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We report a series of difluoroboron β-diketonate fluorophores that manifest temperature-dependent emission wavelength accompanied by a change of fluorescence from green to orange. The distinct emission changes allow convenient and accurate measurements of temperature. [ABSTRACT FROM AUTHOR]

We report a series of organic fluorophores that undergo selective self-sensitized photooxidation upon light irradiation in air accompanied by a change of fluorescence from yellow to blue on the seconds timescale. The distinct emission changes allow the ratiometric quantitation of O2 concentration. [ABSTRACT FROM AUTHOR]

Abstract: The first example of the synthesis of mono‐N,O‐B‐chelated dipyrromethene (BODIPY) derivatives through an unexpected intramolecular nucleophilic displacement of the fluorine by alkenols in the presence of boron trifluoride as Lewis acid is reported. The chlorine in the indacene core allowed for further structural modifications through nucleophilic substitutions or palladium‐catalysed coupling reactions to afford new fluorophores with tuneable photophysical properties. Their expanded conjugation structure resulted in distinct red‐shifted absorption and emission spectra in organic solutions. Furthermore, the twisted steric hindrance of the benzene substitution patterns suppressed aggregation‐induced quenching, leading to an enhanced NIR emission in the aggregate/solid state, which was rarely observed for BODIPY dyes. Nanoparticles of the fluorophores formed by the assembly with the polymeric surfactant F127 were successfully used for bioimaging of living cells and for tumour‐targeted imaging in a tumour‐bearing mouse model. [ABSTRACT FROM AUTHOR]

Difluoroboron β-diketonate complexes (BF 2 bdks) are highly luminescent organoboron complexes with several attributes such as strong fluorescence in both solution and solid state, large extinction coefficients, tunable fluorescent emission, and two-photon excited fluorescence. Some BF 2 bdks exhibit mechanochromic properties and room temperature phosphorescence (RTP) in solid state. Due to their rich photophysical properties, BF 2 bdks have shown wide applications in various areas. This review focuses on the basic chemistry and spectroscopic properties of BF 2 bdks in solution and solid state, as well as their self-assemblies and applications in biosensing, bioimaging and optoelectronic devices. A brief summary and outlook on BF 2 bdks chemistry are also included. [ABSTRACT FROM AUTHOR]

A carbazole-containing difluoroboron β-diketonate complex ( BCZ), which shows strong fluorescence in both the solid state and in organic solutions, is reported. The crystalline materials of BCZ obtained from different solvents display different emission colors. Single-crystal analysis reveals that the enhanced overlap between adjacent molecules induces increased excited-state delocalization and is responsible for the variation of the emission colors from yellow to red. The emission colors of the materials are effectively tuned by external stimuli such as grinding, heating, and solvent vapor. The powder X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, and 1H NMR studies on materials of BCZ reveal that the thermochromic properties of BCZ are closely related to the removal of solvent molecules from the crystalline powders upon heating. Moreover, uniform 1D microstructures of BCZ obtained by solvent exchange in solution exhibit optical waveguide property with low optical loss. [ABSTRACT FROM AUTHOR]

Glutathione (GSH) and cysteine (Cys) play different roles in biological systems, thus the discrimination between them is of great importance. Herein we report a multi-emissive fluorescent probe for the selective detection of GSH and Cys. The probe was composed of covalently linked BODIPY and coumarin fluorophores. The BODIPY fluorophore was designed to react with GSH and Cys and generate different products with distinct photophysical properties, and the coumarin fluorophore acted as an internal standard. The probe exhibited green emission in aqueous solution. Upon addition of Cys, it yielded nitrogen-substituted BODIPY with weak fluorescence and free coumarin with blue emission. In the presence of glutathione, it generated mono- and di-sulfur substituted BODIPY and coumarin, resulting in various emission colors at different concentrations of GSH. Interestingly, the solution exhibited white fluorescence at GSH concentration of 0.4 mM. The probe was capable of detecting and imaging GSH and Cys in living HeLa cells, indicating its significant potential in biological applications. [ABSTRACT FROM AUTHOR]

We report the first highly efficient artificial light-harvesting systems based on nanocrystals of difluoroboron chromophores to mimic the chlorosomes, one of the most efficient light-harvesting systems found in green photosynthetic bacteria. Uniform nanocrystals with controlled donor/acceptor ratios were prepared by simple coassembly of the donors and acceptors in water. The light-harvesting system funneled the excitation energy collected by a thousand donor chromophores to a single acceptor. The well-defined spatial organization of individual chromophores in the nanocrystals enabled an energy transfer efficiency of 95 %, even at a donor/acceptor ratio as high as 1000:1, and a significant fluorescence of the acceptor was observed up to donor/acceptor ratios of 200 000:1. [ABSTRACT FROM AUTHOR]

Summary The Maillard reaction (MR) under wet reaction conditions with several common saccharides, such as xylose, glucose, lactose, dextran and maltodextrin, were applied to improve the functional properties of wheat germ protein (WGP). The MR products (MRPs) prepared with dextran at pH 11.0 heated at 90 °C in 2% aqueous dispersions heating for 20 min showed better solubility and emulsifying properties. The fluorescence intensity analysis proved the MR occurred, and thinner sheet MRPs were observed by scanning electron microscope (SEM). The relative contents of Cys, Lys and Arg were decreased, which could reduce the chance of protein aggregation through -S-S bonds. Circular dichroism (CD) spectrum expressed the difference in the secondary structures between WGP and MRPs, which may make MRPs show better functional properties than WGP. These results suggested that MR with dextran under wet reaction conditions can be a promising way to improve functional properties of WGP. [ABSTRACT FROM AUTHOR]

Zinc plays important roles in regulating physiological and pathological processes. Regrettably, mild to moderate zinc deficiency is common worldwide. Hair Zn 2+ concentration, which reflects a zinc storage status, is useful for tracking trends in zinc status within populations. In this work, we report BODIPY-based self-assembled nanoparticles (NPs) as fluorescence turn-on sensor for the selective sensing of Zn 2+ in human hair. The BODIPY monomers ( BAN ) self-assemble in aqueous medium to form nonfluorescent NPs. In the presence of Zn 2+ ions, the NPs selectively show an obvious turn-on fluorescence change. This selective response of the NPs allows the determination and quantification of Zn 2+ in human hair with a detection limit of 61.3 nM. This study demonstrates that the small molecule self-assembled nanoparticle is a versatile and useful tool, and shows great potential for applications in sensing of important analytes in biological systems. [ABSTRACT FROM AUTHOR]