共查询到18条相似文献,搜索用时 171 毫秒
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利用化学自组装方法,首先在色谱玻璃小瓶的内壁吸附上一层PDDA阳离子聚电解质,然后通过静电吸附作用将带有负电荷的银纳米粒子组装到内壁;比较了不同色谱瓶作为吸附银纳米粒子的载体的优缺点;用紫外-可见吸收光谱监测吸附到玻璃瓶内壁的银纳米粒子的表面等离子体共振峰,跟踪银纳米粒子的组装情况;利用对-巯基苯胺作为探针分子研究了基底的表面增强拉曼散射(SERS)活性。结果表明:所制备的SERS小瓶基底具有良好的SERS活性,并且使用简单,保存时间长,适合SERS现场快速检测的需要。 相似文献
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采用电化学沉积法分别在不同孔径的阳极氧化铝(AAO)模板上沉积一系列直径不同,排列规则的银纳米阵列。以对氨基苯甲酸(PABA)和三聚氰胺两种分子分别作为探针分子, 研究了银纳米阵列的直径大小对其表面增强拉曼散射(SERS)效果的影响。结果表明, 在波长为514.5 nm的激光激发下, 探针分子的SERS信号强度随银纳米阵列直径的改变而明显变化, 并在银纳米阵列直径约为53 nm时, SERS强度达到最大。利用电磁增强机制对此实验结果进行了分析和解释。 相似文献
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WANGLi-ran ZHANGFang FANGYan 《光散射学报》2005,17(1):53-55
将银纳米颗粒覆盖在覆有铟锡氧化物的导电玻璃上,可以将其作为一种新型的表面增强拉曼散射(SERS)活性基底。将三种羟基苯甲酸分子作为探针分子在这种新的基底上进行检测,得到了很好的SERS信号,从中可反映出大量分子振动信息 相似文献
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以多孔阳极氧化铝(porous anodic alumina,PAA)膜为模板,采用真空电子束蒸镀技术,分别在PAA多孔层以及阻挡层表面形成了银纳米孔和银纳米帽有序阵列表面增强拉曼散射(surface-enhancedRaman scattering,SERS)活性基底,并以膀胱肿瘤细胞作为分子探针,测试和分析了这两种SERS活性基底的表面增强拉曼光谱的特性。结果表明,两种SERS活性基底对膀胱肿瘤细胞的拉曼散射信号均有很好的增强作用。银纳米帽有序阵列SERS活性基底不仅具有较高的SERS增强和荧光猝灭效应,而且不存在与PAA膜中草酸根杂质相关的干扰峰,可获得膀胱肿瘤细胞拉曼散射光谱的更多细节信息。 相似文献
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提出一种新型的荧光及表面增强拉曼散射(SERS)双模式光学纳米探针。首先,通过再沉淀-包覆法合成二氧化硅包覆香豆素6的纳米颗粒,再在二氧化硅表面静电吸附多聚赖氨酸分子形成包覆层,随后通过原位还原的方法在多聚赖氨酸壳层复合银纳米颗粒,最后在银纳米颗粒表面吸附拉曼分子即形成双模式纳米探针。该探针通过二氧化硅包覆的荧光分子产生荧光信号,以多聚赖氨酸表面的银纳米颗粒作为SERS增强基底,利用拉曼分子获得SERS信号,实现了荧光及SERS双模式成像。荧光与表面增强拉曼散射相结合的双模式分析技术可同时发挥二者的优点,提高成像的分辨率和灵敏度,在生物医学领域具有重要的应用价值。 相似文献
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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。 相似文献
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在直流10V电压下电解聚乙烯醇和硝酸银的混合液3h制备纳米银胶,将经过半胱氨酸修饰后的载玻片浸入银胶24h制得纳米银膜。用紫外可见分光光度计对银胶进行了观测,由于其吸收峰半高宽较窄可知银胶中纳米银颗粒粒径分布较为均匀。同时,使用扫描电镜对银膜进行了表征。通过对半胱氨酸分子SERS信号的分析得出了纳米银粒子在玻璃表面上可能的组装方式。以结晶紫(Crystal Violet)和孔雀石绿(Malachite Green)作为探测分子,采用便携式拉曼光谱仪测得两种分子不同浓度下的SERS谱。发现该方法所制得的纳米银膜有很好的表面增强效果。最后分析了半胱氨酸分子SERS信号对探针分子光谱的影响。 相似文献
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使用种子生长法制备得到银纳米立方,扫描电镜的表征结果表明制备得到的银纳米立方尺寸为(61.5±4.4) nm,相对标准偏差为7.2%。利用表面替换技术将其表面的CTAC替换为更有利于SERS检测的柠檬酸根。然后基于具有超润滑特性的SLIPS衬底,构建出以银立方作为组装单元的具有三维热点的SERS基底。利用该三维SERS基底分别检测了水中的三环唑和乙醇中的福美双,检测限分别可达到52.8和41.6 nmol·L-1。实验结果表明银立方三维热点SERS基底具有较高的灵敏度,能够应用于多种溶剂中农药的快速检测,对于实际场景下农药残留的快速检测具有重要的意义。 相似文献
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W. C. Zhang X. L. Wu C. X. Kan F. M. Pan H. T. Chen J. Zhu Paul K. Chu 《Applied Physics A: Materials Science & Processing》2010,100(1):83-88
Scanning electron microscopy and X-ray diffraction reveal that four different types of crystalline silver nanostructures including nanoparticles, nanowires, nanocubes, and bipyramids are synthesized by a solvothermal method by reducing silver nitrate with ethylene glycol using poly(vinylpyrrolidone) as an adsorption agent and adding different quantities of sodium chloride to the solution. These nanostructures which exhibit different surface plasma resonance properties in the ultraviolet–visible region are shown to be good surface-enhanced Raman scattering (SERS) substrates using rhodamine 6G molecules. Our results demonstrate that the silver nanocubes, bipyramids with sharp corners and edges, and aggregated silver nanoparticles possess better SERS properties than the silver nanowires, indicating that they can serve as high-sensitivity substrates in SERS-based measurements. 相似文献
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HUJia-wen ZHOUHai-hui ZHANGYong JIANGYang RENBin TIANZhong-qun 《光散射学报》2005,17(1):100-102
本文研究了尺寸可控的Au -Pd核壳纳米粒子和银纳米立方颗粒的表面增强拉曼散射(SERS)活性。发现Au-Pd核壳纳米粒子的增强能力要比粗糙的钯电极强;银纳米立方颗粒的增强能力和粗糙的银电极相当。更为重要的是,银纳米立方颗粒既具有原子级平整的小单晶面又处于纳米尺度,因而它们可以作为粗糙表面和结构确定的单晶表面之间的桥梁,对其SERS效应的研究可以加深人们对SERS机理的认识。 相似文献
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Hongjun Chen Yuling Wang Jianying Qu Shaojun Dong 《Journal of Raman spectroscopy : JRS》2007,38(11):1444-1448
