铕螯合物的制备及光谱性质研究

稀土螯合物的制备是均相时间分辨荧光免疫分析中的关键部分,为了合成理想的稀土螯合物,以2,6-二(溴甲基)吡啶-3,5-二甲酸二乙酯为原料,首先优化合成了Li+⊂2,6-{N,N’,N,N’-[二(2,2’-联吡啶-6,6’-二甲基)]二(氨甲基)}-吡啶-二羧酸乙酯,使其产率明显提高。进一步选择乙腈和甲醇两种反应体系合成铕螯合物,并比较了不同反应体系下合成的铕螯合物的光谱性质。研究表明,乙腈和甲醇两种反应体系所得铕螯合物的激发光谱(最大激发波长为310 nm)、发射光谱(最大发射波长为616 nm)、量子产率基本相同,荧光强度在10-8～10-5 mol·L-1范围内与Eu3+浓度均成线性,相关系数分别为0.993 73和0.986 65,两种铕螯合物(c=2.5×10-5 mol·L-1)的荧光强度略有差异,荧光寿命分别为825和830 μs。因此,两种反应体系所得铕螯合物具有斯托克斯位移大、荧光强度强以及荧光寿命长等优点,并且此种穴状螯合剂结构中的吡啶-2,2-联吡啶可保护铕离子免受其他物质的干扰,是理想的稀土螯合物,可用于蛋白质、核酸等生物分子的标记。本研究不仅拓展了合成新型稀土螯合物的方法,而且为进一步建立均相时间分辨荧光免疫分析奠定了基础。     

时间分辨激光荧光光谱技术在免疫分析中的应用

本研究以时间分辨激发荧光光谱分析技术为基础 ,进行稀土离子标记的激光激发的时间分辨荧光免疫分析 (TRFIA)研究。实验以自行合成的二乙三胺五醋酸酐 (DTPAA)为双功能螯合剂。用 Eu3+标记兔抗人 (RAH) Ig G抗体 ,依据解离增强原理 (DEL FIA) ,研究了 Eu3+ -β萘甲酰三氟丙酮 (β- NTA)的荧光分辨体系 ,测定了荧光光谱和荧光寿命 ,建立了铕离子分析检出方法 ,其工作曲线范围为 1× 10 - 7～ 1× 10 - 1 1g· m L- 1 ,检测限为 1× 10 - 1 3g· m L- 1 ,相对标准偏差为 6 .4%。结合 TRFIA方法学研究 ,进行了人血清丙型肝炎病毒抗体 (Anti- HCV)检测。并同酶联免疫法 (EL ISA)对比。取得 TRFIA法阳性检测率明显高于EL ISA法的结果。     

JYM-1型时间分辨激光荧光免疫分析仪技术鉴定会在合肥举行

由安徽省医药管理局、中科院合肥分院联合召开的“JYM-1型时间分辨激光荧光免疫分析仪技术鉴定会”,于1990年6月18日在安徽省合肥市举行.参加会议的代表22名.时间分辨荧光免疫分析(TrFIA)是利用微量稀土元素Eu的螯合物与抗体结合形成共轭体作为发光记物,与体液中的抗原结合形成复合物,经增强液解高作用,Eu可从复合物中解高出来,形成一种新的螯合物,在紫外光(340nm)激发下,发出高强荧光(613nm),这种荧光衰变时间很长(10～100μs).采用时间分辨光谱技术,使蛋白质等所发的短寿命荧光(1～10ns),完全衰变后再测螯合物的荧光,可完全排除背景     

二苯甲酰基甲烷2,2′-联吡啶混合稀土配合物中钆、钇对铕发光的影响

在乙醇溶液中合成了以二苯甲酰基甲烷 (DBM )和 2 ,2′联吡啶 (Dipy)为配体 ,三价铕、等摩尔三价铕 钆及等摩尔三价铕 钇混合稀土为中心体的配合物。测定了配合物的组成 ,研究了其红外光谱和荧光光谱。结果表明 :配合物的最佳激发波长为 4 2 5nm ;在 4 2 5nm波长光激发下 ,配合物发出较强的荧光 ;不发光的Gd3 + 和Y3 + 离子对Eu3 + 离子的发光有一定增强作用 ,其中钇使铕的荧光发射增强大于钆 ;这两个不发光稀土离子对铕的发射峰位影响不大     

二苯甲酰基甲烷2,2''-联吡啶混合稀土配合物中钆、钇对铕发光的影响

在乙醇溶液中合成了以二苯甲酰基甲烷(DBM)和2,2'联吡啶(Dipy)为配体,三价铕、等摩尔三价铕-钆及等摩尔三价铕-钇混合稀土为中心体的配合物.测定了配合物的组成,研究了其红外光谱和荧光光谱.结果表明:配合物的最佳激发波长为425nm;在425nm波长光激发下,配合物发出较强的荧光;不发光的Gd3+和Y3+离子对Eu3+离子的发光有一定增强作用,其中钇使铕的荧光发射增强大于钆;这两个不发光稀土离子对铕的发射峰位影响不大.     

