2018 |
Liao, Y. Y., Melissen, S. T. A. G., Audibert, J. F., Vu, T. T., Clavier, G., Meallet-Renault, R., Retailleau, P., Lemaistre, J. P., Genot, V., & Pansu, R. (2018). Fluorescence Spectroscopy of AdamBODIPY Single Crystals. Chemphotochem, 2(2), 72–80.
Résumé: Interest in the fluorescence of organic solids is increasing with the development of nanosensors and research into new molecules with aggregation-induced fluorescence properties. We have gone beyond the qualitative observation of fluorescence by analyzing the luminescence properties of planar single crystals of a 4,4'-difluoro-4-bora-(3a,4a)-diaza-s-indacene (BODIPY) derivative with micrometric dimensions. A simple Frenkel exciton model applied to this crystal predicts one band. From time-resolved fluorescence spectra, three emissions were distinguished. The shortest-lived one at lambda = 547 nm was predicted by theory and corresponds to an exciton lifetime of 0.9 ns. A trap with an intermediate emission lifetime of 1.2 ns was found at 569 nm and a final trap at 620 nm has a lifetime of 1.9 ns. These attributions were confirmed by the study of the polarization of these emissions. The 547 nm emission was polarized along the long axis of the crystal as predicted by the Frenkel exciton model. The 569 nm emission was polarized perpendicularly to the plane of the crystal and the 620 nm emission was polarized along the short axis. Thus, the two red-shifted bands were related to well-defined defects with specific orientations in the crystal. Fluorescence lifetime imaging measurements showed that the density of these defects is not uniform and that under our synthesis conditions, they are formed in the initial steps of the growth and therefore appear in the center of the crystals.
|
|
2017 |
|
Piard, J., Bon, C., Jegat, C., Doré, C., Petcut, V., Montanelli, R., & Méallet-Renault, R. (2017). Thermoluminochromisme de complexes de type Cu4I4(pyridine)4. Bulletin de l’Union des Physiciens, 991, 205–224.
|
|
|
Piard, J., Gatin-Fraudet, B., Grenier, A., Maujean, T., Péault, L., & Méallet-Renault, R. (2017). Thermochromisme d’un complexe de cobalt (II). Bulletin de l’Union des Physiciens, 999, 1221–1253.
|
|
2016 |
Baczko, K., Fensterbank, H., Berini, B., Bordage, N., Clavier, G., Meallet-Renault, R., Larpent, C., & Allard, E. (2016). Azide-Functionalized Nanoparticles as Quantized Building Block for the Design of Soft-Soft Fluorescent Polystyrene Core-PAMAM Shell Nanostructures. Journal Of Polymer Science Part A-Polymer Chemistry, 54(1), 115–126.
Résumé: This work deals with the covalent coupling of azide-functionalized polymeric nanoparticles as a reactive core and amino-terminated PAMAM dendrons as a reactive shell. The nanoassemblies thereby obtained could be modified after the dendronization step by grafting an alkynyl Bodipy dye on the unreacted azide moieties. Only a few steps are required to attain nanoassemblies that could mimic dendrimers of high generation with sizes of nano-objects beyond those of dendrimers. The structure of the nanoassemblies are composed of a polystyrene core, an inner shell including the Bodipy dyes along with the internal branches of the PAMAM, and the terminal amino groups from the outer shell. The dendritic shell acts as a protective layer that prevents NP from aggregation in a surfactant free aqueous solution. The nano-objects display absorption and emission maxima above 500 nm with brightness that are the same order of magnitude than Qdots. (C) 2015 Wiley Periodicals, Inc.
|
|
Chagas, G. R., Xie, X., Darmanin, T., Steenkeste, K., Gaucher, A., Prim, D., Meallet-Renault, R., Godeau, G., Amigoni, S., & Guittard, F. (2016). Electrodeposition of Polypyrenes with Tunable Hydrophobicity, Water Adhesion, and Fluorescence Properties. Journal Of Physical Chemistry C, 120(13), 7077–7087.
