腐植酸与铜（Ⅱ）和铅（Ⅱ）离子相互作用的荧光光谱和电导率及红外吸收光谱分析

采用荧光光谱、电导法及红外吸收法研究了腐植酸与Cu（Ⅱ）、Pb（Ⅱ）相互作用的荧光光谱、电导率及红外吸收光谱。试验结果表明,     

汞(Ⅱ)与明胶蛋白质相互作用的荧光光谱研究

利用荧光光谱技术,研究了pH为7.30时Hg2+离子与明胶的相互作用,用不同的公式对实验结果进行对比处理,计算了结合常数(K)和结合位点数(n)。推测了Hg2+离子对明胶荧光的猝灭机制为Hg2+离子浓度较低时主要是动态猝灭,浓度较高时表现为静态猝灭。     

铜（Ⅱ）与明胶络合反应的酸效应研究

本文利用分光光度法,测定了ｐＨ值为８．０～１３．０时,Ｃｕ＾２＋与明胶的络合比。结果发现,随溶液ｐＨ值的增大,其络合比增加。这是因为在该ｐＨ值范围内,明胶发生去质子化作用而带负电,提供了更多的ＮＨ２－和ＣＯＯ＾－。通过络合物的荧光光谱表明,由于Ｃｕ＾２＋与明胶分子的强烈络合作用,使得Ｃｕ＾２＋成为明胶有效的荧光猝灭剂。     

四环素-铜（Ⅱ）配合物与DNA相互作用的吸收光谱研究

用紫外光谱方法研究了四环素(TC)-Cu(Ⅱ)配合物与DNA的相互作用．吸收光谱研究表明，DNA能与四环素(TC)及Cu(Ⅱ)形成的配合物发生反应，配合物与DNA的作用方式随着配合物类型及DNA浓度的不同而不尽相同：当四环素与铜形成1：1型配合物时，较低浓度的DNA能与配合物以嵌插方式相互作用，而较高浓度的DNA与该配合物除了发生嵌插作用外，还存在另外的作用方式；当四环素与铜形成1：2型配合物时，DNA与该配合物则主要以嵌插方式相互作用，并且这两种配合物与DNA的嵌插作用均是通过四环素配体插入的．     

荧光猝灭法研究Mn（Ⅱ）和Zn（Ⅱ）与牛血清白蛋白的结合竞争

应用荧光光谱法研究了Mn（Ⅱ）与牛血清白蛋白（BsA）间的结合作用;采用荧光猝灭法计算出不同温度下Mn（Ⅱ）与BSA结合的结合常数、结合位点数、热力学参数;采用同步荧光技术考察了Mn（Ⅱ）对BSA构象的影响,并讨论了Mn（Ⅱ）与BSA的结合模式。结果表明,Mn（Ⅱ）与BSA的结合位点数为1,猝灭过程为动态猝灭,结合过程主要是熵驱动,相互作用力主要为疏水作用力。在此基础上采用荧光猝灭法进一步研究了Mn（Ⅱ）-BSA-Zn（Ⅱ）双金属体系中Mn（Ⅱ）、Zn（Ⅱ）与BSA的相互作用;在Stern-Volmer方程的基础上推导出双金属体系中荧光猝灭的缔合公式;在与单金属体系对比后,推测出Zn（Ⅱ）会竞争Mn（Ⅱ）与BSA的结合。     

锡离子（Ⅳ）与牛血清白蛋白相互作用的研究

应用荧光光谱和紫外可见吸收光谱研究了锡离子（Ⅳ）与牛血清白蛋白间的结合作用,确定了锡离子（Ⅳ）对牛血清白蛋白的荧光猝灭过程的猝灭机理.测定了不同温度下该结合反应的结合常数,结合位点数,热力学参数.依据能量转移理论确定了锡离子（Ⅳ）和白蛋白间的结合距离.采用同步荧光技术考察了锡离子（Ⅳ）对牛血清白蛋白构象的影响,并讨论了锡离子（Ⅳ）与白蛋白的结合模式.实验结果表明猝灭机理是动态猝灭,锡离子（Ⅳ）与BSA以物质的量比1∶1的比例结合形成复合物,结合过程主要是熵驱动,相互作用主要为疏水作用力.     

