金纳米粒子的制备及表征研究

以氯金酸为原料,柠檬酸钠为保护剂,成功制备出金纳米粒子,并应用透射电镜和紫外-可见分光光度计对该实验样品进行了表征,结果表明此类纳米粒子尺寸均匀、呈球形单分散分布.     

金纳米粒子的应用研究进展

近年来,由于金纳米粒子独特的物理化学性质以及良好的生物相容性和生物安全性,吸引越来越多的科研工作者对其展开广泛的研究和开发。从金纳米粒子的合成方法、特性以及应用开发等方面的对金纳米粒子近年来的研究进展进行了比较详细的综述。     

金纳米粒子的绿色制备研究

以桔子皮提取液为还原剂兼保护剂,氯金酸溶液为前驱体,采用化学还原法制备了金纳米溶胶,并通过离心和干燥的方法得到金纳米粉末.采用X射线衍射、紫外-可见光谱仪、红外光谱、透射电镜和环境扫描电镜等对所制备的样品的结晶性和粒径进行了表征.研究表明:所制备溶胶中的小粒径金纳米粒子均匀的分布在5 nm-30 nm之间,所制备的金粉...     

聚苯乙烯纳米粒子的制备研究进展

尺寸在10～100 nm左右的聚合物纳米粒子是胶体和材料科学研究中的一个热点,它在光学、催化、微电子、涂料、粘合剂、生物材料和医药等领域都有广泛的应用。白色透明的聚苯乙烯纳米粒子,扩大了其在生物、光学方面的应用,前景广阔。综述了1979年以来国内外12种合成工艺方法,分析了其优缺点。     

MCM-41纳米粒子的制备

以十六烷基三甲基溴化铵(CTAB)为模板剂,通过添加MCM-41前驱体合成了MCM-41纳米粒子,采用XRD、SEM、FTIR等手段对样品进行了分析表征。结果表明加入MCM-41前驱体合成的固体产物具有MCM-41特有的六方排列的孔道结构和较高的有序度,所合成的MCM-41平均粒径为70 nm。     

金纳米颗粒/活性炭纤维的绿色制备及性能表征

采用绿原酸为绿色还原剂,在活性炭纤维(Active Fiber Carbon,ACF)上还原金前驱体形成金纳米颗粒(Gold nanoparticles,Au NPs),制备出Au NPs/ACF纳米复合材料,采用透射电子显微镜(TEM)、扫描电子显微镜(SEM)、比表面及孔径分析仪对其形貌和比表面积进行了表征。结果表明该绿色还原法可以同时制备Au NPs并进行在ACF上的负载,避免了毒性较大的还原剂硼氢化钠的使用,具有较高的环境友好性。     

植物生物质合成金纳米粒子的研究进展

植物生物质合成金纳米粒子具有无毒副作用、生物相容性好、制备简单、商业应用价值大等特点,成为近年来的研究热点.概述了植物生物质合成金纳米粒子的现状,分析了植物生物质合成金纳米粒子的可能作用机制以及植物生物质中起生物还原作用的化合物,同时还探讨了植物生物质还原合成金纳米粒子所面临的挑战.     

金纳米颗粒的制备及其在电化学生物传感器中的应用进展

金纳米颗粒(AuNPs)因其特殊的物理化学性质,其在生物催化及电化学生物传感器中有着越来越多的应用。其制备方式及步骤简单,与电化学生物传感器相结合可更加灵敏、特异地检测重大疾病的核酸、蛋白、肿瘤标志物等。该文章对于AuNPs的制备及在电化学生物传感器中的应用进行介绍。     

银纳米粒子材料制备研究进展

总结了近年来银纳米粒子制备的研究进展,包括化学还原法、电子束辐射法、微生物合成法、植物合成法等。最后总结了银纳米粒子绿色制备的发展方向,即基于微生物和植物的银纳米粒子的绿色制备和应用是未来重要发展方向。     