Résumé: The control in surface hydrophobicity and water adhesion is extremely important for various applications in water harvesting, oil/water separation membrane, energy systems or biosensing, for example. Here, for the first time we show that the use of fluorescent monomers such as pyrene with various substituents differing by their hydrophobicity, size, or rigidity/flexibility can lead to surfaces with tunable hydrophobicity, water adhesion and fluorescence properties by a direct electropolymerization process. Seven original monomers with fluoroalkyl, alkyl, phenyl, adamantyl, and triethylene glycol substituents were synthesized and studied. The surface roughness is highly dependent on the substituent, and it seems that the fluorescence, although complex, correlates with the surface roughness. Superhydrophobic properties and highly oleophobic properties are obtained using fluoroalkyl chains due to the presence of nanostructured microparticles. In comparison to the structured absorption and emission bands of pyrene monomers, the pyrene polymers (oligomers) exhibit a broad structureless spectral shape both in absorption and in emission, which seems to be due to pyrene oligomerization and aggregation. This work is a first tentative attempt to combine superhydrophobic and fluorescent properties using an innovative strategy and opens new doors to explore in this domain.
|
|
|
Delaire, J., Piard, J., & Méallet-Renault, R. (2016). Photophysique et photochimie: Des fondements aux applications.
|
|
Fensterbank, H., Baczko, K., Constant, C., Idttalbe, N., Bourdreux, F., Vallee, A., Goncalves, A. M., Meallet-Renault, R., Clavier, G., Wright, K., & Allard, E. (2016). Sequential Copper-Catalyzed Alkyne-Azide Cycloaddition and Thiol-Maleimide Addition for the Synthesis of Photo- and/or Electroactive Fullerodendrimers and Cysteine-Functionalized Fullerene Derivatives. Journal Of Organic Chemistry, 81(18), 8222–8233.
Résumé: In this study, the functionalization of a fullerene building block in a stepwise process by means of the copper- catalyzed alkyne azide cycloaddition (CuAAC) and thiol- maleimide reactions is reported. Grafting of the fullerene plat- form with a variety of azido derivatives, including Bodipy, pyrene and ferrocene, was carried out first. These fullerene compounds were then reacted with thiol derivatives to yield sophisticated structures comprising photo- and/or electroactive fullerodendrimers and cysteine-functionalized fullerene assemblies. This strategy, which combines the CuAAC and thiol-maleimide processes, could become more widely adopted in the field of fullerene chemistry.
|
|
Grazon, C., Rieger, J., Beaunier, P., Meallet-Renault, R., & Clavier, G. (2016). Fluorescent core-shell nanoparticles and nanocapsules using comb-like macromolecular RAFT agents: synthesis and functionalization thereof. Polymer Chemistry, 7(25), 4272–4283.
Résumé: Fluorescent nanoparticles and nanocapsules (FNPs) were synthesized via a one-pot RAFT miniemulsion process copolymerizing BODIPY-methacrylate and styrene in water. Ultra-bright sub-100 nm core-shell nanoparticles could be obtained with BODIPY covalently linked in the core, and possessing various shells. The nature and architecture of the particle shells could be tuned by using different macromolecular RAFT (macro-RAFT) agents in the miniemulsion polymerization process. The macro-RAFT agents were composed of poly(ethylene oxide) acrylate (PEOA) and/or acrylic acid (AA), owing to their biocompatibility and functionality respectively, in different proportions. Interestingly, with comb-like macro-RAFT agents comprising a high number of PEOA, nanocapsules were formed, while with linear macro-RAFT agents or with those exhibiting a high number of AA, full core-shell nanoparticles were obtained. For all the structures the control over the polymerization, the size, morphology, and zeta-potential as well as the photophysical properties were measured and compared with FNPs exhibiting a linear PEO-b-PAA block copolymer shell structure (C. Grazon, J. Rieger, R. Mallet-Renault, G. Clavier and B. Charleux, Macromol. Rapid Commun., 2011, 32, 699). Regardless of the shell structures, the brightness of the formed nanoparticles was estimated to be 100-1000 times higher than that of quantum dots. Ultimately, the shell of the different FNPs was functionalized with a second fluorophore via the AA's carboxyl groups. Thus, watersoluble ultra-bright FNPs with two fluorophores in distinct environments (water and in polystyrene) were obtained. They should have great potential for bioimaging applications.
|
|
Si, Y., Grazon, C., Clavier, G., Rieger, J., Audibert, J. F., Sclavi, B., & Meallet-Renault, R. (2016). Rapid and accurate detection of Escherichia coli growth by fluorescent pH-sensitive organic nanoparticles for high-throughput screening applications. Biosensors & Bioelectronics, 75, 320–327.
