茶刺蛾颗粒体病毒包涵体的表面增强拉曼散射光谱研究

得到了茶刺蛾颗粒体病毒(DtGY)包涵体在银胶溶液中的表面增强拉曼散射(SERS)谱,并与其在水溶液中的一般拉曼散射(RS)谱作了比较分析。DtGV颗粒体外膜蛋白通过COO~-和NH_2基团吸附到银表面上。Tyr和Phe残基侧链远离金属表面,而Trp残基侧链接近银表面。多肽链被蛋白质中氨基酸残基侧链所屏蔽而妨碍有关振动的有效增强。     

马尾松毛虫核型多角体病毒粒子的SERS谱研究

获得并研究了马尾松毛虫核型多角体病毒粒子在银胶中的表面增强拉曼散射（ＳＥＲＳ）谱。ＳＥＲＳ谱的增强特性与ｐＨ值有关，其ＳＥＲＳ谱在ｐＨ＝８时获得了最好的增强，该粒子是通过其衣壳蛋白的ＣＯＯ和ＮＨ２基因吸附的银表面上，色氨酸（Ｔｒｐ）和酪氨酸（Ｔｙｒ）残基侧链远离银表面，酰胺Ｉ和酰胺Ⅲ的光谱带在ＳＥＲＳ谱中未出现，增强机制以化学增强为主。     

银胶体系中皮考酸的原位变温表面增强拉曼散射研究

研究了温度对皮考酸(2-吡啶羧酸)分子在银胶体系中表面增强拉曼散射(SERS)谱的影响。变温范围在22℃～80℃时,皮考酸吸附在银纳米颗粒表面的SERS谱是可逆的,说明银胶体系在此温度范围内是一种稳定的SERS活性基底。银胶与皮考酸的混合液在持续加热的过程中,SERS谱的整体强度增强,但各谱峰的相对强度变化不大,分析认为在22℃～80℃范围内,皮考酸分子在银纳米颗粒表面的吸附方式基本不变,一直以羧基和N原子上的孤对电子共同作用侧立吸附在银纳米颗粒表面,文中还解释了SERS强度整体增强的原因。     

氨基酸在银胶溶液中的表面增强拉曼效应

文章报道了通过制备合适的银胶盐纳米溶液 ,得到的甘氨酸、缬氨酸和赖氨酸在银胶溶液中的表面增强拉曼光谱。低波数 2 38cm-1谱带的出现 ,表明氨基酸分子已与银表面产生明显吸附。在所得SERS图谱中 ,表征C—C基团的 90 0～ 930cm-1谱带、表征NH2 基团的 110 0cm-1左右谱带和表征COO-基团的14 0 0cm-1附近的谱带振动都得到显著加强 ,其原因主要是通过羧基基团及氨基基团与银粒子表面产生吸附 ,增强机制属于化学增强 ,为短程效应。本实验中 ,当银胶溶液 pH值降低时 ,对拉曼散射的增强效果影响不大。     

温度对苯甲酸衍生物在银胶体系中的SERS的影响

本文报道了温度对银胶体系中的苯甲酸衍生物(PHBA,MHBA,SA)水溶液的表面增强拉曼散射(SERS)的影响。将苯甲酸衍生物水溶液与银溶胶混合后加热至沸腾,再冷却至室温(20℃左右)后测得SERS谱。将其与未加热混合液的SERS谱相比较发现这些分子加热前后的SERS谱中存在许多明显的差异。这种差异可能来自于苯甲酸衍生物在银胶颗粒表面的吸附方式的变化以及吸附的分子与溶液中残留的柠檬酸根在加热作用下发生的相互影响共同作用的结果。     

维生素C在不同PH值下的拉曼光谱和表面增强拉曼光谱

报道了维生素C(VC)的FT-拉曼光谱和在银胶基底上的表面增强拉曼光谱(SERS),并对它的拉曼特征谱带进行了初步的指认和归属.结合pH值的变化探讨了吸附作用的特点和规律.实验结果表明,1748、1651、1372、1256、562、446cm-1、和149cm-1处都能看到表面增强,VC的内酯环是以倾斜的方向吸附于银胶表面,并且VC分子是通过O-H键吸附在银胶表面上的,并在吸附过程中与银发生了电荷转移而形成负离子自由基,碳氧双键打开.     

