Metallic nanoparticles supporting a localized surface plasmon resonance have emerged as promising platforms for nanoscopic labels, sensors, and (photo-) catalysts. To use nanoparticles in these capacities, and to gain mechanistic insight into the reactivity of inherently heterogeneous nanoparticles, single-particle characterization approaches are needed. Single-particle scattering spectroscopy has become an important, highly sensitive tool for localizing single plasmonic nanoparticles and studying their optical properties, local environment, and reactivity. In this review, we discuss approaches taken for collecting the scattered light from single particles, their advantages and disadvantages, and present some recent applications. We introduce techniques for the excitation and detection of single-particle scattering such as high-angle dark-field excitation, total internal reflection dark-field excitation, scanning near-field microscopy, and interferometric scattering. We also describe methods to achieve polarization-resolved excitation and detection. We then discuss different approaches for scanning, ratiometric, snapshot, and interferometric hyperspectral imaging techniques used to extract spectral information. Finally, we provide a brief overview of specialized setups for in situ measurements of nanoparticles in liquid systems and setups coupled to scanning tip microscopes.

中文翻译：

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单粒子散射光谱：基本原理和应用

支持局部表面等离子体共振的金属纳米颗粒已经成为纳米标签，传感器和（光）催化剂的有前途的平台。为了以这些能力使用纳米颗粒，并获得对固有异质纳米颗粒反应性的机械洞察力，需要使用单颗粒表征方法。单粒子散射光谱法已成为一种重要的，高度敏感的工具，可用于定位单个等离激元纳米粒子并研究其光学性质，局部环境和反应性。在这篇综述中，我们讨论了从单个粒子收集散射光的方法，它们的优缺点，并介绍了一些最新的应用。我们介绍了用于激发和检测单粒子散射的技术，例如高角度暗场激发，全内反射暗场激发，扫描近场显微镜和干涉散射。我们还描述了实现偏振分辨激发和检测的方法。然后，我们讨论用于提取光谱信息的扫描，比率式，快照和干涉式高光谱成像技术的不同方法。最后，我们简要概述了用于液体系统中纳米颗粒的原位测量的专用设置以及与扫描尖端显微镜耦合的设置。我们还描述了实现偏振分辨激发和检测的方法。然后，我们讨论用于提取光谱信息的扫描，比率式，快照和干涉式高光谱成像技术的不同方法。最后，我们简要概述了用于液体系统中纳米颗粒的原位测量的专用设置以及与扫描尖端显微镜耦合的设置。我们还描述了实现偏振分辨激发和检测的方法。然后，我们讨论用于提取光谱信息的扫描，比率式，快照和干涉式高光谱成像技术的不同方法。最后，我们简要概述了用于液体系统中纳米颗粒的原位测量的专用设置以及与扫描尖端显微镜耦合的设置。