荧光光谱法研究类人胶原蛋白与Zn(Ⅱ)的相互作用

以最终制备对人体安全无毒且补锌效果良好的类人胶原蛋白-锌螯合物为目标,利用紫外-可见吸收光谱法和荧光光谱法对类人胶原蛋白分子(HLC)与金属Zn(Ⅱ)离子之间的相互作用方式和机理进行了研究,其中Zn(Ⅱ)离子浓度为1.0×10-5—1.0×10-4mol/L;并通过荧光猝灭法计算出不同温度下(298 K和273 K)HLC分子与Zn(Ⅱ)离子之间的结合常数以及相应的热力学参数。研究结果表明:Zn(Ⅱ)离子对类人胶原蛋白的内源荧光有猝灭作用;根据Stern-Volmer方程的求解结果可知猝灭机制属于动态猝灭和静态猝灭;类人胶原蛋白分子和Zn(Ⅱ)离子以摩尔比1∶1形成胶原蛋白-锌螯合物;二者间的结合为自发反应,且相互作用力主要为疏水作用力。因此,文中的研究结果对类人胶原蛋白-Zn(Ⅱ)螯合物的工业化制备、理化性质探究以及进一步的应用研究提供了实验依据和理论基础。     

功能聚氨酯泡沫的制备及其对铜（Ⅱ）吸附性能研究

以组合聚醚、多异氰酸酯（PAPI）和8-羟基喹啉等为原料,制备了一种含喹啉基团的功能聚氨酯泡沫,研究了该泡沫对铜（Ⅱ）的吸附性能,并用于含铜废水的处理。结果表明,在置于50mL含铜（Ⅱ）200μg／mL、pH=6条件下,当8-羟基喹啉用量为2．0份,该泡沫对铜（Ⅱ）的饱和吸附容量为19．18mg／g;吸附平衡时间为2h,对废水中铜（Ⅱ）的去除率可达91．48％。     

光谱法研究蛋白质与胆红素及铜的相互作用

应用荧光光谱研究了胆红素(BR)及铜与牛血清白蛋白(BSA)的相互作用机制.结果表明,BSA-BR的光谱图在有Cu2 存在时,发生了明显的变化,表明能够形成BSA-Cu2 -BR三元络合物.胆红素主要以静态猝灭的方式使得牛血清白蛋白荧光强度显著降低,胆红素和牛血清白蛋白主要凭借范德华力和氢键作用结合.测定了BSA-BR、BSA-Cu2 以及BSA-Cu2 -BR体系的组成和结合常数.探讨了铜离子及胆红素与牛血清白蛋白间的结合反应,阐明了铜离子浓度对胆红素和蛋白质结合的影响.     

Tetrachloridocuprates(II)-Synthesis and Electron Paramagnetic Resonance (EPR) Spectroscopy

Ionic liquids (ILs) on the basis of metal containing anions and/or cations are of interest for a variety of technical applications e.g., synthesis of particles, magnetic or thermochromic materials. We present the synthesis and the results of electron paramagnetic resonance (EPR) spectroscopic analyses of a series of some new potential ionic liquids based on tetrachloridocuprates(II), [CuCl(4)](2-), with different sterically demanding cations: hexadecyltrimethylammonium 1, tetradecyltrimethylammonium 2, tetrabutylammonium 3 and benzyltriethylammonium 4. The cations in the new compounds were used to achieve a reasonable separation of the paramagnetic Cu(II) ions for EPR spectroscopy. The EPR hyperfine structure was not resolved. This is due to the exchange broadening, resulting from still incomplete separation of the paramagnetic Cu(II) centers. Nevertheless, the principal values of the electron Zeemann tensor (g(║) and g(┴)) of the complexes could be determined. Even though the solid substances show slightly different colors, the UV/Vis spectra are nearly identical, indicating structural changes of the tetrachloridocuprate moieties between solid state and solution. The complexes have a promising potential e.g., as high temperature ionic liquids, as precursors for the formation of copper chloride particles or as catalytic paramagnetic ionic liquids.     

