Free-Standing Optical Gold Bowtie Nanoantenna with Variable Gap Size for Enhanced Raman Spectroscopy
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- 作者：Nahla A. Hatab ; Chun-Hway Hsueh ; Abigail L. Gaddis ; Scott T. Retterer ; Jia-Han Li ; Gyula Eres ; Zhenyu Zhang ; Baohua Gu
- 刊名：Nano Letters
- 出版年：2010
- 出版时间：December 8, 2010
- 年：2010
- 卷：10
- 期：12
- 页码：4952-4955
- 全文大小：305K
- 年卷期：v.10,no.12(December 8, 2010)
- ISSN：1530-6992
文摘
We describe plasmonic interactions in suspended gold bowtie nanoantenna leading to strong electromagnetic field (E) enhancements. Surface-enhanced Raman scattering (SERS) was used to demonstrate the performance of the nanoantenna. In addition to the well-known gap size dependence, up to 2 orders of magnitude additional enhancement is observed with elevated bowties. The overall behavior is described by a SERS enhancement factor exceeding 1011 along with an anomalously weak power law dependence of E on the gap size in a range from 8 to 50 nm that is attributed to a plasmonic nanocavity effect occurring when the plasmonic interactions enter a strongly coupled regime.