Construction of ultrasensitive devices for visualization and quantification of phosgene based on FRET-mediated two-photon chemosensor

摘要

As a widely used but highly toxic chemical species, phosgene is threatening to human health because of possible accidental leakage during industrial manufacture. Herein, we exploited a turn-on fluorescent sensor F671 for phosgene detection. The exact distance of nitro benzoxadiazole (NBD) and boron dipyrromethene (BODIPY) in F671 was changed from 5.027 angstrom to 15.535 angstrom after reaction with phosgene, accompanied with obvious fluorescence enhancement, which is attributed to the inhibition of Forster resonance energy transfer (FRET) process. The FRET-associated strategy possesses the capacity of detecting phosgene with a rapid response time (<6 s), ultra-sensitivity (LOD = 0.36 nM in solution and 0.14 ppm in gas phase) and remarkable selectivity to phosgene in solutions and in gas phase. Furthermore, the F671-embedded degreasing cotton, has been fabricated to serves as a specific gaseous phosgene device, for facile, selective and visual detection of phosgene gas. Confocal imaging of F671-embedded degreasing cotton displayed increasing emission intensity in the presence of phosgene in both of one-photon and two-photon patterns. It is envisioned that the developed convenient device is a promising tool for phosgene gas detection and quantification in real industrial and environmental applications.