稀土铕三元配合物-甲基丙烯酸甲酯共聚物的合成和荧光性能研究

在较温和的条件下,利用二苯甲酰甲烷为第一配体,甲基丙烯酸为第二配体与氯化铕在乙醇中反应,合成了一个新的稀土三元配合物Eu(DBM)2MA.2H2O[DBM:C6H5COCHCOC6H5,MA:CH2C(CH3)COO-]。然后将铕三元配合物与甲基丙烯酸甲酯(MMA)进行共聚反应,制备了一个新的键合型稀土高分子共聚物。通过元素分析、EDTA配位滴定分析、红外、紫外、荧光光谱分析测定了配合物及共聚物的组成、结构和发光性能;利用差热-热重分析测定了共聚物的热稳定性,用差示扫描量热法和凝胶色谱法测定了共聚物的玻璃化温度和平均分子量。研究结果表明,稀土三元配合物和相应的共聚物在612.94 nm处均能发出强的Eu3+特征荧光。     

铕-2-甲硫基烟酸掺杂配合物的合成及荧光性质研究

由2-甲硫基烟酸(HA)与Eu(Ⅲ)合成了二元配合物和13种分别掺杂La(Ⅲ),Y(Ⅲ),Zn(Ⅱ)的三元配合物。通过红外、紫外、元素分析、荧光光谱和热重分析对配合物进行了表征。并着重研究了掺杂离子、溶剂、配合物溶液的浓度对配合物中Eu(Ⅲ)发光性能的影响。紫外光谱显示HA与铕离子配位后其吸收峰强度发生较大改变。红外光谱表明2-甲硫基烟酸中的羧基与铕离子以螯合双齿配位,且单一配合物和掺杂配合物具有相似的配位结构。荧光光谱表明La(Ⅲ),Y(Ⅲ),Zn(Ⅱ)掺杂可以提高铕配合物的荧光强度,其中La(Ⅲ)掺杂荧光强度增强最明显。配合物(Eu0.5Zn0.5)(A)2.5·3H2O以乙醇为溶剂,浓度为5×10-5mol·L-1时,其荧光强度是最强的。     

对苯二甲酸-铕-钇配合物的合成及荧光性质

以对苯二甲酸(H2L)为配体,合成了系列(Eu1-xYx)2L3.3H2O固体粉末配合物.通过元素分析、紫外吸收光谱、X射线衍射和红外光谱确定了配合物的组成和结构,并通过荧光光谱研究了它们的荧光性质.结果表明钇掺入配合物后,能增强Eu3+的特征荧光,当铕与钇的摩尔比为0.05∶0.95时荧光强度最强.     

铕三元配合物-聚氨酯丙烯酸酯发光材料的合成与荧光性能研究

以1,10-邻菲啰啉和2,7-二羟基萘-3,6-二磺酸钠为配体,合成了铕-2,7-二羟基萘-3,6-二磺酸-邻菲啰啉三元配合物{[Eu(HL)(phen)(H2O)](H2O)3}∞;利用配合物中未参与配位的-OH作为活性基团,以二月桂酸二丁基锡为催化剂,与具有活性基团-NCO的异佛尔酮-二异氰酸酯反应制备铕三元配合物-聚氨酯丙烯酸酯发光材料。通过X射线单晶衍射、红外、热分析和荧光光谱分析,测定了配合物及发光材料的组成、结构、热稳定性和发光性能。结果表明,在496 nm波长激发下,配合物及发光材料在610 nm处能发出较强的特征荧光,且随着配合物含量的增加,荧光性能增强,同时在测试范围内没有发生荧光淬灭现象,是一种极具潜在应用的新型发光材料。     

激光诱导荧光测定β-萘甲酰三氟丙酮合铕配合物的荧光寿命

本文采用激光诱导荧光的方法测定了九种L₄EuQH型β-二酮铕配合物的荧光寿命(其中Q表示胺的衍生物)。结果表明,对相同Q的配合物的6130Å,5910Å和5797Å三个荧光峰所测得的寿命均相同。不同的Q可能通过氢键作用对配合物的荧光寿命有一定影响。     

吡唑-吡啶铕配合物的合成、结构及荧光效应

以硝酸铕为金属源,2,6-二-[3-(5-苯基-1-氢-吡唑基)]吡啶(L)为配体,在水热反应条件下合成了一种新型配合物Eu(L)(MeOH)(NO₃)₃。 通过元素分析、红外光谱、热重分析、X射线粉末衍射以及X射线单晶衍射方法对该配合物进行了表征。 结构分析表明,配合物的中心金属为九配位,每个中心金属铕原子与L配体中的3个N原子和硝酸根离子和配位甲醇分子上的6个氧原子配位,形成轻微扭曲的三帽三角棱柱体的空间构型。 荧光性能研究发现,该配合物对金属离子铜和镍有较强的荧光猝灭效应。即使在其它竞争金属离子的存在下,配合物仍然可以选择性地检测Cu²⁺,但对选择性的检测Ni²⁺有一定影响。     

