表面增强拉曼散射基底的研究进展

表面增强拉曼光谱(SERS)由于其高的灵敏度、抗干扰能力强等优点,被广泛应用在表面科学、分析化学、物理学等领域,是研究表面和界面过程的重要工具,是定性鉴定化学组成相近化合物的有力手段.因此,高品质、高活性的SERS基底一直是科研工作者们追求和研究的重点.本文对SERS活性基底的发展进行了介绍,从金、银金属纳米粒子作为基底的拉曼效应的科学研究,又进一步总结了非金属纳米粒子ZnO、TiO₂、ZnS、Cu₂O、CdTe、CdS等SERS基底.今后,将贵金属与半导体纳米材料复合将是SERS基底的研究热点.SERS光谱目前可以在液相色谱分析的检测器、医学检测仪器、刑侦分析检测等众多领域得到应用.     

应用表面增强拉曼光谱检测儿童化妆品中二噁烷的研究

文章以金纳米粒子作为表面增强拉曼散射(SERS)基底,用SERS法检测儿童化妆品中的二噁烷含量。探讨了儿童化妆品中其它物质和金纳米粒子作为SERS基底对儿童化妆品中二噁烷SERS特征峰的影响。     

自组装纳米阵列SERS基底的发展及应用进展

表面增强拉曼散射(SERS)的谱峰窄以及分子指纹特性使其在分析化学、环境检测、生物医药及食品安全等领域具有广泛应用。而稳定、均一、重复性好的SERS活性基底的制备至关重要。自组装法可制备出均一、稳定、高度有序、可控的纳米阵列,提高SERS检测的重现性和灵敏度。本文对自组装纳米阵列技术制备SERS活性基底及SERS的应用进行了综述。     

基于LSPR效应的高活性SERS基底研究进展

简要介绍了表面增强拉曼散射(SERS)的发展历程及拉曼增强机理,重点综述了不同类型SERS基底:简单SERS基底、复合SERS基底和多功能活性基底的特点和研究应用进展,最后展望了SERS基底的研究方向和发展趋势。     

基于LSPR效应的高活性SERS基底研究进展

简要介绍了表面增强拉曼散射(SERS)的发展历程及拉曼增强机理,重点综述了不同类型SERS基底:简单SERS基底、复合SERS基底和多功能活性基底的特点和研究应用进展,最后展望了SERS基底的研究方向和发展趋势。     

自组装金纳米粒子薄膜SERS研究

采用静电自组装技术制备了金纳米粒子薄膜,研究了薄膜的表面增强拉曼散射(SERS)活性。自组装金纳米粒子薄膜具有明显的SERS效应,其中2双层薄膜的增强效应最强。金纳米粒子相互靠近但又不至于连通的状态具有最强的增强效果。若金纳米粒子通过点、面接触形成连通网络,将导致入射光激发表面等离子体波的机率下低,使增强效果降低。     

金纳米星的制备及对塑化剂的快速检测

采用两步法合成了金纳米星,通过消光光谱和透射电镜的表征,发现金纳米星的表面有多个针尖状纳米结构。针尖状结构末端的尺寸5～10 nm,可形成多个拉曼热点。将其作为表面增强拉曼散射(SERS)活性基底,通过拉曼光谱检测了塑化剂DBP的含量,检出限可达到10 ng。金纳米星可作为一种灵敏的SERS活性基底为食品、生活用品等环境中的塑化剂提供快速的检测。     

MOF@ Ag-TiN纳米管阵列复合SERS基底构筑及性能研究

通过阳极氧化结合氨气还原氮化法制备了氮化钛纳米管阵列结构，再利用电化学沉积技术结合原位生长法制备出MOF@Ag-TiN复合SERS基底。结果表明，所制备的MOF@Ag-TiN复合基底存在面心立方晶型TiN、银单质和钴基MOF三种物相，通过扫面电镜技术发现TiN纳米管阵列结构均匀完整，银纳米粒子均匀分布在阵列结构表面，同时基底表面包覆有形状规则的MOF纳米粒子。MOF@Ag-TiN复合基底具有较好的拉曼增强性能，对探针分子R6G的检测限为10^-12 M,同时还具有良好的稳定性。     

