Polyurethane derivatives for highly sensitive and selective fluorescence detection of 2,4,6-trinitrophenol (TNP)

A series of luminescent non-conjugated polyurethane derivatives (PUs) has been obtained in a facile way in high yields. The polymers show highly selective and sensitive detection of 2,4,6-trinitrophenol (TNP) (picric acid). The selectivity for TNP is accomplished via combination of a strong inner filter effect (IFE), Forster resonance energy transfer (FRET) and photoinduced electron transfer (PET). A convenient indicator paper for the visual detection of TNP has been constructed by immobilization of the polymer PU1 on filter paper. The PU1-coated filter paper presents a rapid detection of TNP in water with a low concentration limit of 10−10 M, ∼0.229 ag cm−2. This is a simple, low-cost and highly efficient method for the detection of TNP.