Fluorescence Lifetime Correlation Spectroscopy (FLCS): Concepts, Applications and Outlook

Fluorescence Lifetime Correlation Spectroscopy (FLCS) is a variant of fluorescence correlation spectroscopy (FCS), which uses differences in fluorescence intensity decays to separate contributions of different fluorophore populations to FCS signal. Besides which, FLCS is a powerful tool to improve quality of FCS data by removing noise and distortion caused by scattered excitation light, detector thermal noise and detector after pulsing. We are providing an overview of, to our knowledge, all published applications of FLCS. Although these are not numerous so far, they illustrate possibilities for the technique and the research topics in which FLCS has the potential to become widespread. Furthermore, we are addressing some questions which may be asked by a beginner user of FLCS. The last part of the text reviews other techniques closely related to FLCS. The generalization of the idea of FLCS paves the way for further promising application of the principle of statistical filtering of signals. Specifically, the idea of fluorescence spectral correlation spectroscopy is here outlined.     

Removal of Copper (II) and Nickel (II) Ions from Aqueous Solutions by a Composite Chitosan Biosorbent

Abstract

A composite chitosan biosorbent (CCB) was prepared by coating chitosan on to ceramic alumina. The adsorption characteristics of the sorbent for copper and nickel ions were studied under batch equilibrium and dynamic flow conditions at pH 4.0. The equilibrium adsorption data were correlated with Langmuir, Freundlich, and Redlich‐Peterson models. The ultimate monolayer capacities, obtained from Langmuir isotherm, were 86.2 and 78.1 mg/g of chitosan for Cu(II) and Ni(II), respectively. In addition, dynamic column adsorption studies were conducted to obtain breakthrough curves. After the column was saturated with metal ions, it was regenerated with 0.1 M sodium hydroxide. The regenerated column was used for a second adsorption cycle.     

Removal of Copper(II) and Zinc(II) from Aqueous Solutions Using a Lignocellulosic-Based Polymeric Adsorbent Containing Amidoxime Chelating Functional Groups

In this study, the adsorption of Cu(II) and Zn(II) ions from aqueous solutions onto amidoximated polymerized banana stem (APBS) has been investigated. Infrared spectroscopy was used to confirm graft copolymer formation and amidoxime functionalization. The different variables affecting the sorption capacity such as pH of the solution, adsorption time, initial metal ion concentration, and temperature have been investigated. The optimum pH for maximum adsorption was 10.5 (99.99%) for Zn²⁺ and 6.0 (99.0%) for Cu²⁺ at an initial concentration of 10 mg L^?1. Equilibrium was achieved approximately within 3 h. The experimental kinetic data were analyzed using pseudo-first-order and pseudo-second-order kinetic models and are well fitted with pseudo- second-order kinetics. The thermodynamic activation parameters such as ΔG^o, ΔH^o, and ΔS^o were determined to predict the nature of adsorption. The temperature dependence indicates an exothermic process. The experimental isotherm data were well fitted to the Langmuir model with maximum adsorption capacities of 42.32 and 85.89 mg g^?1 for Cu(II) and Zn(II), respectively, at 20°C. The adsorption efficiency was tested using industrial effluents. Repeated adsorption/regeneration cycles show the feasibility of the APBS for the removal of Cu(II) and Zn(II) ions from water and industrial effluents.     

