Search

Visible light-mediated photocatalysis leads to the efficient hydrogel coating of individual mammalian cells, functionalized with biocompatible anchor molecules tagged with fluorescein serving as a trifecta: photocatalyst, initiator, and fluorophore. NIH3T3 fibroblast cells are encapsulated within hydrogel shells of poly(ethylene glycol) diacrylate (PEGDA) and N-vinylpyrrolidone without any noticeable decrease in cell viability. [ABSTRACT FROM AUTHOR]

This study explored FL-H2S, a novel fluorescein-based H2S donor, as an anti-inflammatory agent. The results demonstrated the efficient release of H2S by FL-H2S, along with its biocompatibility, real-time intracellular H2S release and imaging capability. In vivo experiments using a rat model confirmed the anti-inflammatory effects of FL-H2S, evidenced by reduced foot swelling. We also successfully elucidated the anti-inflammatory mechanism through ELISA and WB analysis. [ABSTRACT FROM AUTHOR]

Molecular de-aggregation was observed at the air/water interface of aqueous microdroplets. We probed this phenomenon using dyes such as Rhodamine 6G (R6G), Rhodamine B, acridine orange, and fluorescein, which show aggregation-induced shift in fluorescence. The fluorescence micrographs of microdroplets derived from the aqueous solutions of these dyes show that they are monomeric at the air/water interface, but highly aggregated at the core. We propose that rapid evaporation of the solvent influences the de-aggregation of molecules at the air–water interface of the microdroplets. [ABSTRACT FROM AUTHOR]

Hydrogen production through an artificial photocatalytic process in the solar light region using a water-stable Co-Tz (Tz = 1,2,4-triazolate) framework was demonstrated. Possessing such a high photostability and highly reactive sites at the tetrahedral cobalt centers, Co-Tz exhibits a great photocatalytic performance converting water into hydrogen of 9.32 mmol g−1 at 4 h in the presence of fluorescein (FI) and triethylamine (TEA) as a photosensitizer and sacrificial agent, respectively. In addition, the framework is reusable without losing its catalytical integrity. [ABSTRACT FROM AUTHOR]

Fluorene-based analogues of fluorescein, rhodol, and rhodamine exhibit absorption and fluorescence beyond 800–900 nm in water, 300–400 nm red-shifted compared to the original oxygen-bridged xanthene dyes, giving potential access to low molecular weight fluorescent markers for the second biological window (NIR-II, ca. 1000–1350 nm). [ABSTRACT FROM AUTHOR]

We report here a near-infrared (NIR) emitting lanthanide-based metal–organic framework (MOF) in which Yb3+ are sensitized by fluorescein (FL) as a low energy absorbing chromophore (FL@CD-MOF-161). The unique design of CD-MOF-161 allows for the entrapment of FL molecules in its pores during the synthesis and crystal growth, ensuring the efficient loading and spreading of chromophores within the crystal volume. [ABSTRACT FROM AUTHOR]

The introduction of phosphine oxide into a fluorescein scaffold has yielded phospha-fluorescein with bathochromically shifted spectra, reliable photostability and solubility. Moreover, ratiometric and turn-on fluorescence in the decaging process has ensured that the phospha-fluorescein is a unique scaffold for fluorescence bioimaging. Probe DiMe-PF-Gal without further structural decoration was designed for accurately monitoring β-galactosidase in vivo. [ABSTRACT FROM AUTHOR]

A series of phosphinate-containing rhodol and fluorescein dyes are disclosed. These new fluorophores increase the color palette of phosphinate-based xanthenes in the far-red spectral region. The new chemical functionality of these scaffolds is leveraged to produce a sensitive, no-wash imaging probe for cellular esterase activity. The reported phosphinate-containing dyes provide platforms for the further development of imaging probes and self-reporting delivery vehicles. [ABSTRACT FROM AUTHOR]

