SERS中的活性基底

从表面增强拉曼光谱(SERS)在分析科学、表面科学固体表面物理化学及纳米科学应用方面活性SERS基底的角度,总结了SERS研究中制备相对简便而有效的活性基底;对金、银胶体、棒、线、立方体状纳米金银、金银复合纳米粒子、有序金属纳米粒子组装阵列及电极的SERS基底的方法技术、基本原理、应用及其最新进展进行了概述。希望以此为SERS工作者提供参考。     

基于Ostwald ripening自组装工艺的银纳米颗粒活性衬底的高稳定性

利用Ostwald ripening自组装工艺对拉曼增强衬底进行处理,得到粒径和密度不同的银纳米颗粒拉曼增强衬底。用龙胆紫生物大分子作为探针,对其表面增强拉曼散射（SERS）和表面增强荧光（SEF）进行研究发现,拉曼和荧光光谱强度存在着相似的变化趋势,且随着自组装工艺时间的递增,强度的变化趋于稳定。研究结果表明：Ostwald ripening自组装工艺可以优化SERS和SEF增强效果及其稳定性,故其可为研制具有长期稳定性、低成本的基于SERS和SEF效应生物化学传感器件提供研究基础。     

应用表面增强拉曼光谱检测儿童化妆品中二噁烷的研究

文章以金纳米粒子作为表面增强拉曼散射(SERS)基底,用SERS法检测儿童化妆品中的二噁烷含量。探讨了儿童化妆品中其它物质和金纳米粒子作为SERS基底对儿童化妆品中二噁烷SERS特征峰的影响。     

“核—卫星”状金纳米粒子组装体的自组装方法与应用

"核—卫星"状金纳米粒子组装体(CSNAs)因其新颖的构型和特殊的性能而备受关注,在表面增强拉曼光谱(SERS)、光电器件、生化传感器和特异材料方面引起了科学家们的极大兴趣。文章总结了目前用于构建CSNAs的几种主要的自组装方法,并对组装体的应用进行了介绍。     

金纳米颗粒组装体中粒子数目的精确可逆调控研究

通过正硅酸乙酯水解生成二氧化硅,包裹金纳米粒子部分表面,在溶液相中有效制备出非对称金纳米粒子(Janus金纳米粒子)。在Janus金纳米粒子表面修饰偶氮苯和环糊精,借助偶氮苯与环糊精之间的光响应超分子作用,精确可逆诱导Janus金纳米粒子自组装形成低聚体;调整粒子表面二氧化硅覆盖区域与裸露金表面的比例,调节特定数目的金纳米粒子进行自组装,可以精确调控自组装体中金纳米粒子数目。     

核壳结构Ag@SiO_2组装体的表面增强荧光效应

利用还原法制备Ag纳米粒子,利用Stber法成功制备了不同壳层厚度的核壳结构Ag@SiO_2纳米粒子。并利用重力沉积方法在玻璃基片上构筑了纳米粒子二维自组装膜结构,探讨了该自组装体对荧光物质的等离子体共振增强荧光性能。结果表明:通过简单的包覆方法,可控制得到不同壳层厚度的Ag@SiO_2纳米粒子;Ag@SiO_2纳米粒子的二维组装薄膜对荧光物质增强作用具有显著的距离依赖性,当壳层厚度为(5±1)nm时,纳米粒子薄膜对罗丹明B荧光增强作用达到最大,增强倍数约为5倍;当壳层厚度大于22 nm时,纳米粒子薄膜对罗丹明B几乎没有荧光增强效应。以Cy5~羊抗兔蛋白为荧光物质,进一步证实了该核壳结构Ag@SiO_2组装体的有效增强荧光性能。     

