Fluorescence-based sensors and preconcentration techniques for buried explosives detection

Trace detection of explosives is an important challenge in both humanitarian landmine clearance and in homeland security scenarios. The ability to detect the presence of explosives across an area of interest would be of particular use in technical surveys of suspected minefields. In this paper we present the development and application of fluorescence-based trace-explosives sensors based on organic semiconductor thin films. We show that these can be used to detect nano-gram level quantities of nitroaromatic (TNT-like) molecules, and combine them for the first time with a novel preconcentration approach to detect buried explosives. Initial field trials on a test minefield will also be presented, in which the sensors are used to detect trace explosives collected by colonies of foraging honeybees.