Tailored Synthesis of Superparamagnetic Gold Nanoshells with Tunable Optical Properties

Multifunctional Au nanoshells with tunable optical properties and fast magnetic response have been fabricated through a sequence of sol–gel, surface-protected etching, and seed-mediated growth processes. The use of a porous silica layer enhances the uniformity of nanoshell growth, the reproducibility of the synthesis, and the structural and optical stability of the products.