Tunable, self-curing polymers for the forensic collection of latent signatures from within porous materials

Self-curing polysiloxane polymers have been developed for the forensic collection of latent signatures of explosives, organophosphates, and their degradation products. These polymeric materials penetrate the sample substrate as viscous liquids and subsequently harden to a semi-soft solid that can be peeled away from the substrate to extract signatures via the non-covalent interaction of the newly formed polymeric material with the analytes buried within the substrate. This paper discusses experiments aimed at altering the chemical and physical properties of the polysiloxane sampling materials to optimize signature recovery from porous substrates. The utility of this approach is demonstrated by the collection of explosives, organophosphates, and their degradation products from within concrete. The recovery of these signatures using the self curing polymeric formulations is compared to current operational sampling alternatives such as adhesive fingerprint lifters and swabs. Demonstration of the preparation, extraction, and analytical methods for the detection of the target compounds is also be presented.