Optical Properties of Silica-Coated Au Nanorods: Correlating Theory and Experiments for Determining the Shell Porosity

EDUARDO A. CORONADO

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Lugar: Washington; Año: 2021 vol. 125 p. 15516 - 15516

1932-7447

old nanorods (GNRs) coated with mesoporous silica (GNRs@m-SiO2) have proven to be a robust nanostructure with useful applications in biomedical, catalysis, and molecular sensing areas, among others. The m-SiO2 shell improves the nanoparticle stability and grants a concomitant molecular loading capability. One of the factors that determine the specific application of GNRs@m-SiO2 is the porosity degree of the m-SiO2 shell. In the present work, we first studied how the extinction spectra features of GNRs@m-SiO2 in combination with electrodynamics modeling can be used to determine the porosity degree of the m-SiO2 shell produced at two different concentrations of the porogenic surfactant cethyl trimethylammonium bromide (CTAB). The changes on the intensity in the low-frequency region are explained qualitatively in terms of the optical properties of the mesoporous silica spheres formed as byproducts. Varying the CTAB concentration produces a change not only on the porosity but also on the