Boltwoodite [K(UO2)(SiO3OH)(H2O)1.5] and compreignacite K2[(UO2)3O2(OH)3]2.7H2O characterized by laser fluorescence spectroscopy

Synthetically prepared boltwoodite and compreignacite were characterized with time-resolved laser-induced fluorescence spectroscopy (TRLFS). The obtained TRLFS emission spectra of both synthesized uranium minerals differ from each other in their positions of the vibronic peak maxima and in their fluorescence lifetimes. Also, the shapes of the spectra and their respective intensities are different. The TRLFS-spectrum of boltwoodite showed well-resolved sharp vibronic peaks at 485.1, 501.5, 521.2, 543.0, 567.4, and 591.4nm with deep notches between them and compreignacite is characterized by two broad peaks with various shoulders. Here five emission bands were identified at 500.7, 516.1, 532.4, 554.3, and 579.6nm. The shape of the TRLFS spectra of compreignacite is typical for uranium in a hydroxide coordination environment. For both minerals two fluorescence lifetimes were extracted. The two species of boltwoodite and compreignacite, respectively, showed the same positions of the peak maxima showing that the coordination environments are similar, but differ in the chemistry and number of possible quenchers, e.g. water molecules and hydroxide groups. For boltwoodite fluorescence lifetimes of 382 and 2130ns, and for compreignacite shorter ones of 202 and 914ns, respectively, were determined. The spectroscopic signatures of the two uranyl minerals reported here could be useful for identifying uranyl(VI) mineral species as colloids, as thin coatings on minerals, as minor component in soils, or as alteration products of nuclear waste.     

聚乙二醇200基硝苯柳胺与钥孔戚血蓝蛋白的相互作用

采用荧光光谱、紫外吸收光谱和圆二色谱(CD)研究了聚乙二醇200基硝苯柳胺与钥孔戚血蓝蛋白(KLH)的相互作用。结果表明,聚乙二醇200基硝苯柳胺对KLH的荧光猝灭机制属于静态猝灭;由Lineweaver-Burk方程计算出不同温度下结合常数K,由Van’t Hoff方程计算出△H和△S平均值,结合力主要为静电作用力;根据F rster非辐射能量转移机制求得给体与受体间的结合距离r=5.76 nm;同步荧光光谱表明,聚乙二醇200基硝苯柳胺能够被KLH存储和转运,但结合时对蛋白的构象有一定的影响;圆二色光谱的数据表明相互作用后KLH的二级结构发生了改变:KLH的α-螺旋的含量从43.1%下降到37.8%。     

Investigation of nitroxoline-human serum albumin interactions by spectroscopic methods

Nitroxoline is a wide spectrum antibacterial and is one of the most important urinary antiseptics.The interaction between nitroxoline and human serum albumin(HSA)has been investigated systematically by fluorescence spectroscopy,synchronous fluorescence,three-dimensional fluorescence,CD spectroscopy and UV-Vis absorption spectroscopy.The results indicated that the quenching of HSA by nitroxoline was static.The corresponding thermodynamic parameters △H,△S and △G calculated according to van’t Hoff equation revealed that the intermolecular forces acting between nitroxoline and HSA were mainly hydrogen bonding and van der Waals forces.The conformational changes in the interaction were studied by synchronous fluorescence,CD spectroscopy and three-dimensional fluorescence spectra which showed changes in the microenvironment and conformation of HSA.     

苯胺蓝黑与人血清白蛋白的相互作用及对其构象的影响

利用荧光光谱和同步荧光光谱研究了不同温度下苯胺蓝黑与人血清白蛋白相互作用时的荧光猝灭及构象的变化情况。实验结果表明,苯胺蓝黑与人血清白蛋白之间可以发生相互作用,而且有较强的结合。同步荧光光谱研究了人血清白蛋白与苯胺蓝黑的相互作用中人血清白蛋白构象的变化,结果显示二者结合改变了蛋白质的微环境。热力学参数说明小分子与蛋白质的作用以疏水作用为主。     

