Combined pre-concentration and real-time in-situ chemical detection of explosives in the marine environment

ICx Nomadics has developed the first known real-time sensor system that is capable of detecting chemical signatures emanating from underwater explosives, based upon the same amplifying fluorescent polymer (AFP) fluorescence-quenching transduction mechanism that the Fido® family of explosives detectors utilizes. The SeaPup is capable of real-time detection of the trace chemical signatures emanating from submerged explosive compounds and has been successfully tested on various marine platforms, including a crawler robot, an autonomous underwater vehicle (AUV), and a remotely operated underwater vehicle (ROV). The present work is focused on advances in underwater in-situ chemical sensing; wherein trace amounts of dissolved explosive compounds may be detected and discriminated from other chemical species found in the marine environment. Recent progress with the SeaPup platform have focused on increasing the sensitivity of the AFP matrix through the development of a preconcentration system designed to harvest explosive analytes from a larger sample volume over a predetermined period of time. This permits real time monitoring of chemical plumes during the approach to a potential source, combined with the lowered limit of detection from extended sampling of targeted items. SeaPup has been shown to effectively map "explosive scent plumes" emanating from an underwater source of TNT, and the preconcentration system has previously been demonstrated to enhance sensitivity be over 2 orders of magnitude in a time window of minutes.