A fluorescent probe decorated with an alkynyl ester unit (e.g. propiolate) displayed a selective turn-on type fluorescent response towards cysteine. Following a sequential addition–cyclisation pathway mediated by the addition of cysteine, the pre-fluorescent dye rapidly transformed into a new structure and induced a fluorescent response clearly observable with the naked eye. [ABSTRACT FROM AUTHOR]

A new photon up-conversion system with a TADF fluorescein derivative as a photosensitizer was developed to achieve a quite large anti-Stokes shift from red to blue with a fairly high up-conversion emission quantum yield. This TADF photosensitizer has a very small ΔEST to provide a 207 nm anti-Stokes shift photon up-conversion. Meanwhile, it has a quite long triplet state lifetime (22.11 μs) and a large molar extinction coefficient to assure a high up-conversion efficiency of 11.2%. These results fully demonstrated the potential of the TADF fluorescein derivative as the photosensitizer used in photon up-conversion for the first time. [ABSTRACT FROM AUTHOR]

A reaction-based luminescence chemosensor was synthesized for sulfite detection based on a fluorescein derivative with thermally activated delayed fluorescence (TADF). The chemosensor exhibited a fluorescence turn-on effect on sulfite with good sensitivity and selectivity. Importantly, utilizing the long luminescence lifetime of the TADF compound, the chemosensor realized photoluminescence lifetime imaging for sulfite in living cells with the luminescence lifetime distribution mainly around 14 μs. [ABSTRACT FROM AUTHOR]

We report herein for the first time that the aggregation-induced emission and strong solid fluorescence of fluorescein derivatives can be realized by slightly modifying their structure, which provides a new option for AIEgens and solid fluorescent materials. [ABSTRACT FROM AUTHOR]

Water-dispersed silicon nanoparticles (SiNPs) are facilely prepared in an aqueous phase via microwave-assisted synthesis. The whole synthetic procedure is accomplished in a one-pot microwave reaction, without the requirement of additional surface modification. Remarkably, the resultant SiNPs feature ultrahigh fluorescence (photoluminescent quantum yield (PLQY): ∼90%), robust pH- and photo-stability, and favourable biocompatibility. [ABSTRACT FROM AUTHOR]

A series of Fe(iii) complexes was recently reported that are active for photocatalytic hydrogen generation when paired with fluorescein and triethylamine. Herein we report an Fe(iii) complex immobilized on TiO2 and SrTiO3 that is significantly more active than the homogeneous system, achieving up to 7800 turnovers in 31 hours. [ABSTRACT FROM AUTHOR]

The far-red emissive fluorescent probe CaPF-1 based on a phospha-fluorescein scaffold enables the detection of cytosolic calcium ions in living cells. The probe can be excited in the red region (λabs = 636 nm) and exhibits a sufficiently high fluorescence turn-on response in the far-red region (λem = 663 nm) upon complexation with calcium ions. The hydrophilic and anionic characteristics of this phospha-fluorescein fluorophore allowed the cytosolic localization of CaPF-1. Moreover, it was possible to visualize histamine-induced calcium oscillation in HeLa cells using CaPF-1. [ABSTRACT FROM AUTHOR]

Two fluorescein-based chemosensors have been developed. They exhibited rapid and selective detection of 2,4,6-trinitrophenol (TNP) via fluorescence quenching both in ethanol and water solution when excited by visible light. [ABSTRACT FROM AUTHOR]

Seminaphtho-phospha-fluorescein (SNAPF), a phosphine-oxide-containing unsymmetric fluorescein dye, was synthesized based on the consecutive arylation of PhPCl2, followed by Friedel–Crafts cyclization. The resulting SNAPF exhibited several attractive photophysical properties including an intense fluorescence in the NIR region and a large Stokes shift. [ABSTRACT FROM AUTHOR]

In this work, we designed a ratiometric core–shell nanoarchitecture composed of an indium UV plasmonic core, an internal reference (rhodamine B), a pH-sensitive probe (fluorescein), and a halide ion sensor (6-methoxyquinolinium). Immobilizing the fluorophores in distinct silica layers at precise distances from the core modulates the plasmon coupling and tunes the linear concentration range of halide ion detection. [ABSTRACT FROM AUTHOR]