各向异性Janus纳米粒子的制备表征化学实验设计

设计了一个“一种各向异性的Janus纳米粒子的制备及表征”的综合化学实验。本实验设计将具有各向异性的Janus纳米粒子的合成、分离提纯、结构表征和应用功能融为一体,在实验过程中,引导学生探索Janus纳米粒子的合成机理,掌握分析仪器在材料结构和性能表征过程中的应用,激发学生的科研兴趣,培养学生基础实验操作技能以及使用现代仪器对产物进行结构分析的专业科研能力。     

Plant‐mediated synthesis of silver and gold nanoparticles and their applications

Nanobiotechnology deals with the synthesis of nanostructures using living organisms. Among the use of living organisms for nanoparticle synthesis, plants have found application particularly in metal nanoparticle synthesis. Use of plants for synthesis of nanoparticles could be advantageous over other environmentally benign biological processes as this eliminates the elaborate process of maintaining cell cultures. Biosynthetic processes for nanoparticles would be more useful if nanoparticles were produced extracellularly using plants or their extracts and in a controlled manner according to their size, dispersity and shape. Plant use can also be suitably scaled up for large‐scale synthesis of nanoparticles. In view of this, we have reviewed here the use of plants or their extracts in the synthesis of silver and gold nanoparticles for various human applications. Copyright © 2008 Society of Chemical Industry     

Size-dependent antimicrobial properties of sugar-encapsulated gold nanoparticles synthesized by a green method

The antimicrobial properties of dextrose-encapsulated gold nanoparticles (dGNPs) with average diameters of 25, 60, and 120 nm (± 5) and synthesized by green chemistry principles were investigated against both Gram-negative and Gram-positive bacteria. Studies were performed involving the effect of dGNPs on the growth, morphology, and ultrastructural properties of bacteria. dGNPs were found to have significant dose-dependent antibacterial activity which was also proportional to their size. Experiments revealed the dGNPs to be bacteriostatic as well as bactericidal. The dGNPs exhibited their bactericidal action by disrupting the bacterial cell membrane which leads to the leakage of cytoplasmic content. The overall outcome of this study suggests that green-synthesized dGNPs hold promise as a potent antibacterial agent against a wide range of disease-causing bacteria by preventing and controlling possible infections or diseases.     

金催化研究进展

近年来，金被认为是均相和多相反应催化剂的重要组成成分，能广泛、有效地应用于多种氧化反应。本文综述了金催化刑的最新研究进展。     

Effect of accelerator in green synthesis of silver nanoparticles

Silver nanoparticles (Ag-NPs) were successfully synthesized in the natural polymeric matrix. Silver nitrate, gelatin, glucose, and sodium hydroxide have been used as silver precursor, stabilizer, reducing agent, and accelerator reagent, respectively. This study investigated the role of NaOH as the accelerator. The resultant products have been confirmed to be Ag-NPs using powder X-ray diffraction (PXRD), UV-vis spectroscopy, and transmission electron microscopy (TEM). The colloidal sols of Ag-NPs obtained at different volumes of NaOH show strong and different surface plasmon resonance (SPR) peaks, which can be explained from the TEM images of Ag-NPs and their particle size distribution. Compared with other synthetic methods, this work is green, rapid, and simple to use. The newly prepared Ag-NPs may have many potential applications in chemical and biological industries.     

Spontaneous synthesis of gold nanoparticles on gum arabic-modified iron oxide nanoparticles as a magnetically recoverable nanocatalyst

A novel magnetically recoverable Au nanocatalyst was fabricated by spontaneous green synthesis of Au nanoparticles on the surface of gum arabic-modified Fe₃O₄ nanoparticles. A layer of Au nanoparticles with thickness of about 2 nm was deposited on the surface of gum arabic-modified Fe₃O₄ nanoparticles, because gum arabic acted as a reducing agent and a stabilizing agent simultaneously. The resultant magnetically recoverable Au nanocatalyst exhibited good catalytic activity for the reduction of 4-nitrophenol with sodium borohydride. The rate constants evaluated in terms of pseudo-first-order kinetic model increased with increase in the amount of Au nanocatalyst or decrease in the initial concentration of 4-nitrophenol. The kinetic data suggested that this catalytic reaction was diffusion-controlled, owing to the presence of gum arabic layer. In addition, this nanocatalyst exhibited good stability. Its activity had no significant decrease after five recycles. This work is useful for the development and application of magnetically recoverable Au nanocatalyst on the basis of green chemistry principles.     

