Detection of explosives and latent fingerprint residues utilizing laser pointer–based Raman spectroscopy


  Itamar Malka  ,  Alona Petrushansky  ,  Ilana Bar  ,  Salman Rosenwaks  
Ben-Gurion University

Despite the ongoing efforts in research, detection of hazardous materials as explosives and improvised explosive devices, still remains a great challenge. One method that can be considered to be used for detection is that of vibrational spectroscopy, in particular spontaneous Raman scattering. Raman spectroscopy provides spectral signatures with narrow features that enable to distinguish between different compounds.  Here we show that a modular, compact Raman spectrometer, based on a green laser pointer, an air cooled intensified charged coupled device and a x, y motorized translation was developed and applied for point and for short distances standoff detection.  Its performance was tested for measurements of Raman spectra of liquids, trace amounts of explosives and individual particles, as well as for locating individual particles of interest and for chemical imaging of residues of latent human fingerprints. This system was found to be highly sensitive, identifying masses as low as ~1 ng in short times. The real-time detection capabilities of the spectrometer, together with the portability that it offers, make it a potential candidate for replacing existing Raman microscopes and for field applications.