Abstract: The invention is directed to a system and method for detecting substances, such as explosives and/or drugs, using, in part, short bursts of energy light from a relatively low energy strobe. Embodiments include coupling the strobe with a detector for use in a portable hand-held unit, or a unit capable of being carried as a backpack. Embodiments further include placement of one or more stroboscopic desorption units and detectors in luggage conveyors systems, carry-on X-ray machines, and check-in counter locations. Embodiments further comprise the use of a strobe or another energy source to assist in maintaining the integrity of a SERS substrate surface operatively associated with the detector system, wherein the SERS substrate may be positioned in hand wand spaced apart from at least a portion of the detector. In another embodiment, the Raman excitation source may be located directly in the hand wand of a portable stroboscopic detection system.