铕(Ⅲ)三元配合物荧光性质的研究

利用Ｅｕ（Ⅲ）、Ｔｂ（Ⅲ）等稀土离子有机配合物发光性能作为蛋白质的荧光标记,对抗体或抗原进行微量分析是近年发展起来的免疫荧光分析的一种重要分析测试技术［１］。氟代β－二酮配合物不仅能有效提高配合物分子内能量传递,同时也减少有机配体和稀土离子非辐射跃迁能量散射,并与金属离子形成具有较强荧光的稀土配合物［２,３］。为了避免溶剂分子及水分子所引起荧光淬灭,中性配体也十分重要［４．５］。本文选用噻吩甲酰三氟丙酮（ＴＴＡ）、苯甲酰三氟丙酮（ＢＴＡ）、苯甲酰丙酮（ＢＡ）为配阴离子,以１,１０－邻菲绕啉（Ｐｈ…     

纳米银对铕-吡啶-2,6-二羧酸配合物荧光增强效应的研究

研究了纳米银对分别以水、重水、乙醇和二甲基甲酰胺为溶剂的铕-吡啶-2,6-二羧酸(Eu(III)DPA)配合物溶液的荧光增强效应.研究结果表明,Eu(III)DPA溶液中加入纳米银,电偶极跃迁(5D0→7F2)和磁偶极跃迁(5D0→7F1)发射强度先增强而后逐渐下降,5D0→7F2的荧光增强效率高于5D0→7F1的荧光增强效率.在乙醇溶剂中纳米银对Eu(III)DPA溶液的荧光增强效应最大.在水或重水或乙醇溶剂中,Eu(III)DPA的不对称率明显提高,而在二甲基甲酰胺溶剂中几乎不变.分析认为,纳米银对Eu(III)DPA溶液荧光的影响与纳米银表面等离子体共振与激发态荧光中心强烈耦合以及表面等离子体再吸收有关.     

2-噻吩乙醛酸-三苯基氧化膦-铕配合物的合成、结构表征及荧光性能的研究

用硝酸铕、2-噻吩乙醛酸(HL)和三苯基氧化膦(TPPO)合成了一种新型固体发光配合物;用元素分析、电导率、红外光谱和核磁共振确定了该配合物的分子式为EuL3TPPPO((H2O)2;在室温下测定了该配合物的荧光激发光谱和发射光谱;配合物中Eu(Ⅲ)离子的3个主要跃迁5D0→7F1,5D0→7F2和5D0→7F4分别位于593.4,618.8和699.4 nm.该固体配合物于室温下被紫外灯照射可以发出很强的红色荧光.IR光谱中2-噻吩乙醛酸在与稀土铕离子形成配合物后,vas(-COO-)由钠盐的1632 cm-1移至1612 cm-1,vs(-COO-)由1389 cm-1移至1409cm-1;vc=o(α-酮基)由HL的1654 cm-1移至1662 cm-1.配合物的vEu-o吸收峰出现在541 cm-1.在1HNMR谱图中,噻吩环上的3个氢原子的化学位移在形成配合物后移向高场;三苯基氧化膦中苯环上5种不同环境的质子的化学位移在形成配合物后向低场移动.TG分析证明,该固态配合物于空气中在常温至190℃以内是稳定的.     

均苯三甲酸铕二元配合物的合成及其荧光性质

以1,3,5-苯三甲酸(H3BTC)为配体,采用溶液沉淀法合成了均苯三甲酸铕二元发光配合物Eu(BTC).2H2O(1),其结构经IR,元素分析和等离子体原子发射光谱(ICP)表征.荧光光谱分析结果表明,1在紫外光照射下,发出Eu3+的特征红光,其中电偶极跃迁(5D0→7F2,613 nm)的发射最强;同时1还具有相对...     

流动注射化学发光法测定呋塞米

在酸性条件下呋塞米对Ce(Ⅳ)-Na_2SO_3弱化学发光体系具有很强的增敏作用,据此建立了流动注射化学发光法测定呋塞米的新方法.该法测定呋塞米的线性范围为0.01～1.0 mg/L,检出限为4×10~(-3)mg/L(3σ),RSD为2.2%(n=11,ρ=0.2mg/L),回收率为95%～105%.该法已应用于片剂和针剂中呋塞米含量的测定.     

