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 共查询到19条相似文献,搜索用时 46 毫秒
1.
高淑琴  里佐威 《分析化学》1997,25(5):501-504
在液芯光纤内产生预共振和共振喇曼效应,可大度提高喇曼光谱强度,用波长远离样品吸收峰的激光激发观察到了α-甲基吡啶的预共振喇曼光谱。用长1.1m,内径200μm的液芯光纤,波长514.5nm,功率0.80W激光激发获得了β-胡萝卜素在CS2中的共振喇曼光谱,其浓度为2×10^-8mol/L,比普通方法的样品的浓度低2-3个数量级。  相似文献   

2.
Ag-CV的表面增强共振散射光谱研究   总被引:15,自引:0,他引:15  
采用共振散射光谱和紫外可见光谱研究了银胶与结晶紫的相互作用。在PH为4.0的HAc-NaAc缓冲溶液中,奶胶在345nm和700nm有两个共振散射峰;当加入带下辈民的阳离子染料结晶紫后,产生表面增强效应,345nm和700nm处的共振散身信号大为增强,从而获得灵敏的表面增强共振散射光谱。  相似文献   

3.
表面增强喇曼光谱已广泛应用于物质分子在金属表面吸附的研究.人们发现,不仅无机物和有机小分子能产生SERS,而且生物分子,如核酸、色蛋白以及蛋白质均能产生SERS效应,并以此来研究生物分子-蛋白质的变性问题.  相似文献   

4.
薛奇  丁建夫 《应用化学》1991,8(4):56-59
表面增强喇曼散射(SERS)光谱在研究唑类化合物如苯并三氮唑(BTAH),苯并咪唑(BIMH)和2-巯基苯并咪唑(MBIH)在铜表面的行为及缓蚀作用方面已有较多应用。然而这类研究主要在电化学池中进行,存在一定局限性。本文报导利用硝酸蚀刻铜表面,用SERS直接研究铜表面在空气中的氧化以及唑类化合物对此氧化过程的阻碍作用。  相似文献   

5.
表面增强喇曼光谱技术应用于生物体系的最新进展   总被引:3,自引:0,他引:3  
本文综述了近几年来表面增强喇曼光谱技术应用于以下几个方面的生物体系的最新资料:(1)核酸及其组分,(2)蛋白质及其组分,(3)儿茶酚胺,(4)有色生物质,(5)膜制品。总结了表面增强喇曼光谱技术的一般性结论,并对这一技术应用于生物体系的发展作了展望  相似文献   

6.
研究了荧光素(nu)的共振光散射(RLS)光谱的形成机理与影响因素.在中性和碱性条件下,Flu溶液的共振散射光显著增强.实验发现,随着溶液pH的增加,Flu溶液的RLS光谱与其荧光光谱、吸收光谱在强度大小、最大吸收峰位移上变化趋势一致.荧光素的荧光激发光谱与发射光谱有部分重叠,共振散射峰处于荧光激发峰与荧光发射峰之间.在光偏振实验中,测得共振散射光的偏振度P≈0.020.碱性环境中,随Flu溶液浓度的增加,其RLS光谱和荧光光谱的变化情况,同样表明两者之间有密切联系.上述实验结果揭示Flu的共振散射光就是共振荧光.  相似文献   

7.
利用轴向配位作用将5,10,15-20-四苯基钴(Ⅱ)卟啉(CoTPP)固定在4-巯基吡啶自组装膜表面上,形成CoTPP单分子膜,通过组装金纳米粒子的方法,成功地获得了膜中CoTPP分子的喇曼光谱。研究结果表明,CoTPP分子是通过钴原子与氮原子之间的配位作用与巯基吡啶分子结合的,且其分子平面与基底表面近似平行。  相似文献   

8.
研究了四苯基卟啉(H2TPP)及其金属配合物(AgTPP和MgTPP)在AgBr胶体上的表面增强喇曼光谱(SERS).SERS光谱表明,吸附在AgBr胶体粒子表面的MgTPP和H2TPP分子分别发生银离子交换和银配位反应生成AgTPP,这种表面反应可能与激光照射有关.AgTPP分子在胶体粒子表面的吸附导致卟啉大环的非平面化,使vs振动(M-N键伸缩振动)向高波数方向移动近10 cm-1.632.8 nm激发下的表面喇曼谱以化学增强为主,而488.0 nm激发下表面喇曼谱除化学增强效应外,还存在共振增强效应.  相似文献   

