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.

Dynamic Light Scattering of Short Au Rods with Low Aspect Ratios

“…Since then, a plethora of studies have dealt with the production and characterization of noble metal colloids in a wide range of sizes [2][3][4], and for a variety of applications, including catalysis [5], biolabelling [6], biosensing [7], optical switches [8], among others. Only recently, variations in nanoparticle shape have been recognized as having a strong impact on their properties, which has motivated the development of synthetical methods for the preparation of particles with various geometries, such as rods [9][10][11][12][13], wires [14][15][16], prisms [17][18][19][20][21], cubes [22][23][24] and other polyhedrons [25,26].…”

The surface plasmon modes of self-assembled gold nanocrystals

“…MPS was purchased from Sigma Aldrich. Spherical gold nanoparticles were prepared using the wet chemical synthesis developed by Rodriguez-Fernandez et al 43 Briefly, citrate seeds were prepared by bringing 100 ml of aqueous 0.25 mM chloroauric acid (HAuCl4) to boiling temperature. Seed growth is initiated by the addition of 3.5 ml of aqueous 1 wt% sodium citrate solution.…”

Biocompatible Gold Submicrometer Spheres with Variable Surface Texture Fabricated by Pulsed Laser Melting in Liquid

“…24 Furthermore, they can also be used for catalysis 5,6 as well as bioimaging and phototherapy 7 because of their extremely high scattering cross sections in the NIR regime and their well-defined uniform shapes. SMSs have been synthesized by chemical routes for a multitude of metal, 8,9 metal oxide, 1012 and semiconductor 13 materials; however, chemical reduction was frequently observed along with the formation of crystal facets, leading to deviations from the spherical shape. Another impediment arises from the presence of ligands on the surface of chemically synthesized SMSs, which are known to increase noise levels in SERS experiments.…”