聚丙烯酸/聚(苯乙烯-丙烯酸)二苯酰基甲烷铕(Ⅲ)配合物的合成及其荧光性能

铕(Ⅲ)和二苯甲酰甲烷(HDBM)形成的有机配合物与聚丙烯酸(PAA)(M_n=5000)、聚(苯乙烯-丙烯酸)(PSAA)(M_n=3000)发生配位反应,分别得到配位聚合物Eu(Ⅲ)-DBM-PAA和NaEu(Ⅲ)-DBM-PSAA,产率分别为89.7%和87.3%.红外光谱、紫外光谱、X光电子能谱测试表明,Eu³⁺分别与PAA,PSAA和DBM-发生配位,元素分析和电导率测定结果证明,1个Eu³⁺分别与PAA中2个链节或PSAA中3个链节的羧基和1个DBM-发生配位.Eu³⁺离子在配位聚合物Eu(Ⅲ)-DBM-PAA和Eu(Ⅲ)-DBM-PSAA中的含量分别为28.46%和12.23%.荧光光谱表明,常温下配位聚合物在紫外光下发出强的红光,主要是Eu³⁺离子的5D0→7F2的能级跃迁.     

Novel lanthanide pH fluorescent probes based on multiple emissions and its visible-light-sensitized feature

A new type of Eu(III) ofloxacin complex as the fluorescent pH indicator has been presented. Compared to pure ligand, the complex offers more distinguished color changes (green–red–blue) derived from both lanthanide line emissions and the secondary ionization steps of ofloxacin. During the concentration dependence experiments, the photoluminescence studies on the complex showed that the excitation of this pH probe can occur at a very long wavelength which extends to visible range (Ex = 427 nm). Furthermore, the functional complex was successfully incorporated into soft networks and two novel luminescent hydrogels (rod and film) were fabricated. The soft materials also exhibited specific responses towards the pH variation. Finally, the onion cell-stain experiments were carried out to further confirm the validity of pH dependence and the results support the idea that the material will be suitable for monitoring biological samples in the future.     

Multicommuted flow-through fluorescence optosensor for determination of furosemide and triamterene

Multicommutation implemented with flow-through optosensors is a very promising area of research. This recent approach benefits from the advantages of both methods and results in high sensitivity, selectivity, and speed, and little waste generation. This paper reports the simultaneous determination of furosemide and triamterene, two widely used diuretics, by measurement of their native fluorescence. The system has been proved to be useful for determination of both analytes in pharmaceutical preparations and for determination of triamterene in human urine and serum. A minicolumn filled with Sephadex SPC-25 microbeads was used to achieve separation of both analytes before detection in a flow-through cell filled with the same resin. The sensor is linear in the range 50–1200 and 0.4–8 ng mL⁻¹ with detection limits of 15 and 0.1 ng mL⁻¹ for furosemide and triamterene, respectively.     

A novel fluorescent epoxy resin for organophosphate pesticide detection

In this work,a novel bisbenzimidazolylpyridine-functionalized fluorescent epoxy resin was synthesized for organophosphate pesticide detection.The epoxy resin was characterized by Fourier-transform infrared spectroscopy(FT-IR),proton nuclear magnetic resonance spectroscopy(~1H NMR),gel permeation chromatography(CPC),differential scanning calorimetry(DSC) and fluorescence spectroscopy.After loading with Eu(Ⅲ) ions,the epoxy resin showed a strong fluorescence emission.The fluorescence emission was observed to be instantaneously quenched when exposed to trace amount of diethyl chlorophosphate in solution.The Stern-Volmer quenching constants K_(sv) for quenching at617 nm was determined to be 0.377 × 10~3 L/mol.This sensitive emission-quenching function and easy processing nature of the polymeric support enable the resin to be a promising chemosensor candidate for the detection of organophosphates.     

Application of PLS regression to fluorimetric data for the determination of furosemide and triamterene in pharmaceutical preparations and triamterene in urine

Multivariate calibration methods that use fluorescence data for the simultaneous determination of furosemide and triamterene were developed. One of the most salient advantages of them is that the vast amount of information provided by the whole spectrum of the sample is not required. This makes analyses simple and fast. The methods require selecting chemometric parameters such as the specific spectral region and number of factors to be used. Both spectral region and number of factors are selected, simultaneously, by minimising the prediction residual error sum of squares (PRESS).The proposed methods were used for the simultaneous determination of the two drugs in real samples (pharmaceutical preparations) with no excipient separation pre-treatment, with furosemide and triamterene contents of 1.68E−3 to 4.31E−2 and 1.03E−3 to 3.12E−2 μg ml⁻¹, respectively; as well as that of triamterene at concentrations of 5.00E−4 to 5.80E−3 μg ml⁻¹ in urine samples. The ability to construct the calibration validation sets directly from the urine samples itself avoids the need to consider matrix interferences or to pre-treat the sample and/or separate some analytes The results were quite good in all cases.     

