a method for detecting trace explosives which includes obtaining a sample believed to contain explosives residue and contacting the sample and a carrier container containing the sample with a reagent . the sample and the carrier is illuminated by an appropriate laser or other light source while it is contained within a light tight box . the sample and the carrier is observed during the elimination to determine photoluminescence of the sample as an indication that it contains trace explosives . the reagent may be an alkaline containing substance , a lanthanide complex , a lanthanide complex containing sensitizing ligands or nanocrystals .