Synergistic fluorescence enhancement of Tb with aromatic monocarboxylic acids and TOPO-Triton X-100: role of Triton X-100 in synergism

Fluorescence enhancement of Tb3+ has been studied, using substituted benzoic acids as ligands. These ligands enhance the fluorescence of Tb3+ by about three orders of magnitude. The enhancement is observed due to ligand sensitized fluorescence. The fluorescence of Tb3+ in these complexes is synergistically enhanced by the addition of trioctylphosphine oxide (TOPO) in Triton X-100. The synergism displayed by TOPO was observed only when Triton X-100 micellar medium was used. TOPO dissolved in SDS/DTAB micellar medium did not result in synergistic fluorescence enhancement of Tb3+. These observations are discussed in detail and the synergism displayed by TOPO is rationalized on the basis of the structure of the surfactants.     

Spectrophotofluorimetric determination of terbium, europium and samarium with pivaloyltrifluoroacetone and tri-n-octylphosphine oxide in micellar solution of nona-oxyethylene dodecyl ether

The fluorescence intensities of terbium, europium and samarium complexes with several beta-diketone derivatives in the absence and presence of tri-n-octylphosphine oxide (TOPO) in micellar solution of nona-oxyethylene dodecyl ether (BL-9EX) were examined. The spectrophotofluorimetric determination of terbium (1.5-1500 ng/ml) has been investigated with pivaloyltrifluoroacetone (PTA) and TOPO in 0.5% micellar solution (pH 3.8-4.5) of BL-9EX. The excitation and emission wavelengths were 309 and 542 nm, respectively. Europium and samarium could be determined by a similar method.     

Effect of ligand structure on synergism in Tb3+-aromatic acid complexes: fluorescence lifetime studies

The fluorescence of Tb3+ sensitized by aromatic carboxylic acid ligands (benzoic, monomethylphthalic, monomethylterephthalic, trimesic, terephthalic, isophthalic, phthalic and mellitic acids) and the synergism displayed by these complexes when treated with TOPO/Triton X-100 have been studied by measuring lifetimes of Tb3+ emission. The lifetime of Tb3+ fluorescence was not significantly altered following complex formation with aromatic carboxylic acids, even though a significant enhancement in the Tb3+ fluorescence intensity was observed in every single case. However, when these Tb3+-aromatic acid complexes were treated with TOPO/Triton X-100, the lifetimes of the Tb3+ fluorescence increased markedly, but only with certain acids. Interestingly, even amongst the acids that showed an increase in lifetime with TOPO/Triton X-100, the lifetimes as a function of the pH of the solution was strongly dependent on the structure of the ligand. These differences and the reasons for such behavior are discussed, which shed light on the role of the structure of the ligand on the synergism process.     

铽-氟罗沙星配合物光化学荧光增强研究

铽 氟罗沙星 (FLRX)配合物在 36 5nm紫外光照射一定时间后 ,Tb3 的特征荧光强度大大提高。通过对该体系的荧光光谱、磷光光谱、荧光量子效率和荧光寿命等的测定 ,证实Tb3 FLRX配合物光照后发生了光化学反应 ,形成了更有利于分子内能量传递的Tb3 配合物。探讨了其荧光增敏机制。     

Observations on photochemical fluorescence enhancement of the terbium(III)-sparfloxacin system.

Fluorescence of terbium(III) was sensitized when excited in the presence of sparfloxacin (SPFX) in the aqueous solution because a Tb(III)-SPFX complex was formed. The sensitized fluorescence was further enhanced when this system was exposed to 365 nm ultraviolet light. By the spectral properties and contrast experiments, it is proved that irradiation makes this system undergo photochemical reactions and a new terbium complex which is more favorable to the intramolecular energy transfer is formed. The mechanism of photochemical fluorescence enhancement of the Tb(III)-SPFX system is discussed and a new sensitive and selective photochemical fluorimetry for the determination of SPFX is established. Under the optimum conditions, the linear range is 1.0-50 x 10(-7) M for SPFX, the detection limit is 3.0 x 10(-9) M and the R.S.D. for 5.0 x 10(-7) M SPFX is 1.3% (n = 9). Without any pretreatment the recovery of SPFX in human urine was determined with satisfaction.     

The new fluorescence enhancement system Tb-N-(2-pyridinyl) ketoacetamide-Et(3)N-Zn and its application

A sensitive fluorescence enhancement system was developed for the determination of terbium. The fluorescence intensity of the Tb-N-(2-pyridinyl) ketoacetamide (PKAA) system was greatly enhanced by the addition of triethylamine (Et(3)N) and zinc nitrate in the methanol solution. The excitation and emission wavelengths were 329 and 546 nm, respectively. Under optimal conditions, the fluorescence intensities varied linearly with the concentration of Tb(3+) in the range of 7.5 x 10(-8)-8.2 x 10(-6)M with a detection limit of 6.4 x 10(-8)M. The interferences of some rare earth ions were described. This method was applied to the determination of trace amounts of terbium (III) in a synthetic rare earth oxide and a high purity Y(2)O(3) matrix. The mechanism of fluorescence enhancement was also studied.     

Enhanced fluorescence of 3-(naphthalene-2-ylimino)-1-phenylbutan-1-one-Tb with 1,10-phenanthroline ternary system and its analytical application

A new Schiff base ligand: 3-(naphthalene-2-ylimino)-1-phenylbutan-1-one (NPB) was synthesized. Its fluorescence intensity with terbium(III) was greatly enhanced by the addition of 1,10-phenanthroline (Phen) in the chloroform solution. The mechanism of fluorescence enhancement was studied. The results indicate the formation of a ternary NPB-Phen-Tb complex. In the ternary system, Phen can transfer the energy absorbed by Phen and NPB to Tb(3+).     

