表面增强拉曼光谱技术研究进展

表面增强拉曼光谱(SERS)具有检测灵敏度高、分析速度快等优点,是一种颇具潜力的痕量分析技术。SERS技术的关键在于通过机理研究制备出稳定性高、灵敏度高、重现性好的活性基底,从而实现痕量物质的定量分析。对SERS活性基底的发展和SERS在一些领域的应用进行了综述,提出了亟待解决的问题。     

静电纺纳米复合纤维柔性表面增强拉曼散射传感基底的研究进展

表面增强拉曼散射(Surface enhanced Raman scattering,SERS)是一种分子检测光谱技术,借助SERS基底,可对生物、化学等复杂体系中的痕量分子进行分析。 其中静电纺纳米纤维SERS基底由于具有高比表面积、可透气透水、柔韧可折叠弯曲等特点,在复杂体系中提取、过滤、浓缩痕量分子等应用场景中,其表面结构具有其他刚性SERS基底不可比拟的优势。然而,静电纺纳米纤维SERS基底的发展却受到制备方法的限制,存在检测灵敏度较低、制备过程复杂等问题。 因此,目前的研究工作主要集中在新型制备方法及工艺的开发。 本文综述了静电纺纳米金银复合纤维SERS基底的几种常用制备方法,包括直接混合纺丝法、化学吸附法、静电吸附法、物理沉积法和原位化学还原法,并总结了静电纺纳米纤维SERS基底在复杂体系中提取、过滤、浓缩待测分子的应用,最后对静电纺纳米复合纤维SERS基底的发展进行了展望。     

基于贵金属纳米粒子的SERS活性基底研究进展

表面增强拉曼光谱(SERS)是一种新兴的分析技术,具有很高的检测灵敏度,可以实现单分子量级的检测,并且能够提供丰富的分子结构信息。将SERS发展成为一种具有实际应用意义的分析技术,其关键是制备灵敏度高、稳定性高、重现性好、选择性高的SERS活性基底。对贵金属纳米粒子表面进行分子修饰,或者将贵金属纳米粒子与基质材料进行复合,可以组成融合贵金属纳米粒子的SERS活性并弥补其缺陷的新型SERS基底材料。本文综述了近年来基于贵金属纳米粒子常见的分子修饰和基质复合型SERS活性基底的研究进展。     

基于聚合物／金属纳米结构镶嵌型柔性基底的表面增强拉曼光谱技术

表面增强拉曼光谱（SERS）技术可极大增强传统拉曼光谱的信号强度,从而拓展拉曼光谱的应用范围．针对SERS技术在分析对象、分析环境的普适性和分析效率方面的限制,本文设计并发展了一种透明、柔性、自支撑SERS基底的制备、保存和使用方法．该基底由聚合物聚甲基丙烯酸甲酯（PMMA）和在其表面镶嵌的金属纳米结构组成,可以通过背入射法用于任意形貌样品表面的直接和在线检测．柔性SERS（Ag）基底在R6G水溶液表面的检测限小于1pmol／L．     

基于“热点”结构的表面增强拉曼散射基底构建策略

表面增强拉曼散射(SERS)技术以其独特的性质和优势,已在生物医学、分子识别、痕量检测、材料研究等众多领域得到了越来越广泛的应用。制备出成本低廉、性能优良的SERS基底是推动SERS技术进一步发展,实现SERS技术更加广泛应用于各个领域的关键之一。本文综述了SERS基底的基本制备方法,总结了基于"热点"结构的一维、二维和三维基底构建策略,并对未来SERS基底的研究动向进行了展望。     

基于Au-Ag合金的EC-SERS光谱监测多巴胺氧化还原反应

采用一锅法即柠檬酸盐还原法合成了大小形貌均匀的Au-Ag纳米颗粒,接着利用咖啡环效应,在ITO玻璃表面固定Au-Ag纳米颗粒,制备出了具有表面增强拉曼散射（SERS）响应的活性基底,该基底表现出优异的SERS重现性与均一性。将其作为EC-SERS的工作电极,通过电化学和SERS相结合的方法来检测Au-Ag表面多巴胺（苯酚）和多巴胺（苯醌）的光谱性质,发现可采用H2O2和GSH调制其在1270、1335和1455 cm-1处的SERS光谱强度。最后通过恒电位法探究了多巴胺（DA）在电极上氧化还原的电位依赖性变化,为研究其氧化还原性质提供了新的依据。     

