Novel molecular laser-induced photoluminscence signature with hyperspectral imaging for instant and remote detection of trace explosive materials

Abstract

Instant detection of explosive material is highly appreciated for counterterrorism activity and homeland security. Nitro group (high energy rich bond) is responsible for explosive characteristics. Nitro group includes intense competition between two highly electronegative atoms. Nitro group is frequently encountered in all explosive materials. This function group includes delocalized π bond; that could secure intense photoluminescence (fluorescence and phosphorescence) signature. In this study, the main classes of explosive materials including nitro-compounds (i.e. TNT), nitramines (i.e. RDX), and nitric esters (i.e. PETN) were stimulated with green laser source of 532 nm and 5 mW power. The photoluminescence signature of each tested material was captured via hyperspectral camera. The tested explosives demonstrated characteristic fluorescence signature at 571, 587, and 613 nm for RDX, PETN, and TNT respectively. Furthermore, TNT demonstrated characteristic phosphorescence signature at 975 nm. The customized laser induced photoluminescence technique offered facile detection of trace explosive material via clustering approach based on K-m clustering (k = 8); this technique was able to detect RDX, PETN and TNT traces on the finger nail via processed hyperspectral images at 581 nm, 797 nm and 953 nm, respectively. This study shaded the light on novel customized photoluminescence technique for facile detection and identification of trace explosive materials.