Wang Huihui, Zhang Ting, Zhou Xiaochun
School of Nano Technology and Nano Bionics, University of Science and Technology of China, Hefei 230026, People's Republic of China. Division of Advanced Nanomaterials, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123, People's Republic of China.
J Phys Condens Matter. 2019 Nov 27;31(47):473001. doi: 10.1088/1361-648X/ab330a. Epub 2019 Jul 17.
Dark-field microscopy (DFM) is an effective method to detect the scattering signal from single nanoparticles. This technique could break through the 200 nm limit resolution of ordinary optical microscopes. It even can observe the submicron particles of 20-200 nm. Moreover, from 2000, DFM was coupled with a spectrometer to measure the scattering spectra of single silver nanoparticles. Then, dark-field spectroscopy becomes a very important plasmon spectroscopy technique for single nanoparticles. Usually, plasmonic nanoparticles are the major research target, because they have unique optical properties due to their localized surface plasmon resonance (LSPR), which can be influenced by many factors, such as composition, size, morphology, the refractive index of the surrounding medium etc. When surface chemical reactions occur on a single nanoparticle, it could induce the variation of these factors. Then, the structure-activity relationship for these nanoparticle catalysts can be studied at a single nanoparticle level and in real time. This review mainly summarized the development of dark-field spectroscopy, spectrometers, light sources, and other accessories, which greatly improved the imaging capabilities of dark-field spectroscopy. Meanwhile, the applications of dark-field spectroscopy in single-particle catalysis such as chemocatalysis, photocatalysis, electrocatalysis and biocatalysis are also reviewed.
暗场显微镜（DFM）是检测单个纳米颗粒散射信号的有效方法。该技术能够突破普通光学显微镜200nm的分辨率极限。它甚至可以观察到20 - 200nm的亚微米颗粒。此外，自2000年起，暗场显微镜与光谱仪联用，用于测量单个银纳米颗粒的散射光谱。于是，暗场光谱学成为一种用于单个纳米颗粒的非常重要的等离子体光谱技术。通常，等离子体纳米颗粒是主要研究对象，因为它们由于局域表面等离子体共振（LSPR）具有独特的光学性质，而这种共振会受到许多因素影响，例如组成、尺寸、形态、周围介质的折射率等。当单个纳米颗粒上发生表面化学反应时，会引起这些因素的变化。进而，可以在单个纳米颗粒水平上实时研究这些纳米颗粒催化剂的构效关系。本综述主要总结了暗场光谱学、光谱仪、光源及其他配件的发展，这些极大地提升了暗场光谱学的成像能力。同时，还综述了暗场光谱学在单颗粒催化如化学催化、光催化、电催化和生物催化中的应用。