基于MOF@TiN-Ag/银溶胶复合基底的茶碱表面增强拉曼检测

以制备的MOF@TiN-Ag/银溶胶复合基底为表面增强拉曼光谱(SERS)活性基底，对茶碱进行SERS检测，探讨了基于该复合基底的表面增强拉曼技术在药物检测方面的应用。首先，利用电化学阳极氧化结合氨气还原氮化法制备了氮化钛纳米管阵列，随后通过电化学沉积法制备TiN-Ag复合基底，并在其表面原位生长金属有机框架(MOF)包覆层得到MOF@TiN-Ag复合基底，将茶碱与银溶胶混合后滴加在该复合基底上进行表面增强拉曼光谱检测。结果表明，MOF@TiN-Ag/银溶胶复合基底中存在面心立方晶型TiN、金属单质Ag和MOF钴基3种物相；扫描电镜结果显示，TiN纳米管排列整齐，Ag纳米结构呈树枝状均匀分散在其表面；作为隔绝层的MOF粒子形状规整，覆盖在TiN-Ag表面；银溶胶纳米粒子呈圆球状分布在MOF@TiN-Ag复合基底表面。由于银纳米粒子与TiN-Ag复合基底可发生协同增强作用，加之MOF的富集特性，使得该复合基底具有优异的SERS性能，其对茶碱溶液的SERS检出限为1×10^-5 mol/L，检测性能良好。所制备的MOF@TiNAg/银溶胶复合基底拓宽了SERS在药物检测...     

用于低浓度三聚氰胺选择性检测的铝/银纳米传感器的组装及其SERS性能

通过置换法在铝板上快速制备了一种即插即用型的Al/Ag纳米表面增强拉曼光谱(SERS)活性基底。结果表明该SERS基底较好地解决了银纳米颗粒在支撑物质上的吸附问题,能够快速实现对三聚氰胺的检测,而且具有操作简单、成本低、无损伤检测等优点,最低检测浓度能达到10^-7 mol·L^-1,满足国家食品安全要求的最低标准。另外,Al/Ag活性基底对三聚氰胺检测具有较高的拉曼测试重现性,连续测定15 h的过程中拉曼强度波动不大;且该Al/Ag活性基底能够在三乙醇胺、N,N-二甲基甲酰胺和1,2-丙二胺等胺类物质中实现对三聚氰胺的选择性检测。     

银纳米材料表面增强拉曼散射基底研究进展

表面增强拉曼散射（SERS）技术在环境保护、食品工业、医学检测、生物检测等领域有广泛的应用前景。SERS基底材料和结构是影响性能的关键因素,而银纳米材料SERS基底已被广泛应用。本文介绍了SERS基底的增强机理,对近年来纯银纳米材料和银基复合纳米材料SERS基底的研究进展进行了综述,并介绍了银纳米材料SERS基底发展面临的问题,对其发展趋势进行了分析和展望。     

一种新型表面增强拉曼活性基底的制备方法

表面增强拉曼光谱技术 (SERS)具有极高的灵敏度 ,对某些分子其灵敏度比常规拉曼光谱高一百万倍 ,能检测吸附在金属表面的单分子层和亚单分子层的分子 ,并提供丰富的分子结构信息 [1～ 5] .活性基底的制备是获得 SERS信号的前提 ,电化学粗糙化的电极、贵金属溶胶及真空蒸镀的金属岛膜是SERS分析中最常用的 3种活性基底 ,在实际应用中各有利弊 .本文报道一种新的制备银纳米粒子基底的方法 ,可使银纳米粒子生长到合适的尺寸 ,以达到最佳SERS增强效果 .利用紫外 -可见光谱和 AFM研究该 SERS基底纳米粒子的尺寸分布和形貌 ,以 1 ,4-(双…     

