Direct Fabrication of Monodisperse Silica Nanorings from Hollow Spheres – A Template for Core–Shell Nanorings

详细信息    查看全文

• 作者：Kuo Zhong ; Jiaqi Li ; Liwang Liu ; Ward Brullot ; Maarten Bloemen ; Alexander Volodin ; Kai Song ; Pol Van Dorpe ; Niels Verellen ; Koen Clays
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：April 27, 2016
• 年：2016
• 卷：8
• 期：16
• 页码：10451-10458
• 全文大小：463K
• 年卷期：0
• ISSN：1944-8252

文摘

We report a new type of nanosphere colloidal lithography to directly fabricate monodisperse silica (SiO₂) nanorings by means of reactive ion etching of hollow SiO₂ spheres. Detailed TEM, SEM, and AFM structural analysis is complemented by a model describing the geometrical transition from hollow sphere to ring during the etching process. The resulting silica nanorings can be readily redispersed in solution and subsequently serve as universal templates for the synthesis of ring-shaped core–shell nanostructures. As an example we used silica nanorings (with diameter of ∼200 nm) to create a novel plasmonic nanoparticle topology, a silica-Au core–shell nanoring, by self-assembly of Au nanoparticles (<20 nm) on the ring’s surface. Spectroscopic measurements and finite difference time domain simulations reveal high quality factor multipolar and antibonding surface plasmon resonances in the near-infrared. By loading different types of nanoparticles on the silica core, hybrid and multifunctional composite nanoring structures could be realized for applications such as MRI contrast enhancement, catalysis, drug delivery, plasmonic and magnetic hyperthermia, photoacoustic imaging, and biochemical sensing.