一种简单方法制备CuO/Au纳米复合薄膜及表面增强拉曼散射效应研究

本文通过一种简单、可控的方法,用金纳米粒子复合氧化铜纳米板阵列,并研究了金纳米粒子复合后的的氧化铜纳米板阵列的结构和表面增强拉曼性能。结果表明,用金纳米粒子复合后的氧化铜纳米板阵列拉曼增强性能显著提高,CuO/Au纳米复合薄膜显现出较强的表面增强拉曼散射效应,并且能够准确反映探针分子的物质成分。从罗丹明6G的特征峰强度可以看出,随着Au纳米粒子含量的增加,R6G的特征峰强度有显著增加。当前驱液体积为0.4ml时,样品的增强因子可以达到2.7×10~4。CuO/Au纳米复合薄膜的表面增强拉曼散射主要来自于CuO与金属Au结合后所产生的电磁增强效应。这一结果表明,CuO/Au纳米复合薄膜在有机分子检测方面具有十分广阔的应用前景。     

自组装纳米阵列SERS基底的发展及应用进展

表面增强拉曼散射(SERS)的谱峰窄以及分子指纹特性使其在分析化学、环境检测、生物医药及食品安全等领域具有广泛应用。而稳定、均一、重复性好的SERS活性基底的制备至关重要。自组装法可制备出均一、稳定、高度有序、可控的纳米阵列,提高SERS检测的重现性和灵敏度。本文对自组装纳米阵列技术制备SERS活性基底及SERS的应用进行了综述。     

表面增强拉曼散射基底的研究进展

表面增强拉曼光谱(SERS)由于其高的灵敏度、抗干扰能力强等优点,被广泛应用在表面科学、分析化学、物理学等领域,是研究表面和界面过程的重要工具,是定性鉴定化学组成相近化合物的有力手段.因此,高品质、高活性的SERS基底一直是科研工作者们追求和研究的重点.本文对SERS活性基底的发展进行了介绍,从金、银金属纳米粒子作为基底的拉曼效应的科学研究,又进一步总结了非金属纳米粒子ZnO、TiO₂、ZnS、Cu₂O、CdTe、CdS等SERS基底.今后,将贵金属与半导体纳米材料复合将是SERS基底的研究热点.SERS光谱目前可以在液相色谱分析的检测器、医学检测仪器、刑侦分析检测等众多领域得到应用.     

基于功能化金纳米粒子灵敏检测水溶液中的镉离子

MPA通过Au—S键自组装金纳米粒子表面,GSH中的氨基与MPA中的羧基形成羧铵盐吸附到金纳米表面,形成了表面带有大量官能团的Au—MAP—GSH纳米粒子。由于Cd2＋能与GSH中的羧基、氨基、巯基可以共同形成稳定的络合物,金纳米粒子能以cd2＋离子为桥梁发生大量聚集,引起金纳米表面等离子吸收和溶液颜色发生变化,从而实现对cd2＋进行裸眼检测。     

Control of locally deposited gold nanoparticle on polyaniline films

Local and bulk deposition of gold particles was accomplished by the spontaneous reaction between chemically reduced polyaniline (PAN) thin films and AuCl₄⁻ ions. PAN layers were electrodeposited on glassy carbon (GC). Characterization of the PAN films was carried out by microscopy and electrochemistry. Local deposition of gold particles was performed by means of scanning electrochemical microscopy, where a gold microelectrode was used to produce a flux of gold ions in close vicinity to an unbiased PAN film. We found that the nature of the gold particles was greatly affected by the potential applied at the microelectrode as well as the oxidation state of the PAN films.     

The role of silver minerals on the cyanidation of gold particles embedded within multi‐sulphidic mineral matrices