金属离子及其配合物荧光探针在核酸分析中的应用

核酸是生命现象的物质基础,对于核酸的研究已经成为生命科学的重要内容。荧光法是研究核酸结构、功能和定性、定量的一种重要方法,而稀土离子及其配合物是荧光分析中最常用的探针技术。本文介绍了近十几年来稀土离子及其配合物荧光探针在核酸分析中的应用。     

Eu3+离子在微晶玻璃研究中的探针作用

制备出单掺Eu3+离子的氟氧化物玻璃陶瓷系列样品,利用Eu3+离子作为荧光探针,通过热处理前后Eu3+离子发射光谱中电偶极子跃迁与磁偶极子跃迁强度比值的变化表征在玻璃材料中微晶是否形成,分析了Eu3+离子荧光发射谱中电偶极子跃迁与晶体场对称性的关系,进一步表征了稀土离子所处微晶晶格场的变化.     

基于固相抗体模式时间分辨荧光免疫分析测定雌三醇

采用二步标记法,借助二乙烯三胺五乙酸酐,将Eu3+标记到雌三醇完全抗原上,基于固相抗体竞争反应模式,建立了时间分辨荧光免疫分析测定雌三醇的新方法。在优化的条件下,方法的线性范围为0.005—1000ng·mL-1,检出限为4pg·mL-1。该方法用于检测血清中雌三醇的含量,结果令人满意。     

稀土乙酰丙酮苯并咪唑三元配合物合成和荧光性质研究

用稀土氯化物与乙酰丙酮及苯并咪唑在 95 %乙醇溶液中反应 ,合成了 6个稀土 (L a3 +、Sm3 +、Eu3 +、Tb3 + 、Dy3 + 、Y3 + )乙酰丙酮苯并咪唑三元配合物。用红外光谱和紫外光谱表征了配合物并对其荧光性质进行了研究。结果表明 ,Sm、Eu、Tb和 Dy的配合物能发出中心离子的特征荧光 ,发光强度顺序为 Tb>Dy>Sm>Eu     

二苯甲酰甲烷2，2′—联吡啶混合稀土配合物中钆、钇对铕发光的影响

在乙醇溶液中合成了以二苯甲酰基甲烷（DBM）和2，2′联吡啶（Dipy)为配体，三价铕、等摩尔三价铕－钆及等摩尔三价铕－钇混合稀土为中心体的配合物。测定了配合物的组成，研究了其红外光谱和荧光光谱。结果表明：配合物的最佳激发波长为425nm；在425nm波长光激发下，配合物发出较强的荧光；不发光的Gd^3 和Y^3 离子对Eu^3 离子的发光有一定增强作用，其中钇使铕的荧光发射增强大于钆；这两个不发光稀土离子对铕的发射峰位影响不大。     

铕螯合物及其溶液的光致发光

噻吩甲酰三氟丙酮合铕,2、4、6-三甲基吡啶络合物〔(TTA)4·E·(2、4、6-Me3Py)·H〕Ⅰ和噻吩甲酰三氟丙酮合铕,4-甲基吡啶络合物〔(TTA)4·(4-MePy)·H〕(Ⅱ)属于β-二酮类化合物。β-二酮类化合物在有机溶剂和塑料中具有很高的溶解度,它可以制成无定形透明发光体,并且在晶态、溶液及塑料中具有较高的光输出,因此引起人们的注意。     

A Magnetic Nanoparticle-Based Time-Resolved Fluoroimmunoassay for Determination of the Cytokeratin 19 Fragment in Human Serum

A sensitive, rapid and novel measurement method for cytokeratin 19 fragment (CYFRA 21–1) in human serum by magnetic particle-based time-resolved fluoroimmunoassay (TRFIA) is described. Built on a sandwich-type immunoassay format, analytes in samples were captured by one monoclonal antibody coating onto the surface of magnetic beads and “sandwiched” by another monoclonal antibody labeled with europium chelates. The coefficient variations of the method were lower than 7 %, and the recoveries were in the range of 90–110 % for serum samples. The lower limit of quantitation of the present method for CYFRA 21–1 was 0.78 ng/ml. The correlation coefficient of CYFRA 21–1 values obtained by our novel TRFIA and CLIA was 0.980. The present novel TRFIA demonstrated high sensitivity, wider effective detection range and excellent reproducibility for determination of CYFRA 21–1 can be useful for early screening and prognosis evaluation of patients with non-small cell lung cancer.     

