共查询到17条相似文献,搜索用时 453 毫秒
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本文提出了一种新型的基于银修饰的氨基改性粉末多孔材料的表面增强拉曼光谱(SERS)检测方法,以乐果为探针分子,分析了银溶胶的量和反应时间对基底SERS活性的影响。乐果和水胺硫磷在以银溶胶为基底时,分别只能检测到100mg/L和7mg/L,而以银修饰的氨基改性粉末多孔材料为基底时,乐果和水胺硫磷的最低检测浓度分别达到0.5mg/L和0.14mg/L,说明该基底具有很好的增强效果。此外,检测低浓度下乐果和水胺硫磷的混合农药溶液,各农药的特征峰在谱图中仍然能清晰可辨。根据实验结果可以推测,银修饰的氨基改性粉末多孔材料作为SERS基底,可以有效地应用于有机磷农药残留的检测。 相似文献
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十二烷基硫酸钠(SDS)增强若丹明6G水溶液激光激发荧光谱研究 总被引:3,自引:1,他引:2
报道了若丹明6G水溶液添加不同浓度的表面活性剂十二烷基硫酸钠(SDS)时激光激发染料的变化,发现较低的掺入量导致R6G荧光减弱,适量SDS的加入使荧光增强,在5×10-5 mol·L-1的R6G水溶液中,加入6×10-2 mol·L-1 SDS,荧光增强因子达到3.1。当R6G浓度为1×10-4 mol·L-1时,加入2×10-2 mol·L-1,染料激光阈值显著降低。测量了不同浓度的R6G溶液的吸收光谱及加入不同浓度SDS后的荧光谱,分析了不同SDS加入量下R6G荧光减弱及增强的物理机制。 相似文献
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FU Xing-hu WANG Zhen-xing MA Shuang-yu ZHAO Fei LU Xin FU Guang-wei JIN Wa BI Wei-hong 《光谱学与光谱分析》2021,41(9):2800-2806
提出了一种基于银修饰的微腔型光纤表面增强拉曼散射(SERS)探针,采用湿法检测,将光纤SERS探针直接放入待测溶液中,以罗丹明6G(R6G)溶液为探针分子,对所制备的光纤SERS探针进行远端实验性能研究。利用氢氟酸化学腐蚀的方法制备了一种微腔型光纤结构,通过控制氢氟酸的腐蚀时间得到了一系列不同腐蚀时间、不同微腔长度的光纤结构。实验研究了光纤结构的微腔长度对光纤SERS探针性能的影响,以浓度为10-3 mol·L-1的R6G溶液为探针分子,通过不断地优化纳米银溶胶与R6G溶液的混合顺序及比例,采用裸光纤微腔结构对混合溶液进行拉曼检测,发现当混合溶液的混合顺序及比例为先后混合等体积的纳米银溶胶和R6G溶液时,此时得到的混合溶液的拉曼信号增强性能最佳。利用得到的混合溶液去寻找拉曼信号增强效果最高时光纤微腔结构的结构参数,实验结果表明,在相同的实验条件下,当光纤放入氢氟酸中腐蚀时间为5 min时,此时光纤微腔结构的拉曼信号增强效果最佳。在显微镜下测量的多组腐蚀时间为5 min的光纤,其微腔长度平均约为81 μm。对得到的光纤微腔结构,采用制备过程可控的磁控溅射技术制备了一系列银纳米薄膜/多模光纤(Ag/MMF)的复合材料。当磁控溅射时间为10 min时,获得了光纤SERS探针(Ag/MMF-10)。实验以去离子水配制了不同浓度的R6G溶液,以不同浓度的R6G溶液为探针分子,Ag/MMF-10探针的远端检测限(LOD)低至10-7 mol·L-1。该光纤SERS探针拉曼信号的再现性光谱检测中显示各个特征峰的相对标准偏差(RSD)均小于10%。同时,该光纤SERS探针对浓度为10-6 mol·L-1的R6G溶液的增强因子(AEF)可高达2.64×106。实验结果表明所制备的银修饰的光纤SERS基底具有较高的灵敏度和良好的再现性。因此,该光纤SERS探针在生物医学检测、农残化学分析等痕量检测方面有潜在的应用价值。 相似文献
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以硅纳米孔柱阵列(Si-NPA)为衬底,采用浸渍法制备出一种具有规则表面形貌特征的银/硅纳米孔柱阵列(Ag/Si-NPA),并以R6G为探测目标材料,对其表面增强拉曼(SERS)效应进行了研究。结果表明,对于R6G浓度低至10-15M,Ag/Si-NPA均能表现出清晰的特征SERS峰。随着浓度的降低,R6G的荧光淬灭,所测拉曼光谱的基线降低,但特征峰峰位基本保持不变。在低浓度10-15M时得到的SERS光谱,理论上证明为单分子光谱。此外,Ag/Si-NPA活性基底具有较好的稳定性,在长达28天的自然老化过程中,Ag/Si-NPA能够保持对R6G较高的探测水平,光谱具有较好的信噪比和分辨率。Ag/Si-NPA是一种理想的SERS活性基底。 相似文献
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以新型银胶为衬底的超低浓度R6G的拉曼光谱检测 总被引:5,自引:3,他引:2
利用柠檬酸钠还原硝酸银的原理,提出了一种微波加热制备银胶体粒子的新方法,得到了颗粒大小较均匀的灰色银胶体。以提纯后的银胶为表面增强拉曼散射衬底,研究了超低浓度染料大分子罗丹明6G分子的表面增强拉曼散射,得到浓度分别为10-12mol/L、10-13mol/L和10-14mol/L的罗丹明6G的表面增强拉曼散射光谱,初步实现了罗丹明6G的单分子检测,证明该新型银胶衬底有非常强的表面增强拉曼活性。同时根据表面增强拉曼散射“热点”的增强机理,分析了获得超低浓度R6G的表面增强拉曼光谱的原因。 相似文献
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通过溶胶-凝胶法以四甲氧基硅烷(TMOS)和甲基三甲氧基硅烷(MTMS)作为混合的前体,聚乙二醇(PEG)为致孔剂,制备了具有贯通孔道结构的双孔硅胶整体柱,采用3-巯基丙基三甲氧基硅烷(MTPMS)对硅胶整体柱表面进行巯基化修饰后,分别将金、 银纳米粒子组装在整体柱材料表面。 利用透射电子显微镜(TEM)、 紫外-可见吸收光谱(UV-Vis)、 扫描电子显微镜(SEM)对金、 银纳米粒子形貌、 吸收光谱及组装金、 银纳米粒子前后整体柱的形貌进行了表征。 以对巯基苯胺(PATP)为探针分子,分别采用波长为633和532 nm的激发光作为激发光源,研究金和银纳米粒子修饰的硅胶整体柱的在柱表面增强拉曼光谱(SERS)性能。 结果表明,该基底呈现出很强的SERS活性,结合整体柱的分离富集优势将在食品/环境领域现场痕量检测方面具有广泛的应用前景。 相似文献
