Extended π-conjugated pyrene-based chemosensors for highly sensitive and selective detection of nitro-contaminants

Nitro-containing compounds ( NCCs ) are a class of chemicals with high risk and toxicity, and the trace detection of NCCs has become an urgent technology in terms of both the security and environment. Herein, two K-region tetra-substituted pyrene-based luminogens were designed and synthesized, which present efficient deep blue emitting properties. More interestingly, both luminogens with π-electron rich and deep blue emission properties exhibited fast sensing of NCCs . A selective and sensitive response towards o -nitroaniline was obtained with a low limit of detection (LOD) of about 9.55 × 10 −9 M in the 2,7-di- tert -butyl-4,5,9,10-tertrakis(phenylethynyl)pyrene ( TPPy ) system, while a more efficient quenching behavior was observed at ppt level (142 ppt), and the LOD for p -nitroaniline as low as 1.03 × 10 −9 M. The quenching mechanisms are attributed to the Förster resonance energy transfer (FRET) and photo-induced electron transfer (PET), respectively. These results provided a convenient and efficient strategy for trace NCCs sensing.