Nitroolefin-based coumarin as a colorimetric and fluorescent dual probe for biothiols.

A coumarin-based thiol probe featuring the 1,4-addition reaction of thiols to nitroolefin was reported. The molecular probe exhibited higher selectivity toward biothiols (Cys, Hcy and GSH) than other amino acids.

A ratiometric fluorescent probe for cyanide based on FRET.

On the basis of FRET from 4-(N,N-dimethylamino)benzamide to fluorescein, a new ratiometric fluorescence probe bearing a hydrazone binding unit was developed for highly selective and sensitive detection of CN(-) in aqueous solution.

An 2-(2'-aminophenyl)benzoxazole-based OFF-ON fluorescent chemosensor for Zn2+ in aqueous solution.

A water-soluble fluorescent sensor, 1, based on the "receptor-spacer-fluorophore" [2-(2'-aminophenyl)benzoxazole-amide-2-picolylamine] sensor platform, demonstrates the high sensitivity for Zn(2+) with a 25-fold fluorescence enhancement upon chelation to Zn(2+) and also exhibits high selectivity to Zn(2+) over other metal ions. X-ray crystal structure of Zn(2+) complex reveals that the amide oxygen (O2) cooperates with 2-picolylamine unit (N3, N4) as a receptor bind Zn(2+).

Highly sensitive and selective turn-on fluorescent and chromogenic probe for Cu2+ and ClO- based on a N-picolinyl rhodamine B-hydrazide derivative.

A new rhodamine B-based dual-function chromo- and fluorogenic probe for Cu(2+) and ClO(-) has been designed, synthesized, and characterized. The probe comprises a spectroscopic unit of rhodamine B and a Cu(2+)-specific chelating unit of pyridinecarboxamide as well as a ClO(-)-specific reactive moiety of diacylhydrazine, and is a highly selective and extremely sensitive fluorescent and colorimetric sensor for Cu(2+) and ClO(-) in different pH conditions. Compared with the reported probes for Cu(2+) or ClO(-), this is the first chemosensor based on a small molecule that can detect both Cu(2+) and ClO(-), respectively, at 1 nM level.

Rhodamine-based chemosensor for Hg(2+) in aqueous solution with a broad pH range and its application in live cell imaging.

A new fluorescent probe, rhodamine B derivative (1) bearing an 8-hydroxyquinoline group, was synthesized and displayed highly selective and sensitive Hg(2+)-amplified absorbance and fluorescence emission above 500 nm in aqueous solution with a broad pH range 4-9. It was found that mercury ions coordinate reversibly to 1 and the spirolactam ring of 1 was opened, forming a 1 : 1 metal-ligand complex. Furthermore, this sensor was applied for in vivo imaging in HeLa cells to confirm that 1 can be used as a fluorescent probe for monitoring Hg(2+) in living cells.

A novel fluorescent and chromogenic probe for cyanide detection in water based on the nucleophilic addition of cyanide to imine group.

A fluorescent and colorimetric probe bearing salicylaldehyde hydrazone functionality has been prepared for cyanide sensing. The detection of cyanide was performed via the nucleophilic attack of cyanide anion on the imine group of the probe with a 1:1 binding stoichiometry, which could be confirmed by (1)H NMR and MS studies. The specific reaction results in a prominent fluorescence enhancement and a color change from colorless to yellow.