9.
吡啶在几种金属纳米线阵列上的表面增强喇曼光谱   总被引:2,自引:0,他引:2  
近20多年来利用表面增强喇曼光谱(SERS)的研究还仅限于Ag,Au,Cu这三种具有强SERS效应的金属,最近,田中群等利用合适的表面处理方法和共焦曼光谱技术成功地获得了许多无机离子和有机小分子吸附在一系列的过渡金属(如Pt,Ni,Fe,Pd,Rh,Co,Ru等)上的SERS光谱,拓宽了SERS的应用范围,但这些表面处理方法对基底进行处理时存在着较大的随机性,从而导致对所得SERS信号的解释困难。近年来通过自组装膜、模板合成等技术可得比较有序具有强SERS效应的或表面,例如Nie等最近发现尺寸分布狭窄的Ag溶胶粒子(约80-100nm)能诱导出巨大的SERS增强;Freeman和C tffumj m jf rbutb uqf At A 体微粒组装在聚合物基底上,制得高活性的SERS基底,以上工作都表明制备有序纳米级金属颗粒表面将推动SERS的应用和机理研究,迄今,3半导体纳米线阵列上的喇曼光谱已有报道,而利用金属纳米线阵列作为SERS基底除半于样模合成法制备的Ag纳米线阵列上的SERS之外,尚未见其它相关报道,本文主要研究样模合成法制备金属纳米线的过程,并以此为基底研究吡啶吸附的SERS光谱。  相似文献   

10.
本文研究了异烟酸吸附在银溶胶表面的表面增强喇曼散射(SERS)光谱以及卤素离子、溶液pH值及溶液浓度对异烟酸SERS光谱的影响。文章提出了离子在银溶胶表面的吸附方式,即主要以—COO~-端吸附于银溶胶表面。最后,对所述实验现象作了定性讨论。  相似文献   

11.
Hypericin has been found to exhibit a variety of photodynamic effects. To correlate biological activity with molecular structure, complete physical characterization of hypericin is required. The vibrational spectrum has been determined and resonance Raman and surface enhanced resonance Raman scattering spectra are reported. In addition, the Raman spectrum of a model compound has been studied to facilitate assignment of the vibrational modes of hypericin.  相似文献   

12.
本文研究了呫吨类染料分子(R110, RB, SRB, R_6G, R101和SF)吸附于化学沉积银岛膜上的表面增强共振喇曼散射(SERRS)光谱。文中详细的介绍了获得SERRS的实验条件, 对谱线的归属作了指认, 并讨论了共振、表面增强、吸附状态和衬底制备条件等因素对SERRS的特征和对喇曼散射截面的增强的影响。结果表明, SERRS是研究强荧光染料分子以及它们与金属表面相互作用的一种新的有效手段。  相似文献   

13.
荧光素钠乙醇溶液的光谱研究   总被引:2,自引:0,他引:2  
1 前言荧光素钠作为黄绿光区的一种激光染料,由于它具有高的激光能量转换效率而引起人们的关注.这种染料的发光波长及发光效率都与其溶液的pH值直接有关。我们在前文中详细地研究了这种染料溶液的激光能量转换效率与其pH值的依赖关系,论述了染料分子在不同pH值的溶液中存在着多种不同的变型,并且讨论了其发光效率与pH值存在依赖关系的原因。本文进一步研究该染料在不同pH值的溶液中的吸收光谱、荧光光谱和荧光寿命以探  相似文献   

