Dynamic Imaging of Multiple SERS Hotspots on Single Nanoparticles,ACS Photonics

当前位置： X-MOL 学术 › ACS Photonics › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Dynamic Imaging of Multiple SERS Hotspots on Single Nanoparticles
ACS Photonics ( IF 6.5 ) Pub Date : 2020-01-22 , DOI: 10.1021/acsphotonics.9b01395
Carlos Diego L. de Albuquerque _{1,

2} , Kallai M. Hokanson ₃ , Sarah R. Thorud ₃ , Regivaldo G. Sobral-Filho _{1,

2} , Nathan C. Lindquist ₃ , Alexandre G. Brolo _{1,

2}

Affiliation

Signal intensity fluctuations are a ubiquitous characteristic of single-molecule surface-enhanced Raman scattering (SERS). In this work, we observed SERS intensity fluctuations (SIFs) from single nanoparticles fully coated with an adsorbate layer. Fluctuations from dry, fully coated nanoparticles are assigned to a dynamic molecule/metal environment wherein atomic-scale reconstructions support SERS. Using super resolution imaging techniques, we were able to pinpoint the positions of the fluctuations with subparticle precision. We observed that the fluctuation events were separated spatially, temporally, and were unique to different laser excitation wavelengths and polarizations. Dual-wavelength super-resolution SERS imaging with green and red lasers reveal various classes of SIFs that occur either simultaneously or nonsimultaneously and from either the same or different location on a single nanoparticle. Similar results were seen when the particle is excited with different polarizations. This suggests that single molecule responses from several different hotspots in the same nanoparticle were readily probed. Furthermore, each nanoparticle contains multiple unique hotspots of different strengths, and resonance conditions, which are accessible by the different illumination conditions. The plasmon resonances localized by the roughness features at the nanoparticle’s surface play a significant role in the fluctuation events. Our experiments show that SERS hotspots that support single molecules are not a static feature of the nanoparticle. This information should be useful to guide future single-molecule SERS experiments.

中文翻译：

单个纳米粒子上多个SERS热点的动态成像

信号强度波动是单分子表面增强拉曼散射（SERS）的普遍特征。在这项工作中，我们观察到了完全覆盖有吸附剂层的单个纳米颗粒的SERS强度波动（SIF）。来自干燥的，完全涂覆的纳米颗粒的波动被分配给动态分子/金属环境，其中原子级重建支持SERS。使用超分辨率成像技术，我们能够以亚粒子精度来精确确定波动的位置。我们观察到波动事件在空间，时间上是分开的，并且对于不同的激光激发波长和偏振是唯一的。用绿色和红色激光进行的双波长超分辨率SERS成像揭示了不同类别的SIF，它们同时发生或不同时发生，并且发生在单个纳米粒子的相同或不同位置。当粒子以不同的极化激发时，观察到相似的结果。这表明很容易探测到来自同一纳米颗粒中几个不同热点的单分子响应。此外，每个纳米粒子包含具有不同强度和共振条件的多个独特热点，可通过不同照明条件访问这些热点。由粗糙度特征局限在纳米颗粒表面的等离子体激元共振在波动事件中起重要作用。我们的实验表明，支持单个分子的SERS热点不是纳米颗粒的静态特征。此信息应有助于指导未来的单分子SERS实验。

更新日期：2020-01-23

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11