荧光光谱法研究左氧氟沙星、拉米夫定同时与牛血清白蛋白的相互作用

在模拟生理条件(pH值为7.40的Tris-HCl缓冲溶液)下,应用荧光光谱法研究了左氧氟沙星和拉米夫定对牛血清白蛋白(BSA)的荧光猝灭过程。结果表明:BSA与2种药物发生强烈猝灭,主要是静态猝灭;2种药物之间存在着相互作用,一种药物的存在提高了另一种药物与BSA之间结合的稳定性,减少了游离药物含量,药效降低。左氧氟沙星和拉米夫定之间的相互作用为临床合理用药提供了帮助。     

A Computational Study of Calcium(II) and Copper(II) Ion Binding to the Hyaluronate Molecule

The hyaluronate molecule is a negatively charged polysaccharide that performs a plethora of physiological functions in many cell tissues depending on its conformation. In the present paper, molecular modeling at three levels of theory and two basis sets was used to gain a deeper insight in the complex molecular structure of calcium(II) and copper(II) hyaluronate. Simulation results were compared with the experimental data (EXAFS or X-ray). It was found that B3LYP does not properly reproduce the experimental data while the HF and M06 methods do. Simulation data confirm that the N-acetyl group of the N-acetylglucosamine residue does not participate in the coordination bonding to the calcium(II) or copper(II) ion, as evident from the experimental data.     

Interaction of DNA with Simple and Mixed Ligand Copper(II) Complexes of 1,10-Phenanthrolines as Studied by DNA-Fiber EPR Spectroscopy

The interaction of simple and ternary Cu(II) complexes of 1,10-phenanthrolines with DNA has been studied extensively because of their various interesting and important functions such as DNA cleavage activity, cytotoxicity towards cancer cells, and DNA based asymmetric catalysis. Such functions are closely related to the DNA binding modes of the complexes such as intercalation, groove binding, and electrostatic surface binding. A variety of spectroscopic methods have been used to study the DNA binding mode of the Cu(II) complexes. Of all these methods, DNA-fiber electron paramagnetic resonance (EPR) spectroscopy affords unique information on the DNA binding structures of the complexes. In this review we summarize the results of our DNA-fiber EPR studies on the DNA binding structure of the complexes and discuss them together with the data accumulated by using other measurements.     

明胶与Ag^＋相互作用的XPS研究

X射线光电子能谱(XPS)技术是一种高灵敏、高分辨的元素定性定量和结构分析技术．本文用该技术研究了照相明胶中S原子与Ag^ 相互作用的本质．研究结果表明，照相明胶中的蛋氨酸、蛋氨酸亚砜残基均能通过S原子与Ag^ 作用，而且在所研究的明胶中蛋氨酸亚砜残基的含量远高于蛋氨酸残基的含量，这意味着在与Ag^ 键合过程中前者占有更重要的地位．此外，本文还比较了不同原料制成的明胶与Ag^ 的作用情况．     

荧光光度法研究明胶的等电点

根据酪氨酸的特征荧光光谱,测定了一定浓度的明胶溶液的荧光强度与pH值的关系,并与不同pH值时明胶溶液的粘度值进行了对比。结果表明,在一定的pH值范围内,荧光光度法测定明胶的等电点是可行的;对该法的测量原理和明胶分子的存在状态进行了讨论。     

螯合树脂对铜离子的吸附动力学和热力学

针对以谷氨酰胺-铜(II)配合物为供体酶法制备茶氨酸体系,研究了D401螯合树脂对Cu2+的吸附,探讨了吸附过程的热力学和动力学,通过红外光谱鉴定了树脂的配位结构. 结果表明,树脂吸附量随离子浓度和温度升高而增加,当pH为5.6时吸附量最大,达1.887 mmol/g. 不同温度下Langmuir方程均呈现很好的拟合度. 热力学平衡方程计算得DG<0, DH=21.5 kJ/mol, DS>0,表明该吸附过程是自发的、吸热、熵增加的过程. 动力学研究表明,该过程符合准二级动力学模型,吸附反应速率由颗粒扩散和液膜扩散共同控制. 该树脂在较宽的pH范围内对Cu2+具有很好的选择吸附性,可用于酶转化茶氨酸体系中Cu2+的去除.