Pyrene excimer-based fluorescent sensor for detection and removal of Fe and Pb from aqueous solutions.

Pyrene excimer usually serves as a chromogenic unit for developing ratiometric fluorescent sensors. But this study used excimer as a large hydrophobic group to regulate the molecular hydrophobicity, and obtained a new fluorescent sensor, N, N-bi[4(1-pyrene)-butyroyl]ornithine (1), for detection and removal of Fe and Pb from aqueous solutions. The coordination of 1 and Fe in the aqueous solution or even pure water forms removable flocculent precipitates, accompanied by obvious fluorescent quenching of emission spectra.

2-(1-Pyrenyl) benzimidazole as a ratiometric and "turn-on" fluorescent probe for iron(III) ions in aqueous solution.

A highly selective and sensitive ratiometric and "turn-on" fluorescent probe for Fe(3+), 2-(1-pyrenyl) benzimidazole (L), was synthesized by a one-step process. In emission spectra, the relative intensity ratio of excimer to monomer fluorescence (IE450/IM387) of L increased 510-fold upon the addition of 30 equiv. of Fe(3+) with a detection limit of 0.

Selective and sensitive fluorescence-shift probes based on two dansyl groups for mercury(ii) ion detection.

Two probes ( and ) bearing two dansyl fluorophores were synthesized and applied to the detection of mercury(ii) ions in aqueous solution. These probes exhibited a selective response to Hg(2+) in a buffered solution, with high sensitivity and a unique fluorescence response signal which displayed a blue-shift effect in the fluorescence emission peak. The Hg(2+) recognition mechanisms of the probes were determined by NMR spectroscopy, ESI-MS and UV-vis spectroscopy.