RT Journal Article
T1 Supramolecular Control over the Interparticle Distance in Gold Nanoparticle Arrays by Cyclodextrin Polyrotaxanes
A1 Coelho, Joao Paulo
A1 Osío Barcina, José De Jesús
A1 Junquera González, María Elena
A1 Aicart Sospedra, Emilio
A1 Tardajos Rodríguez, Gloria
A1 Gómez Graña, Sergio
A1 Cruz Gil, Pablo
A1 Salgado, Cástor
A1 Díaz Núñez, Pablo
A1 Peña Rodríguez, Ovidio
A1 Guerrero Martínez, Andrés
AB Amphiphilic nonionic ligands, synthesized with a fixed hydrophobic moiety formed by a thiolated alkyl chain and an aromatic ring, and with a hydrophilic tail composed of a variable number of oxyethylene units, were used to functionalize spherical gold nanoparticles (AuNPs) in water. Steady-state and time-resolved fluorescence measurements of the AuNPs in the presence of α-cyclodextrin (α-CD) revealed the formation of supramolecular complexes between the ligand and macrocycle at the surface of the nanocrystals. The addition of α-CD induced the formation of inclusion complexes with a high apparent binding constant that decreased with the increasing oxyethylene chain length. The formation of polyrotaxanes at the surface of AuNPs, in which many α-CDs are trapped as hosts on the long and linear ligands, was demonstrated by the formation of large and homogeneous arrays of self-assembled AuNPs with hexagonal close packing, where the interparticle distance increased with the length of the oxyethylene chain. The estimated number of α-CDs per polyrotaxane suggests a high rigidization of the ligand upon complexation, allowing for nearly perfect control of the interparticle distance in the arrays. This degree of supramolecular control was extended to arrays formed by AuNPs stabilized with polyethylene glycol and even to binary arrays. Electromagnetic simulations showed that the enhancement and distribution of the electric field can be finely controlled in these plasmonic arrays.
PB MDPI
SN 2079-4991
YR 2018
FD 2018-03-16
LK https://hdl.handle.net/20.500.14352/12724
UL https://hdl.handle.net/20.500.14352/12724
LA eng
NO Ministerio de Economía y Competitividad (MINECO)
NO Comunidad de Madrid
DS Docta Complutense
RD 6 oct 2024