Synthesis of gold Nanoshells through Improved Seed-Mediated Growth Approach: Brust-like, in Situ Seed Formation

Gold nanoshells have shown great potentials in various fields. However, the widely used seed-mediated growth method based on a silica template for gold nanoshells is a complex and time-consuming procedure. In this work, mercaptosilica was first used as a template to synthesize gold nanoshells through improved seed-mediated growth method. It is verified that gold seeds were formed and attached onto the mercaptosilica nanospheres through Brust-like, in situ process, which makes this method extremely time-saving and easy to manipulate. Importantly, the key factors affecting the in situ process were demonstrated, allowing fine control on the synthesis in a highly reproducible manner. The as-synthesized nanoshells are monodisperse with well-defined morphology and tunable near-IR plasmon resonance. Furthermore, other metal nanoparticles such as Pt and Pd could be grafted onto the surface of mercaptosilica nanospheres through the same Brust-like, in situ process. These provide new insights into seed attachment, and the improved seed-mediated growth approach based on Brust-like, in situ seed formation will take an important step forward toward the widespread application of gold nanoshells.