Shedding Light on Surface-Enhanced Raman Scattering Hot Spots through Single-Molecule Super-Resolution Imaging

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• 作者：Katherine A. Willets ; Sarah M. Stranahan ; Maggie L. Weber
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2012
• 出版时间：May 17, 2012
• 年：2012
• 卷：3
• 期：10
• 页码：1286-1294
• 全文大小：390K
• 年卷期：v.3,no.10(May 17, 2012)
• ISSN：1948-7185

文摘

Super-resolution imaging has recently been utilized to develop a better understanding of the properties of surface-enhanced Raman scattering (SERS) hot spots. SERS hot spots are much smaller than the diffraction limit of light, and therefore, obtaining a clear picture of the enhanced electromagnetic (EM) fields comprising these hot spots is a challenging task. In this Perspective, we discuss recent work applying super-resolution imaging to single-molecule SERS (SM-SERS) of rhodamine 6G (R6G) adsorbed to randomly assembled silver colloidal aggregates, allowing the shape, size, and local enhancement of the hot spots to be imaged with <5 nm resolution. The results are compared with studies applying super-resolution imaging to surface-enhanced fluorescence (SEF) of analytes diffusing into silver nanoparticle hot spots. Both studies show a strong correlation between emission intensity and position, allowing the EM field enhancements of SERS hot spots to be mapped with sub-5 nm resolution.