Crosslinked fluorescent conjugated polymer nanoparticles for high performance explosive sensing in aqueous media

In this work, water dispersible crosslinked fluorescent poly(triphenylamine-co-benzothiadiazole)s (PTPABT) nanoparticles have been synthesized via Suzuki-type coupling (A3 + B2) in a toluene/water miniemulsion. Dialysis method was used to purify the PTPABT nanoparticles with a diameter range of 40-70 nm. The good dispersion property of the polymer in water could be attributed to the small sizes of the PTPABT nanoparticles. The obtained PTPABT nanoparticles possess microporous characteristic and display bright red emission in aqueous solution, which makes them possible to detect the nitro-aromatic explosive in aqueous media by monitoring the photoluminescence. The sensing property of the polymer nanoparticles towards 1,3,5-trinitrobenzene (TNB) in aqueous media has been researched, resulting a Stern-Volmer quenching constant Ksv of 1.22 × 104 M−1. The most attractive character of the conjugated polymer nanoparticles is the combination of both physical stability and solution-processability, thus making them good candidates for sensors and optoelectronic applications.