Résumé: Rapid detection of bacterial growth is an important issue in the food industry and for medical research. Here we present a novel kind of pH-sensitive fluorescent nanoparticles (FANPs) that can be used for the rapid and accurate real-time detection of Escherichia coil growth. These organic particles are designed to be non-toxic and highly water-soluble. Here we show that the coupling of pH sensitive fluoresceinamine to the nanoparticles results in an increased sensitivity to changes in pH within a physiologically relevant range that can be used to monitor the presence of live bacteria. In addition, these FANPs do not influence bacterial growth and are stable over several hours in a complex medium and in the presence of bacteria. The use of these FANPs allows for continuous monitoring of bacterial growth via real-time detection over long time scales in small volumes and can thus be used for the screening of a large number of samples for high-throughput applications such as screening for the presence of antibiotic resistant strains. (C) 2015 Elsevier B.V. All rights reserved.
|
|
Vu, T. T., Meallet-Renault, R., Clavier, G., Trofimov, B. A., & Kuimova, M. K. (2016). Tuning BODIPY molecular rotors into the red: sensitivity to viscosity vs. temperature. Journal Of Materials Chemistry C, 4(14), 2828–2833.
Résumé: Viscosity variations in the microscopic world are of paramount importance for diffusion and reactions. In the last decade a new class of fluorescent probes for measuring viscosity has emerged termed 'molecular rotors', which allows quantitative mapping of viscosity in microscopically heterogeneous environments. Here we attempt to tune the absorption and emission of one such 'molecular rotor' based on the BODIPY fluorescent core into the red region of the spectrum, to allow better compatibility with the 'tissue optical window' and imaging of cells and tissues. We consequently find that our redemitting BODIPY fluorophores are sensitive to environmental temperature rather than to viscosity, thus suggesting a new prototype for a 'molecular thermometer'.
|
|
2014 |
Celia, E., Amigoni, S., de Givenchy, E. T., Pieters, G., Gaucher, A., Prim, D., Audibert, J. F., Meallet-Renault, R., Pansu, R., & Guittard, F. (2014). A spiral designed surface based on amino-perylene grafted polyacrylic acid. Chemical Communications, 50(81), 12034–12036.
Résumé: This communication shows the possibility of inducing spontaneous special surface organisation by means of grafting a fluorescent aminobenzo[g,h,i]perylene derivative onto surface grown polyacrylic chains.
|
|
Grazon, C., Rieger, J., Charleux, B., Clavier, G., & Meallet-Renault, R. (2014). Ultrabright BODIPY-Tagged Polystyrene Nanoparticles: Study of Concentration Effect on Photophysical Properties. Journal Of Physical Chemistry C, 118(25), 13945–13952.
Résumé: Fluorescent nanomaterials are invaluable tools for bioimaging. Polymeric nanoparticles labeled with organic dyes are very promising for this purpose. It is thus very important to fully understand their photophysical properties. New fluorescent core-shell nanoparticles have been prepared. The outer part is a poly(ethylene glycol)-block-poly(acrylic acid) copolymer, and the core is a copolymer of styrene and methacrylic BODIPY fluorophore. The hydrophilic and hydrophobic parts are covalently linked, ensuring both stability and biocompatibility. We prepared nanoparticles with increasing amounts of BODIPY, from 500 to 5000 fluorophores per particles. Increasing the concentration of BODIPY lowers both the fluorescence quantum yield and the lifetime. However, the brightness of the individual particles increases up to 8 X 10(7). To understand the loss of fluorescence efficiency, fluorescence decays have been recorded and fitted with a mathematical model using a stretched exponential function. This result gives an insight into the fluorophore arrangement within the hydrophobic core.
|
|
|
Nodin, L., Méallet-Renault, R., & Piard, J. (2014). Séparation et étude des pigments des épinards par spectrofluorimétrie. Bulletin de l’Union des Physiciens, 961, 293–310.
|
|
Rampazzo, E., Bonacchi, S., Genovese, D., Juris, R., Montalti, M., Paterlini, V., Zaccheroni, N., Dumas-Verdes, C., Clavier, G., Meallet-Renault, R., & Prodi, L. (2014). Pluronic-Silica (PluS) Nanoparticles Doped with Multiple Dyes Featuring Complete Energy Transfer. Journal Of Physical Chemistry C, 118(17), 9261–9267.
Résumé: We report here the design of two sets Of multifltiorophoric silica nanoparticles, observing unprecedented efficiencies in the energy-transfer processes among the doping dyes. These nanomaterials show a very high overall sensitization, allowing under a single wavelength excitation to obtain many different colors (one per nanoparticle) in emission with negligible crosstalk. Moreover, each particle can present very large and tunable pseudo-Stokes shifts (up to 435 nm), a very high brightness even exciting the bluest donor, and a negligible residual emission intensity from all donor dyes. All these features, combined with colloidal stability and synthetic method reliability, make these multicomponent nanoparticles very promising for multiplex analysis and for all the diagnostic techniques requiring high sensitivity associated with a large Stokes shift.
|
|
