In Situ Growth of Hollow Gold鈥揝ilver Nanoshells within Porous Silica Offers Tunable Plasmonic Extinctions and Enhanced Colloidal Stability

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• 作者：Chien-Hung Li ; Andrew C. Jamison ; Supparesk Rittikulsittichai ; Tai-Chou Lee ; T. Randall Lee
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2014
• 出版时间：November 26, 2014
• 年：2014
• 卷：6
• 期：22
• 页码：19943-19950
• 全文大小：367K
• ISSN：1944-8252

文摘

Porous silica-coated hollow gold鈥搒ilver nanoshells were successfully synthesized utilizing a procedure where the porous silica shell was produced prior to the transformation of the metallic core, providing enhanced control over the structure/composition of the bimetallic hollow core. By varying the reaction time and the precise amount of gold salt solution added to a porous silica-coated silver-core template solution, composite nanoparticles were tailored to reveal a readily tunable surface plasmon resonance that could be centered across the visible and near-IR spectral regions (鈭?45鈥?00 nm). Characterization by X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, scanning electron microscopy, and transmission electron microscopy revealed that the synthetic methodology afforded particles having uniform composition, size, and shape. The optical properties were evaluated by absorption/extinction spectroscopy. The stability of colloidal solutions of our composite nanoparticles as a function of pH was also investigated, revealing that the nanoshells remain intact over a wide range of conditions (i.e., pH 2鈥?0). The facile tunability, enhanced stability, and relatively small diameter of these composite particles (鈭?10 nm) makes them promising candidates for use in tumor ablation or as photothermal drug-delivery agents.

Keywords:

hollow nanoshells; tunable plasmon; silica-coated; gold鈭抯ilver; bimetallic