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1.
用表面增强拉曼散射光谱(SERS)和时间分辨SERS光谱(TRSERS)等技术首次研究了烯丙基硫脲(ATU)在HClO4、H2SO4和HNO3介质中与无机阴离子在银电极上的电化学共吸附行为.提出ATU很可能以S端与银电极表面形成化学吸附键,仲氨基相对伯氨基距离表面较近,整个分子偏向烯丙基一侧倾斜吸附在表面上.ClO-4、SO2-4和NO-3等弱吸附无机阴离子均能被ATU诱导共吸附在其质子化了的仲氨基上,这3种无机阴离子被ATU诱导共吸附的强弱顺序是ClO-4>SO2-4>NO-3.被诱导共吸附的无机阴离子对ATU在电极表面的化学吸附起到稳定剂的作用,有利于ATU在电极表面形成致密的吸附层  相似文献   

2.
制备了四种苯并噻唑基尾式铁(Ⅲ)卟啉,用元素分析和^1HNMR,FAB-MS,UV-is等谱对自由卟啉及其铁(Ⅲ)配合物进行了表征,通过铁(Ⅲ)卟啉ESR和MCD光谱的分析以及与咪唑加合反应稳定常数的测定,考察了铁(Ⅲ)卟啉的轴向配位状态。  相似文献   

3.
水溶性游离碱阳离子卟啉与核酸作用的光谱研究   总被引:27,自引:1,他引:27  
研究了meso-四(对-三甲基氨基苯基)卟啉(TAPP)和meso-四(对-甲基吡啶基)卟啉(TMpyP-4)与核酸作用的电子吸收光谱、荧光光谱和共振光散射光谱的特性,电子吸收和荧光光谱研究表明,这两个水溶性阳离子卟啉与核酸的摩尔比(R)大于0.25时,核酸对卟啉的Soret带有减色效应和荧光猝灭效应;当R〈0.25时,核酸与卟啉作用形成新的荧光复合物,共振光散射光谱研究表明,核酸使TAPP的共振  相似文献   

4.
微乳液法制备超细包裹型铁粉   总被引:21,自引:0,他引:21  
应用W/O型微乳流法制备了纳米量级包裹型超细铁粉,由XRD、SEM、TEM和IR谱测试表明:它属于表面活性剂包裹型超细微粒。平均粒径约120nm,微粒的密度为3.00g/cm^3。比饱和磁化强度σs=92.4Am^2/kg,矫顽力He=43(Oe),剩磁r=3.89Am^2/kg。将其用于制备磁流变液(MRF),具有良好的磁流变(MR)性能和优良的沉降稳定性。  相似文献   

5.
用表面增强拉曼光谱研究BMAT对不锈钢的缓蚀机理   总被引:1,自引:0,他引:1  
查英华  田中群 《电化学》1995,1(2):152-158
应用表面增强拉曼散射光谱(SERS)技术,研究0.5%HCl体系中缓蚀剂在18-8不锈钢表面的吸附。谱图是在不锈钢表面电沉积不连续Ag颗粒条件下测得的。缓蚀剂BMAT通过电极表面与缓蚀剂中的N原子,以及苯并咪唑环的共轭大π键形成化学吸附,BMAT斜卧于电极表面。其烯丙基起到空间的阻碍的作用。  相似文献   

6.
用沉积银胶的银镜作活性载体,获得了中位-四-(4-N-乙氧羧甲基吡啶)卟啉络铜(Ⅱ)(Cu(Ⅱ)NEAE)、中位-四-(4-N-氰甲基吡啶)卟啉络酮(Ⅱ)(Cu(Ⅱ)NACN)的近红外富里叶变换-表面增强喇曼光谱(NIRFTSERS),对其谱峰位移作了归属,并与它们的可见激光表面增强共振喇曼光谱(SERRS)作了比较。  相似文献   