苯甲酸的羟基取代物在银纳米颗粒表面的吸附行为的研究

分别以覆银滤纸和银胶溶液中的银纳米颗粒为基底,对苯甲酸的三种羟基取代物(n-HBA,n=P,M,O)进行了表面增强拉曼散射(SERS),发现PHBA分子在覆银滤纸上的SERS光谱和银胶中的SERS光谱明显不同,而MHBA分子和OHBA分子在两种基底上的SERS光谱却很相近。分析表明这些变化都来源于分子在银纳米颗粒表面吸附行为的变化,基底的表面特性和分子的表面构型对分子在基底表面的吸附行为会产生很大的影响。     

菜粉蝶颗粒体病毒包涵体在银胶中的表面增强拉曼光谱研究

本文讨论了菜粉蝶(preris rtpae)颗粒体病毒(简称 PrGV )包涵体在银胶中的表面增强拉曼光谱。PrGV 包涵体的 SERS 谱与其 RS 谱之间存在一定对应关系。PrGV 包涵体蛋白分子通过羧基和氨基基团吸附于银粒子表面,并构成阴离子形式(NU_2RCOO~-)存在于溶液中。PrGV 在银胶中的表面增强的增强机制属于短程作用。PrGV 包涵体与银胶表面的吸附主要是化学吸附。     

肿节风的表面增强拉曼光谱检测

提出一种基于表面增强拉曼光谱的中药材肿节风饮片的检测方法。采用柠檬酸三钠还原硝酸银制备银溶胶,以银胶纳米粒子为增强基底测得肿节风茎切片的表面增强拉曼光谱(SERS)。发现银胶直接作用于药材表面的SERS信号明显增强,肿节风茎切片SERS光谱中在637,1 176,1 309,1 476,1 612 cm^-1处都可观察到明显的拉曼特征峰。通过一阶导数拉曼光谱分析技术和对照品异嗪皮啶谱峰指认,可将获得的SERS峰位分别归属于吡喃酮环、甲氧基和酚羟基分子结构。研究结果表明,SERS技术可为肿节风和其他中草药的生产和质量监控提供一种快速、方便和直接的检测方法。     

非水电化学体系中激光照射时间对SERS光谱影响的实验研究

本文报道了非水电化学体系中激光照射时间对咪唑在甲醇溶剂中吸附在电化学粗糙了的银电极表面上的表面增强拉曼散射(SERS)效应的影响及咪唑吸附在银电极表面上的SERS谱的连续背景的研究。结果表明,甲醇介质中咪唑吸附在银电极表面上的SERS谱强度随激光照射时间而变化,并且咪唑在甲醇介质中的SERS谱背景较强。初步探讨了咪唑吸附在银电极表面上的SERS效应的增强机制。     

表面等离子体共振与表面增强拉曼散射相关性研究

本实验利用实验室搭建的SPR-SERS显微拉曼光谱仪同时检测了吸附在40 nm银膜上的4-amin-othiophenol(4-ATP)自组装膜的表面等离子体共振(Surface Plasmon Resonance,简称SPR)消光谱及表面增强拉曼散射(Surface-Enhanced Raman Scattering,简称SERS)光谱,研究了两者之间的相关性。实验发现随着SPR吸收的增强,SERS强度也急剧增强,在SPR共振角附近SERS强度是远离共振角处的20多倍。因此在共振角附近能够极大的提高SERS的检测灵敏度并扩展SERS的应用。     

The role of surface electronic states in surface enhanced raman scattering

The dependence of the surface enchanced Raman scattering (SERS) intensity on the electrode potential is considered in terms of the nonresonant adiabatic charge-transfer mechanism. Surface electronic states of a substrate metal are proposed to be responsible for the observed potential dependence of the SERS signal. The contribution of surface states to the nonlinear metal polarizability was found from electroreflectance spectra of silver single-crystals. Good agreement between the measured and calculated potential behaviour of the SERS signal was found for pyridine absorbed on the silver electrode.     