多孔Fe2O3-Ag纳米复合材料的制备及其在表面增强Raman散射光谱中应用EI北大核心CSCD

以多孔α-Fe2O3作为固相载体,通过水热合成法在α-Fe2O3孔道内沉积银纳米粒子。测试4种不同硝酸银用量时Fe2O3-Ag复合物的表面增强Raman散射光谱性能(SERS)。利用扫描电子显微镜、透射电子显微镜、X射线衍射和N2吸附等表征手段对Fe2O3-Ag复合物结构及组成进行分析表征。结果表明,当银纳米粒子的负载量为6.5%时(质量分数),Fe2O3-Ag纳米复合物的比表面积为26.57 m2/g,增强因子可以达到102~103,SERS活性最好。所制备的Fe2O3-Ag纳米复合物具有良好的SERS活性和吸附性能,可以进一步应用于其他待测物的吸附检测。     

多孔Fe_2O_3-Ag纳米复合材料的制备及其在表面增强Raman散射光谱中应用

以多孔α-Fe_2O_3作为固相载体,通过水热合成法在α-Fe_2O_3孔道内沉积银纳米粒子。测试4种不同硝酸银用量时Fe_2O_3-Ag复合物的表面增强Raman散射光谱性能(SERS)。利用扫描电子显微镜、透射电子显微镜、X射线衍射和N_2吸附等表征手段对Fe_2O_3-Ag复合物结构及组成进行分析表征。结果表明,当银纳米粒子的负载量为6.5%时(质量分数),Fe_2O_3-Ag纳米复合物的比表面积为26.57 m~2/g,增强因子可以达到10~2～10~3,SERS活性最好。所制备的Fe_2O_3-Ag纳米复合物具有良好的SERS活性和吸附性能,可以进一步应用于其他待测物的吸附检测。     

表面增强拉曼散射及其在缓蚀剂研究中的应用

表面增强拉曼散射技术作为一种提供分子结构信息的分析手段,具有广泛的应用前景。综述了表面增强拉曼散射技术的基本原理、特点和增强机理,介绍了表面增强拉曼散射技术在缓蚀剂研究中的应用,展望了表面增强拉曼散射技术的发展动态。     

一种新的能产生强SERS谱的金电极粗糙方法

首次提出利用金电极在2 M HCl中阳极溶解时的歧化反应(Au+→Au3++Au0)进行表面粗糙的方法。这种方法能产生很好的SERS基底,对吸附在金电极表面的探针吸附子如氯离子和吡啶起到强而稳定的增强作用。原子力显微镜AFM结果显示在电极粗糙过程中由于金的再沉积形成了均匀的直径约为200～400 nm的椭圆形和球形金粒,是一种深度粗糙方法,我们提出了可能的表面激活的SERS增强机理。     

Zn-Ni合金共沉积影响机理的拉曼光谱研究

首次利用现场表面增强拉曼光谱研究了Zn-Ni合金共沉积的机理。通过研究Ni电极在NiCl2溶液与纯水中的拉曼光谱、Ni电极与Au电极在KCl溶液中的拉曼光谱以及这2种电极在NiCl2溶液中现场电沉积的拉曼光谱,并根据前人提出的理论,得出如下结论:Zn-Ni合金共沉积中存在着较易在电极表面放电的NiClad,使Ni沉积的过电位降低,促进了Ni的沉积,导致Zn的异常共沉积。     

Characterization of Polyphasic Silicon Carbide Using Surface-Enhanced Raman and Nuclear Magnetic Resonance Spectroscopy

The present report explores the use of cross-polarization (CP) and single-pulse magic angle spinning nuclear magnetic resonance (MAS-NMR) as well as normal and surfaceenhanced Raman spectroscopy (SERS), in concert, for characterizing highly crystalline polymorphic silicon carbide ceramics. The combined use of these techniques provides a wealth of information regarding bulk, near-surface, and surface speciation. Both Raman and SERS are promising techniques for fracture surface characterization of these systems. The application of CPMAS-NMR and SERS to the study of ceramics is reported for the first time in this investigation.     

Excitation wavelength dependent surface enhanced Raman scattering of 4-aminothiophenol on gold nanorings

Detailed understanding of the underlying mechanisms of surface enhanced Raman scattering (SERS) remains challenging for different experimental conditions. We report on an excitation wavelength dependent SERS of 4-aminothiophenol molecules on gold nanorings. SERS and normal Raman spectra, combined with well-characterized surface morphology, optical spectroscopy and electromagnetic (EM) field simulations of gold nanoring substrates indicate that the EM enhancement occurs at all three excitation wavelengths (532, 633 and 785 nm) employed but at short wavelengths (532 and 633 nm) charge transfer (CT) results in additional strong enhancements of particular Raman transitions. These results pave the way to further understanding the origin of the SERS mechanism.     