7.
表面增强拉曼技术及FT-拉曼的研究及应用   总被引:5,自引:0,他引:5  
叶勇  胡继明 《大学化学》1998,13(1):6-10
本文综述了拉曼光谱分析法的建立与发展、表面增强拉曼光谱(SERS)法及傅立叶变换拉曼光谱(FTRaman)法的应用进展。  相似文献   

8.
首次观测到Ag2CO3溶胶体系中的吸附分子(对氨基苯甲酸PABA)表面增强拉曼散射(SERS)效应特强,该体系对PABA的增强程度比Ag胶还强。同时,分别向该体系加入少量的S2O3,Fe(CN)6,H2O2和NO3-溶液后,观测其对PABA的SERS谱带强度的影响,探讨该体系的增强机制。结果表明,胶体表面的Ag+或Agδ+是该体系的SERS活位吸附点,而表面络合物对其SERS起到一定的作用。  相似文献   

9.
利用化学沉积法和溶胶法制备了粒径在20~100nm范围内不同的表面增强纳米结构活性银膜,系统地研究了单壁碳纳米管(SWCNT)的表面增强拉曼光谱(SERS)的G—band和D—band、比较玻璃和石英两种不同基片上的结果发现,单壁碳管的SERS谱随银膜粒径的变化有相同的变化趋势,G-band峰移对20~100nm范围内活性银膜粒径的差异不敏感,表明该波段所对应的碳管六元环本征振动比较稳定,与界面的化学相互作用较弱.D—band的峰形随基片和活性银膜粒径不同均有改变,且随着粒径变小,高频振动贡献有增大的趋势,表明无序碳与活性银膜间存在很强的相互作用。  相似文献   

10.
用ICP—AES研究茶碱负载树脂对银离子的吸附行为   总被引:2,自引:0,他引:2  
采用浸渍法将茶碱负载子阳离子交换树脂上,制得茶碱负载树脂(TCR)。在一定浓度的硝酸或氨水溶液中,茶碱负载树脂具有较好的化学稳定性。以ICP-AES作为检测手段,考察了其对银离子的吸附性能。结果表明,TCR在pH4~7范围内可定量吸附Ag^+,2mg/mL硫脲-0.5mol/L HNO3的混合溶液可作为银的良好解吸剂。该负载树脂对银的吸附容量大,选择性好,适用于痕量银的富集分离。  相似文献   

11.
用一种廉价的电解方法制备了纳米银膜,并详细研究了在这种银膜上的表面增强拉曼散射效果.结晶紫为本实验的检测性分子.通过实验发现,这种银膜用便携式拉曼光谱仪测试并计算出的表面增强拉曼散射的增强因子为603,并对结晶紫的最小检出限为0.1nmol/L.  相似文献   

12.
Surface-enhanced Raman scattering (SERS) spectrum of very good quality of "silver nano-particles/sample molecules/silver film" system was reported by nesting the sample molecules to the gap of silver nano-particles and silver film, indicating that "silver nano-particles/sample molecules/silver film" is a highly SERS-active system. Not only was the number of the vibrational modes increased, but also were the frequencies of Raman bands up and down shifted. It is difficult to separate the contributions of the electromagnetic and chemical mechanisms to the great enhancement of the Raman signal. The shift by 5-30cm(-1) of the SERS bands and the change in their relative intensity compared with the ordinary Raman spectrum indicate the chemisorption of the sample molecules on the silver-modified silver surface. Furthermore, the silver nano-particles modified on the rough silver film surface play an important role in magnifying the surface local electric field near the silver surface through resonant surface plasmon excitation. From the rich information, obtained from high-quality SERS of PHBA in ternary system, we inferred that PHBA molecules in ternary system adsorb onto the metal surfaces through carboxyl at a perpendicular orientation.  相似文献   