Determination of trace amounts of mercury using hierarchically nanostructured europium oxide

This work reports a highly sensitive procedure for the determination of trace amounts of mercury, based on fluorescence quenching of thenoyltrifluoroacetone (TTA) capped hierarchically nanostructured europium oxide (cHN-Eu₂O₃). The HN-Eu₂O₃ consisted of nanometer-thick Eu₂O₃ sheets self-organized into nano- and micro-sized monoliths with a hierarchical architecture while retaining its desirable fluorescence properties. The fluorescence intensity of the cHN-Eu₂O₃ was 1000 times higher than that of commercial Eu₂O₃ nanoparticles (equivalent weight) when it was capped with TTA, suggesting that a synergetic effect, confining the longtime Eu³⁺ excitation within the nanostructure and light-harvesting effect of the capping agent, is responsible for this fluorescence enhancement. Excellent interaction between the cHN-Eu₂O₃ and solution species is expected owing to its large surface area, high surface-to-bulk ratio, and ultrahigh fluorescence intensity. As an example, aqueous suspensions of the cHN-Eu₂O₃ were used as sensing agent for the determination of trace amounts of mercury. A linear relationship between the concentration of mercury and fluorescence quenching was observed from 10 ppb to 10 ppm with a correlation coefficient of 0.997 and a detection limit of 5.0 ppb. Mercury in various samples was analyzed using the cHN-Eu₂O₃ suspension.     

The preparation and fluorescence properties of europium nanoparticles

A new structured metallic nanomaterial of europium nanoparticle was prepared using tannic acid as the reductive agent,and nanoeuropium protein conjugates were synthesized by the method of lipoic acid modification on the surface of nanoparticle,which opens a new field of application of lanthanides in nanotechniques.Their properties were also characterized by UV-vis absorption spectroscopy,transmission electron microscopy (TEM),and fluorescence spectroscopy.The europium nanoparticle and its protein conjugates solution were stable and water-soluble.The fluorescence intensity of the composite europium nanoparticles was significantly increased in the presence of trace protein,and was linear proportional to the concentration of proteins under optimum conditions.According to this,a fluorimetric method for the determination of protein was developed in this paper.     

Fluorescence enhancement of the Eu-Tb-benzoylacetone-phenanthroline system

The Eu-benzoylacetone-phenanthroline system, which has strong fluorescence intensity, was studied. It was found that the fluorescence intensity can be greatly increased by La, Gd, Tb, Lu and Y, Tb giving the greatest enhancement (ca. two orders of magnitude). The maximum fluorescence intensity was obtained at pH 8.0. Beer's law was obeyed from 1.0 × 10^?9 to 2.0 × 10^?7 M Eu. The detection limit for europium was 2.0 × 10^?11 M.     

A novel nonenzymatic fluorescent sensor for glucose based on silica nanoparticles doped with europium coordination compound

Amino-functionalized luminescent silica nanoparticles (LSNPs) doped with the europium(III) mixed complex, Eu(TTA)₃phen with 2-thenoyltrifluoroacetone (TTA) and 1,10-phenanthroline(phen) were synthesized successfully using an revised Stöber method. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared (FTIR), and fluorescence spectroscopy were performed for characterizing the synthesized nanoparticles. In the presence of glucose, the fluorescence intensity of the amino-functionalized LSNPs was enhanced due to the enhanced fluorescence resonance energy transfer. Based on fluorescence-enhancing effect, a simple and sensitive method for the determination of glucose was proposed. Under the optimized experimental conditions, the enhanced fluorescence intensity ratio (ΔF/F₀) was linear with the concentration of glucose (c) in the range of 0.0-180 μg ml⁻¹ with a detection limit of 0.8 μg ml⁻¹ (S/N = 3). The R.S.D. values were 0.33% and 0.37% at the levels of 22.5 and 100 μg ml⁻¹, respectively. The proposed method was applied to the determination of glucose in synthetic samples with satisfactory results. The proposed method was also performed to the analysis of blood glucose in human serum samples and the results were in good agreement with clinical data provided by the hospital, which indicates that the method presented here is not only simple, sensitive, but also reliable and suitable for practical applications.