紫外光辐照法制备金纳米盘及其反应机理

用紫外光辐照氯金酸、聚乙烯吡咯烷酮(PVP)和纳米金种子的混合溶液, 在室温下用30 min制备出尺度小于100 nm的截角三角形或六边形金纳米盘. X射线能谱和衍射分析表明粒子是以{111}面为盘状面的高纯面心立方金单晶, 红外透射光谱表明金粒子与PVP之间存在作用. 产物的可见吸收光谱表现出纳米盘的各向异性表面等离子体共振吸收峰. 不同实验条件下产物的吸收光谱分析表明: PVP起还原剂和包覆剂的作用; 高强度紫外光加速了反应进行; 种子对反应具有催化作用; 种子的加入量有最佳值, 在该值下纳米盘平均尺度最大(达80 nm), 吸收谱上的面内偶极共振峰位于950 nm处; 种子的加入量超过该值时, 纳米盘尺度变小, 面内偶极共振峰发生蓝移.     

金纳米粒子的表面等离子体共振吸收光度法研究和分析应用

在阴离子表面活性剂十二烷基苯磺酸钠存在下的水溶液中，基于金纳米粒子产生的表面等离子体共振吸收的原理，提出了一个分光光度方法。结果表明在524nm处的共振吸收强度与金质量浓度在2．4-120μg/mL范围内服从比尔定律。其线性回归方程为：c＝55．58A 0．78，相关系数为0．9998。方法适用于载金炭中的金分析。     

金纳米棒的生长及与FeCl_3的作用

采用三氯化铁选择性刻蚀法获得了预定长径比的金纳米棒.相比于晶种生长法,三氯化铁选择性刻蚀法可以更加简便快捷地调控金纳米棒形貌.以三氯化铁为刻蚀剂的刻蚀反应优先发生在金纳米棒尖端,这是因为金纳米棒尖端反应活性更高且表面活性剂钝化作用更弱.通过控制刻蚀反应时间及刻蚀剂浓度,可以精确调控金纳米棒的长径比.实验结果表明,增加刻蚀剂浓度、卤素离子浓度以及升高反应温度可以加快刻蚀反应速率.进一步讨论了金属离子的刻蚀作用机理.     

利用紫外-可见光谱研究水溶液中银纳米盘的生长过程及稳定性

Sliver nanoplates were prepared through a visible light induced reduction process by a reaction between sodium citrate and silver nitrate in an aqueous solvent at room temperature. UV-Vis spectra were employed to monitor the growth of the silver nanoplates. The resulting spectra indicated that, at an early stage,the products were spherical particles with planar nanoparticles appearing and growing subsequently. In the last stages of the process, some spherical particles were consumed by the growth of the nanoparticles,through an Ostwald ripening mechanism. Furthermore, it was found that the addition of either Poly(Vinyl Pyrrolidone) (PVP) or excessive citrate could stabilize the colloidal system effectively, and that rigorous stirring was necessary for the anticipant products. Introduction of a large quantities of sodium hydroxide can dramatically accelerate the reactive rate of the photoreduction process.     

谷胱甘肽修饰金纳米棒的制备及与Cu~(2+)的作用

制备了谷胱甘肽(GSH)功能化的金纳米棒复合材料,根据金纳米棒的等离子体吸收峰对其组装排列敏感的特性,研究了功能化的金纳米棒在不同p H值下的组装行为及与Cu2+离子作用后引起的聚集程度、排列方式和光学吸收等变化.同时,测试了纯金纳米棒和谷胱甘肽修饰的金纳米棒分别与铜离子作用后所得复合材料的光热转换性能.结果表明,相对于纯金纳米棒材料强的光热转换效应,铜离子能明显降低复合材料的光热转换效应,与其它金属离子比较,GSH修饰的金纳米棒的等离子光学特性对铜离子具有选择性的变化.     

金纳米粒子共振散射与共振吸收的关系

金纳米粒子共振散射与共振吸收的关系;金纳米粒子;共振散射;共振吸收     

基于血红蛋白/纳米金/二氧化锆-壳聚糖修饰的过氧化氢生物传感器

将二氧化锆(ZrO2)分散于壳聚糖(CS)中得到稳定的CS-ZrO2复合物,制备了Hb/nano-Au/CS-ZrO2/Au过氧化氢生物传感器。 用循环伏安法和计时电流法考察该修饰电极的电化学特性,发现该修饰电极对过氧化氢(H2O2)的还原有良好的电催化作用。 实验结果表明,该传感器对H2O2的线性响应范围为3.9×10-6～1.8×10-3 mol/L,线性相关系数R=0.9956,检测下限为5.6×10-7 mol/L(S/N=3),并具有选择性高、线性范围宽和响应快等优点。     

金纳米粒子/壳聚糖/石墨烯纳米复合材料的制备及其生物相溶性

利用壳聚糖(CTS)的氨基对石墨烯(GNS)进行表面改性制得石墨烯基纳米复合材料(E).利用E中CTS对金纳米粒子(Au)良好的保护作用,在E的表面固载Au制备了Au/CTS/GNS纳米复合材料(F),其结构经UV-Vis和FT-IR表征.并用Zeta电位,XRD和TEM对F的性质进行了研究.结果表明,F不仅具有良好的生物相溶性,而且具有较好的导电性能.     

