4 research outputs found
Étude et application de l'exaltation plasmonique pour le développement de nouvelles sondes fluorescentes
No full textTableau d'honneur de la FÉS
Nano-supramolecular complex synthesis: Switch on/off enhanced fluorescence control and molecular release using a simple chemistry reaction
Get PDFA nanosensor based on β-cyclodextrin (ßCD) macrocycles linked to gold nanoparticles for rhodamine B (RhB) sensing was developed applying the metal-enhanced fluorescence effect (MEF). Hence, we have developed many ways to control the distance of supramolecular systems to nanoparticle surface with different bioconjugation strategies in order to optimize signal detection. Different PEG spacer arm lengths were used to cover the nanoparticle surface with molecular spacers. This type of molecular shell is biocompatible, enabling to switch on/off the MEF effect using a dithiane linker by a simple reduction reaction. In the presence of the nanosensor obtained, an increase was observed in RhB fluorescence emission depending on molecular length, that is a characteristic effect ofMEF. Themajor increase measuredwas 60% compared with RhB emission in buffer at 1 nM level, for a spacer length of 3.58 nm and an 80% increase as compared with that in the presence of ßCD. These differences are ascribed to the fact that, in the presence of macrocycle, we can observe a well-known quenching effect that is overcome by the presence of the metallic core. Even at shorter spacer distances, with PEG lengths of 1.2 and 2.17nm, increases of 25 and 47% respectively allowthe analyte detection by the RhB complexation with ßCD. The optimal MEF enhancement was measured with the maximal emission signal stabilized after 50 min due to plasmonic effects based on inter nanoparticle interactions. Moreover, the emission increase, in the presence of the metallic core, was accompanied with a diminution in the fluorescence lifetime's decay value averages, characteristic of MEF. This fact shows that the excited state is protected from the non-radiative emission decays enhancing the analytical signal.Fil: Bracamonte, Angel Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Brouard, Danny. Université Laval; CanadáFil: Lessard Viger, Mathieu. Université Laval; CanadáFil: Boudreau, Denis. Université Laval; CanadáFil: Veglia, Alicia Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin
Smart multifunctional nanoparticles design as sensors and drug delivery systems based on supramolecular chemistry
Get PDFSupramolecular chemistry is a well-known field that, applied to analytical chemistry gives, as a result, supramolecular analytical chemistry. Based in its interactions, this field is part of a new area of nanomedicine, called supramolecular medicine. In order to improve the detection of biological molecules to be applied in cell tracking, health problems and biological events, supramolecular chemistry has lately been combined with supra-nanostructures design. In other words, supramolecular systems can be used as tools in the nano-design of nano-systems for the bio-recognition of biological events, host of ions and organic molecules with different structures and intrinsic chemical properties, as enhancer of the solubility, modification of surface properties, bioconjugation for the nanoparticles design, etc. The versatility of these types of systems is very wide; specifically their use in the nanosensor design using nanoparticles was not highly applied. However, in the last years, the bioconjugation of supramolecular systems, such as macrocycles and antibodies, and proteins with metallic and polymeric nanoparticles has increased, as well as the development of supramolecular nanoparticles based on host guest interactions of macrocycles. Therefore, this review focuses on the application of supramolecular systems as signal transducers in the nanosensors design for bio-recognition events, detection of biological targets, and drug delivery system. These nanosystems, as transducer hosts and building blocks, are linked to metallic and polymeric nanoparticles; and organize molecular systems for different applications.Fil: Gontero, Daniela. Laval University. Centre Hospitalier de L'universite Laval; CanadáFil: Lessard Viger, Mathieu. Laval University; CanadáFil: Brouard, Danny. Groupe Évaluation Optimisation; CanadáFil: Bracamonte, Angel Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Boudreau, Denis. Universite Laval; FranciaFil: Veglia, Alicia Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin
FRET Enhancement in Multilayer Core−Shell Nanoparticles
No full textThis study describes the preparation and characterization of novel multilayer core−shell nanoparticles displaying metal-enhanced Förster resonant energy transfer. The increase in range and efficiency of Förster resonant energy transfer in these fluorescent nanocomposites and their vastly improved luminosity make them promising optical probes for a variety of applications such as cell imaging and biosensing