Surface-enhanced Raman spectroscopy: substrate-related issues

After over 30 years of development, surface-enhanced Raman spectroscopy (SERS) is now facing a very important stage in its history. The explosive development of nanoscience and nanotechnology has assisted the rapid development of SERS, especially during the last 5 years. Further development of surface-enhanced Raman spectroscopy is mainly limited by the reproducible preparation of clean and highly surface enhanced Raman scattering (SERS) active substrates. This review deals with some substrate-related issues. Various methods will be introduced for preparing SERS substrates of Ag and Au for analytical purposes, from SERS substrates prepared by electrochemical or vacuum methods, to well-dispersed Au or Ag nanoparticle sols, to nanoparticle thin film substrates, and finally to ordered nanostructured substrates. Emphasis is placed on the analysis of the advantages and weaknesses of different methods in preparing SERS substrates. Closely related to the application of SERS in the analysis of trace sample and unknown systems, the existing cleaning methods for SERS substrates are analyzed and a combined chemical adsorption and electrochemical oxidation method is proposed to eliminate the interference of contaminants. A defocusing method is proposed to deal with the laser-induced sample decomposition problem frequently met in SERS measurement to obtain strong signals. The existing methods to estimate the surface enhancement factor, a criterion to characterize the SERS activity of a substrate, are analyzed and some guidelines are proposed to obtain the correct enhancement factor.     

Novel Bottom‐Up SERS Substrates for Quantitative and Parallelized Analytics

Surface‐enhanced Raman spectroscopy (SERS) is an emerging technology in the field of analytics. Due to the high sensitivity in connection with specific Raman molecular fingerprint information SERS can be used in a variety of analytical, bioanalytical, and biosensing applications. However, for the SERS effect substrates with metal nanostructures are needed. The broad application of this technology is greatly hampered by the lack of reliable and reproducible substrates. Usually the activity of a given substrate has to be determined by time‐consuming experiments such as calibration or ultramicroscopic studies. To use SERS as a standard analytical tool, cheap and reproducible substrates are required, preferably with a characterization technique that does not interfere with the subsequent measurements. Herein we introduce an innovative approach to produce low‐cost and large‐scale reproducible substrates for SERS applications, which allows easy and economical production of micropatterned SERS active surfaces on a large scale. This approach is based on an enzyme‐induced growth of silver nanostructures. The special structural feature of the enzymatically deposited silver nanoparticles prevents the breakdown of SERS activity even at high particle densities (particle density >60 %) that lead to a conductive layer. In contrast to other approaches, this substrate exhibits a relationship between electrical conductivity and the resulting SERS activity of a given spot. This enables the prediction of the SERS activity of the nanostructure ensemble and therewith the controllable and reproducible production of SERS substrates of enzymatic silver nanoparticles on a large scale, utilizing a simple measurement of the electrical conductivity. Furthermore, through a correlation between the conductivity and the SERS activity of the substrates it is possible to quantify SERS measurements with these substrates.     

表面增强拉曼光谱技术在快速、灵敏检测食源性致病菌中的应用

食源性致病菌的快速、灵敏检测是食品和药品安全领域关注的重点.表面增强拉曼光谱(SERS)技术凭借其检测速度快、信息丰富、灵敏度高、无损等优势在食源性致病菌的快速、灵敏检测中受到广泛关注.本文从SERS检测基底材料入手,综述了液相基底、刚性固相基底、柔性固相基底等材料的特点和性能,并对其在致病菌快速、灵敏检测中的应用进行...     

Silver Nanostructures on Graphene Oxide as the Substrate for Surface-Enhanced Raman Scattering (SERS)

Nanosized surface-enhanced Raman scattering (SERS) substrates fabricated by the controlled growth of metal nanostructures on water-dispersed two-dimensional nanomaterials can open a new avenue for SERS analysis of liquid samples in biological fields. In this work, regular and uniform Ag nanostructures were grown on the surface of graphene oxide (GO) through a microwave-assisted hydrothermal method. Polyamidoamine (PAMAM) dendrimers were assembled on the surface of GO to form GO/PAMAM templates for growing Ag nanostructures, which are primarily comprised of Ag dimers and trimers. The prepared Ag/GO nanocomposites are highly dispersed and stable in aqueous solution and may be used as substrates for enhanced Raman detection of rhodamine 6?G (R6G) in aqueous solution. This special substrate provides high-performance SERS and suppresses R6G fluorescence in aqueous solution and is promising as a nanosized material for the enhanced Raman detection of liquid samples in biological diagnostics.     

