Prevention of IED threats: a non-destructive and multiparametric detection of pre-blast explosive residues in fabrics...

Improvised explosive devices (IEDs) are widespread among criminal and terrorist cells since such organizations are more and more capable of creating evermore powerful and easily concealable explosive devices. This makes their detection not only challenging but also crucial to prevent bomb attacks. In particular, textiles are often a source of evidence of contamination as a consequence of manipulating explosives. This work proposes a novel, rapid and accurate confocal Raman microscopy method for the detection and identification of pre-blast explosive residues related to the handling, packaging, and carriage of explosive devices. Raman spectra were collected from explosive residues of TNT, TATP, PETN, Pyrodex, RDX, and ANFO trapped in different types of fibers (natural/synthetic, dyed/undyed) in order to evaluate the spectroscopic response in conditions that are as realistic as possible and to quantify the interfering effect of the substrate. The results demonstrated that all the investigated explosives were correctly identified with 100% accuracy, showing no sample thermodegradation or interfering contributions related to the textile substrate. This innovative approach permits the simultaneous detection of the most common explosives involved in IEDs by a fast, accurate and non-destructive platform able to be used as confirmatory analysis and to provide timely support for forensic investigation for homeland security.