金纳米粒子的电化学合成及光谱表征

采用电化学方法合成各种形状的金纳米粒子,生成的金纳米粒子形貌与施加电流有关,通过匀速递增电流电解的方法,可制备得到哑铃形,球形以及棒状金纳米粒子,采用恒电流电解方法主要获得球形及哑铃形纳米粒子。利用透射电镜、紫外-可见光谱及拉曼光谱对金纳米粒子进行相关表征。紫外-可见光谱研究发现金纳米棒出现位于近红外区间的吸收峰(985 nm),由此推测棒的长径比约为6。以结晶紫为探针分子,研究了金纳米粒子的表面增强拉曼光谱(SERS)效应,并分析得出其平躺的吸附模式。根据形貌表征的结果推断了纳米粒子的生长机理。     

憎水性金属纳米粒子及其LB膜的制备与光谱表征

用油酸钠和十四烷基硫醇作为稳定剂,制备了高度单分散的疏水性银和金纳米溶胶。考察了单粒子层的π－Ａ曲线并建造了纳米粒子的ＬＢ膜。通过紫外可见光谱讨论了纳米粒子的分散状态,由红外光谱结果讨论了纳米粒子表面有机吸附层的状态。     

Spectroscopic and Electrochemical Characterization of Benzoylglycine-Modified Glassy Carbon Electrode: Electrocatalytic Effect Towards Dioxygen Reduction in Aqueous Media

Present work aims to create a benzoylglycine (BG)-modified glassy carbon (GC) substrate exploiting the electroreduction of diazonium salts. Dopamine was used to confirm the attachment of benzoylglycine molecules onto the glassy carbon surface by observing the blockage of the electron transfer using cyclic voltammetry (CV). BG-modified GC surface (BG-GC) was also characterized by Raman spectroscopy and electrochemical impedance spectroscopy (EIS) techniques. The ellipsometric thickness of the BG film was measured as approximately 14 nm for seven CV cycles. The electrocatalytic effect of BG-GC electrode surface against dioxygen reduction was investigated. The catalytic effect for dioxygen reduction of the BG-GC surface was compared with that of 2-benzo[c]cinnoline, 2-benzo[c]cinnoline 6-oxide- and diethylene glycol bis(2-aminophenyl)ether-modified GC surfaces to clarify the mechanism of catalysis of the surfaces in terms of molecular structure.     

Magnetic Properties of Nanoparticles Useful for SQUID Relaxometry in Biomedical Applications

We use dynamic susceptometry measurements to extract semiempirical temperature-dependent, 255-400 K, magnetic parameters that determine the behavior of single-core nanoparticles useful for SQUID relaxometry in biomedical applications. Volume susceptibility measurements were made in 5 K degree steps at nine frequencies in the 0.1-1000 Hz range, with a 0.2 mT amplitude probe field. The saturation magnetization (M_s) and anisotropy energy density (K) derived from the fitting of theoretical susceptibility to the measurements both increase with decreasing temperature; good agreement between the parameter values derived separately from the real and imaginary components is obtained. Characterization of the Néel relaxation time indicates that the conventional prefactor, 0.1 ns, is an upper limit, strongly correlated with the anisotropy energy density. This prefactor decreases substantially for lower temperatures as K increases. We find, using the values of the parameters determined from the real part of the susceptibility measurements at 300 K, that SQUID relaxometry measurements of relaxation and excitation curves on the same sample are well described.     

牛血红蛋白与纳米雄黄相互作用的光谱研究

采用紫外-可见吸收光谱、荧光光谱研究牛血红蛋白(bovine hemoglobin,简称BHb)与纳米雄黄的相互作用。从紫外-可见吸收光谱可观察到,随着纳米雄黄浓度的增加,牛血红蛋白406 nm附近的特征Soret吸收带红移至413 nm,且强度逐渐降低。强度的降低表明纳米雄黄可能使部分血红素辅基逐渐从它们的键腔中脱离出来。特征峰位的红移推测为纳米雄黄中的砷结合了血红蛋白中的氧,诱导血红蛋白脱氧,变成脱氧血红蛋白,其构象由R态转变成T态。由荧光光谱研究可以得出随着纳米雄黄浓度的增加,牛血红蛋白338 nm处的荧光强度逐渐减弱,Stern-Volmer方程分析表明,纳米雄黄静态猝灭牛血红蛋白的内源荧光。紫外-可见吸收光谱与荧光光谱的计算结果均表明,牛血红蛋白与纳米雄黄的结合常数k的数量级达到109。     

斑蝥素及其衍生物的谱学研究

研究了斑蝥素、去甲斑蝥素以及去甲斑蝥酸钠结构的光波谱特征,为控制该原料和产品的质量提供依据,并对用喷雾干燥法制备的去甲斑蝥酸-壳聚糖固体分散体的红外光谱进行分析研究. 通过紫外光谱、红外光谱、核磁共振氢谱和质谱手段对各化合物进行结构分析. 样品斑蝥素、 去甲斑蝥素、去甲斑蝥酸钠及去甲斑蝥酸-壳聚糖固体分散体的光波谱均符合其结构特征. 研究表明紫外光谱、红外光谱、核磁共振氢谱和质谱是确定已知化合物结构的有效手段,可为斑蝥素衍生物的原料及产品提供定性定量依据.     

