Visual Detection of Trace Nitroaromatic Explosive Residue Using Photoluminescent Metallole‐Containing Polymers

Abstract

The detection of trace explosives is important for forensic, military, and homeland security applications. Detection of widely used nitroaromatic explosives (trinitrotoluene [TNT], 2,4-dinitrotoluene [DNT], picric acid [PA]) was carried out using photoluminescent metallole-containing polymers. The method of detection is through the quenching of fluorescence of thin films of the polymer, prepared by spray coating organic solutions of the polymer, by the explosive analyte. Visual quenching of luminescence (lambda(em) approximately 400-510 nm) in the presence of the explosive is seen immediately upon illumination with near-UV light (lambda(ex)=360 nm). Detection limits were observed to be as low as 5 ng for TNT, 20 ng for DNT, and 5 ng for PA. In addition, experiments with normal production line explosives and their components show that this technology is also able to detect composition B, Pyrodex, and nitromethane. This method offers a convenient and sensitive method of detection of trace nitroaromatic explosive residue.

Investigation of common fluorophores for the detection of nitrated explosives by fluorescence quenching

“…As mentioned above, one of the most promising approaches for explosives detection is fluorescence quenching [16,[31][32][33][34][35][36][37][38][39][40]. The term "fluorescence quenching" describes any event in which the observed fluorescence signal is decreased [44].…”

“…In industrial quality control, manufacturers of explosive materials must assure consumers that their products are safe, effective, and free from contamination by monitoring the composition throughout the manufacturing process. Because the requirements in each of these fields are [8][9][10]24,29], indirect laser-induced fluorescence [4,19,20,30], and fluorescence quenching [16,[31][32][33][34][35][36][37][38][39][40]. Unfortunately, many of these methods are difficult to adapt for field use owing to the size of laboratory-scale instrumentation and the need for other accessories that limit portability.…”

Hybrid Cadmium Tellurium Quantum Dots for Rapid Visualization of Trace-Level Nitroaromatic Explosives

“…Due to the high signal output and detection simplicity, fluorescence-based chemosensors are highly desirable for the detection of nitroaromatics. To date, various kinds of fluorescent materials have been studied for nitroaromatics such as conjugated polymers (Yang and Swager 1998;Zahn and Swager 2002;Rose et al 2005;Toal and Trogler 2006), molecularly imprinted polymers (Stringer, Gangopadhyay, and Grant 2010), ploymetalloles (Toal et al 2007), silica microspheres , 8-hydroxyquinoline aluminum nanospheres (Ma, Peng, and Wang 2012), polysiloles (Sohn et al 2001), trimethylsilylethynyl (Shanmugaraju, Joshi, and Mukherjee 2011), zinc(salicylaldimine) (Germain and Knapp 2008), and quantum dots (QDs) (Stringer et al 2010;Goldman et al 2005;Wilson et al 2007;Shi et al 2008;Freeman and Willner 2009;Chen et al 2010;Algarra et al 2011;Wang and Zou 2011;Xia, Song, and Zhu 2011;K. Zhang et al 2011;Zou, Sheng, et al 2011;Say et al 2012;Jin et al 2013;Pazhanivel et al 2013).…”

Functional hybrid materials for the optical recognition of nitroaromatic explosives involving supramolecular interactions

“…51 In relation to this, the different polymers showed intense emission bands (510 nm for 27, 500 nm for 50, 495 nm for 40 and 475 nm for 52 (M = Ge or Si) and 360 nm for 51 and 41)…”

“…Mesoporous silicas of different pore sizes and morphologies have been selected and used as inorganic scaffolds in gated ensembles. 51 In relation to the gate, several molecular and supramolecular systems have been developed which are able to trigger at will the delivery of the entrapped cargo using several external stimuli such as light, 52 49 56 The design of gated mesoporous materials proves to be a promising starting point for applying the versatility of supramolecular ideas to the design of nanoscopic gating solids, and a way of studying the factors that can influence the design of molecular gating functions based on molecular/biomolecular/supramolecular concepts. 57 Several examples of these solids have been designed in last years.…”