title: Seeded growth of submicron Au colloids with quadrupole plasmon resonance modes.
abstract: A modified seeded growth process has been used for the controlled synthesis of quasispherical, CTAB-stabilized gold nanoparticles from 12 up to 180 nm with narrow size distributions. The UV-visible spectra of the aqueous colloids show distinct bands corresponding to dipole and quadrupole plasmon modes, for diameters above 100 nm, in close agreement with predictions based on Mie theory. The assignment of the modes is demonstrated by calculation of near field enhancement maps based on the boundary element method. Apart from other applications, since absorption is drastically reduced above 600 nm, while scattering is largely increased, these particles open new possibilities for construction of highly efficient photonic structures.
authors.affiliation: Departamento de Química Física, Universidade de Vigo, 36310 Vigo, Spain.
authors.forename: Jessica
authors.initials: J
authors.lastname: Rodríguez-Fernández
authors.forename: Jorge
authors.initials: J
authors.lastname: Pérez-Juste
authors.forename: F Javier
authors.initials: FJ
authors.lastname: García de Abajo
authors.forename: Luis M
authors.initials: LM
authors.lastname: Liz-Marzán