基于光力捕获金纳米立方体的拉曼光谱增强  

Enhancement of Raman Spectra Based on Optical Trapping of Gold Nanocubes

作　　者：荣升 刘洪双 钟莹[2] 刘海涛[1] Rong Sheng;Liu Hongshuang;Zhong Ying;Liu Haitao(Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology,Institute of Modern Optics,College of Electronic Information and Optical Engineering,Nankai University,Tianjin 300350,China;State Key Laboratory of Precision Measurement Technology and Instruments,School of Precision Instrument and Opto-Electrcmics Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]南开大学电子信息与光学工程学院现代光学研究所天津市微尺度光学信息技术科学重点实验室,天津300350 [2]天津大学精密仪器与光电子工程学院精密测试技术及仪器国家重点实验室,天津300072

出　　处：《光学学报》2021年第17期196-206,共11页Acta Optica Sinica

基　　金：国家自然科学基金(62075104,61775105)。

摘　　要：表面增强拉曼散射(SERS)是一种能够在低浓度(体积分数)下精确检测物质成分的光谱学技术。当采用金属纳米结构时,其局域表面等离激元共振(LSPR)导致的电磁场增强能够实现SERS增强。近年来,各种LSPR金属纳米结构被用于SERS研究,如纳米天线、纳米孔、纳米槽等。但这些结构一旦被加工完成后将不可改变,进而无法满足拉曼检测对灵活性的需求,而光镊能够解决这一问题。提出一种采用光力捕获金纳米立方体,并利用光热对流进一步促成金纳米立方体聚集的方法,实现了对低浓度(10^(-12) mol/L)下拉曼分子信号的显著增强和探测,并且其增强效果优于金纳米球。与传统的SERS相比,所提方法具有实时操作、动态操作和原位操作的优势,在生物细胞探测、物质成分与结构分析、分子传感等重要领域具有潜在的应用价值。Surface-enhanced Raman scattering(SERS)is a spectroscopic technique capable of accurately analyzing the compositions of materials at low concentration(volume fraction).In the case of metallic nanostructures,SERS enhancement is dependent on the electromagnetic field enhancement caused by the localized surface plasmon resonance(LSPR).In recent years,various LSPR metallic nanostructures are widely employed in SERS research,such as nanoantennas,nanoholes,and nanogrooves.However,once manufactured,these structures are immutable,which cannot meet the flexibility required by Raman detection.This problem can be solved by optical tweezers.In this paper,we develop a method of trapping gold nanocubes by optical force and facilitating gold nanocubes aggregation by photothermal convection.On this basis,the Raman signal at a low concentration(10-12 mol/L)is significantly enhanced and detected,with the enhancement effect being better than that of gold nanospheres.Compared with traditional SERS,the proposed method has the advantages of real-time operation,dynamic operation and in-situ operation,thus showing potential application values in many important fields such as biological cell detection,analysis of substance composition and structure,and molecular sensing.

关 键 词：光谱学 光镊 拉曼光谱 表面等离激元 纳米颗粒 

分 类 号：O436[机械工程—光学工程]