The optimization of the enhancement of Raman scattering by plasmonic effects is largely determined by the properties of the enhancing substrates. The main parameters behind this effect are related to the morphology of plasmonic nanoparticles and their relative distribution within the substrate. We focus this tutorial review on the effects of nanoparticle morphology, for the particular case of anisotropic metal nanoparticles. Anisotropy in silver and gold nanoparticles offers the possibility to tailor their plasmonic properties and intrinsic electromagnetic “hotspots”. We describe the effect of varying particle size and shape on the SERS signal, focusing on the most common anisotropic morphologies used for SERS. Especial emphasis is made on existing comparative studies that shed light on the effect of nanoparticle anisotropy on their enhancement capabilities. We aim at providing a general perspective toward understanding the general key factors and highlighting the difficulty in quantitatively determining SERS performance.

中文翻译：

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用于表面增强拉曼散射的各向异性金属纳米粒子

通过等离激元效应增强拉曼散射的优化很大程度上取决于增强基质的性能。该效应背后的主要参数与等离子体纳米颗粒的形态及其在底物中的相对分布有关。我们专注于本教程审查对于各向异性金属纳米颗粒的特殊情况，研究了纳米颗粒形态的影响。银和金纳米颗粒的各向异性提供了调整其等离子体性能和固有电磁“热点”的可能性。我们重点介绍了用于SERS的最常见的各向异性形态，即粒径和形状的变化对SERS信号的影响。特别强调现有的比较研究，这些研究揭示了纳米粒子各向异性对其增强功能的影响。我们旨在提供一个一般的观点，以了解一般的关键因素并强调定量确定SERS性能的困难。