Single-Molecule Surface-Enhanced Raman Scattering Sensitivity of Ag-Core Au-Shell Nanoparticles: Revealed by Bi-Analyte Method

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• 作者：Partha Pratim Patra ; G. V. Pavan Kumar
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2013
• 出版时间：April 4, 2013
• 年：2013
• 卷：4
• 期：7
• 页码：1167-1171
• 全文大小：330K
• 年卷期：v.4,no.7(April 4, 2013)
• ISSN：1948-7185

文摘

Single-molecule surface-enhanced Raman scattering (SM-SERS) is an important application of localized surface plasmons in metallic nanostructures. Conventionally, Ag nanoparticles are used in solution-based SM-SERS experiments, but their usage is limited due to toxicity and oxidation issues. Au nanoparticle solutions are relatively biocompatible and SERS-active, but they do not facilitate large-scale SERS enhancement factors, which is an important prerequisite for SM-SERS. Under such constraints, silver-core gold-shell nanoparticles can be an excellent alternative for SM-SERS. Motivated by this, herein we report on the experimental evidence of SM-SERS sensitivity of Ag-core Au-shell nanoparticles by employing bianalyte method. Additionally, by detecting resonant molecules at femtomolar concentrations, we show that Ag-core Au-shell nanoparticle can be harnessed for ultrasensitive detection of molecules. The provided evidence will further motivate usage of such gold-shell-based bimetallic nanostructures for SM-SERS in biological environments.

Keywords:

SERS; single molecule; plasmonics; core鈭抯hell nanoparticles; bimetallic