Fluorescein was found to possess intrinsic peroxidase-like activity, which could catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by H2O2 to produce a color reaction. It opens the possibility of using such small molecules as peroxidase-like catalysts. [ABSTRACT FROM AUTHOR]

Phospha-fluorescein (POF), a phosphine oxide-containing analogue of fluorescein, was synthesized and its photophysical properties were examined. Compared with fluorescein and sila-fluorescein, POF displayed significantly red-shifted absorption and fluorescence as well as superior photobleaching resistance, while retaining the pH-responsive characteristics of fluorescein dyes. [ABSTRACT FROM AUTHOR]

A new series of palladium sensors based on fluorescein bis(allyl ether) compounds has been designed. We utilized reduced fluoresceins as key synthetic intermediates. These probes exhibit negligible background fluorescence and rapid reaction with palladium, allowing a concentration of ＜100 ppt to be detected in minutes using a handheld UV lamp. [ABSTRACT FROM AUTHOR]

We propose a visual volumetric sensor with 5,6-dicarboxylic fluorescein cross-linked amine-functionalized polyacrylamide hydrogel. The sensor undergoes volume response to Cu2+ ions at the μM level, which enables naked-eye quantitative detection by reading the graduation on a pipette. [ABSTRACT FROM AUTHOR]

A luminescent probe for determination of pH was designed based on a Förster resonance energy transfer (FRET) system, combining a europium chelate as the donor and carboxynaphtho-fluorescein as a pH sensitive acceptor. The FRET system enables referenced pH detection in an exceptional broad dynamic range from pH 3 to 9. [ABSTRACT FROM AUTHOR]

A simple but efficient sweat pore mapping method based on a fluorescein–PVP composite film was developed for fingerprint analysis. The composite film displays a fluorometric turn-on response upon contact with a small quantity of water secreted from human sweat pores, allowing precise mapping of sweat pores on a fingertip. [ABSTRACT FROM AUTHOR]

We report a simple, effective method to assess the cytosolic delivery efficiency and kinetics of cell-penetrating peptides using a pH-sensitive fluorescent probe, naphthofluorescein. [ABSTRACT FROM AUTHOR]

A recently proposed 2′,7′-dichlorofluorescein (DCF)-derived fluorescent probe for the detection of ozone shows good selectivity against a number of reactive oxygen species and good pH stability for biological and environmental applications. It is found, however, that over oxidation of the fluorescent product (Pittsburgh green) can occur. This could render quantitative measurements inaccurate due to a reduction in fluorescence and overlapping fluorescence signals from over oxidation by-products and it requires careful experimental design. Although difficult to assess by fluorescence measurements, the over oxidation can be conveniently monitored by 1H NMR spectroscopy. [ABSTRACT FROM AUTHOR]

Linking decyl-triphenyl-phosphonium to fluorescein yields a fluorescent probe that accumulates in energized mitochondria, facilitates proton transfer across membranes and stimulates mitochondrial respiration. This features a mitochondria-targeted uncoupler, being of potential interest for therapeutic use against oxidative stress-related diseases. [ABSTRACT FROM AUTHOR]

A novel technique for protein immobilization onto CrAsH-modified surfaces is presented. This approach enables an efficient, reversible and fluorogenic immobilization of proteins. Moreover, expressed proteins can also be directly immobilized from cellular lysates without prior purification. The immobilized proteins are suitable for protein-protein interaction studies and the fluorescence enhancement upon immobilization can be employed for the direct detection of the immobilized protein without the need for secondary detection methods. [ABSTRACT FROM AUTHOR]

A table of contents for the January 18, 2013 issue of the periodical "Chemical Communications" (ChemComm) is presented.

