Preparation, optical properties and cell staining of water soluble amine-terminated PAMAM G 2.0-Au nanocomposites

The solution chemical and optical characteristics of formation of amine-terminated polyamidoamine dendrimer G2.0(NH₂-PAMAM G2.0)-Au nanocomposites in the aqueous solution of NH₂-PAMAM G2.0 at various mole ratios of Au(III) to NH₂-PAMAM G2.0 were studied by both UV-visible spectrometry and fluorospectrometry. The NH₂-PAMAM G2.0-Au nanocomposites, with a type of structure in which one Au nanoparticle is surrounded by several NH₂-PAMAM G2.0 dendrimers, emit strong bluish violet fluorescence, and are uniform, water soluble and biocompatible as well as very stable in frozen conditions. The size of gold nanoparticles in the nanocomposites is about 2.5 nm and decreases with the increase of NH₂-PAMAM G2.0 concentration. The NH₂-PAMAM G2. 0 plays an important role in acting as host or micro-reactor for Au(III) before Au(III) reduction and acting as dispersant and stabilizer for gold nanoparticles after Au(III) reduction. Preliminary experiments of cells staining to human embryonic lung fibroblast cell lines show that the NH₂-PAMAM G2.0-Au nanocomposites can be used as optical imaging markers for bioanalyses and medical diagnoses.     

Mechanism of gold dissolving in alkaline thiourea solution

Reaction mechanism of gold dissolving in alkaline thiourea solution was studied by electrochemical methods,such as cyclic voltammetry,chronopotentiometry,AC impedance,linear sweep voltammetry.Apparent activation energy of anodic process of gold electrode dissolving in alkaline thiourea solution is 14.91 kJ/mol.Rate determining step is the process of gold thiourea complex diffusing away from electrode surface to solution.The results of AC impedance and chronopotentiometry indicate that thiourea adsorbs on gold electrode surface before dissolving in solution.There does not exist proceeding chemical reactions.Formamidine disulfide,the decomposed product of thiourea,does not participate the process of gold dissolution and thiourea complex.Species with electro-activity produced in the process of electrode reaction adsorbs on the electrode surface.In alkaline thiourea solution,gold dissolving mechanism undergoes the following courses:adsorption of thiourea on electrode surface;charge transfer from gold atom to thiourea molecule;Au[SC(NH2)2]ads receiving a thiourea molecule and forming stable Au[SC(NH2)2]2 ;and then Au[SC(NH2)2]2 diffusing away from the electrode surface to solution,the last step is the rate-determining one.     

001A强酸性树脂吸附硫脲金的研究

研究了强酸性苯乙烯系阳离子交换树脂００１－Ａ在ｐＨ＝ ２．０的Ｈ２ＳＯ４－ ＣＳ（ＮＨ２）２－ Ｈ２Ｏ２ 体系中,吸附、富集硫脲金的性能。结果表明,该树脂对硫脲金离子Ａｕ（Ｔｕ）＋２ （Ｔｕ＝ 硫脲）具有吸附率高,吸附容量大等优异性能。Ａｕ 负载柱可用Ｎａ２Ｓ２Ｏ３ 溶液定量洗脱,用过的树脂可再生。     

氮氧化物的催化还原研究与展望

综述了传统催化剂和一些新型复合型催化剂在氮氧化物催化还原方面的研究进展,并展望以氧化铋纳米材料为载体,通过不同方法将金属（Ag、Au、Pt、Pd和Rh等）纳米颗粒负载在氧化铋材料上形成金属-氧化铋纳米复合材料用于NOX的催化还原.利用氧化铋晶体结构中较多的氧空位以及金属纳米颗粒的高催化活性的特点提高复合材料对NOX的催化活性,并降低催化剂成本.期望通过考察复合材料的不同组分、金属负载量、反应温度以及还原剂种类对NOX催化还原效果的影响,寻求具有最佳催化活性的金属-氧化铋复合材料,为进一步的工业化应用奠定基础.     

