Turn-on Fluorescent Chemosensor Research Articles

Fluorescence turn-on chemosensor for Hg2+ based on a rhodamine derivative and its application in bioimaging

A fluorescence turn-on chemosensor based on rhodamine B derivative (FD10) has been developed as a highly sensitive chemosensor for Hg2+. A prominent fluorescence enhancement was measured in the presence of Hg2+, which was in agreement with the changes in the absorption spectrum. Furthermore, by means of laser scanning fluorescence microscopy experiments, it was demonstrated that FD10 was cell-permeable and could be used as a fluorescent probe for monitoring Hg2+ in living cells.

A highly selective and sensitive fluorescent turn-on sensor for Hg2+ and its application in live cell imaging

A boron-dipyrromethene (BODIPY) derivative containing a tridentate diaza-oxa ligand (8H-BDP) was synthesized as a fluorescent turn-on chemosensor for Hg(2+) with high sensitivity (detection limit < or = 2 ppb), a rapid response time (< or = 5 seconds) and specific selectivity over other cations under physiological conditions and in live cells according to the confocal fluorescence microscopy experiment.

A turn-on fluorescent anion receptor based on N, N′ -di-β-naphthyl-1,10-phenanthroline-2,9-diamide

A simple turn-on fluorescent anion chemosensor with amide moiety as binding sites was designed, synthesized and characterized. Binding ability of the receptor 1 with anions was evaluated through the fluorescence titration in DMSO and the 1H NMR titration in DMSO-d 6 and coordination of anions to 1 led to a visible enhancement in fluorescence intensity. The fluorescence enhancement could be explained on the basis of two signaling transduction mechanisms: (1) inhibition of a photoinduced electronic transfer (PET) mechanism and (2) anion-induced increase of the rigidity of the host molecules. In addition, the results of 1H NMR titrations suggested that a host–guest hydrogen-bonding complex with an association constant K ass=7379 mol −1 L was formed between 1 and F − and the mode of host–guest interactions was provided.