The recent Yemeni bomb threat has only highlighted the need for quick, accurate ways of detecting explosives. With their excellent sense of smell and the ability to discern individual scents, even when they’re combined or masked by other odors, this task is usually given to man’s best friend. But training these animals can be expensive and good sniffer dogs can be hard to find. Scientists have now developed an electronic sensor they say is more sensitive and more reliable at detecting explosives than any sniffer dog.

The new sensor, developed by scientists at Tel Aviv University, is able to detect multiple kinds of explosives and is especially effective at detecting TNT – an explosive that currently requires equipment that is high cost, has lengthy decoding times, is large and needs expert analysis to be detected.

"There is a need for a small, inexpensive, handheld instrument capable of detecting explosives quickly, reliably and efficiently," says lead researcher Prof. Fernando Patolsky of Tel Aviv University's Raymond and Beverly Sackler School of Chemistry.

The device is made from an array of silicon nanowires, coated with a compound that binds to explosives to form a nanotransistor. To enhance the device’s sensitivity, the scientists developed each one with 200 individual sensors that work together to detect different kinds of explosives with what the scientists say is an unprecedented degree of reliability, efficiency and speed.

In addition to being portable, the device is also capable of detecting explosives at a distance. This means it can be mounted on a wall, with no need to bring it into contact with the item being checked. Also, unlike other explosives sensors, the device provides a definitive identification of the explosive that it has detected. Its developers say that, to date, the device has not produced a single detection error.