(718g) Microstructured Conducting Polymer Swabs for Enhanced Trace Explosive Detection

The detection of trace amounts of explosive materials is critical to national security, and ion mobility spectrometer (IMS)-based analysis of trace explosives collected using contact sampling continues to be the most common explosives and chemical agent detection method used in airports and high security checkpoint locations. In this process a swab (or particle trap) is used to probe a surface of interest (e.g., the hands and luggage of passengers) to collect and transfer particulate residue to an IMS for analysis. However, the collection of residue from a surface remains the limiting step in this process. As such there is a significant need to develop new materials with the improved ability to interrogate surfaces and to increase the adhesion to trace explosive residues of interest.

In this work, we present a novel swabbing material for the enhanced removal of explosive particles from surfaces. Polypyrrole (PPy) microstructured films were synthesized with a variety of form factors through a templated electropolymerization process. The removal of representative fluorescent particles from aluminum surfaces was examined as a function of polymer microstructure. PPy-based microstructured films displayed an increase in particle removal properties when compared to PPy-based non-microstructured films and commercial of-the-shelf (COTS) swabs. This increase in removal is due to an increase in particle-swab contact from the increased surface area of the microstructured films. Furthermore, these polymer films were easily functionalized with surface groups with increased adhesion to explosive compounds such as trinitrotoluene (TNT) to develop next generation materials for trace explosive detection.