A low dose, highly selective and sensitive colorimetric and fluorescent probe for biothiols and its application in bioimaging.

A new colorimetric and fluorescent probe was reported, which can be used in a very low dosage (<20 nM) for rapid, highly selective and sensitive detection of biothiols.

Rapid and ratiometric fluorescent detection of cysteine with high selectivity and sensitivity by a simple and readily available probe.

We report a simple and readily available fluorescent probe for rapid, specific, and ratiometric fluorescent detection of the biologically important cysteine (Cys). This probe uses a visible-light excitable excited-state intramolecular proton transfer (ESIPT) dye (4'-dimethylamino-3-hydroxyflavone) as the fluorophore and an acrylate group as the ESIPT blocking agent as well as the recognition unit. Cleavage of the acrylate moiety can be achieved specifically and rapidly by Cys in aqueous solution under mild conditions, which leads to restore the ESIPT process and enables the probe to show a rapid, ratiometric fluorescent detection process for Cys with high selectivity over various analytes, including homocysteine (Hcy) and glutathione (GSH). The detection limit of this probe for Cys was found to be ∼0.2 µM and bioimaging of intracellular Cys by this probe was successfully applied in living cells, indicating that this probe holds great potential for biological applications.

Near-infrared fluorescent probe for detection of thiophenols in water samples and living cells.

The development of probes for rapid, selective, and sensitive detection of the highly toxic thiophenols is of great importance in both environmental and biological science. Despite the appealing advantages of near-infrared (NIR) fluorescent detection, no NIR fluorescent probes have been reported for thiophenols to date. Using the chemical properties of thiophenols that are able to cleave sulfonamide selectively and efficiently under mild conditions, we herein report a dicyanomethylene-benzopyran (DCMB)-based NIR fluorescent probe for thiophenols. This probe features remarkable large Stokes shift and shows a rapid, highly selective, and sensitive detection process for thiophenols with significant NIR fluorescent turn-on responses. The potential applications of this new NIR fluorescent probe were demonstrated by the quantitative detection of thiophenol in real water samples and by fluorescent imaging of thiophenol in living cells.

Aldehyde group assisted thiolysis of dinitrophenyl ether: a new promising approach for efficient hydrogen sulfide probes.

We report herein a new approach, which combines fast nucleophilic addition of H2S to an aldehyde group and the subsequent intramolecular thiolysis of dinitrophenyl ether, and can be used to develop efficient and effective H2S probes.