Gap Structure Effects on Surface-Enhanced Raman Scattering Intensities for Gold Gapped Rods

被引：101

作者：

Li, Shuzhou ^{[1
]}

Pedano, Maria L. ^{[1
]}

Chang, Shih-Hui ^{[1
]}

Mirkin, Chad A. ^{[1
]}

Schatz, George C. ^{[1
]}

机构：

[1] Northwestern Univ, Dept Chem, Evanston, IL 60208 USA

来源：

NANO LETTERS | 2010年 / 10卷 / 05期

基金：

美国国家科学基金会;

关键词：

SERS; nanogap; roughness; ON-WIRE LITHOGRAPHY; TRANSPORT JUNCTIONS; SPECTRAL PROPERTIES; NANORODS; NANOSTRUCTURES; RESONANCES;

D O I：

10.1021/nl100099g

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Gapped rods provide a unique platform for elucidating structure/function relationships, both for single-molecule electrochemical techniques and for surface-enhanced Raman scattering (SERS). This paper attempts to elucidate the dependence of SERS intensities on gap topography and gap distance for gold gapped rods with segment lengths varying over a wide range (40-2000 nm). Significantly, we have determined that rough gaps lead to a smaller SERS enhancement than smooth gaps for these structures even though the rough gaps have a larger total surface area. Both theory and experiment show periodic variation of SERS intensity with segment length as determined by odd-symmetry plasmon multipoles. Excitation of even-symmetry modes is dipole forbidden (for polarization along the rod axis), but this selection rule can be relaxed by roughness or, for smooth gaps, by near-field coupling between the rod segments.

引用

页码：1722 / 1727

页数：6

共 24 条

[1] Electrochemical approach to and the physical consequences of preparing nanostructures from gold nanorods with smooth ends [J].