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Qingqing Li Yiping Du Huirong Tang Xuan Wang Guiping Chen Jibran Iqbal Wenming Wang Weibing Zhang 《Journal of Raman spectroscopy : JRS》2012,43(10):1392-1396
A novel ultrasensitive detection method utilizing surface‐enhanced Raman scattering (SERS) based on monolithic column was developed in the present study. Monolithic column is a kind of chromatographic stationary phase that contains highly interconnected pores and absorbs chemical components efficiently. Dropping a mixture solution containing analyte, silver colloid, and NaCl on the surface in advance, SERS signals were collected on the surface of the monolithic column. With this method, five commonly used probe molecules of Rhodamine 6G (R6G), p‐aminothiophenol, Rhodamine 123, crystal violet, thymine, and two chemicals that are used in agriculture (paraquat and flusilazole) were detected. Especially, R6G and p‐aminothiophenol can be detected at extremely low concentrations of 10–18 and 10–16 mol/L at milliliter level, respectively. The enhancement factor was calculated to be approximately 1014 for R6G detection. The results suggest that the monolithic column does improve the sensitivity of SERS detection dramatically and the topography of the monolithic column is essential for the enhancement. The easy operability and the significant enhancement are the greatest advantages of this method. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Yuling Wang Hongjun Chen Shaojun Dong Erkang Wang 《Journal of Raman spectroscopy : JRS》2007,38(5):515-521
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. 相似文献
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微波法制备银胶体及其在表面增强拉曼散射中的应用 总被引:5,自引:2,他引:3
本文提出了一种利用微波加热的原理,合成一种新型的银胶体溶液。该银胶具有高效的表面增强拉曼活性。以这种新型银胶体粒子作为活性衬底,测得的强荧光物质R6G的表面增强拉曼光谱,体现出荧光背景低,信噪比高的特点。通过两种不同方法制备的银胶体粒子的表面增强拉曼散射效果的比较,发现这种新型银胶纳米粒子通过聚集,形成更多的具有很强的提高样品表面增强拉曼散射强度作用的“热点”,从实验的角度验证了表面增强拉曼中的“热点”理论。 相似文献
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A simple method for the preparation of ultrahigh sensitivity surface enhanced Raman scattering (SERS) active substrate 总被引:3,自引:0,他引:3
By immersing mica modified with cetyltrimethylammonium bromide (CTAB) into the silver colloid, a high efficient surface enhanced Raman scattering (SERS) active substrate was formed within 2 h at room temperature. The limit of detection of the substrate for Rhodamine 6G is up to 1×10−14 M. Changing the concentration of silver colloid and the treating time, various silver aggregates such as nanocrystals, clusters and films were found, and the SERS spectra of these aggregates were also obtained. The results of SERS revealed that CTAB could accelerate aggregation of the silver colloid and cause great Raman enhancement. Bilayer of CTAB is very important for aggregation of silver colloid and the aggregation extent is the main factor for the enormous enhancement on this substrate. 相似文献
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