甘氨酸镧（Ⅲ）配合物与牛血清白蛋白的相互作用研究

红外光谱和X射线衍射分析表明甘氨酸与镧(Ⅲ)作用形成配合物。利用同步荧光光谱和荧光光谱探究了牛血清白蛋白(BSA)和甘氨酸镧(Ⅲ)配合物之间的相互作用。结果可知甘氨酸镧(Ⅲ)配合物与牛血清白蛋白的荧光猝灭为静态猝灭,根据双对数方程处理荧光猝灭数据得到了甘氨酸镧(Ⅲ)配合物与牛血清白蛋白在不同温度下的结合常数Kb和结合位点数n。热力学数据表明配合物与BSA作用主要是疏水作用力。利用同步荧光光谱法研究了甘氨酸镧(Ⅲ)配合物对于牛血清白蛋白的构象影响。     

豆奶粉提取碳点及含碳点荧光纳米纤维的制备

以豆奶粉为碳源, 以有机硅烷为钝化剂, 用水热合成法制备碳点, 采用静电纺丝技术, 以碳点与聚乙烯吡咯烷酮(PVP)共混溶液为纺丝液, 制备了含碳点的纳米纤维. 通过紫外吸收光谱、 荧光吸收光谱和荧光发射光谱表征了碳点性质. 结果显示, 所得碳点纳米纤维直径分布均匀, 形貌良好, 碳点分散溶液在340~540 nm的紫外光激发下发出强青绿色荧光, 荧光发射峰出现在550 nm处, 并且随着激发波长增加有微弱的红移.     

桂皮酸-8-羟基喹啉稀土配合物的合成、表征及与牛血清白蛋白的作用

合成了以桂皮酸、8-羟基喹啉为配体,以镱、铕为中心离子的稀土配合物,采用元素分析、摩尔电导、红外光谱、紫外光谱和荧光光谱法进行表征,并采用紫外光谱和荧光光谱研究了配合物与牛血清白蛋白(BSA)的相互作用。结果表明,随着配合物浓度的增加,BSA紫外光谱表现出明显的增色效应,配合物可有规律地猝灭BSA的荧光。     

Interaction of sodium benzoate with trypsin by spectroscopic techniques

The toxicity of sodium benzoate to trypsin was investigated by fluorescence spectroscopy, synchronous fluorescence spectroscopy, UV-visible absorption spectroscopy and circular dichroism (CD) spectroscopy under mimic physiological conditions. Sodium benzoate could unfold trypsin by decreasing the β-sheet structure, which leads to more exposure of internal amino acid groups and the obvious intrinsic fluorescence quenching with the rising concentration of sodium benzoate. The results of spectroscopic measurements indicated that sodium benzoate changed the internal microenvironment of trypsin and induced the alteration of the whole molecule, which were performed toxic effects on the organism. Trypsin and sodium benzoate interacted with each other to produce a substance by van der Waals forces and hydrogen bond, the model of which was shown by AutoDock software.     

中药成分五味子甲素及其金属离子复合物与血清白蛋白相互作用的研究

在模拟人体生理条件下,采用紫外光谱法、荧光光谱法和同步荧光光谱法研究五味子甲素及其金属离子复合物与血清白蛋白(SA)的结合作用。结果表明:五味子甲素与金属离子形成1∶1复合物;五味子甲素对SA的荧光猝灭机制为静态猝灭和非辐射能量转移;五味子甲素与牛血清白蛋白(BSA)和人血清白蛋白(HSA)的结合常数K、结合位点数n、结合距离r分别为3.58×104L·mol-1和6.42×103L·mol-1、0.944和0.993、2.18nm和1.63nm,其作用力以氢键和范德华力为主。同步荧光光谱法的结果表明:结合位点靠近色氨酸,并使色氨酸的疏水性减弱。共存金属离子对五味子甲素与SA的相互作用有一定的影响。     

荧光光谱法研究茶碱与牛血清白蛋白的相互作用

荧光光谱法研究茶碱与牛血清白蛋白的相互作用;茶碱;牛血清白蛋白;荧光猝灭;能量转移     

Studies of the Interaction Between Ronidazole and Human Serum Albumin by Spectroscopic and Molecular Docking Methods