吡啶-氯化钾水溶液/n型硫化镉电极界面上的表面增强喇曼散射

本文研究了在吡啶-KC1水溶液中吡啶吸附在n-CdS电极上的表面增强喇曼散射(SERS)。在光照下,CdS电极经过正极化予处理数分钟,就能观察到吡啶吸附在CdS电极上的很强的SERS谱。其特征峰是1010和1036cm~(-1)与纯吡啶的喇曼特征峰991,1030cm~(-1)相比有了明显位移。又SERS谱随着吡啶浓度的增加而增强。外加电位对SERS也有一定影响,其曲线形状与CdS的I～V曲线很相似。对这些实验结果,本文用n型CdS电极的光电化学特性进行了初步的考察和讨论。     

Flexible and mechanical strain resistant large area SERS active substrates

We report a cost effective and facile way to synthesize flexible, uniform, and large area surface enhanced Raman scattering (SERS) substrates using an oblique angle deposition (OAD) technique. The flexible SERS substrates consist of 1 μm long, tilted silver nanocolumnar films deposited on flexible polydimethylsiloxane (PDMS) and polyethylene terephthalate (PET) sheets using OAD. The SERS enhancement activity of these flexible substrates was determined using 10(-5) M trans-1,2-bis(4-pyridyl) ethylene (BPE) Raman probe molecules. The in situ SERS measurements on these flexible substrates under mechanical (tensile/bending) strain conditions were performed. Our results show that flexible SERS substrates can withstand a tensile strain (ε) value as high as 30% without losing SERS performance, whereas the similar bending strain decreases the SERS performance by about 13%. A cyclic tensile loading test on flexible PDMS SERS substrates at a pre-specified tensile strain (ε) value of 10% shows that the SERS intensity remains almost constant for more than 100 cycles. These disposable and flexible SERS substrates can be integrated with biological substances and offer a novel and practical method to facilitate biosensing applications.     

基于Ostwald ripening自组装工艺的银纳米颗粒活性衬底的高稳定性

利用Ostwald ripening自组装工艺对拉曼增强衬底进行处理,得到粒径和密度不同的银纳米颗粒拉曼增强衬底。用龙胆紫生物大分子作为探针,对其表面增强拉曼散射（SERS）和表面增强荧光（SEF）进行研究发现,拉曼和荧光光谱强度存在着相似的变化趋势,且随着自组装工艺时间的递增,强度的变化趋于稳定。研究结果表明：Ostwald ripening自组装工艺可以优化SERS和SEF增强效果及其稳定性,故其可为研制具有长期稳定性、低成本的基于SERS和SEF效应生物化学传感器件提供研究基础。     

Surface-Enhanced Raman Scattering from Dye Molecules in Silicon Nanowire Structures Decorated by Gold Nanoparticles

Silicon nanowires (SiNWs) prepared by metal-assisted chemical etching of crystalline silicon wafers followed by deposition of plasmonic gold (Au) nanoparticles (NPs) were explored as templates for surface-enhanced Raman scattering (SERS) from probe molecules of Methylene blue and Rhodamine B. The filling factor by pores (porosity) of SiNW arrays was found to control the SERS efficiency, and the maximal enhancement was observed for the samples with porosity of 55%, which corresponded to dense arrays of SiNWs. The obtained results are discussed in terms of the electromagnetic enhancement of SERS related to the localized surface plasmon resonances in Au-NPs on SiNW’s surfaces accompanied with light scattering in the SiNW arrays. The observed SERS effect combined with the high stability of Au-NPs, scalability, and relatively simple preparation method are promising for the application of SiNW:Au-NP hybrid nanostructures as templates in molecular sensorics.     

Monitoring enzymatic degradation of pericellular matrices through SERS stamping

We introduce a surface enhanced Raman spectroscopy (SERS) stamping approach for acquiring cell-surface specific vibrational spectra of individual living cells under physiological conditions. The SERS stamping approach utilizes a nanostructured metal surface on top of a lithographically defined piston that can be translated in 3-dimensions with nanometer resolution to contact living cells in solution with a pristine metal surface. We applied this approach to characterize the chemical composition of the cellular surface of living MCF7 breast cancer cells and to monitor its change upon addition of the enzyme hyaluronidase, which degrades major constituents of the pericellular matrix. Although the cell surface spectra show significant cell-to-cell fluctuations, a statistical barcode analysis of the spectra ensembles reveals systematic changes in the cell surface SERS spectra upon addition of hyaluronidase, which are consistent with a thinning of the pericellular matrix.