食源性致病菌的表面增强拉曼光谱检测技术研究进展

食源性致病菌引起的疾病的快速管控与预防是当前各国面临的食品安全监管难题之一,受到社会各界的广泛关注.目前常用的食源性致病菌检测方法存在步骤复杂、耗时、灵敏度低或选择性差等局限,发展快速、可靠的食源性致病菌检测方法仍是食品安全和公众健康的热点研究领域.表面增强拉曼光谱(SERS)作为一种新型的光谱快检技术,具有灵敏度高、...     

Sub-wavelength Raman spectroscopy on isolated silver islands

Surface Enhanced Raman Spectroscopy (SERS) is a valuable analytical tool for the investigation of molecules adsorbed on roughened noble metal surfaces. The shape, size, and surrounding of the metal protrusions play an important role in the Raman scattering enhancement. By combining scanning near-field optical microscopy (SNOM) with Raman spectroscopy the spatial resolution suffices for investigating isolated silver islands on SERS active substrates. We demonstrate an optical resolution below 70 nm for recording spectra on specifically prepared and fully characterized SERS substrates. For a quantitative evaluation of the SERS signal the spatial distribution of Rhodamine 6G (R6G) deposited on the SERS substrate was determined by friction force measurements. By comparing the Raman intensities of the SERS substrates with those of unmetallized support plates absolute SERS enhancement factors at specific locations on top and in the vicinity of the silver islands were determined directly.     

Surface-enhanced Raman scattering substrates fabricated using electroless plating on polymer-templated nanostructures

Surface-enhanced Raman scattering (SERS) has great potential as an analytical technique based on the unique molecular signatures presented even by structurally similar analyte species and the minimal interference of scattering from water when sampling in aqueous environments. Unfortunately, analytical SERS applications have been restricted on the basis of limitations in substrate design. Herein, we present a simple SERS substrate that exploits electroless deposition onto a nanoparticle-seeded polymer scaffold that can be fabricated quickly and without specialized equipment. The polymer-templated nanostructures have stable enhancement factors that are comparable to the traditional silver film over nanospheres (AgFON) substrate, broad localized surface plasmon resonance spectra that allow various Raman excitation wavelengths to be utilized, and tolerance for both aqueous and organic environments, even after 5 day exposure. These polymer-templated nanostructures have an advantage over the AgFON substrate based on the ease of fabrication; specifically, the ability to generate fresh SERS substrates outside the laboratory environment will facilitate the application of SERS to new analytical spectroscopy applications.     

等离激元激励表面增强拉曼光谱检测技术与仪器

本文总结了近年来基于传播型表面等离激元（Propagafingsurfaceplasmons,PSPs）参与的表面增强拉曼（Surface—enhancedRamanscattering,SERS）技术和仪器方面的研究进展．内容主要包括3部分：（1）基于PSPs激励拉曼散射的装置和技术,包括在消逝场下激发PSPs共振增强拉曼的原理与装置、与表面等离子体共振（Surfaceplasmonresonance,SPR）传感技术的联用及新型结构的长程等离激元激励拉曼技术的研究进展;（2）通过引入局域型表面等离激元（Localizedsurfaceplasmons,LSPs）进一步增强SERS,进而实现PSPs-LSPs共同增强拉曼的超灵敏检测技术,包括在消逝场激发的PSPs基础上,增加纳米粒子实现的PSPs与LSPs共同增强拉曼的原理、装置,以及用该方法进行生物体系的免疫识别检测,此外,还在微纳周期结构上实现了PSPs与LSPs共同激励拉曼;（3）基于PSPs耦合的定向SERS技术,包括在消逝场结构和周期结构上实现SERS定向耦合发射以达到高激发和高收集效率的新技术．