The fluorophores based on xanthene scaffolds, mainly containing rhodamine and fluorescein dyes, have attracted considerable interest from chemists due to their excellent photophysical properties such as high absorption coefficient, high fluorescence quantum yield, high photostability and relatively long wavelengths of fluorescence emission spectra. In this feature article, we overview the strategies in the development of fluorescent probes that are operating through the modification of the skeletons of fluorescein and rhodamine dyes, and the fluorescent behaviors of these probes toward specific analyte are discussed. [ABSTRACT FROM AUTHOR]

We previously developed Pittsburgh Green homoallyl ether to quantify trace ozone. Independently, problems were reported when the method was used for excess ozone. Here, we discuss the origin of the reported problems and demonstrate that when this method is used according to our previous report, no problems occur. [ABSTRACT FROM AUTHOR]

Besides a traditional use for the development of organic conducting materials, the tetrathiafulvalene (TTF) unit and its derivatives have recently appeared as key constituents for new applications, exploiting remarkable redox properties: a high π-donating ability and occurrence of three stable redox states. Indeed, in very recent years, an impressive variety of switchable TTF-based molecular and supramolecular (multifunctional) architectures have been designed and synthesized. In this feature article, we discuss recent developments of TTF-based molecular and supramolecular systems in this respect, including molecular sensors, redox-fluorescent switches, multi-input systems for logic gates, electrochemically-driven conformational controls, molecular clips and tweezers, and redox-controlled gelation processes. [ABSTRACT FROM AUTHOR]

Parallel affinity screening of a DNA-encoded chemical library against rat, bovine and human serum albumin allowed the identification of small-molecule ligands with distinctive binding specificities to the individual proteins. [ABSTRACT FROM AUTHOR]

A pillar[6]arene-based supramolecular amphiphile has been constructed in water. The supramolecular amphiphile formed vesicles, which could be regulated by pH, light and enzymes, and thus the loaded dye in the vesicles could be released in a controlled manner. [ABSTRACT FROM AUTHOR]

We examined the cellular uptake of the nanoparticles self-assembled from a bola-shaped cytidylic acid-appended fluorescein derivative (C-FLU-C). The accumulation of fluorescence in the Caco-2 cell nucleus was observed mainly after the plateau phase of cell growth, indicating that C-FLU-C permeated the nuclear envelope without nuclear-localizing tags. [ABSTRACT FROM AUTHOR]

The methylation status of each CpG site can be monitored by Fl-dGTP incorporated asymmetric PCR assay. The ability of quantitative detection makes it a good choice for detecting partial methylation at CpG sites compared with others. And the monitoring is not limited to sites within PCR primers or restriction enzymerecognition sites. [ABSTRACT FROM AUTHOR]

A radical ion from electroreduced p-benzoquinone (BQ) was introduced as a new source of convenient in situ base for colour/emission switching of fluorescein in thin film devices. The devices show excellent switchability and reversibility with no degradation during our extended switching test of 1500 cycles. [ABSTRACT FROM AUTHOR]

A crosslinked poly(N-isopropylacrylamide) ionogel encapsulating an ionic liquid exhibits improved transmittance properties, enhanced water uptake/release, greater thermal actuation behaviour and distinct solvatomorphology over its hydrogel equivalent. It was also found that the rate of release of fluorescein pre-loaded into membranes was considerably enhanced for ionogels compared to equivalent hydrogels, and could be triggered through changes in pH and temperature. [ABSTRACT FROM AUTHOR]

A pyridinyl-functionalized tetraphenylethene (Py-TPE) was synthesized and it demonstrated colorimetric and ratiometric fluorescent responses to trivalent metal cations (M3+, M = Cr, Fe, Al) over a variety of mono- and divalent metal cations. [ABSTRACT FROM AUTHOR]

Controlling maleimide hydrolysis allows the modular construction of bromomaleimide-mediated bioconjugates which are either stable or cleavable in an aqueous, thiol-mediated reducing environment. The application of this methodology to reversible protein biotinylation, the irreversible labeling of peptide disulfide bonds and the assembly of stable, fluorescein-labelled glycoprotein mimics is described. [ABSTRACT FROM AUTHOR]