13.
A simple and sensitive method, based on surface-enhanced Raman scattering (SERS), for immunoassay and label-free protein detection is reported. A series of bowl-shaped silver cavity arrays were fabricated by electrodeposition using a self-assembled polystyrene spheres template. The reflection spectra of these cavity arrays were recorded as a function of film thickness, and then correlated with SERS enhancement using sodium thiophenolate as the probe molecule. The results reveal that SERS enhancement can be maximized when the frequency of both the incident laser and the Raman scattering approach the frequency of the localized surface plasmon resonance. The optimized array was then used as the bottom layer of a silver nanoparticle–protein–bowl-shaped silver cavity array sandwich. The second layer of silver was introduced by the interactions between the proteins in the middle layer of the sandwich architecture and silver nanoparticles. Human IgG bound to the surface of this microcavity array can retain its recognition function. With the Raman reporter molecules labeled on the antibody, a detection limit down to 0.1 ng mL?1 for human IgG is easily achieved. Furthermore, the SERS spectra of label-free proteins (catalase, cytochrome C, avidin and lysozyme) from the assembled sandwich have excellent reproducibility and high quality. The results reveal that the proposed approach has potential for use in qualitative and quantitative detection of biomolecules.
Schematic diagram of sandwich structure for labelled and label-free protein detection.  相似文献   

14.
表面增强拉曼光谱法对水中残留绿麦隆的检测   总被引:6,自引:0,他引:6  
利用银镜反应原理在玻璃片上镀一层具有表面增强拉曼散射(SERS)效应的表面粗糙的银膜,通过测定农药绿麦隆在银镜表面上的表面增强拉曼光谱,探讨了绿麦隆在银镜表面的吸附取向。结果表明,在银镜表面,当绿麦隆浓度小到10-10mol L时,仍然能得到明确的光谱信息,且吸附饱和时间仅为2h,这为探索水体中微量污染物的检测方法提供了一个很好的途径。  相似文献   

15.
The spectroscopic properties and surface-enhanced spectra of Langmuir-Blodgett (LB) films of methacrylic homopolymer (HPDR13) are presented. It is shown that LB film displays strong fluorescence attributed to the spatial restrictions imposed by its structure. The emission is observed in conjunction with photoisomerization, a process clearly demonstrated by the formation of surface-relief gratings in the LB film [C.R. Mendon?a et al., Macromolecules 32 (1999) 1493]. Surface-enhanced Raman scattering (SERS), Surface-enhanced resonance Raman scattering (SERRS) and surface-enhanced fluorescence (SEF) were observed for LB films of HPDR13 deposited onto silver island films. SERS measurements were also carried out on a sample fabricated with one monolayer LB film deposited onto silver islands followed by one overlayer of silver (LB sandwiched between two layers of silver islands). The polymer interacts very weakly with the metal surface (physisorption), and the enhancement effect is determined by the local electric field enhancement. The strong SERS and SERRS signals were suitable for micro-Raman imaging. Line, area mapping and global images of the LB monolayer on silver island are reported. The transfer ratio in the fabrication of the LB suggests a homogeneous coating of the silver islands, thereby the chemical images show the variation of the SERS intensity due to surface enhancement.  相似文献   

16.
水汽界面二维银颗粒表面上的单分子拉曼光谱检测   总被引:5,自引:0,他引:5  
随着各种超灵敏分析仪器的发展 ,已经可以在低温固体中、室温液体中和电介质表面检测、鉴定单分子及其动力学行为 .这种新进展为科学家在分析化学、分子生物学和纳米结构材料等各种学科的应用开辟了许多新的视窗 .单分子谱学的研究在基础科学和应用科学方面引起了人们广泛的兴趣 .人们不仅希望能够“看到”单分子 ,而且希望了解单分子的物理化学行为 .在各种超灵敏检测技术中 ,拉曼光谱成为一种重要的技术 .由于原子力显微等微区技术的发展 ,并结合高灵敏度检测技术的进步 ,拉曼光谱已经发展成为一种检测灵敏度可以达到分子级的检测技术 [1,…  相似文献   

