title: Plasmonic bipyramids for fluorescence enhancement and protection against photobleaching.
abstract: A great number of studies focus their interest on the photophysical properties of fluorescent hybrid gold nanoparticles for potential applications in biotechnologies such as imaging and/or treatment. Spherical gold nanoparticles are known to quench a chromophore fluorescent signal, when moieties are located in their close vicinity. The use of a polymer spacer on such a system allowed only partial recovery of the dye emission by controlling the surface to dye distance. Gold-based anisotropic sharp nanostructures appear to exhibit more interesting features due to the strong electric field generated at their edges and tips. In this paper, a complete study of hybrid fluorescent bipyramidal-like gold nanostructures is presented. We describe the chemical synthesis of gold bipyramids functionalized with fluorescent water-soluble polymers and their photophysics both in solution and on a single object. We show that the use of a bipyramidal shape instead of a spherical one leads to total recovery of the fluorescence and even to an enhancement of the emission of the dyes by a factor of 1.4.
authors.affiliation: Ecole Normale Supérieure de Lyon, CNRS, Université Lyon 1, Laboratoire de Chimie UMR 5182, 46, allée d'Italie, F-69364, Lyon Cedex 07, France. stephane.parola@univ-lyon1.fr.
authors.forename: J R G
authors.initials: JR
authors.lastname: Navarro
authors.forename: F
authors.initials: F
authors.lastname: Lerouge
authors.forename: G
authors.initials: G
authors.lastname: Micouin
authors.forename: C
authors.initials: C
authors.lastname: Cepraga
authors.forename: A
authors.initials: A
authors.lastname: Favier
authors.forename: M T
authors.initials: MT
authors.lastname: Charreyre
authors.forename: N P
authors.initials: NP
authors.lastname: Blanchard
authors.forename: J
authors.initials: J
authors.lastname: Lermé
authors.forename: F
authors.initials: F
authors.lastname: Chaput
authors.forename: M
authors.initials: M
authors.lastname: Focsan
authors.forename: K
authors.initials: K
authors.lastname: Kamada
authors.forename: P L
authors.initials: PL
authors.lastname: Baldeck
authors.forename: S
authors.initials: S
authors.lastname: Parola