title: Explosive and chemical threat detection by surface-enhanced Raman scattering: a review.
abstract: Acts of terror and warfare threats are challenging tasks for defense agencies around the world and of growing importance to security conscious policy makers and the general public. Explosives and chemical warfare agents are two of the major concerns in this context, as illustrated by the recent Boston Marathon bombing and nerve gas attacks on civilians in the Middle East. To prevent such tragic disasters, security personnel must be able to find, identify and deactivate the threats at multiple locations and levels. This involves major technical and practical challenges, such as detection of ultra-low quantities of hazardous compounds at remote locations for anti-terror purposes and monitoring of environmental sanitation of dumped or left behind toxic substances and explosives. Surface-enhanced Raman scattering (SERS) is one of todays most interesting and rapidly developing methods for label-free ultrasensitive vibrational "fingerprinting" of a variety of molecular compounds. Performance highlights include attomolar detection of TNT and DNT explosives, a sensitivity that few, if any, other technique can compete with. Moreover, instrumentation needed for SERS analysis are becoming progressively better, smaller and cheaper, and can today be acquired for a retail price close to 10,000 US$. This contribution aims to give a comprehensive overview of SERS as a technique for detection of explosives and chemical threats. We discuss the prospects of SERS becoming a major tool for convenient in-situ threat identification and we summarize existing SERS detection methods and substrates with particular focus on ultra-sensitive real-time detection. General concepts, detection capabilities and perspectives are discussed in order to guide potential users of the technique for homeland security and anti-warfare purposes.
authors.affiliation: Division of Bionanophotonics, Department of Applied Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden. Electronic address: Hakonen@chalmers.se.
authors.forename: Aron
authors.initials: A
authors.lastname: Hakonen
authors.affiliation: Swedish Defense Research Agency FOI, Division of CBRN Defence & Security, SE-90182 Umeå, Sweden.
authors.forename: Per Ola
authors.initials: PO
authors.lastname: Andersson
authors.affiliation: DTU Nanotech, Technical University of Denmark, Department of Micro- and Nanotechnology, Ørsteds Plads, Building 345 East, 2800 Kgs. Lyngby, Denmark.
authors.forename: Michael
authors.initials: M
authors.lastname: Stenbæk Schmidt
authors.affiliation: DTU Nanotech, Technical University of Denmark, Department of Micro- and Nanotechnology, Ørsteds Plads, Building 345 East, 2800 Kgs. Lyngby, Denmark.
authors.forename: Tomas
authors.initials: T
authors.lastname: Rindzevicius
authors.affiliation: Division of Bionanophotonics, Department of Applied Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Käll
mesh_terms: D002619:Chemical Warfare Agents / Q000032:analysis*; D053834:Explosive Agents / Q000032:analysis*; D006046:Gold / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D013059:Spectrum Analysis, Raman
chemical_list: D002619:Chemical Warfare Agents; D053834:Explosive Agents; D011108:Polymers; D012834:Silver; D006046:Gold
keywords: Chemical warfare agents; Explosives; Nerve gas; Portable Raman spectroscopy; Surface-enhanced Raman scattering; Trinitrotoluene