Ronidazole (RNZ) is widely used for the therapeutic treatment of farmed animals and is suspected of being a human carcinogen and mutagen. The interaction between RNZ and human serum albumin (HSA) was investigated systematically by fluorescence spectroscopy, synchronous fluorescence, three-dimensional fluorescence, CD spectroscopy, UV–vis absorption spectroscopy and a molecular docking study. The results indicate that the probable quenching mechanism of HSA by RNZ is dynamic quenching. The corresponding thermodynamic parameters, such as ΔH, ΔS and ΔG, etc., were calculated according to the van’t Hoff equation. The results indicate that the forces acting between RNZ and HSA are mainly hydrogen bonds and van der Waals forces. The conformational changes in the interaction were studied by synchronous fluorescence, CD spectroscopy and three-dimensional fluorescence spectra. The results reveal that the microenvironment and conformation of HSA has been changed. A molecular modeling study further confirmed the binding mode obtained by the experimental studies.     

水溶性羟基化单壁碳纳米管与人血清白蛋白之间的相互作用研究

利用荧光光谱、UV吸收光谱、同步荧光光谱和透射电子显微镜等技术较为系统地研究了水溶性羟基化单壁碳纳米管与人血清白蛋白(HSA)的相互作用. 实验发现, 这种羟基化单壁碳纳米管可以明显猝灭HSA的内源荧光, 且猝灭效应随碳纳米管浓度增大而增强. 同时, HSA对水溶性羟基化单壁碳纳米管起到一定的分散和稳定作用. 同步荧光光谱表明, 二者之间的相互作用可导致HSA的构象发生变化, HSA的色氨酸残基荧光信号发生2 nm的红移, 表明色氨酸残基周围微环境的极性降低.     

一种聚丙烯酸接枝型荧光纳米粒子的制备、性能及细胞成像

将N-氨基-4-N-甲基哌嗪-1,8-萘酰亚胺(AMN)通过酰胺化反应接枝到聚丙烯酸链上,利用生成的聚合物在水溶液中的自组装, 制备了一种水溶性荧光纳米粒子(PAAMN).采用紫外可见光谱、核磁共振氢谱、透射电镜、动态光散射和荧光光谱方法对PAAMN进行了表征,MTT法检测其细胞相容性,最后用荧光显微镜观察其自身荧光及细胞成像效果.实验结果表明, PAAMN为球状结构,萘酰亚胺荧光团的摩尔取代度为4.1%;在生理pH条件下,以390 nm为激发波长,PAAMN在534 nm处发射较强的荧光,且光稳定性较好;在pH 4.0~10.0范围内,其荧光波长无明显变化,荧光强度随pH值增大而逐渐减小,但pH敏感程度小于AMN.PAAMN具有良好的细胞相容性,能进入细胞,且在~390 nm激发光下发射绿色荧光,可用于细胞成像.     

Cationic Lanthanide Luminescent Copolymer: Design,Synthesis and Interaction with DNA

Polymerizable rare earth complex Eu(AA)₃Phen was synthesized by complexion of europium ion, acrylic acid (AA), and 1,10-phenanthroline (Phen). The structure and fluorescence properties of the complex were studied by elemental analysis, ¹H-NMR spectroscopy, and fluorescence spectroscopy. Eu-containing copolymer poly(PEGMA-co-MMA-co-METAC-co-Eu(AA)₃Phen) (PPMMEu) was then synthesized by free radical copolymerization of Eu(AA)₃Phen and other functional monomers including poly(ethylene glycol) methyl ether methacrylate (PEGMA) and [2-(Methacryloyloxy) ethyl] trimethylammonium chloride (METAC). ¹H-NMR spectroscopy and fluorescence spectroscopy were used to characterize the copolymer and the interactions between the copolymer and DNA was investigated by TEM, fluorescence spectroscopy, and agarose gel electrophoresis. The desired luminescent cationic copolymer was successfully obtained. The copolymer can form micelles in water solution and can efficiently bind to DNA molecules through electrostatic interaction. The results suggest the potential use of PPMMEu in bioprobes and gene vectors.     