一种新型铂/金纳米材料管状电极的制备及其用于H_2O_2传感器的电化学研究

以φ50μm的银丝为模板,利用恒电位电化学沉积方法制备了一种新型的纳米铂/金管状电极,利用纳米金和铂对过氧化氢的催化氧化,制备无酶过氧化氢传感器。应用场发射扫描电镜(SEM)和X射线能谱(XPS)对其形貌进行了表征,并对制备条件进行了优化。利用微分脉冲伏安法(DPV)对过氧化氢浓度进行了检测,在2.0×10-6～2.0×10-5 mol.L-1范围内氧化峰电流与过氧化氢浓度成线性关系,线性回归方程为I(μA)=1.262 1c(mol.L-1)+8.160 5(n=6,r=0.995),信噪比为3σ时,检测限为9.04×10-7 mol.L-1。     

光度法分析矿样中的金

制定了用乙基紫为显色剂的光度法分析金溶液、金矿浸取液及矿样中金的定量分析操作方法。此法与目前采金工业上使用的吸附一碘量法相比,具有简便、迅速、适用范围宽及准确度高等优点。     

基于巯基己烷和纳米金组装的酪氨酸酶传感器的研制

通过自组装技术构制了一种简单有效的电流型酪氨酸酶传感器.该法先通过1,6二巯基己烷在金电极表面自组装形成有机单层,进而通过巯基与纳米金的强力相互作用将纳米金结合到电极表面形成纳米金层,最后借助纳米金的吸附作用将酪氨酸酶固定在电极表面.结果表明,酪氨酸酶能很好地保持其生物活性,所构制的传感器达到95%稳定状态电流的时间在10 s以内,3种酚类化合物测定的灵敏度顺序为:邻苯二酚>苯酚>对甲基苯酚.另外,对表观米氏常数(Kmapp)和酶电极的稳定性也进行了考察.     

Construction of amperometric glucose biosensor based on <Emphasis Type="Italic">in-situ</Emphasis> fabricated hierarchical meso-macroporous SiO<Subscript>2</Subscript> modified Au film electrodes

Gold nanoparticles (GNPs) modified hierarchical meso-macroporous (HMMP) SiO₂ layer on the surface of Au film electrode was developed as a novel enzyme immobilization matrix for biosensors construction. HMMP SiO₂-Au bilayer film electrodes were in-situ fabricated with magnetron sputtering process and templating method. The as-prepared HMMP SiO₂ films were characterized by SEM, TEM, and cyclic voltammetry (CV). The modified layer of HMMP SiO₂ has interconnected pore channels, and the sizes of macropores and mesopores are about 330 nm and 9 nm, respectively. The HMMP SiO₂ modified gold film electrodes not only have no diffusion barrier for electrochemical probes, but also exhibit good electrochemical properties. In addition, the activity and stability of the immobilized enzyme can be commendably retained in HMMP SiO₂. The biosensor exhibits an excellent bioelectrocatalytic response to glucose with a linear range of 1.0×10^-4 M-1.0×10^-2 M, high sensitivity of 18.0 μA·mM^-1·cm^-2, as well as good reproducibility and stability.     

离子液体中纳米金催化剂的制备及其催化活性

介绍了在离子液体[C6mim]PF6中,以HAuCl4为金源,以水合肼为还原剂,用溶胶-凝胶法一步合成复合纳米Au/SiO2催化剂,并考察了离子液体用量在制备催化剂的过程中的作用。利用XRD、TEM、N2吸附等表征手段对合成的产物进行表征。表征结果显示,SiO2负载Au纳米粒子呈现球形外观,尺寸均匀,分散度良好,而其中Au纳米粒子的粒径在2～3nm。在对甲烷催化氧化的反应中,以复合纳米Au/SiO2作为催化剂,甲烷的转化率最高可以达到24.9%。     

咔唑保护的金纳米粒子的光限幅性质研究

利用波长为532 nm,脉宽为8 ns的激光研究了咔唑保护的金纳米粒子在二甲苯中的光限幅特性.研究表明,这种金纳米粒子具有很强的光限幅效应.利用基于米氏散射理论的模型分析了光限幅效应,实验及分析表明,强的光限幅效应是由非线性散射引起的.     