Separation of biosynthesized gold nanoparticles by density gradient centrifugation

The electronic, optical, magnetic, and catalytic properties of noble metal nanoparticles (NPs) strongly depend on their size. The size control of the noble metal NPs is one of the significant issues in the field of nanotechnology. We demonstrate both theoretically and experimentally that gold NPs can be separated by density gradient centrifugation (DGC) according to their size. By analyzing the force balance in a centrifuge with a horizontal rotor, a model was developed that relates the sedimentation shift to the centrifugation time and can be used to predict the effect of separation by the shift of particles within a specific period of time. The influences of centrifugation time and centrifugal force on the separation effect of DGC were evaluated.     

金纳米分光光度法测定尿中痕量鸟苷

在pH 3.6的BR缓冲溶液中,鸟苷与金纳米间相互作用,可降低金纳米粒子表面之间的静电斥力,从而改变溶液的吸光度。当鸟苷的浓度在1.75×10^-8-6.27×10^-6mol/L时,与体系ΔA630/A530形成良好的线性关系,其回归方程为：ΔA630/A530=1.33c×10^-6mol/L＋0.017 5,相关系数r=0.997。检出限为5.26×10^-9mol/L。相对标准偏差（RSD）为1.97%-3.26%,回收率为96.2%-98.9%。该法具有操作简单、快速、灵敏度高的优点。     

Size-controlled green synthesis of silver nanoparticles assisted by L-cysteine

A green and size-controlled synthesis of silver nanoparticles (Ag NPs) in aqueous solution with the assistance of L-cysteine is presented. The size of Ag NPs decreases with the increase of L-cysteine concentration, and thus can be controlled by adjusting L-cysteine concentration. TEM analysis shows that Ag NPs with an average size of 3 nm can be produced in the presence of 1.0 mmol/L L-cysteine, about one sixth of the size of Ag NPs obtained in the absence of L-cysteine (17 nm). The as-synthesized silver colloidal solution is stable and can be stored at room temperature for at least two months without any precipitation. This L-cysteine assisted method is simple, feasible and efficient, and would facilitate the production and application of Ag NPs.     

金纳米微粒修饰几丁聚糖微胶囊新方法

制备了金-海藻酸钙-几丁聚糖微胶囊,提出了修饰用于蛋白质药物靶向传输的多糖载体-几丁聚糖的新方法,该方法通过在几丁聚糖微胶囊表面结合金的纳米微粒使微胶囊表面结构发生变化,从而改变微胶囊的性质,这种修饰方法目前未见报道.文中对制备条件进行了优化,并对金-海藻酸钙-几丁聚糖微胶囊的粒径分布进行了表征.文中选择在pH值为5时反应2 h,制得的柠檬酸体系和丙烯酸体系的金-海藻酸钙.几丁聚糖微胶囊的平均直径分别为216.686um和196.850um.     

Synthesis of gold nanoparticles in hyperbranched polyol dispersions

In this study, a series of different generation hyperbranched poly(amine‐ester) with hydroxyl as terminal group were synthesized and used as protectants to synthesize gold nanoparticles with a facile and highly reproducible method. The effect of hyperbranched poly(amine‐ester) generation on size and their distribution of gold nanopartciels were discussed. The results of ultraviolet visible absorption spectroscopy, Transmission electron microscopy and scanning electron microscopy showed that the mean diameter were 24.3 ± 2.6 nm, 18.2 ± 2.1 nm, and 13.6 ± 1.5 nm corresponding to the different generation hyperbranched poly(amine‐ester), and the synthesized gold nanoparticles were almost monodisperse with a narrow size distribution. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011