壳聚糖纳米球和纳米金修饰葡萄糖生物传感器的研究

构造了一种以碳纳米管接枝的壳聚糖为基底,然后将羧基二茂铁电聚合在其氨基化的表面,利用负电荷的表面组装PDDA保护的纳米金,最后通过静电吸附葡萄糖氧化酶,制得了新型的葡萄糖生物传感器。在优化的实验条件下,该传感器的响应电流与其浓度在3.0×10-6~2.9×10-3mol/L范围内呈现良好的线性关系,检测限为1.4×10-6mol/L。此外,该传感器还具有灵敏度高、稳定性好和抗干扰能力强等特点。     

金纳米颗粒等离子体共振吸收光谱检测头孢唑啉

根据金纳米粒子等离子体共振吸收引起的溶液颜色变化,建立了一种快速、简便检测头孢唑啉的色度分析方法.方法线性范围为0.1～5.0 μmol/L,检测限为14 nmol/L.将该方法用于头孢唑啉钠粉针剂的分析,回收率在97.4％～100.2％之间,相对标准偏差小于6.1％.     

Octahedral and Cubic Gold Nanoframes with Platinum Framework

Herein, we report a general synthetic pathway to various shapes of three‐dimensional (3D) gold nanoframes (NFs) embedded with a Pt skeleton for structural rigidity. The synthetic route comprises three steps: site‐specific (edge and vertex) deposition of Pt, etching of inner Au, and regrowth of Au on the Pt framework. Site‐specific reduction of Pt on Au nanoparticles (NPs) led to the high‐quality of 3D Au NFs with good structural rigidity, which allowed the detailed characterization of the corresponding 3D metal NFs. The synthetic method described here will open new avenues toward many new kinds of 3D metal NFs.     

Ligand Control over the Electronic Properties within the Metallic Core of Gold Nanoparticles

The behavior of electrons within the metallic core of gold nanoparticles (AuNPs) can be controlled by the nature of the surface chemistry of the AuNPs. Specifically, the conduction electron spin resonance (CESR) spectra of AuNPs of diameter 1.8–1.9 nm are sensitive to ligand exchange of hexanethiol for 4‐bromothiophenol on the surface of the nanoparticle. Chemisorption of the aromatic ligand leads to a shift in the metallic electron’s g‐factor toward the value expected for pure gold systems, suggesting an increase in metallic character for the electrons within the gold core. Analysis by UV/Vis absorption spectroscopy reveals a concomitant bathochromic shift of the surface plasmon resonance band of the AuNP, indicating that other electronic properties of AuNPs are also affected by the ligand exchange. In total, our results demonstrate that the chemical nature of the ligand controls the valence band structure of AuNPs.     

Enhanced Magneto‐optical Properties of Semiconductor EuS Nanocrystals Assisted by Surface Plasmon Resonance of Gold Nanoparticles

Remarkable magneto‐optical properties of a new isolator material, that is, europium sulfide nanocrystals with gold (EuS–Au nanosystem), has been demonstrated for a future photo‐information technology. Attachment of gold particles that exhibit surface plasmon resonance leads to amplification of the magneto‐optical properties of the EuS nanocrystals. To construct the EuS–Au nanosystems, cubic EuS and spherical Au nanocrystals have been joined by a variety of organic linkers, that is, 1,2‐ethanedithiol (EDT), 1,6‐hexanedithiol (HDT), 1,10‐decanedithiol (DDT), 1,4‐bisethanethionaphthalene (NpEDT), or 1,4‐bisdecanethionaphthalene (NpDDT) . Formation of these systems was observed by XRD, TEM, and absorption spectra measurements. The magneto‐optical properties of the EuS–Au nanosystem have been characterized by using Faraday rotation spectroscopy. The Faraday rotation angle of the EuS–Au nanosystem is dependent on the Au particle size and interparticle distance between EuS and Au nanocrystals. Enhancement of the Faraday rotation of EuS–Au nanosystems was observed. The spin configuration in the excited state of the EuS–Au nanosystem was also investigated using photo‐assisted electron paramagnetic resonance.     

