Epoxy-based oligomer bearing naphthalene units: fluorescent sensor for 4-nitrophenol

A simple epoxy-based oligomer 1 bearing naphthalene units at the chain-ends is shown to be ON-OFF type fluorescent sensor for 4-nitrophenol with high sensitivity and selectivity. The recognition mechanism can be attributed to the possibilities of fluorescence resonance energy transfer (FRET) and also photo induced electron transfer (PET) between naphthalene moiety and 4-nitrophenol. In the sensing process, diverse nitroaromatics such as 3-nitrophenol, 2-nitrophenol 1,3-dinitrobenzene, 2-chloronitrobenzene, 2-nitropthalic acid and non-nitroaromatics such as 2-chlorobenzoic acid, 4-hydroxybenzoic acid did not interfere.48