基于聚苯乙烯微球等离激元材料的制备及SERS应用研究进展

Plasmonic Materials Fabricated by Polystyrene Microbeads for Surface-Enhanced Raman Spectroscopic Applications

等离激元是一种存在于电介质和导体界面的电子集体振荡的电磁模式,产生该电磁模式的载体被称之为等离激元材料。通过对等离激元材料的合理设计与构建,可以在纳米尺度实现对光的精确操控,从而获得具有独特光学性质的等离激元材料。在众多的等离激元材料合成策略中,聚苯乙烯微球模板法因其普适、简单、高效、精密等优点被应用于周期性等离激元材料制备。目前,基于该方法已经在二维和三维尺度内实现了几十纳米到几微米范围内高性能周期性等离激元材料的精细化可控制备。周期性表面等离激元材料作为一种兼具高重现性和高增强活性基底,在表面增强拉曼领域获得了广泛的应用。在本综述中,首先简要概述了聚苯乙烯微球的可控自组装和多策略的模板改性方法,然后详细的阐述了极具代表性周期性等离激元材料设计合成工艺以及性能优化策略,最后探讨了周期性等离激元材料在表面增强拉曼领域的前沿热点应用和发展近况。

Plasmon is a kind of electromagnetic mode that exists in the interface between the dielectric and the conductor.Especially for precious metals(gold,silver,copper,platinum,etc.),the freely oscillating electrons on their surface can easily couple with excited photons,inducing the resonance of local surface plasmon.The materials with this unique physical characteristic are generally defined as plasmonic materials,which has attracted extensive attention in the field of nanophotonics due to their superior optical properties of concentrating light beyond the diffraction limit.Among these materials,periodic plasmonic materials exhibit strong tunability and extraordinary light field confinement capabilities,which significantly increase the absorption of photons and enhance the electromagnetic field within the nanometer scale.There have been many synthetic pathways to fabricate plasmonic materials.Typically,the conventional lithography techniques are dominated by ion beam lithography and electron beam lithography;however,such techniques are limited in terms of practical application due to their low-yield,high-cost and excessive reliance on large-scale equipment.Alternatively,the unconventional polystyrene microsphere template technique featuring advantages of high-throughput and low-cost has been prioritized as the universal,facile,efficient and precise synthetic route for the large-scale production.At present,based on this technique,the refined and controllable preparation of high-performance periodic plasmonic materials ranging from tens of nanometers to several micrometers in terms of size has been realized on two-dimensional and three-dimensional scales,such as nanopore array,nanocavity array,nanorod array,nanohole array,nanotriangular array,nanotube array,and some other composite periodic array structures.These periodic plasmonic materials,as an active substrate with high reproducibility and reinforcement,have been widely applied in the field of surface enhanced Raman spectroscopy.In this review,diverse approaches that have been developed to control the self-assembly of polystyrene microspheres and the multi-strategy template modification methods are first briefly introduced followed by the in-depth discussion about the design and synthesis of some representative periodic plasmonic materials.Finally,a comprehensive review about the latest frontier applications of periodic plasmonic materials was presented in the field of surface enhanced Raman spectroscopy.The purpose of this review is to motivate researchers to design ingenious and more practical periodic plasmonic materials,and to promote the rapid development and practical applications of these advanced materials in the field of surface enhanced Raman spectroscopy.