Fiber-optic detection of nitroaromatic explosives with solution-processable triazatruxene-based hyperbranched conjugated polymer nanoparticles

Abstract

Two solution-dispersible hyperbranched conjugated polymer nanoparticles based on triazatruxene, TATF8HBP and TATSFHBP, have been prepared through Suzuki polymerization in a miniemulsion. They can be stably dispersed in common organic solvents. Blue emission of their spin-coated films could be efficiently quenched by DNT and TNT vapors. The steric hindrance of the spirobifluorene unit inside TATSFHBP endowed it with higher fluorescence quantum yield in solid film and better sensitivity toward nitroaromatic explosive vapors. Rapid, sensitive and reversible explosive fiber-optic detection with TATSFHBP has been demonstrated with fluorescence quenching efficiency up to 99% in just 15 s and 93% in 90 s after exposure to DNT and TNT vapors, respectively. TATSFHBP-coated indicating papers can visually detect trace TNT particulates with a low detection limit of 0.23 ng mm⁻².