Department of Physical Chemistry and Biomedical Research Center (CINBIO) , University of Vigo, As Lagoas-Marcosende , 36310 Vigo , Spain.
Donostia International Physics Center (DIPC) , Paseo Manuel de Lardizabal 4 , Donostia-San Sebastián 20018 , Spain.
Acc Chem Res. 2019 Jul 16;52(7):1855-1864. doi: 10.1021/acs.accounts.9b00213. Epub 2019 Jun 25.
For decades, plasmonic nanoparticles have been extensively studied due to their extraordinary properties, related to localized surface plasmon resonances. A milestone in the field has been the development of the so-called seed-mediated growth method, a synthetic route that provided access to an extraordinary diversity of metal nanoparticles with tailored size, geometry and composition. Such a morphological control came along with an exquisite definition of the optical response of plasmonic nanoparticles, thereby increasing their prospects for implementation in various fields. The susceptibility of surface plasmons to respond to small changes in the surrounding medium or to perturb (enhance/quench) optical processes in nearby molecules, has been exploited for a wide range of applications, from biomedicine to energy harvesting. However, the possibilities offered by plasmonic nanoparticles can be expanded even further by their careful assembly into either disordered or ordered structures, in 2D and 3D. The assembly of plasmonic nanoparticles gives rise to coupling/hybridization effects, which are strongly dependent on interparticle spacing and orientation, generating extremely high electric fields (hot spots), confined at interparticle gaps. Thus, the use of plasmonic nanoparticle assemblies as optical sensors have led to improving the limits of detection for a wide variety of (bio)molecules and ions. Importantly, in the case of highly ordered plasmonic arrays, other novel and unique optical effects can be generated. Indeed, new functional materials have been developed via the assembly of nanoparticles into highly ordered architectures, ranging from thin films (2D) to colloidal crystals or supercrystals (3D). The progress in the design and fabrication of 3D supercrystals could pave the way toward next generation plasmonic sensors, photocatalysts, optomagnetic components, metamaterials, etc. In this Account, we summarize selected recent advancements in the field of highly ordered 3D plasmonic superlattices. We first analyze their fascinating optical properties for various systems with increasing degrees of complexity, from an individual metal nanoparticle through particle clusters with low coordination numbers to disordered self-assembled structures and finally to supercrystals. We then describe recent progress in the fabrication of 3D plasmonic supercrystals, focusing on specific strategies but without delving into the forces governing the self-assembly process. In the last section, we provide an overview of the potential applications of plasmonic supercrystals, with a particular emphasis on those related to surface-enhanced Raman scattering (SERS) sensing, followed by a brief highlight of the main conclusions and remaining challenges.
几十年来，由于其局域表面等离激元共振相关的非凡性质，等离子体纳米粒子得到了广泛的研究。该领域的一个里程碑是所谓的种子介导生长方法的发展，这是一种合成途径，它提供了对具有定制尺寸、几何形状和组成的金属纳米粒子的非凡多样性的访问。这种形态控制伴随着对等离子体纳米粒子的光学响应的精确定义，从而增加了它们在各个领域的应用前景。表面等离激元对周围介质中微小变化的敏感性，或者对附近分子中光学过程的扰动（增强/猝灭），已经被广泛应用于从生物医学到能量收集的各种应用中。然而，通过将等离子体纳米粒子精心组装成无序或有序的 2D 和 3D 结构，甚至可以进一步扩展等离子体纳米粒子的可能性。等离子体纳米粒子的组装会产生耦合/杂化效应，这些效应强烈依赖于粒子间的间距和取向，从而产生极其高的电场（热点），局限在粒子间的间隙中。因此，将等离子体纳米粒子组装体用作光学传感器可以提高各种（生物）分子和离子的检测极限。重要的是，在高度有序的等离子体阵列的情况下，可以产生其他新颖和独特的光学效应。事实上，已经通过将纳米粒子组装成高度有序的结构来开发出新型功能材料，范围从薄膜（2D）到胶体晶体或超晶体（3D）。3D 超晶体设计和制造方面的进展可能为下一代等离子体传感器、光催化剂、光磁组件、超材料等铺平道路。在本综述中，我们总结了高度有序的 3D 等离子体超晶格领域的一些最新进展。我们首先分析了它们在各种系统中的迷人光学性质，这些系统的复杂性逐渐增加，从单个金属纳米粒子到具有低配位数的粒子簇，再到无序自组装结构，最后是超晶体。然后，我们描述了 3D 等离子体超晶体的制造的最新进展，重点介绍了特定的策略，但没有深入研究自组装过程中起作用的力。最后一节概述了等离子体超晶体的潜在应用，特别强调了与表面增强拉曼散射（SERS）传感相关的应用，随后简要强调了主要结论和剩余挑战。
