Search results for "Fluorophore"
showing 10 items of 71 documents
A modified guanosine phosphoramidite for click functionalization of RNA on the sugar edge
2012
A propargyl containing guanosine phosphoramidite was synthesized and incorporated into siRNA, enabling click-ligation with an azido fluorophore onto the nucleobase sugar edge. Duplex stability was not affected by labeling at this new site, which allowed deconvolution of the effects of label, structure and attachment site on RNAi activity.
Efficient electroluminescence from a perylenediimide fluorophore obtained from a simple solution processed OLED
2009
Simple solution processed organic light emitting diodes are used to screen the performance of two types of highly efficient, narrow band red emitting fluorescent perylenediimides (PDIs). PDIs substituted at the diimide positions seem to form aggregates in the thin film architecture as evidenced by the shifted electroluminescent spectrum. When substituted on the bay position and when used both as the emitting and the electron transporting specie, bright electroluminescence with a narrow width around 610 nm reaching 500 cd m−2 at moderate voltages was observed, demonstrating the usefulness of these fluorophores for OLED applications.
Alkoxy-styryl DCDHF fluorophores
2010
A photostable dicyanomethylenedihydrofuran fluorophore which contains electron-donating alkoxy groups is described. This chromophore is highly environmentally-sensitive, which is a remarkable property for a fluorescent reporter. Its light excitation also enables, in low viscous solvents, the formation of dark states whose radical or triplet nature is ruled out.
Covalent and non-covalent coupling of a Au102 nanocluster with a fluorophore: energy transfer, quenching and intracellular pH sensing
2021
Interactions between an atomically precise gold nanocluster Au102(p-MBA)44 (p-MBA = para mercaptobenzoic acid) and a fluorescent organic dye molecule (KU, azadioxatriangulenium) are studied. In solution, the constituents form spontaneously a weakly bound complex leading to quenching of fluorescence of the KU dye via energy transfer. The KU can be separated from the complex by lowering pH, leading to recovery of fluorescence, which forms a basis for an optical reversible pH sensor. However, the sensor is not a stable entity, which could be delivered inside cells. For this purpose, a covalently bound hybrid is synthesized by linking the KU dye to the ligand layer of the cluster via an ester b…
Inter/intramolecular Cherenkov radiation energy transfer (CRET) from a fluorophore with a built-in radionuclide.
2014
The Cherenkov radiation (CR) from [(18)F]-FDG, [(177)Lu]-LuCl3 and [(90)Y]-YCl3 was detected and CR energy transfer (CRET) to several fluorophores was examined. Subsequent fluorescence emission was found to be a function of the position of absorption bands with respect to the CR peak, energy of emitted particles, radionuclide/fluorophore loading, and fluorophore brightness. A variant of the best fluorophore with a built-in radionuclide was synthesized to achieve inter- and intra-molecular CRET.
A new method for fluoride determination by using fluorophores and dyes anchored onto MCM-41
2002
A new colourimetric and fluorimetric method for fluoride determination in aqueous samples based on the specific reaction between fluoride and silica has been developed and applied on real samples. Descalzo Lopez, Ana Belen, adeslo@alumni.uv.es ; El Haskouri, Jamal, Jamal.Haskouri@uv.es ; Beltran Porter, Daniel, Daniel.Beltran@uv.es ; Amoros del Toro, Pedro Jose, Pedro.Amoros@uv.es
Spontaneous Self-Assembly of a 1,8-Naphthyridine into Diverse Crystalline 1D Nanostructures: Implications on the Stimuli-Responsive Luminescent Behav…
2014
The previously reported organic solid-state fluorophore 7-(3,4-dimethoxyphenyl)-2-ethoxy-4-phenyl-1,8-naphthyridine-3-carbonitrile 1 was found to spontaneously self-organize into diverse 1D crystalline nanostructures by choosing appropriate liquid phase self-assembly conditions. Experimental results, as well as DFT quantum calculations (at the M06-2X/6-31+G(d) level), shed light on the aggregation mechanism. This was found in good agreement with molecules being primarily joined together through intermolecular alignment caused by electrostatic interactions, as well as minimization of the steric repulsions. This alignment provokes the preferential growth of the crystalline materials into 1D a…
Boehmite Supported Pyrene Polyamine Systems as Probes for Iodide Recognition
2013
New organic–inorganic fluorescent probes made by attaching the tripodal polyamine (tris(2-aminoethyl))amine (tren), propylamine, or diethylenetriamine functionalized with pyrene as a fluorophore to an γ-aluminum oxohydroxide matrix have been prepared and studied both in solution and supported on the surface of boehmite nanoparticles. Both kinds of systems have been revealed as sensitive and selective fluorescence turn-off chemosensors for iodide in aqueous solution with an estimated detection limit that reaches 36 ppb. The recognition characteristics and photophysical properties of these molecules are essentially preserved when they are grafted to the surface of the particles. Since the nan…
Further insight into the photostability of the pyrene fluorophore in halogenated solvents.
2012
Pyrene fluorophores of pyrene-functionalized CdSe quantum dots (QD@Py), as well as alkylpyrene and pyrene itself (Py), undergo fast degradation in aerated chloroform under ultraviolet-A (UV-A, 316<λ<400 nm) illumination. Steady-state fluorescence studies of irradiated chloroform solutions of QD@Py show formation of new bands, red-shifted compared to that of the pyrene moiety. Similar behaviour is observed for pyrene and the alkylpyrene system. Column chromatography of the pyrene photolysate in chloroform allowed us to isolate photoproducts arising from pyrene degradation, and to obtain information on the structure of the photoproducts responsible for the emission bands. The most predominant…
A spectrofluorimetric study of binary fluorophore-cyclodextrin complexes used as chiral selectors
2005
Abstract Six binary complexes between three fluorophores (pyrene, xanthone and anthraquinone) and β-cyclodextrin (β-CD) or heptakis-(6-amino)-(6-deoxy)-β-cyclodextrin (am-β-CD) were tested at two pH values (8.0 and 9.0) as chiral selectors for three α-amino acids chosen as model. The conditional constant (β2T) values for ternary complexes (fluorophore-CD-amino acid), determined by means of fluorescence spectroscopy, showed that the binary complexes are suitable receptors for chiral recognition. The effect of α-amino acids on stability and stoichiometric ratio of the binary complexes has also been studied. The binary complexes were in most cases stabilized by adding the ternary agent. The tr…