the prototype phase, can identify several different types of explosives in real time, even at a distance of several meters from the source.
It is small enough to be portable yet so sensitive that it can pick out explosives traces that would otherwise be masked by stronger chemicals.
"Different explosive species display a distinctive pattern of interaction with the nanosensing array, thus allowing for a simple and straightforward identification of the molecule under test," the team wrote in the study.
Existing detection methods can detect few explosive types and only at higher concentrations, the Israeli team said. They also require bulky equipment and tedious sample preparation by a trained operator.
The nanomaterials used by Tracense, 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 clusters of nano-sized transistors used in the prototype are extremely sensitive to chemicals, which cause changes in the electrical conductance of the sensors upon surface contact.
The device has been tested with explosives like TNT, RCX and HMX, which are used in commercial blasting and military applications, as well as peroxide-based explosives like TATP and HMTD. The latter are commonly used in home-made bombs and are very difficult to detect with existing methods.
TATP particles could be detected five meters from the source and TNT at 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," the team wrote.
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