Novel yolk–shell structured silica nanosphere with a movable silica-coated gold core

In this article, a novel yolk–shell structure of silica-based nanosphere with a spherical silica-coated nanogold core was successfully fabricated on the basis of layer-by-layer co-assembly and selective etching strategies. The resulting nanospheres were characterized by transmission electron microscopy, scanning electron microscopy, ultraviolet and visible spectrophotometry, X-ray diffractometry, and nitrogen adsorption–desorption. The results showed that the uniform yolk–shell structured nanospheres have a narrow size distribution. Specially, the as-synthesized particles possess a specific surface area (270 m 2 g −1 ) and pore volume (0.57 cm 3 g −1 ). It is believed that the material obtained possesses great potential applications in the fields of biomedical engineering, catalysis, and computed tomography contrast for its above properties. Graphical Abstract Apparently, the graphical abstract lets out two important messages. Firstly, the synthesis process is intelligible at first glance. Secondly, the TEM image of resulting particle shown in right corresponds well with the schematic illustration.