光谱法与共焦荧光成像法研究罗丹明B与ct-DNA的相互作用

采用吸收光谱、荧光光谱以及共焦荧光成像技术研究生理条件下罗丹明B(Rhodamine B,RB)与小牛胸腺DNA(ct-DNA)的相互作用以及相互作用模式。光谱研究结果显示,在450~650 nm的吸收光谱范围内,ct-DNA溶液对罗丹明B有减色作用;在560~660 nm荧光发射光谱范围内,ct-DNA对罗丹明B有荧光猝灭作用。同时,随着ct-DNA的加入,罗丹明B溶液的荧光偏振值发生变化,说明罗丹明B与ct-DNA能发生相互作用。在竞争性实验中,罗丹明B未能将亚甲基蓝(MB)从MB-ct-DNA复合体系中置换出来,说明罗丹明B与ct-DNA通过沟槽结合方式发生相互作用。共焦荧光成像结果显示,ct-DNA加入后,罗丹明B的荧光猝灭十分明显。利用罗丹明B和4',6-二脒基-2-苯基吲哚(DAPI)对He La细胞染色后进行共焦荧光成像,结果进一步证实罗丹明B与ct-DNA是通过沟槽结合作用将细胞核染成红色。     

碳量子点荧光猝灭法检测药物中的异鼠李素

以L-天冬氨酸为碳源,尿素为氮源,采用微波加热法制备荧光碳量子点(CDs),得到的CDs具有球形结构和单一分散性,平均粒径约为5 nm。红外光谱、X射线光电子能谱、紫外和荧光光谱的表征结果表明,合成的CDs具有较高的荧光稳定性,良好的水溶性和对异鼠李素(ISOR)高的选择性。在优化条件下,ISOR浓度在0.22～180 nmol/L范围内时与CDs荧光猝灭程度(I_(F_0)/I_F)呈良好的线性关系,检出限(LOD)为1.32 nmol/L,回收率为90.8%～107%。结果表明,该CDs可用于ISOR的快速、高效、灵敏检测。     

绞股蓝皂苷与牛血清白蛋白相互作用的荧光光谱研究

用荧光光谱技术研究了绞股蓝皂苷与牛血清白蛋白(BSA)在pH=7.40的Tris-HCl缓冲溶液中的相互作用;通过计算确定了绞股蓝皂苷与BSA的结合位点数和结合常数,利用热力学分析探讨了绞股蓝皂苷与BSA之间的结合方式;同时采用同步荧光技术考察了绞股蓝皂苷对BSA构象的影响.结果表明,绞股蓝皂苷对牛血清白蛋白的荧光猝灭过程为静态猝灭;二者主要靠疏水作用和静电引力结合.     

Zinc phthalocyanine labelled polyethylene glycol: preparation, characterization, interaction with bovine serum albumin and near infrared fluorescence imaging in vivo

Zinc phthalocyanine labelled polyethylene glycol was prepared to track and monitor the in vivo fate of polyethylene glycol. The chemical structures were characterized by nuclear magnetic resonance and infrared spectroscopy. Their light stability and fluorescence quantum yield were evaluated by UV-Visible and fluorescence spectroscopy methods. The interaction of zinc phthalocyanine labelled polyethylene glycol with bovine serum albumin was evaluated by fluorescence titration and isothermal titration calorimetry methods. Optical imaging in vivo, organ aggregation as well as distribution of fluorescence experiments for tracking polyethylene glycol were performed with zinc phthalocyanine labelled polyethylene glycol as fluorescent agent. Results show that zinc phthalocyanine labelled polyethylene glycol has good optical stability and high emission ability in the near infrared region. Imaging results demonstrate that zinc phthalocyanine labelled polyethylene glycol can track and monitor the in vivo process by near infrared fluorescence imaging, which implies its potential in biomaterials evaluation in vivo by a real-time noninvasive method.     

光谱法与分子模拟技术研究丽春红2R与牛血清蛋白的相互作用

采用荧光光谱、同步荧光光谱、紫外-可见吸收光谱及分子模拟技术研究了模拟生理条件下丽春红2R(P2R)与牛血清白蛋白(BSA)的相互作用。实验结果表明,P2R-BSA体系的荧光猝灭机制为内源荧光猝灭,猝灭原因为静态猝灭和非辐射能量转移;计算了不同温度下体系的结合常数Ka及结合位点数n;根据热力学参数推断出作用力类型;求出室温下荧光给体-受体间的结合距离;同步荧光法证实丽春红2R对BSA构象未产生影响;分子模拟研究结果表明二者间的主要作用力为氢键和疏水作用力。