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

Abstract

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 Å to 15.535 Å after reaction with phosgene, accompanied with obvious fluorescence enhancement, which is attributed to the inhibition of Förster 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.