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A fluorophilic fluorescent probe based on a perfluoroalkyl‐substituted bis(binaphthyl) compound was designed and synthesized. It displayed a highly enantioselective fluorescence response toward structurally diverse amino acids in a biphasic fluorous/aqueous system with enantiomeric fluorescent enhancement ratio (ef; ΔID/ΔIL) values up to 45.2 (histidine). It can be used to determine the enantiomeric compositions of amino acids and also allows the amino acid enantiomers to be visually discriminated. NMR and mass‐spectroscopic investigations provided insights into the observed high enantioselectivity. This biphasic fluorescent recognition was used to determine the enantiomeric composition of the crude phenylalanine products generated by an enzyme‐catalyzed asymmetric hydrolysis under various reaction conditions. The fluorous‐phase‐based fluorescence measurement under the biphasic conditions was able to minimize the interference of other reaction components and thus has potential in asymmetric reaction screening. [ABSTRACT FROM AUTHOR]

The ability to monitor and quantify glutathione (GSH) in live cells is essential in order to gain a detailed understanding of GSH-related pathological events. However, owing to their irreversible response mechanisms, most existing fluorescent GSH probes are not suitable for this purpose. We have developed a ratiometric fluorescent probe (QG- 1) for quantitatively monitoring cellular GSH. The probe responds specifically and reversibility to GSH with an ideal dissociation constant ( Kd) of 2.59 m m and a fast response time ( t1/2=5.82 s). We also demonstrate that QG- 1 detection of GSH is feasible in a model protein system. QG- 1 was found to have extremely low cytotoxicity and was applied to determine the GSH concentration in live HeLa cells (5.40±0.87 m m). [ABSTRACT FROM AUTHOR]

The ability to analyze highly toxic chemical warfare agents (CWAs) and related chemicals in a rapid and precise manner is essential in order to alleviate serious threats to humankind and public security caused by unexpected terrorist attacks and industrial accidents. In this investigation, we designed a o-phenylenediamine-pyronin linked dye that is capable of both fluorogenic and colorimetric discrimination between phosgene and the prototypical nerve-agent mimic, diethyl chlorophosphate (DCP) in the solution or gas phase. Moreover, this dye has been used to construct a portable kit that can be employed for real-time monitoring of DCP and phosgene in the field, both in a discriminatory manner, and in a simple and safe way. [ABSTRACT FROM AUTHOR]

A new strategy for fast fluorescent detection of cysteine (Cys), based on a response-assisted electrostatic attraction, is demonstrated. By utilizing this strategy, we designed and synthesized three fluorescent probes for the specific detection of Cys under actual physiological conditions. The probe m- CP, a coumarin fluorophore conjugated with a substituted methyl pyridinium group through an unsaturated ketone unit, showed highly selective and sensitive detection for cysteine (Cys) over homocysteine (Hcy) and glutathione (GSH). The kinetic analysis indicated that the sensing process was highly accelerated (a response time less than 1 min) by the response-assisted electrostatic attraction. More importantly, control experiments with isomeric probes first demonstrated that the spatial charge configuration of the probe played an important role in Cys-preferred selectivity and kinetic rate acceleration. Furthermore, the practical utility of the probe m- CP in the fluorescent labeling of Cys residues within proteins was demonstrated. Finally, these probes were employed in living cell imaging with HeLa cells, in which it displayed satisfactory cell permeability and enabled us to distinguish active thiols in the cytoplasm, nucleus, and mitochondria. [ABSTRACT FROM AUTHOR]