The effect of silver minerals on the dissolution behaviour of gold particles embedded within multi‐sulphidic minerals was investigated. A multi‐layer packed‐bed reactor approach was used to study the leaching behaviour of free gold (within silica) and gold associated with a series of synthetic multi‐mineral systems consisting of pyrite, silica, and successively, X = chalcopyrite, sphalerite, and stibnite. The reactor was filled with sieved powders of sulphidic minerals (pyrite, X), gold and silica and arranged as electrically‐isolated three‐layer //Pyrite//X//Silica// and two‐layer //Pyrite + X//Silica// systems. Gold powder was introduced successively in each layer of the three‐ and two‐layer mineral systems and the gold leaching behaviour was studied. The highest gold recovery was achieved for the gold particles within the pyrite layer while the lowest was within the silica layer. In case of the //Pyrite//Stibnite//Silica// system, the surface passivation inhibited gold leaching strongly. Gold cyanidation experiments were also performed with the addition of silver minerals, with both Au and Ag minerals dispersed in a three‐layer //Pyrite//X//Silica// and two‐layer //Pyrite + X//Silica// systems. Silver minerals addition proved beneficial for the pyrite‐sphalerite‐silica system. Gold leaching was severely retarded for the pyrite‐chalcopyrite‐silica and pyrite‐stibnite‐silica systems. Passivating films were observed at the surface of gold particles in case of gold cyanidation with pyrite‐chalcopyrite‐silica and pyrite‐stibnite‐silica systems.

     

Ordering of block copolymer/nanoparticle composite thin films

The ordering behavior of polymer nanocomposites composed of gold nanoparticles confined in the polystyrene (PS) domains of PS based block copolymers was investigated. The results reveal that the self‐assembly of nanoparticles in the PS domains improved the ordering of microdomains. This is attributed to the presence of nanoparticles that reduced the degree of segregation of the system, causing slow phase separation. This facilitates the packing of the cylindrical microdomains, leading to a well‐ordered structure of the composite. When particles were incorporated into the major domains of cylindrically ordered block copolymer, the connectivity of the domains allowed particles to move to the top of the film to gain additional entropy of the system. In contrast, when particles were organized in parallel cylinders in the block copolymer, they were confined in the cylinders which prevented them from diffusing in the depth direction. The aggregation of nanoparticles was amplified when the composite was annealed in air. We believe that the results from this study will enable more understanding of the effects of nanoparticles on the ordering of block copolymer/nanoparticle composite thin films and will provide a tool in the fabrication of composite thin films. Copyright © 2012 Society of Chemical Industry     

Preparation and characteristics of a waterborne preventive stain coating material with organic-inorganic composites

With the goal of developing a waterborne coating material that prevents staining, organic-inorganic composites prepared from colloidal silica and two types of acrylic resin emulsions were investigated as exterior coatings. conventional acrylic resin emulsion and organic silane hybridized acrylic resin emulsion prepared by emulsion polymerization were mixed with colloidal silica to form organic-inorganic comiposite films. The addition of colloidal silica to emulsions yielded films with higher hydrophilicities, as indicated by lower water contact angles for these films in comparison to films without colloidal silica. The water contact angles of organic silane hybridized acrylic resin emulsion/colloidal silica films were lower than those of acrylic resin emulsion/colloidal silica films. Composite films containing colloidal silica particles smaller than 100 nm in diameter showed high hydrophilicities. Observations of the dispersed state of colloidal silicaparticles in organic-inorganic composite films by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) demonstrated that colloidal silica particles were densely aggregated on the film surface. Outdoor exposure tests of the coating materials prepared from organic silane hybridized acrylic resin and colloidal silica particles with diameters of 7.5 nm showed excellent stain resistance.     

负载型Au催化剂的应用研究概述

本文概述了Au催化剂的研究进展，各类反应对Au催化剂的微观结构非常敏感，催化剂的活性与载体的种类，催化剂表面Au晶粒大小，载体与Au相互作用的强弱以及制备方法密切相关，载体主要包括各种氧化物和分子筛；表面Au粒子平均直径小于5nm，一般会有较好的催化活性，常用沉积－沉淀法或共沉淀法来制备，Au催化剂主要应用于CO低温氧化与丙烯环氧化等反应中。     