17.
Sandwich surface-enhanced Raman scattering (SERS) substrates (3S) utilizing coupling between continuous metal films and plasmonic particles were fabricated using silver mirrors, electrochemically roughened films, and various sizes of silver nanoparticles. The effect of excitation wavelength and nanoparticle size on SERS spectra of poly(vinylpyridine), selected as a model compound, was studied to determine the optimum conditions for the strongest SERS signal. The Raman enhancement resulted from the plasmon coupling of silver nanoparticles to the underlying continuous film as well as the lateral plasmon coupling between the silver nanoparticles. The formation of the charge transfer complex was also observed. The 3S configuration was used to obtain SERS spectra of dipicolinic acid (DPA), a chemical signature for Bacillus anthracis.  相似文献   

18.
通过匹配激光光斑直径与胶体微球的尺寸, 设计制备了银纳米粒子的表面增强拉曼散射(SERS)基底, 并将其用于研究单个银纳米粒子簇的表面增强拉曼光谱. 在制备纳米粒子的过程中, 考察了等离子体刻蚀时间与银沉积厚度对“单”银纳米粒子结构与形貌的影响. 将吡啶、 巯基苯和罗丹明R6G作为SERS探针分子, 研究了其SERS效应, 通过荧光共振能量转移(FRET)机理, 实现了染料分子在单银纳米粒子簇上的SERS效应. SERS光谱测试与相关计算结果表明, 单个银纳米粒子簇的拉曼增强因子能够达到约106.  相似文献   

19.
Surface-enhanced Raman scattering (SERS) spectra of four amphiphilic nucleolipids in single-layer Langmuir-Blodgett (LB) films deposited on silver island film substrates from pure water and complementary nucleotide-containing subphase and corresponding powder normal Raman spectra were obtained. The analysis of these spectra indicates that the SERS effect is mainly caused by a charge-transfer mechanism, and only the nucleobase headgroup moieties and complementary bases combined with them through hydrogen bonds, which are directly in contact with the silver island film substrates, could be enhanced. For the amphiphilic nucleolipids with the identical nucleobase headgroups, the SERS spectra of the LB films are similar, implying that the orientations of these nucleobase moieties on the silver substrates are analogous. However, the nucleobase takes different orientations on the silver substrates before and after complementary binding. The nucleobases in the LB films deposited from pure water are nearly lying flat on the silver surface, while the complementary binding pairs transferred from the air/water interface tend to take an end-on orientation on the metal surface.  相似文献   

20.
The silver-modified gold nanoplate arrays as bimetallic surface-enhanced Raman scattering (SERS) substrates were optimized for the surface-enhanced Raman detection of streptavidin/biotin monolayer assemblies. The bimetallic gold–silver nanoplate arrays were fabricated by coating silver nanoparticles uniformly on the gold nanoplate arrays. Depending on silver nanoparticle coating, the localized surface plasmon resonance (LSPR) peak of the bimetallic gold–silver nanoplate arrays blue-shifted and broadened significantly. The common probe molecule, Niel Blue A sulfate (NBA) was used for testing the SERS activity of the bimetallic gold–silver nanoplate arrays. The SERS intensity increased with the silver nanoparticle coating, due to a large number of hot spots and nanoparticle interfaces. The platforms were tested against a monolayer of streptavidin functionalized over the bimetallic gold–silver nanoplate arrays showing that good quality spectra could be acquired with a short acquisition time. The supramolecular interaction between streptavidin (strep) and biotin showed subsequent modification of Raman spectra that implied a change of the secondary structure of the host biomolecule. And the detection concentration for biotin by this method was as low as 1.0 nM. The enhanced SERS performance of such bimetallic gold–silver nanoplate arrays could spur further interest in the integration of highly sensitive biosensors for rapid, nondestructive, and quantitative bioanalysis, particularly in microfluidics.  相似文献   

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