Synergetic Effect of Mo6 Clusters and Gold Nanoparticles on the Photophysical Properties of Both Components

Photodynamic and photothermal therapies (PDT, and PTT, respectively) are promising candidates for multimodal anticancer therapies (i.e., combinations of therapies), since their action is based on mechanisms that generally cannot be resisted by cancer cells, that is, generation of highly oxidizing oxygen species and high temperature, respectively. Herein, hybrid materials that combine octahedral molybdenum clusters as potential PDT agents and plasmonic spherical gold nanoparticles (AuNPs) as PTT agents are reported. Partial overlap of the photoemission spectrum of the cluster and the surface plasmon resonance band of the AuNPs facilitates energy transfer between the photoactive components, which resulted in synergetic enhancement of their photophysical properties. Specifically, by careful selection of the spacing between the cluster and the gold nanoparticle, a significant increase in luminescence and photosensitizing properties of the cluster was achieved in comparison with similar, but gold-free, particles. On the other hand, the cluster complex facilitated energy conversion to heat by gold particles and hence increased the heating rate under laser irradiation.     

DNA‐Encoded Tuning of Geometric and Plasmonic Properties of Nanoparticles Growing from Gold Nanorod Seeds

Systematically controlling the morphology of nanoparticles, especially those growing from gold nanorod (AuNR) seeds, are underexplored; however, the AuNR and its related morphologies have shown promises in many applications. Herein we report the use of programmable DNA sequences to control AuNR overgrowth, resulting in gold nanoparticles varying from nanodumbbell to nanooctahedron, as well as shapes in between, with high yield and reproducibility. Kinetic studies revealed two representative pathways for the shape control evolving into distinct nanostructures. Furthermore, the geometric and plasmonic properties of the gold nanoparticles could be precisely controlled by adjusting the base compositions of DNA sequences or by introducing phosphorothioate modifications in the DNA. As a result, the surface plasmon resonance (SPR) peaks of the nanoparticles can be fine‐tuned in a wide range, from visible to second near‐infrared (NIR‐II) region beyond 1000 nm.     

Gold Nanoparticles as a Biosensor for Cancer Biomarker Determination

Molecular biology applications based on gold nanotechnology have revolutionary impacts, especially in diagnosing and treating molecular and cellular levels. The combination of plasmonic resonance, biochemistry, and optoelectronic engineering has increased the detection of molecules and the possibility of atoms. These advantages have brought medical research to the cellular level for application potential. Many research groups are working towards this. The superior analytical properties of gold nanoparticles can not only be used as an effective drug screening instrument for gene sequencing in new drug development but also as an essential tool for detecting physiological functions, such as blood glucose, antigen-antibody analysis, etc. The review introduces the principles of biomedical sensing systems, the principles of nanomaterial analysis applied to biomedicine at home and abroad, and the chemical surface modification of various gold nanoparticles.     

基于金纳米粒子的等离子体共振吸收测定阿莫西林

在pH=1.89的Britton-Robinson（BR）缓冲溶液中,阿莫西林与氯金酸反应生成金纳米粒子,在537和720 nm产生了特征等离子体共振吸收信号,其537 nm处的吸收强度与阿莫西林浓度在一定范围内呈线性关系,据此建立了基于金纳米粒子的等离子体共振吸收测定阿莫西林的方法。 在优化条件下（pH=1.89,反应温度65 ℃,反应时间40 min）,测定阿莫西林的线性范围为2.0×10-6~3.6×10-5 mol/L,检出限为1.3×10-7 mol/L。 该方法用于合成样品中阿莫西林的测定,回收率在90.4%~103.2%之间,RSD小于4.6%,将所建立的方法用于2个厂家生产的阿莫西林胶囊中阿莫西林含量测定,并与HPLC法对比,结果满意。     

Zeolite‐Supported Gold Nanoparticles for Selective Photooxidation of Aromatic Alcohols under Visible‐Light Irradiation

With new photocatalysts of gold nanoparticles supported on zeolite supports (Au/zeolite), oxidation of benzyl alcohol and its derivatives into the corresponding aldehydes can proceed well with a high selectivity (99 %) under visible‐light irradiation at ambient temperature. Au/zeolite photocatalysts were characterised by UV/Vis, X‐ray photoelectron spectroscopy (XPS), TEM, XRD, energy‐dispersive spectroscopy (EDS), Brauner–Emmet–Teller (BET) analyses, IR and Raman techniques. The surface plasmon resonance (SPR) effect of gold nanoparticles, the adsorption capability of zeolite supports and the molecular polarities of aromatic alcohols were demonstrated to have an essential correlation with the photocatalytic performances. In addition, the effects of light intensity, wavelength range and the role of molecular oxygen were investigated in detail. The kinetic study indicated that the visible‐light irradiation required much less apparent activation energy for photooxidation compared with thermal reaction. Based on the characterisation data and the photocatalytic performances, we proposed a possible photooxidation mechanism.