title: Solution self-assembly of plasmonic Janus nanoparticles.
abstract: Janus nanoparticles bearing two different properties on a single particle are amenable to self-assembly into higher-order structures via their directional interaction. We show that gold/silica Janus nanoparticles self-assemble in solution into clusters resembling colloidal micelles upon addition of a hydrophobic thiol which provides them with a surface active amphiphilic character. As the nanoparticles spontaneously assemble, the color of the solution evolves due to the coupling of the surface plasmons. Time resolved spectrophotometry in the visible and near-infrared ranges coupled to simulations were used to probe the assembly process. A singular value decomposition analysis reveals the presence of dimers as transient species. The structure of the clusters was probed using small angle X-ray revealing that the Janus nanoparticles assemble into clusters containing a few particles.
authors.affiliation: Laboratoire de Physique des Solides, Univ. Paris-Sud, CNRS, UMR 8502, F-91405 Orsay Cedex, France. benjamin.abecassis@u-psud.fr.
authors.forename: Nicolò
authors.initials: N
authors.lastname: Castro
authors.affiliation: Laboratoire de Physique des Solides, Univ. Paris-Sud, CNRS, UMR 8502, F-91405 Orsay Cedex, France. benjamin.abecassis@u-psud.fr.
authors.forename: Doru
authors.identifier: http://orcid.org/0000-0001-5623-9633
authors.initials: D
authors.lastname: Constantin
authors.affiliation: Laboratoire de Physique des Solides, Univ. Paris-Sud, CNRS, UMR 8502, F-91405 Orsay Cedex, France. benjamin.abecassis@u-psud.fr.
authors.forename: Patrick
authors.initials: P
authors.lastname: Davidson
authors.affiliation: Laboratoire de Physique des Solides, Univ. Paris-Sud, CNRS, UMR 8502, F-91405 Orsay Cedex, France. benjamin.abecassis@u-psud.fr and Laboratoire de Chimie, ENS de Lyon, CNRS UMR 5182, Université Claude Bernard, Université de Lyon, F-69342 Lyon, France.
authors.forename: Benjamin
authors.identifier: http://orcid.org/0000-0002-1629-9671
authors.initials: B
authors.lastname: Abécassis