title: Polyrotaxane-mediated self-assembly of gold nanospheres into fully reversible supercrystals.
abstract: The use of a thiol-functionalized nonionic surfactant to stabilize spherical gold nanoparticles in water induces the spontaneous formation of polyrotaxanes at the nanoparticle surface in the presence of the macrocycle α-cyclodextrin. Whereas using an excess of surfactant an amorphous gold nanocomposite is obtained, under controlled drying conditions the self-assembly between the surface supramolecules provides large and homogenous supercrystals with hexagonal close packing of nanoparticles. Once formed, the self-assembled supercrystals can be fully redispersed in water. The reversibility of the crystallization process may offer an excellent reusable material to prepare gold nanoparticle inks and optical sensors with the potential to be recovered after use.
authors.affiliation: Departamento de Química Física I, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid (Spain).
authors.forename: Joao Paulo
authors.initials: JP
authors.lastname: Coelho
authors.forename: Guillermo
authors.initials: G
authors.lastname: González-Rubio
authors.forename: Annette
authors.initials: A
authors.lastname: Delices
authors.forename: José Osío
authors.initials: JO
authors.lastname: Barcina
authors.forename: Cástor
authors.initials: C
authors.lastname: Salgado
authors.forename: David
authors.initials: D
authors.lastname: Avila
authors.forename: Ovidio
authors.initials: O
authors.lastname: Peña-Rodríguez
authors.forename: Gloria
authors.initials: G
authors.lastname: Tardajos
authors.forename: Andrés
authors.initials: A
authors.lastname: Guerrero-Martínez
keywords: cyclodextrins; gold; nanoparticles; rotaxanes; self-assembly