Spectroscopic Characterization of Metamictization and Recrystallization in Zircon and Titanite

Recent applications of infrared and Raman spectroscopy in the study of the metamict (or "amorphized") state, high-temperature recrystallization and radiation-induced OH species in natural zircon (ZrSiO₄) and titanite (CaTiSiO₅) are reviewed.     

in situ FTIR Spectroscopic Characterization of Electroactive Species

A spectroelectrochemical technique based on the Fourier Transform Infrared Reflection Absorption Spectroscopic (FTIR-RAS) method is described, whereby high resolution in situ vibrational spectra of electrogenerated reaction intermediates (including radicals) and species adsorbed on electrode surfaces are obtained. Theoretical and experimental aspects of the method in a single reflection mode are discussed. Details of the cell design and the optimization of the operational parameters for running the FT-IR spectrometer in the RAS mode are also described. Apart from the potential of this technique to identify adsorbed species through their vibrational spectra, it can also be used to determine the orientation of the adsorbed species on the electrode surface by making use of surface selection rules. Using this technique, it has been possible to record the spectra of molecules adsorbed from aqueous and non aqueous media on metal and carbon electrodes. It has been possible to distinguish the vibrational spectra of adsorbed molecules from those in the bulk. Various systems covering a wide range of molecules have been studied and the potential of the technique as a method for the characterization of the electrode-electrolyte interface has been demonstrated.     

Microscopic and Spectroscopic Methods Applied to the Measurements of Nanoparticles in the Environment

Abstract: Currently, thousands of commercially available products contain engineered nanoparticles (ENPs). Because numerous nanoparticles (NPs) are being used in products that will be in contact with water or directly used in water treatment processes, these materials will undoubtedly reside, at least temporarily, in bodies of water. Given the widespread use of NPs and ENPs in consumer goods, a large portion of these materials will soon go into the waste stream, potentially to soil and sediments or added directly to agricultural lands via biosolids. Possible impacts of ENPs on aquatic and terrestrial ecosystems are of great concern. Preliminary data from several research groups have shown that ENPs may have a direct impact on food safety and the food chain. However, our knowledge about detection and characterization of NPs in the environment, especially aquatic environments, is still in its infancy. This review includes the most recent literature about the methods applied to the measurement of NPs and ENPs in the environment. The review covers methods to determine size distribution, shape, structure, surface charge, chemical composition, surface area, agglomeration, surface chemistry, porosity, and solubility.     

Spectroscopic Characterization of Oxime Ligands and Their Complexes

New imine–oxime ligands H₃L¹–H₃L³ have been obtained from reactions of the Schiff base ligands H₂B¹–H₂B³ with monochloroglyoxime. Mononuclear copper(II), cobalt(II), nickel(II), vanadyl(IV) and zinc(II) complexes of the imine–oxime ligands H₃L¹–H₃L³ have been prepared and characterized by elemental analyses, infrared and electronic spectra, magnetic moment and molar conductance data. The molar conductance data show that the complexes are non‐electrolytes. When the imine–oxime ligands react with the metal salts in a 2:1 ratio, they behave as dibasic bidentate ligands towards one metal ion. The nickel(II) and zinc(II) complexes are diamagnetic. The ¹H(¹³C)‐nmr spectra of all ligands and nickel(II) and zinc(II) complexes of the ligands H₃L¹–H₃L³ have been recorded. Mass spectra of the imine–oxime ligands and their nickel(II) and zinc(II) complexes were recorded. Some of the ligands and metal complexes have antibacterial activity.     

芦荟中芦荟苷的结构表征及光谱分析

芦荟以其丰富的多糖、蛋白质、氨基酸、维生素、活性酶及对人体有益的微量元素被广泛用于各个领域。然而其主要活性成分芦荟苷同时也是一种致敏成分,更有甚者可能会引起严重的过敏反应。将红外、拉曼光谱应用于芦荟苷结构的表征,并将密度泛函数理论应用到理论计算中,利用B3LYP/6-31G(d)基组分析振动,可以更好地理解芦荟苷分子的振动频率。通过比较溶液的酸碱性以及最佳溶剂,最终选定在中性条件下,水作为溶剂为最佳实验条件,测定芦荟苷的检测限可以达到5 ppm的水平,为芦荟苷含量的快速检测奠定了理论基础。     

Synthesis and Characterization of CuInS2 Nanoparticles

Optics and Spectroscopy - CuInS2 nanoparticles coated with ZnS are synthesized. The luminescence and absorption spectra of nanoparticles are measured and the dependences of the luminescence spectra...     

