Micro-patterns of Au@SiO2 core-shell nanoparticles formed by electrostatic interactions

In this paper, silica-coated Au nanoparticles (Au@SiO2) were prepared by the technique of vortex mixing. Subsequently, these monodisperse Au@SiO2 nanoparticles were functionalized by the silane reagents 3-aminopropyltriethoxysilane (APS) and 3-mercaptopropyltriethoxysilane (MPTS) respectively. Then, these NH2-terminated and SO32--terminated Au@SiO2 nanoparticles were respectively assembled onto the substrates, which have been patterned with different self-assembly monolayers (SAMs), to form close-packed two-dimensional Au@SiO2 nanoparticle arrays by electrostatic interactions. The morphologies and the optical properties of Au@SiO2 nanoparticles with different silica-shell thicknesses were characterized by TEM and UV-vis. The compositions and zeta potentials of the functionalized Au@SiO2 nanoparticles were examined by X-ray photoelectron spectroscopy (XPS) and dynamic light scattering (DLS). The morphologies of the patterns formed on different templates were characterized by atomic force microscopy (AFM). (c) 2007 Elsevier B.V. All rights reserved.