14.
Strong resonance Raman (RR) and surface-enhanced resonance Raman scattering (SERRS) signals from carotenoids were detected from thylakoid (stromal-side out) vesicles and inside-out (lumenal-side out) vesicles isolated from spinach chloroplasts. The intensity of the signals from both types of membranes was comparable, indicating that plant carotenoids are exposed on or close to both surfaces or sides of the thylakoid membrane. This is in contrast to previous studies with bacterial photosynthetic membranes (Picorel et al., 1988, J. Biol. Chem. 263 , 4374–4380; and 1990, Biochemistry 29 , 707–712) that show carotenoids selectively located on the cytoplasmic side. In addition; strong RR and SERRS signals were detected from stacked and unstacked photosystem-II-enriched membrane fragments, demonstrating that carotenoids are also exposed on both surfaces of the appressed region of the thylakoid membrane. Antibodies against the photosystem (PS) II extrinsic proteins blocked SERRS signals from stacked PS II membrane fragments, but only partially affected the SERRS signals from unstacked membranes. The results indicate that these antibodies, which preferentially cover the surface of the original lumenalside of the appressed region, act as spacers between the membrane and SERRS electrode surfaces. The original stromal-side of the appressed region is unaffected. These findings verify the distance sensitivity of the SERRS technique and underscore the above conclusion about the location of carotenoids in the appressed regions. Finally, SERRS signals are sensitive to membrane aging and storage temperature; caution is suggested to those applying SERRS spectroscopy to intact membrane systems.  相似文献   

15.
用无色荧光素钠—荧光法测定水中的痕量氰化物研究   总被引:1,自引:0,他引:1  
提出了在pH 9.0的硼酸盐缓冲液中,有铜离子存在下,利用无色荧光素钠测定生活饮用水中的痕量氰化物荧光分析新方法。CN~-含量在0.0~0.01μg·ml~(-1)范围内呈线性关系,检出下限为0.40ng·ml~(-1),方法的灵敏度高,用于水中的痕量氰化物测定,结果满意。  相似文献   

16.
A highly concentrated NaClO_4 as a main supporting electrolyte was used to break hydrogen-bonded water structure in systems studied, by which strong surface-enhanced Raman scattering (SERS) signals of water from silver electrodes were detected in the system having a ten times lower halide concentration than the ordinary one; and a similar phenomenon was also observed in a system containing pseudo-halide SCN~- ions. The SERS spectra obtained in 0.1 mol/L LiCl and 3.0 mol/L LiClO_4 indicate the presence of two kinds of water molecules with very different behaviors on the surface. This peculiar phenomenon is discussed in details. It is achievable to extend SERS study on adsorbed water by adequate choice of electrolyte and control of surface treatment to the electrode in order to have a deeper insight into the complex structure of the electrochemical interface.  相似文献   

17.
Abstract —Fourier transform infrared (FTIR) difference spectra of the BR→rK transition in bacteriorhodopsin at 77→K are compared with analogous resonance Raman difference spectra obtained using a spinning sample cell at 77→K. The vibrational frequencies observed in the FTIR spectra of native purple membrane and of purple membrane regenerated with 15-deuterioretinal are in good agreement with the frequencies observed in the Raman spectra, indicating that the lines in the FTIR difference spectra arise predominantly from retinal chromophore vibrations. This agreement confirms that the spinning cell method for obtaining resonance Raman spectra of K minimizes potential contributions from unwanted photoproducts. The unexpected similarity between the resonance Raman scattering intensities and the FTIR absorption intensities for BR and K is discussed in terms of the delocalized electronic structure of the chromophore. Finally, comparison of the Schiff base regions of the K Raman and FTIR spectra provide additional information on the assignment of its Schiff base vibration.  相似文献   

18.
荧光素掺杂的TiO2凝胶的制备及光谱研究   总被引:2,自引:0,他引:2  
近些年来,溶胶-凝胶(Sol-Gel)方法作为一种软化学合成方法具有很多优点[1],例如制作简单、烧结温度低,制得样品稳定、坚韧,制备灵活性高等。作为一种常用的染料,荧光素(FL)常用于研究非线性光学。利用Sol-Gel法可以很好地将染料分子固定在光...  相似文献   

19.
It was observed that the p-aminobenzoic acid(PABA)molecules adsorbed on A92CO3colloids exhibited strong SERS effect,the enhancement factor is estimated at 10~7—10~8 The mechanismof SERS effect on PABA adsorbed on the colloids was discussed.  相似文献   

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