"Turn-on" fluorescent detection of 2, 5-di (4'-carboxylphenyl)-1-phenylpyrrole to amines

2, 5-Di (4'-carboxylphenyl)-1-phenylpyrrole was firstly successfully synthesized. UV-Vis and fluorescence spectra were employed to study the optical properties of TPP-2COONa at different pH values in aqueous media. The compound is found to weaken fluorescence in acidic state and, however, strengthen fluorescence in base state. The experimental results indicated that the fluorescent emission of TPP-2COOH can be "turned-on" by ammonia and some water-soluble alkyl amines (triethylamine, isopropylamine, diisopropylamine). But it remains unchanged upon addition of N-containing aromatic compounds (aniline, pyrrole, and pyridine). Specially, the compound as the fluorescent probe shows the good selectivity and sensitivity toward ammonia. Thus, the "on-line naked eye" detection for amines becomes possible.