A ratiometric fluorescent chemosensor for selective and visual detection of phosgene in solutions and in the gas phase.

A ratiometric fluorescent chemosensor, Phos-1, was constructed with 4,5-diaminonaphthalimide as a fluorophore for selective and visual detection of phosgene. The sensing mechanism was demonstrated to be the phosgene molecule acylating both amine groups of Phos-1. A test paper with Phos-1 was fabricated for facile, selective and visual detection of phosgene gas.