Detection of TNT Vapors by Fluorescence Quenching and Self-Recovery Using Highly Fluorescent Conjugated Silole Polymers

This study presents the synthesis, characterization, and evaluation of two new conjugated polymers for the detection of chemical explosives. The polymers, denoted as P1 and P2, exhibited significant responses to fluorescence quenching and photoluminescence (PL) recovery processes in the presence of TNT vapors. The unique photophysical properties of the polymers were attributed to their aggregation-induced emission (AIE) and intramolecular charge transfer (ICT) effects. The investigation of solvent behavior and ICT properties using density functional theory (DFT) calculations provided insights into the conjugated π-systems of the polymers. The fluorescence and sensing properties of P1 and P2 were studied in various states, including pure THF solution, films, and aggregated states. The quenching effects varied between the solution and solid states, highlighting the differences in sensitivity. However, both polymers exhibited high fluorescence efficiencies in all three states. Overall, these rigid polymers with strong fluorescence show promise as potential candidates for detecting explosives by improving the fluorescent properties of sensor films. The findings of this study contribute to the development of materials with enhanced detection capabilities for explosive compounds.