Pt/C纳米复合材料的合成和表征

以醋酸钠溶液作为稳定剂，采用液体多元醇方法合成了Pt/C纳米复合材料，并利用X射线衍射(XRD)和透射电子显微镜(TEM)对其进行了表征.结果表明，在合成溶液中加入少量的醋酸钠，合成得到的铂纳米粒子具有细小和均匀的粒径，并高度分散在碳载体上.合成溶液中醋酸钠和铂盐的摩尔比是影响铂纳米粒子的粒径和粒径分布的主要因素.     

Optical properties of Au nanoparticles coated on surface of glass or anodic aluminum oxide template

Au nanoparticles coated on the surface of glass (Sample A) or on anodic aluminum oxide template surface (Sample B) were prepared using titanium dioxide sol-gel doped with chloroauric acid and with a reduction process. FE-SEM, UV-Vis spectrum and Fluorescence spectrum tests show that Au nanoparticles have been distributed randomly on the surface of glass, while deposition occurs on the surface of regular hollows for anodic aluminum oxide template. A sharp absorption peak appears at the wavelength of 536 nm for sample B, while there is a red shift, with a broader peak for sample A. A distinct fluorescence emission at the wavelength of 633 nm is detected for sample A, but no noticeable fluorescence emission has been found for Sample B. The results indicate that the microstructure and optical properties of Au nanoparticles can be modulated by different substrate.     

STUDY ON SELECTIVE DISSOLUTION OF GOLD IN ALKALINE THIOUREA MEDIA

Manyresearches[1-3)ondissolutionofgoldinacidicsolutionsofthioureahavebeenreportedsincePlaksin.Generally,itwasconsideredthatthereaction(1)resultsindissolutionofgoldinthioureasolution.An[CS(NH,)sj' e~An ZCS(NH,)2E'~0.38V(1)NH,(NH)CSSC(NH)NH, ZH Ze~ZCS(NH,),E0-0.42V(2)CharleyWRetalthoughtthatthereaction(2)occurredfastly,theproductformamidinedisulfidewasanactiveoxidantandwasveryimportantduringthedissolutionofgold@@['j.However,theconclusionswerelimitedonlyinacidicthioureadissolutio…     

磁性Fe⁃Au复合材料的制备及SERS性能

表面增强拉曼散射光谱(SERS)是一种广泛应用于低浓度分子物种识别并且能够提供结构信息的技术。SERS检测中基底纳米材料的颗粒大小、形状和空间分布对检测结果有着重要影响。探索制备新型纳米结构可以为SERS研究和应用提供新的活性基底和理论基础。由于具有良好的传质和吸附性能,多孔材料广泛应用于构筑SERS活性基底纳米复合物。以多孔磁性纳米材料作固相载体,通过水热合成多孔纳米α⁃Fe2O3,再将其还原成Fe,使Fe的表面也有孔道存在。在Fe表面自组装Au纳米材料构筑SERS基底,以对巯基苯胺（PATP）和三聚氰胺水溶液作为目标分子,对其SERS性能进行测试。调控Au纳米粒子尺寸大小,考察其对SERS性能影响,得到50 nm Au具有最优性能。利用扫描电子显微镜（SEM）、X 射线衍射(XRD)和N2吸附等表征手段,对纳米复合物结构及组成进行分析表征。结果表明,得到了一种同时具有吸附和检测效果的纳米复合物SERS基底。     

Microstructure and optical absorption properties of Au/NiO thin films

Au nanoparticles dispersed NiO composite films were prepared by a chemical solution method.The phase structure,microstructure,surface chemical state,and optical absorption properties of the films were characterized by X-ray diffraction,transmission electron microscopy,X-ray photoelectron spectroscopy,and Uv-vis spectrometer.The results indicate that Au particles with the average diameters of 35-42 nm are approximately spherical and disperse in the NiO matrix.The optical absorption peaks due to the surface p...     

