title: Design and Optical Properties of Active Polymer-Coated Plasmonic Nanostructures.
abstract: The grafting of stimuli-responsive polymer brushes on plasmonic structures provides a perfectly controlled two-dimensional active device with optical properties that can be modified through external stimuli. Herein, we demonstrate thermally induced modifications of the plasmonic response of lithographic gold nanoparticles functionalized by thermosensitive polymer brushes of (poly(N-isopropylacrylamide), PNIPAM). Optical modifications result from refractive local index changes due to a phase transition from a hydrophilic state (swollen regime) to a hydrophobic state (collapsed regime) of the polymer chains occurring in a very small range of temperatures. The refractive index of the polymer in aqueous solution is estimated in both states, deduced from the discrete dipole approximation (DDA) method. The combination of lithographic gold NPs and thermoresponsive polymer chains leads to a new generation of perfectly calibrated and dynamically controlled hybrid gold/polymer system for real-time nanosensors.
authors: †Laboratoire ITODYS, Université Paris Diderot, CNRS UMR 7086, 15 rue Jean de Baïf, 75013 Paris, France.
authors: Hélène
authors: H
authors: Gehan
authors: †Laboratoire ITODYS, Université Paris Diderot, CNRS UMR 7086, 15 rue Jean de Baïf, 75013 Paris, France.
authors: Claire
authors: C
authors: Mangeney
authors: †Laboratoire ITODYS, Université Paris Diderot, CNRS UMR 7086, 15 rue Jean de Baïf, 75013 Paris, France.
authors: Jean
authors: J
authors: Aubard
authors: †Laboratoire ITODYS, Université Paris Diderot, CNRS UMR 7086, 15 rue Jean de Baïf, 75013 Paris, France.
authors: Georges
authors: G
authors: Lévi
authors: ‡Institute of Physics, Karl Franzens University, Universitatsplatz 5, A-8010 Graz, Austria.
authors: Andreas
authors: A
authors: Hohenau
authors: ‡Institute of Physics, Karl Franzens University, Universitatsplatz 5, A-8010 Graz, Austria.
authors: Joachim R
authors: JR
authors: Krenn
authors: §Laboratoire INSP, Université Pierre et Marie Curie, 5 place Jussieu, 75005 Paris, France.
authors: Emmanuelle
authors: E
authors: Lacaze
authors: †Laboratoire ITODYS, Université Paris Diderot, CNRS UMR 7086, 15 rue Jean de Baïf, 75013 Paris, France.
authors: Nordin
authors: N
authors: Félidj
keywords: diazonium salts; discrete dipole approximation; gold nanoparticles; optical properties; thermosensitive polymers