Lei’s recent work on the synthesis of small-size Au nanoframes with internal hotspots has been accepted by the Nano Letters. Congratulations!

Title: “Gold Nanoframes by Nonepitaxial Growth of Au on AgI Nanocrystals for Surface-Enhanced Raman Spectroscopy”

Authors: L. Zhang, T. Liu, K. Liu, L. Han, Y. Yin, C. Gao*

Link to the publisher: http://pubs.acs.org/doi/abs/10.1021/acs.nanolett.5b01544

Highlight by XJTU: http://news.xjtu.edu.cn/info/1033/55223.htm

Highlight by media: X-MOL

Abstract: Plasmonic noble metal nanoparticles with defined interior nanogaps are of great significance to surface-enhanced Raman spectroscopy (SERS) applications owing to the presence of intraparticle hotspots.  In this contribution, we discovered site-selective nonepitaxial growth of Au on nonmetallic AgI nanocrystals, and based on this observation we designed an unconventional route to synthesize monometallic Au nanoframes which possess ~7 nm of interior nanogaps and ~23 nm of overall size by templating of small AgI nanocrystals.  Chemical bonding between Au and the iodide-rich surface of the AgI nanocrystals was proposed to play a critical role in the nonepitaxial growth of the Au nanoframes against the AgI nanocrystals.  The Au nanoframes obtained from this synthesis showed superior SERS activity in detecting molecules of interest in low concentrations owing to the presence of intraparticle hotspots in additional to the interparticle ones, benchmarking against Au nanospheres.  This intriguing synthesis may open up new opportunities towards a variety of noble metal/semiconductor nanoconjugates for a broad range of applications such as synergistic catalysis.

中文简介：

贵金属纳米材料内部的孔隙结构可以成为表面增强拉曼光谱的活性“热点”，从而使该类材料可应用于对于化学或生物分子的高灵敏度检测。本工作将碘化银纳米颗粒引入到贵金属纳米材料的合成体系中，实现了金在其表面上的成核和生长，制得了规整的金纳米框架材料。通过调控碘化银颗粒的尺寸，金纳米框架中的孔隙可以控制在7纳米以内，从而实现了远优于传统金纳米材料的分子检测性能。该工作拓展了贵金属纳米结构设计合成的方法，为金属及金属复合物纳米材料的制备提供了新的思路。

该研究是在国家自然科学基金和中央高校基本科研业务费的支持下完成的，论文发表在纳米材料领域权威期刊Nano Letters（影响因子：13.592）上。