Synthesis of raspberry-like particles using polyelectrolyte multilayer-coated particles

The formation of raspberry particles from polyelectrolyte multilayer-modified particles is described. This synthesis represents a new use for polyelectrolyte multilayers as nanoscale-thick reaction vessels for the immobilization and reaction of inorganic reagents. The dissolution of Au nanoparticles inside PEM layers that are capped with a SiO2 layer leads to the hydrolysis and subsequent redeposition of SiO2 nanoparticles. The size of these particles is in the 200 nm range and their loading can be controlled by adding various amounts of Au nanoparticles to the PEMs.