Room temperature hydrogen sensing performances of multiple networked Ga N nanowire sensors codecorated with Au and Pt nanoparticles

The sensing performances of multiple networked Ga N nanowire(NW) sensor codecorated with Au and Pt nanoparticles were examined. The pristine Ga N nanowires show responses of approximately 108%-173% to 0.05%-0.25% H2 at room temperature. On the other hand, the Ga N nanowires decorated with Au and those decorated with Pt lead to 1.1-1.3 and 1.2-1.6 times,respectively, stronger responses to 0.05%-0.25% H2. In contrast, the Au Pt-codecorated Ga N nanowires show 1.3-2.0 times stronger responses to 0.05%-0.25% H2. In other words, the Ga N nanorods codecorated with Au and Pt nanoparticles show much stronger response to H2 gas than the Au or Pt monometal-decorated counterpart. The underlying mechanism for the enhanced response of the Au Pt-codecorated Ga N nanowire was discussed.     

金—曙红—吡咯啶二硫代氨基甲酸铵体系水相荧光法测定痕量金

本文研究了在聚乙烯醇存在下,金与曙红、吡咯啶二硫代氨基甲酸 形成三元络合物的合宜条件,并据此建立了水相荧光熄灭测定痕量金的新方法。在选定的实验条件下,标准曲线的线性范围为0—160ng·ml-~1Au,考察了三十余种离子的干扰情况,其中Pt、Sn、Mo、V、Os有严重干扰。     

Effects of gold plating on the resistance to high temperature discoloration of the cavity for ceramic packages

The effects of thickness and types of gold plating on the resistance to high temperature discoloration of gold plating on cavity surface of ceramic package were investigated. It was found that the thicker gold plating, the less discoloration degree for ceramic packages. Non-cyanide gold plating performed better resistance to high-temperature aging than cyanide gold plating. The relationship between the gold plating thickness and the amount of diffused Ni to the gold plating of ceramic packages with Au/Ni and Au/Ni-Co platings after heating at 420℃ for 15 min was also studied. When the gold plating thickness reach 2.0 μm and 1.6 μm for Au/Ni and Au/Ni-Co plating systems, respectively, no discoloration was observed on the gold plating surface of cavity, and the corresponding diffused Ni amounts (mass fraction) are 1.0% and 0.4%, while the diffused Co to the gold plating is 0.04%.     

Homogeneous detection of human IgG by gold nanoparticle probes

A simple, and homogeneous detection system for human IgG based on the optical properties of aggregated gold nanoparticles probes were investigated. When gold nanoparticles with about 13 nm in diameter were modified by goat anti-human IgG, the addition of human IgG could change the absorption of colloidal gold solution, and the absorption intensity at 740 nm depended on the amount of human IgG. The aggregation of gold nanoparticles was also validated using transmission electron microscopy (TEM). A series of experiments were carried out to study the effects of pH value, the reaction temperature, and non-specific adsorption on the assay. A dynamic range of 10–500 μg/3 mL human IgG was observed. The new bioassay could be used for the rapid and homogeneous detection of antibodies in bioanalytical chemistry.     

ZnO和ZnO/Au纳米流体的制备及光热转换性能

太阳能光热利用是太阳能利用的重要方面,其中,纳米流体光学特性对太阳能光热利用效率起着决定性作用。通过水热法制备不同形貌的ZnO纳米颗粒,再利用硼氢化钠还原法将Au成功还原在ZnO纳米颗粒上,制备出ZnO/Au复合纳米材料。通过SEM、XRD表征ZnO和ZnO/Au纳米粒子的形貌结构与成分。经紫外/可见/近红外吸收光谱测试表明ZnO/Au纳米流体显著提高了在可见光波段的吸收。通过光热转换实验表明,花状ZnO纳米流体的光热转换性能优于棒状ZnO纳米流体, ZnO/Au纳米流体由于Au的等离激元效应,光热转换特性增强。当浓度为1.0 mg/mL时,棒状ZnO/10%Au纳米流体光热转换效率为59%,比纯导热油纳米流体提高16%;当浓度为0.5 mg/mL时,花状ZnO/10%Au纳米流体光热转换效率为71%,比纯导热油纳米流体提高28%。