title: Detection and mapping of trace explosives on surfaces under ambient conditions using multiphoton electron extraction spectroscopy (MEES).
abstract: Multiphoton electron extraction spectroscopy (MEES) is an analytical method in which UV laser pulses are utilized for extracting electrons from solid surfaces in multiphoton processes under ambient conditions. Counting the emitted electrons as a function of laser wavelength results in detailed spectral features, which can be used for material identification. The method has been applied to detection of trace explosives on a variety of surfaces. Detection was possible on dusty swabs spiked with explosives and also in the standard dry-transfer contamination procedure. Plastic explosives could also be detected. The analytical limits of detection (LODs) are in the sub pmole range, which indicates that MEES is one of the most sensitive detection methods for solid surface under ambient conditions. Scanning the surface with the laser allows for its imaging, such that explosives (as well as other materials) can be located. The imaging mode is also useful in forensic applications, such as detection of explosives in human fingerprints.
authors.affiliation: Research Center for Analytical Sciences, Northeastern University, Shenyang 110819, China.
authors.forename: Shisong
authors.initials: S
authors.lastname: Tang
authors.affiliation: Schulich Faculty of Chemistry and the Center for Security Science and Technology (CSST), Technion - Israel Institute of Technology, Haifa 32000 Israel.
authors.forename: Nataly
authors.initials: N
authors.lastname: Vinerot
authors.affiliation: Schulich Faculty of Chemistry and the Center for Security Science and Technology (CSST), Technion - Israel Institute of Technology, Haifa 32000 Israel.
authors.forename: Danny
authors.initials: D
authors.lastname: Fisher
authors.affiliation: Schulich Faculty of Chemistry and the Center for Security Science and Technology (CSST), Technion - Israel Institute of Technology, Haifa 32000 Israel.
authors.forename: Valery
authors.initials: V
authors.lastname: Bulatov
authors.affiliation: Schulich Faculty of Chemistry and the Center for Security Science and Technology (CSST), Technion - Israel Institute of Technology, Haifa 32000 Israel.
authors.forename: Yehuda
authors.initials: Y
authors.lastname: Yavetz-Chen
authors.affiliation: Schulich Faculty of Chemistry and the Center for Security Science and Technology (CSST), Technion - Israel Institute of Technology, Haifa 32000 Israel. Electronic address: israel@tx.technion.ac.il.
authors.forename: Israel
authors.initials: I
authors.lastname: Schechter
mesh_terms: D004583:Electrons; D053834:Explosive Agents / Q000032:analysis* / Q000737:chemistry; D044707:Forensic Sciences; D057230:Limit of Detection; D017672:Nitrogen Compounds / Q000737:chemistry; D017785:Photons; D010969:Plastics / Q000737:chemistry; D013057:Spectrum Analysis / Q000379:methods*; D013499:Surface Properties
chemical_list: D053834:Explosive Agents; D017672:Nitrogen Compounds; D010969:Plastics
keywords: Explosives; Laser; Mapping; Solids