双金属介观花：在单颗粒水平上的区域特异性过度生长和基底依赖性表面增强拉曼散射。

Bimetallic mesoflowers: region-specific overgrowth and substrate dependent surface-enhanced Raman scattering at single particle level.

机构信息

DST Unit on Nanoscience, Department of Chemistry and Sophisticated Analytical Instrument Facility, Indian Institute of Technology Madras, Chennai 600 036, India.

出版信息

Langmuir. 2010 Jun 1;26(11):8901-7. doi: 10.1021/la904676u.

DOI:10.1021/la904676u

PMID:20178347

Abstract

A strategy for the preparation of bimetallic mesoflowers (MFs) has been demonstrated by a simple overgrowth reaction. We make hybrid MFs containing Au core and shells of different metals, such as Ag and Pt, by tuning the experimental conditions so as to study region-specific overgrowth. This selective growth is attributed to the specific binding affinity of cetyltrimethylammonium bromide (CTAB) at different crystal planes of Au MF surfaces. We also studied the region-specific, composition dependent surface-enhanced Raman scattering (SERS) activity of single bimetallic MFs to understand their chemical environment. Substrate effects on the SERS activity at single particle level were evaluated by a comparative study of the Raman images of Au, Au/Ag, and Au/Pt MFs. Region-specific SERS activity exhibited by single Au/Ag MF provides an insight into the SERS activity of bimetallic MFs over their monometallic analogues.

摘要

一种制备双金属介观花（MFs）的策略是通过简单的超生长反应来实现的。通过调节实验条件，我们制备了含有 Au 核和不同金属（如 Ag 和 Pt）壳的混合 MFs，以研究特定区域的超生长。这种选择性生长归因于十六烷基三甲基溴化铵（CTAB）在 Au MF 表面不同晶面的特定结合亲和力。我们还研究了单双金属 MFs 的区域特异性、组成依赖性表面增强拉曼散射（SERS）活性，以了解它们的化学环境。通过比较 Au、Au/Ag 和 Au/Pt MFs 的拉曼图像，评估了在单粒子水平上基底对 SERS 活性的影响。单 Au/Ag MF 表现出的区域特异性 SERS 活性为理解双金属 MFs 相对于其单金属类似物的 SERS 活性提供了线索。