苏丹红系列染料在有机溶液中的紫外-可见光谱研究

研究了苏丹红Ⅰ、苏丹红Ⅲ和苏丹红Ⅳ在非极性溶剂石油醚和极性溶剂乙腈及乙腈-水混合溶液中的紫外-可见光谱特征。在极性溶剂中苏丹红系列的可见区特征吸收峰比在非极性溶液中略有红移;在乙腈-水混合溶液中,苏丹红Ⅰ的特征吸收峰比在乙腈溶剂中红移,最大红移达13 nm,吸收强度最大增幅为34.5%;苏丹红Ⅲ的特征吸收峰红移8 nm,吸收强度增幅为11%;苏丹红Ⅳ的特征吸收峰先红移后蓝移,吸收强度增幅数仅为2.5%。造成这一变化的原因是在乙腈-水混合溶液中,苏丹红Ⅰ, Ⅲ, Ⅳ分子内氢键被破坏,扩大了π键离域范围所致。     

Synthesis and Spectroscopic Characterization of Fluorescent Boron Dipyrromethene-Derived Hydrazones

Derivatives of 4,4-difluoro-4-bora-3a,4a,diaza-s-indacene (BODIPY? or BDP) that possess a hydrazine substituent on position 5 are potential "turn-on" fluorophores for labeling aldehydes The unnatural amino acid L-3-formyltyrosine can be incorporated into a protein or peptide; thus, these hydrazines are potentially site specific labels for such polymers. In this work, model compounds were synthesized to assess whether the photochemical properties of the BDP-hydrazone would be suitable for protein labeling. Hydrazones were synthesized from the fluorophore 3-chloro-5-hydrazino-BDP and different aldehydes, and the absorption and emission spectra of the products were compared. The hydrazone of an unsubstituted aromatic aldehyde displays absorption and emission maxima (531 nm and 559 nm, respectively in dioxane) that are red shifted relative to those of a hydrazone from an aliphatic aldehyde (513 nm and 543 nm, respectively, in dioxane) and an increased quantum yield (0.21 vs. 0.11, respectively, in dioxane). The presence of a hydroxyl group ortho- to the aldehyde produces a hydrazone in which the absorption and emission maxima are slightly red shifted (528 nm and 564 nm, respectively in dioxane) from the unsubstituted aromatic hydrazone, but the quantum yields of the two hydrazones are equivalent. Thus, an ortho-hydroxy substituted aromatic aldehyde is a suitable electrophile for "turn on" protein labeling using the hydrazino-BDP. The specificity of this labeling reaction for the unnatural amino acid was demonstrated through fluorescent labeling of just the 3-formyltyrosine-containing α-subunit of α,β-tubulin.     

Characterization of TiO2 Nanoparticles in Langmuir-Blodgett Films

In this work we have synthesized TiO₂ nanoparticles, using either a sol–gel base catalysed process in the interior of CTAB reversed micelles (TiO₂ CTAB sol), or the neutralization of a TiO₂/H₂SO₄ solution in the interior of AOT reversed micelles. From the absorption and emission data of the TiO₂ nanoparticles it is possible to conclude that in the sol–gel route there remains alkoxide groups in the structure, originating transitions lower than the energy gap of TiO₂ semiconductor. These transitions disappear in the neutralization procedure, where the alkoxide groups are absent in the structure. We have assigned the observed indirect and direct optical transitions according to the anatase band structure. TiO₂ Langmuir-Blodgett (LB) films were prepared either by direct deposition of titanium isopropoxide or by deposition of the TiO₂ CTAB sol. These films showed photoluminescence, which was attributed to band-gap emission and to surface recombination of defect states.     

The Use of Capping Agents in the Stabilization and Functionalization of Metallic Nanoparticles for Biomedical Applications

The study of nanoparticles (NPs) and their application in different areas of research, including biomedicine, is attracting the attention of researchers worldwide. Numerous investigations published during the last 20 years cover the fabrication of new materials in the nanoscale, and several uses have been proposed. Metallic nanoparticles (MNPs) have generated a high level of interest, based on improved optical, electrical and magnetic properties, ease of manufacturing, small sizes, and easy functionalization. However, when it comes to Biomedicine, particle aggregation, possible toxicity, and the need for effective cell internalization, still demand active investigation. The main strategy to overcome these drawbacks is possibly the use of capping agents to increase the stability of the particles in dispersion, their biocompatibility and functionalization. In this review, important concepts and characteristics of MNPs, are collected and described. The importance of surface coating for biomedical applications of metallic nanoparticles as well as the most used capping agents and metallic nanomaterials, are also discussed. Finally, the text includes examples and essential characteristics for the biomedical use of MNPs, including the consideration of important challenges. Aspects such as relevant biological activity, increased biocompatibility and functionalization potential are among the most desirable attributes of a capping agent.     

掺杂铁的CeO2纳米颗粒的制备与表征

利用反相共沉淀法,合成了掺杂过渡金属铁的CeO2纳米颗粒.通过X射线衍射(XRD)、透射电镜(TEM)、傅里叶变换红外(FTIR)光谱、紫外-可见(UV-Vis)光谱等测试手段对产物进行了分析和表征.结果表明,掺杂铁的CeO2纳米颗粒是纯立方莹石结构;过渡金属铁掺入了CeO2的晶格;其相比于不掺铁的CeO2纳米颗粒吸收...