Gold Nanooctahedra with Tunable Size and Microfluidic-Induced 3D Assembly for Highly Uniform SERS-Active Supercrystals

详细信息    查看全文

• 作者：Sergio G贸mez-Gra帽a ; Cristina Fern谩ndez-L贸pez ; Lakshminarayana Polavarapu ; Jean-Baptiste Salmon ; Jacques Leng ; Isabel Pastoriza-Santos ; Jorge P茅rez-Juste
• 刊名：Chemistry of Materials
• 出版年：2015
• 出版时间：December 22, 2015
• 年：2015
• 卷：27
• 期：24
• 页码：8310-8317
• 全文大小：543K
• ISSN：1520-5002

文摘

Shape-controlled synthesis of uniform noble metal nanoparticles (NPs) is crucial for the development of future plasmonic devices. The use of nanocrystals with well-defined morphologies and crystallinity as seed particles is expected to provide excellent shape control and monodispersity. We report the aqueous-based seed-mediated growth of monodisperse gold octahedra with wide range of sizes (50鈥?50 nm in side length) by reducing different amounts of HAuCl₄ on preformed single crystalline gold nanorods using butenoic acid as reducing agent. Butenoic acid plays a key role as a mild reducing agent as well as favoring the thermodynamic control of the reaction. The uniformity of the as-prepared Au octahedra combined with the use of a microfluidic technique based on microevaporation will allow the self-assembly of octahedra into uniform 3D supercrystals. Additionally, these plasmonic substrates exhibit high and uniform SERS signals over extended areas with intensities increasing with the Au nanoparticle size.