莽草酸FTIR，FT-Raman光谱及SERS研究

报道了莽草酸的FTIR,固态及饱和液态的FT-Raman光谱, 归属并分析了莽草酸分子内各基团的振动峰位及其相应基团在两种振动光谱中的振动峰位变化规律。利用表面增强拉曼散射(SERS)光谱及表面吸附选择定律研究了莽草酸在以银粒子为活性基底表面的吸附状态及其不同浓度变化对其SERS的影响,探讨了莽草酸在银粒子表面的吸附机理和规律。实验结果表明,红外与拉曼光谱结合较为全面地解析了莽草酸的分子结构中各基团的振动情况;获得了莽草酸在银粒子表面的最佳SERS效应的浓度范围, 莽草酸浓度小于1×10-3 mol·L-1时, 其SERS明显趋好;根据SERS作用机制,莽草酸的分子在银粒子表面的吸附主要是通过其羟基、羧基的电荷转移机制及其亚甲基、次甲基的电磁作用机制共同作用;其环内双键没有明显SERS表明其未能在银粒子表面产生有效吸附理。     

树枝状银微米材料的制备及其表面增强拉曼光谱研究

为使表面增量拉曼散射(SERS)衬底的制备方法简单快速且提高的基底增强效果,采用置换反应的制备方法,用锌片和硝酸银反应制备出微米银结构SERS活性基底,其具有稳定性好,易保存,制备方法简单,过程快速等特点。用扫描电子显微镜观察得银微米材料表面形貌呈均匀对称的树枝状结构。实验中控制置换反应的时间分别为40,50,60 s时,得到的树枝状银微米材料的长度分别为3,5,10 μm左右,分支分别为700 nm,2 μm,3 μm,发现随着置换反应的时间的增长,微米银树枝及分枝的长度越长,且树枝分枝上逐渐长出纳米级“树叶”结构, 使得微米级银树枝表面具有纳米结构。并且将微米银材料置于硅片上作为SERS衬底,并以罗丹明6G为探针分子,用激发波长为1 064 nm的傅里叶变换拉曼光谱仪检测,研究其在表面增强拉曼光谱中的应用,结果表明树枝状银微米材料有很好的SERS特性,其中置换反应时间为40 s时制备的微米银树枝的增强效果最佳,其增强因子可达到103左右,并且采用用表面活性剂PVP处理硅片的方法后,保持其他条件不变,微米银衬底的SERS增强效果得到进一步加强,增强因子达到104左右。此外,将树枝状银微米材料用水可封存数月,且实验结果的重复性较好。     

Fabrication and characterization of SERS‐active silver clusters on glassy carbon

In this article, a novel technique for the fabrication of surface enhanced Raman scattering (SERS) active silver clusters on glassy carbon (GC) has been proposed. It was found that silver clusters could be formed on a layer of positively charged poly(diallyldimethylammonium) (PDDA) anchored to a carbon surface by 4‐aminobenzoic acid when a drop containing silver nanoparticles was deposited on it. The characteristics of the obtained silver clusters have been investigated by atomic force microscopy (AFM), SERS and an SERS‐based Raman mapping technique in the form of line scanning. The AFM image shows that the silver clusters consist of several silver nanoparticles and the size of the clusters is in the range 80–100 nm. The SERS spectra of different concentrations of rhodamine 6G (R6G) on the silver clusters were obtained and compared with those from a silver colloid. The apparent enhancement factor (AEF) was estimated to be as large as 3.1 × 10⁴ relative to silver colloid, which might have resulted from the presence of ‘hot‐spots’ at the silver clusters, providing a highly localized electromagnetic field for the large enhancement of the SERS spectra of R6G. The minimum electromagnetic enhancement factor (EEF) is estimated to be 5.4 × 10⁷ by comparison with the SERS spectra of R6G on the silver clusters and on the bare GC surface. SERS‐based Raman mapping technique in the form of line scanning further illustrates the good SERS activity and reproducibility on the silver clusters. Finally, 4‐mercaptopyridine (4‐Mpy) was chosen as an analyte and the lowest detected concentration was investigated by the SERS‐active silver clusters. A concentration of 1.6 × 10⁻¹⁰ M 4‐Mpy could be detected with the SERS‐active silver clusters, showing the great potential of the technique in practical applications of microanalysis with high sensitivity. Copyright © 2006 John Wiley & Sons, Ltd.     