溶胶-凝胶法制备纳米TiO2/SiO2复合薄膜的研究

用溶胶-凝胶法在清洁的玻璃表面成功制备了均匀透明的纳米TiO2/SiO2复合薄膜,并用扫描电镜,红外光谱仪,综合热分析仪和接触角测定仪对薄膜的结构和性质进行了研究。结果表明:TiO2/SiO2复合薄膜由晶粒小于10nm的球形颗粒组成,表面均匀,结构致密,具有平整的组织结构;引入SiO2后可以抑制薄膜中TiO2晶粒的长大,且能显著降低薄膜的接触角,增强薄膜的亲水性。     

Preparation of a Superhydrophilic Thin Film on Glass Substrate Surfaces with Titanium Alkoxide Solution

Thin films of anatase titanium dioxide (TiO₂) were prepared on slide glass substrate surfaces by a titanium alkoxide hydrolysis operation, and the hydrophilicity and the transparency of their films were examined. The contact angles of water and the transmittances of visible light for their substrates changed with the duration of tetraethyl orthotitanate (TEOT) hydrolysis operations. They were influenced by the thickness of the films and the size of the deposited particles on the silicon dioxide-coated slide glass substrate surfaces. The contact angles also changed with the irradiating duration of ultraviolet light. When acetylacetone was added to a TEOT solution, the contact angles on the thin films became larger and the transparency was better during the same duration of TEOT hydrolysis operations. On addition of acetylacetone, nucleation of TiO₂ particles at the initial stages of TEOT hydrolysis operations was restrained and, subsequently, the supersaturations of TiO₂ in the solution became comparatively higher in the later stages of TEOT hydrolysis ones.     

丙烯酸丁酯/VAE互穿聚合物乳液的研究

以互穿聚合物网络(IPN)方法合成丙烯酸丁酯与VAE共聚物乳液。研究了乳化剂、交联剂、溶胀时间、反应时间等条件对转化率的影响。以红外光谱、透射电子显微镜表征互穿共聚物乳胶膜的微观结构。通过吸水性及乳胶膜对水接触角的测定，证明其耐水性较VAE乳胶膜明显增强。。YEM照片表明互穿聚合物胶粒形态结构较VAE乳胶粒发生了明显变化。     

PMMA/SiO_2纳米复合膜表面性能的研究

采用有机硅处理剂对纳米SiO2进行化学修饰,得到表面官能团化的纳米SiO2,然后再通过溶液聚合法制备了聚甲基丙烯酸甲酯/二氧化硅(PMMA/SiO2)纳米复合膜.利用傅里叶红外光谱仪(FT-IR)、扫描电镜(SEM)、原子力显微镜(AFM)、水接触角仪(WCA)对其进行表征.结果表明,经有机硅处理剂官能团化的纳米SiO2能很好地分散于PMMA基体中,SiO2有富集到聚甲基丙烯酸甲酯表面的趋势,加入纳米SiO2降低了聚甲基丙烯酸甲酯表面自由能,提高了膜表面的水接触角.经四氢呋喃溶剂刻蚀后,膜表面的水接触角显著提高,得到憎水型PMMA/SiO2纳米复合膜.     

射频磁控溅射法制备FC/ZnO杂化材料及其基本性质

采用射频磁控溅射法,首先以聚四氟乙烯（PTFE）为靶,氩气为载气,在聚对苯二甲酸乙二醇酯（PET）基底上沉积氟碳（FC）膜;然后以金属锌为靶,氩气为载气,氧气为反应气体,在FC膜上再沉积一层ZnO膜而形成FC/ZnO有机-无机纳米杂化材料。用AFM、XPS、UV以及静态接触角测定仪对杂化材料的基本性质进行了研究。结果表明,该法制得的杂化材料是由纳米粒子组成的岛状结构,岛的表面起伏不平。其生长模式是一种依附于有机核的沉积-扩张生长。杂化材料具有较好的紫外吸收特性,这是由于其分子结构中含有π-π共轭双键、表面的不平整性以及纳米氧化锌粒子对紫外光的吸收共同作用的结果。静态水接触角均大于90°,呈现出良好的疏水性。