有机稀土铕的螯合物的发光和能量传递的研究

本文应用荧光光谱和瞬时时间分辨光谱研究了稀土铕有机螯合物,以及在二苯酮做为三线态敏化剂存在时,对能量的吸收、传递和发光的过程,探讨了有机配位体与稀土离子的能级、三线态敏化剂和配位体分子的性质对发光的影响。     

稀土螯合物BCPDA-Eu3+标记蛋白质研究

通过自制的双功能螯合剂 4 ,7 二氯磺基苯 1,10啡啉 2 ,9二羧酸 (BCPDA)标记牛血清白蛋白(BSA)实验 ,对于BCPDA标记蛋白质的条件进行研究。结果表明 :BCPDA在温和的条件下能与蛋白质反应 ,并在一定条件下与铕离子形成稳定的BSA BCPDA Eu3 标记物。利用自建的分析方法 ,测定了标记过程的有关参数。并对标记物的某些光学特性进行了研究。     

Excitation energy transfer in europium chelate with doxycycline in the presence of a second ligand in micellar solutions of nonionic surfactants

The complexation of Eu³⁺ with doxycycline (DC) antibiotic in the presence of several second ligands and surfactant micelles of different types is studied by the spectrophotometric and luminescence methods. It is found that the efficiency of excitation energy transfer in Eu³⁺-DC chelate depends on the nature of the second ligand and surfactant micelles. Using thenoyltrifluoroacetone (TTA) as an example, it is shown that the second ligand additionally sensitizes the europium fluorescence, and the possibility of intermediate sensitization of DC and then of europium is shown by the example of 1,10-phenanthroline. In all cases, the excitation energy transfer efficiency was increased due to the so-called antenna effect. The decay kinetics of the sensitized fluorescence of the binary and mixed-ligand chelates in aqueous and micellar solutions of nonionic surfactants is studied and the relative quantum yields and lifetimes of fluorescence are determined.     

Effect of varying lanthanide local coordination sphere on luminescence properties illustrated by selected inorganic and organic rare earth complexes synthesized in sol-gel host glasses

Inorganic and organic ligands were carefully selected to illustrate the effect of modifications in the local field environment around the rare earth lanthanide (III) on its emission properties. In this article two strategies were employed to enhance emission of lanthanides encapsulated in sol-gel glass. (i) Changing the symmetry around the lanthanide, which was diagnosed by changing the local environment around the lanthanide using different inorganic counter ions (acetate, nitrate and chloride) these ligands differ in their affinity toward the lanthanide first coordination sphere. The ligand that penetrates the lanthanide more results in more asymmetric environment and thus results in higher emission. The aim of this part was to demonstrate the change of symmetry on emission in the absence of energy transfer. Our results indicate that the acetate ion has the highest affinity toward the first coordination sphere followed by the nitrate while the chloride showed the lowest affinity. Penetration by the ligands ofthe lanthanide also results in removing OH quenchers surrounding the lanthanide and this further explains the boost in emission. (ii) A bulky organic ligand that forms a complex with the lanthanide is used. The organic ligand separates the lanthanide ion from inner O-H oscillators. In this case the chelating organic chromophore with suitable photophysical properties was employed to sensitize the lanthanide and thus energy transfer occurs via the antenna effect. The organic ligand absorbs UV light, then energy is transferred to the lanthanide and finally the lanthanide emits in the visible region. The first coordination environment surrounding europium was controlled by the ligand selection and the outer sphere was modified by doping the synthesized complexes in an optically transparent sol-gel glass host. The glass network carefully prepared by sol-gel process is effective in preventing free oxygen and water from attacking lanthanide -complexes without loss of luminescence. Emission spectroscopy measurements of the doped silica specimens confirmed the variation of Eu (III) emission depending on the first coordination sphere surrounding the europium ion. The encapsulation of the europium complexes was performed for two reasons: (i) to improve the stability of red phosphor with efficient and high color-purity characteristics under ultraviolet excitation and (ii) this work provides a framework for preparing transparent composite glasses that are robust hosts to study the fundamental interactions between nano-materials and light.     

协同发光效应及机理探讨

在研究共存离子对稀土配合物荧光强度影响时发现,许多稀土和非稀土离子在一定浓度范围内可对配合物的荧光产生增强效应.这种现象与协同萃取类似,我们将其命名为“协同发光效应”.本文采用激光诱导荧光光谱法,研究了十四种稀土离子对Eu、Sm-TTA-Phen-Triton X-100体系和Eu、Sm-DBM-CPB体系的协同发光效应.并从稀土离子的化学性质,光谱能级和所形成配合物的化学结构和空间结构等方面综合考虑,提出协同发光机理.拟定出用于痕量铕和钐测定的薪的超高灵敏度分析方法.     

Nuclear magnetism and the trivalent europium ion

Enhanced nuclear moments occur in atoms, molecules and all the transition groups of the periodic table. They are unusually large for lanthanide ions, with electrons of the 4f group, but the mechanism responsible for enhancement for other ions produces “anti-shielding” effects for the trivalent europium ion. These greatly reduce the effective nuclear magnetic moments in the ground state J=0. Here it is suggested that dynamic nuclear polarization can be used to increase the effective nuclear moments, and off-set the anti-shielding. The substance is europium vanadate, “doped” with a small percentage of samarium ions.