PETN nanosensor could improve explosives checks

To date, tests for PETN, a high-explosive chemical compound, are done by wipe tests and an ion-mobility spectrometer.

However, since conducting such tests involves considerable time and effort, it is employed at airports for spot-checking only.

Airport scanners and sniffer dogs are said to have difficulties detecting PETN, since PETN is only slightly volatile and releases only small numbers of molecules into the ambient air.

Working in collaboration with the Rhinemain Polytechnic, scientists at the TU Darmstadt recently developed a nanosensor that is capable of detecting a single PETN molecule among 10 billion air molecules.

Explaining the new type of explosive detector’s operation, Dip-Ing Mario Boehme said: ‘If a PETN molecule enters the sensor’s nanotube, the nitro groups characteristic of PETN adhere to its surface and change its electrical conductivity — and that change may be detected by electronic instrumentation.’

In order to detect PETN using the new sensor, all that is necessary is conducting ambient air across the sensor.