咪唑在铜电极上吸附行为的SERS研究

咪唑在铜电极上吸附行为的ＳＥＲＳ研究张传飞，徐知三，旷富贵，王小华，刘海林（武汉大学分析测试中心武汉４３００７２）（武汉大学环境科学系武汉４３００７２）ＳｔｕｄｙｏｎＴｈｅＡｄｓｏｒｐｔｉｏｎＢｅｈａｖｉｏｕｒｏｆＩｍｉｄａｚｏｌｅｏｎＣｏｐｐｅｒＥ...     

酸性金黄偶氮染料在银镜上的表面增强拉曼光谱研究

以银氨溶液和葡萄糖制备的银镜为吸附基底,获得了酸性金黄G偶氮染料在银镜上的表面增强拉曼光谱,并对其拉曼峰的归属及吸附机理进行了探讨。酸性金黄G靠静电引力和范德华力以带孤对电子的N原子垂直吸附在银镜表面,SERS强度随染料浓度的降低而降低,检出限为10-10mol/L。     

The detection by SERS of resonantly excited desorption of pyridine from silver island films by IR laser absorption

We have shown that when a very thin film of pyridine about two or three monolayers thick on a silver island film is exposed to a pulsed CO₂ laser line whose frequency corresponds to that of a pyridine vibrational mode the physisorbed molecules within the pyridine film can be desorbed even at liquid He temperatures. It is interesting that this observation was first made using surface enhanced Raman scattering. Experimental results are presented from which it is concluded that the phenomenon can be described as resonantly excited desorption. The absorbed IR energy seems to be localized within the pyridine film and the silver film and thermallized to some degree causing some of the physisorbed molecules to desorb. Analysis of the SERS spectra before and after the resonantly excited desorption has enabled us to separate out the SERS spectra due to the physisorbed pyridine and the chemisorbed pyridine.     

Protein adsorption drastically reduces surface‐enhanced Raman signal of dye molecules

There is an increasing interest in developing surface enhancement Raman spectroscopy methods for intracellular biomolecule and for in vitro protein detection that involve dye or protein–dye conjugates. In this work, we have demonstrated that protein adsorption on silver nanoparticle (AgNP) can significantly attenuate the surface‐enhanced Raman spectroscopy (SERS) signal of dye molecules in both protein/dye mixtures and protein/dye conjugates. SERS spectra of 12 protein/dye mixtures were acquired using 4 proteins [bovine serum albumin (BSA), lysozyme, trypsin, and concanavalin A] and three dyes [Rhodamine 6G, adenine, and fluorescein isothiocyanate (FITC)]. Besides the protein/dye mixtures, spectra were also obtained for the free dyes and four FITC‐conjugated proteins. While no SERS signal was observed in protein/FITC mixtures or conjugates, a significantly reduced SERS intensity (up to 3 orders of magnitude) was observed for both R6G and adenine in their respective protein mixtures. Quantitative estimation of the number of dye molecules absorbed onto AgNP implied that the degree of R6G SERS signal reduction in the R6G/BSA sample is 2 to 3 orders of magnitude higher than what could be accounted for by the difference in the amount of the absorbed dyes. This finding has significant implications for both intracellular SERS analyses and in vitro protein detection using SERS tagging strategies that rely on Raman dyes as reporter molecules. Copyright © 2009 John Wiley & Sons, Ltd.