ChemIONS

Polymer based sensors for explosive detection is the one commonly in use nowadays. University of Massachusetts Amherst researchers have created complex molecules containing Zinc, for use in portable sensors that can be employed in sensors detecting explosives.

The commonly used tool for land mine detection today is the hand-held metal detector. Chemical sensors have been investigated for mine detection. For chemical species having favorable spectral properties, remote sensing can be achieved by fluorescence light detection and ranging LIDAR. Nitroaromatic explosives exhibit strong ultraviolet absorption but low fluorescence, thus direct detection is not practical.

Most of the Zinc Metal Complexes are  fluorescent in nature. But they lose this ability when exposed to chemicals contained in plastic explosives. ( commonly reffered as Quenching). Since each of the complexes react by losing different amounts of their fluorescent ability, they can be used to create sensor arrays that produce a different visual display when exposed to different explosives. This differential quenching of the zinc complexes is what permits discrimination within the closely related nitroaromatic family used in explosives.

When tested, these Zn sensors also responded quickly, since the zinc complexes are very efficient at changing energy states, making them suitable for hostile environments.  Moreover they change the energy states  abrupt unlike other complexes. Means they don’t lose energy gradually like metal complexes made with copper. (Source- ScienceDaily May 14, 2008 http://www.sciencedaily.com/releases/2008/05/080513191831.htm).