In this paper, the fabrication of an active surface‐enhanced Raman scattering (SERS) substrate by self‐assembled silver nanoparticles on a monolayer of 4‐aminophenyl‐group‐modified glassy carbon (GC) is reported. Silver nanoparticles are attached to the substrate through the electrostatic force between the negatively charged silver nanoparticles and the positively charged 4‐aminophenyl groups on GC. The active SERS substrate has been characterized by means of tapping‐mode atomic force microscopy (AFM), indicating that large quantities of silver nanoparticles are uniformly coated on the substrate. Rhodamine 6G (R6G) and p‐aminothiophenol (p‐ATP) are used as the probe molecules for SERS, resulting in high sensitivity to the SERS response, with the detection limit reaching as low as 10−9 M . This approach is easily controlled and reproducible, and more importantly, can extend the range of usable substrates to carbon‐based materials for SERS with high sensitivity. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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Zao Yi Xibin Xu Xiaoqiang Wu Chaohua Chen Xibo Li Bingchi Luo Jiangshan Luo Xiaodong Jiang Weidong Wu Yougen Yi Yongjian Tang 《Applied Physics A: Materials Science & Processing》2013,110(2):335-342
Silver nanoplates were prepared in a dual reduction system with NaBH4 and sodium citrate both as reducing agents. And then the as-prepared nanoplates could be growing up through multistage growth methodology. The average edge length of Ag nanoplates can be tailored from 40 nm to 260 nm without changing their shape, crystallinity, and the average thickness. Furthermore, the effectiveness of these silver nanoplates as substrates prepared by the silanization self-assembly method toward surface-enhanced Raman scattering (SERS) detection was evaluated by using 4-aminothiophenol (4-ATP) and rhodamine 6G (R6G) as probe molecules. It was found that the enhancement ability of the silver nanoplates film is remarkable lower than that of the spherical silver nanoparticle film. The reason is attributed to the electromagnetic mechanism and chemical mechanism. This work will be of great significance in understanding the SERS enhancement mechanism and in the fabrication of nanoparticle films for biosensing. 相似文献
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Joshy F. John Shannon Mahurin Sheng Dai Michael J. Sepaniak 《Journal of Raman spectroscopy : JRS》2010,41(1):4-11
A method to stabilize silver surface‐enhanced Raman spectroscopy (SERS) substrates for in situ, high‐temperature applications is demonstrated. Silver island films grown by thermal evaporation were coated with a thin layer (from 2.5 to 5 nm) of alumina by atomic layer deposition (ALD), which protects and stabilizes the SERS‐active substrate without eliminating the Raman enhancement. The temporal stability of the alumina‐coated silver island films was examined by measurement of the Raman intensity of rhodamine 6G molecules deposited onto bare and alumina‐coated silver substrates over the course of 34 days. The coated substrates showed almost no change in SERS enhancement, while the uncoated substrates exhibited a significant decrease in Raman intensity. To demonstrate the feasibility of the alumina‐coated silver substrate as a probe of adsorbates and reactions at elevated temperatures, an in situ SERS measurement of calcium nitrate tetrahydrate on bare and alumina‐coated silver was performed at temperatures ranging from 25 to 400 °C. ALD deposition of an ultrathin alumina layer significantly improved the thermal stability of the SERS substrate, thus enabling in situ detection of the dehydration of the calcium nitrate tetrahydrate at an elevated temperature. Despite some loss of Raman signal, the coated substrate exhibited greater thermal stability compared to the uncoated substrate. These experiments show that ALD can be used to synthesize stable SERS substrates capable of measuring adsorbates and processes at high temperature. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献