表面活性剂存在下铽-镥(钆、钇)-乙酰水杨酸共发荧光体系的研究

本文研究了镥等三种稀土离子与铽-乙酰水杨酸配合物产生的共发荧光效应。在最佳条件下,Lu³⁺、Gd³⁺、Y³⁺的存在可使铽-乙酰水杨酸配合物的荧光分别增强108,58和73倍。讨论了共发光体系的形成条件和荧光特性。利用Tb-Lu-乙酰水杨酸体系和Tb-Lu-乙酰水杨酸-乙二胺四乙酸-十六烷基三甲基溴化铵体系分析了合成稀土样品和包头稀土标准氧化物中的铽,结果满意,加标回收率为90.5～105.6%,并对共发光的机理和表面活性剂的作用进行了初步探讨。     

铕-速尿-TOPO荧光配合物的研究及速尿的测定

在pH7.8的缓冲溶液中,铕离子、速尿和三辛基氧膦(TOPO)反应生成稳定的三元配合物,该配合物溶解在Triton X-100胶束中。以280 nm光波激发,配合物发射出铕离子的特征荧光。分析了三元配合物的紫外及荧光光谱,对配合物的生成及TOPO和Triton X-100的荧光增敏机理进行了探讨。采用时间分辨荧光法测定配合物的荧光强度,其荧光强度和速尿的浓度在一定范围内呈线性关系,建立了工作曲线的线性回归方程。方法的检出限为6.6×10-8mol/L,测定精度RSD为1.3%(4.00×10-6mol/L,n=11)。用此方法测定尿液中痕量速尿,回收率为93.0%～103%。     

基于核酸脱碱基位点的铽离子荧光增强型单核苷酸多态性识别研究

基于核酸脱碱基(AP)位点构建了无机配体稀土铽离子(Tb^3＋)荧光增强型单核苷酸多态性(SNP)识别方法. 在目标链靶标碱基对应的探针链上相应位置引入AP位点, 发现Tb^3＋可以选择性地结合在AP位点, 光激发时发生从DNA碱基到结合的Tb^3＋的能量转移, 使Tb^3＋特征荧光显著增强. 这种荧光增强作用与靶标碱基及AP位点侧翼碱基类型密切相关. 当靶标碱基和侧翼碱基为G时, 荧光最强. 该方法可用于区分肿瘤抑制基因p53密码子177位的C/G碱基变异.     

Synthesis and novel fluorescence phenomenon of terbium complex with a new Schiff base ligand derived from condensation of triaminotriethylamine and 3-indolemethanal

A new Schiff base ligand with tripodal structure, N,N',N'-tri-(3-indolemethanal)-triaminotriethylamine (L), and its complex with terbium was synthesized. The complex was characterized by element analysis, IR spectra, mass spectra, thermal analysis and molar conductivity. The terbium ion was found to coordinate to the Schiff base nitrogen atoms and the bridgehead nitrogen atom. The fluorescence properties of the complex in aqueous solutions were studied. Under the excitation of UV light, the complex exhibits characteristic fluorescence of terbium ion. H(+) concentration could strongly enhance the luminescence of terbium complex with L in aqueous solutions. This phenomenon will make the new complex favorable to be used in the fluorescence switches and sensors. The mechanism of the fluorescence enhancement by protonation of the indole nitrogen atoms is due to the suppressed photoinduced electron transfer (PIET) fluorescence quenching when adding acid.     

铽配合物Tb(PMIP)3(PhCA)的合成及阴离子识别研究

本文设计合成了稀土铽配合物Tb(PMW)3(PhCA)作为阴离子试剂,利用荧光光谱考察了其与F-、Cl-、Br-、I-、ClO4-、NO3-、AcO-和H2PO-4等阴离子的作用.研究结果表明:不同阴离子的加入能够调控,Tb(PMIP)3(PhCA)的发光行为,当一定量的氟离子(醋酸根离子、磷酸二氢根离子)加入到Tb(PMIP)3(PhCA)的乙腈溶液中后,荧光发射增强;过量的氟离子(醋酸根离子、磷酸二氢根离子)加入后则使其荧光淬灭.而在乙腈和水混合溶液中,Tb(PMIP)3(PhCA)则能选择性识别氟离子和磷酸二氢根离子.     

Spectrofluorimetric trace determination of terbium(III) with potassium oxalate

Potassium oxalate acts as a specific reagent in enhancing the fluorescence intensity of terbium in aqueous solutions. Maximum fluorescence intensity is obtained by irradiating (at 255 mμ) terbium(III) dissolved in 0.01 M potassium oxalate solution at pH 7.8. The enhancement and quenching phenomena caused by other lanthanides, errors in the determination, and various examples of spectrofluorimetric analysis of traces of terbium in mixtures with other lanthanides are described. The sensitivity of the method is 5·10^-2μg/ml of terbium.     

Time-resolved fluorimetric detection of terbium-labelled deoxyribonucleic acid separated by gel electrophoresis

Deoxyribonucleic acid (DNA) was reacted with a strong chelating agent and labelled with terbium, yielding a highly fluorescent conjugate with a lifetime of 1.5 ms. When a pulsed source and gated detection electronics were employed, the long-lived decay allowed effective discrimination against background fluorescence and scattered excitation. Detection limits should therefore be significantly improved in comparison with covalent labels with fluorescence lifetimes in the nanosecond regime or stains such as ethidium bromide. The conjugate is very stable, remaining fluorescent on dilution and in an electric field at elevated temperatures (60 degrees C), conditions typically encountered during polyacrylamide gel electrophoresis. As an enhancement solution is not required to develop the fluorescence, this system could be utilised in situations where on-line detection is desirable. Although only DNA was labelled, the method is equally applicable to ribonucleic acid.     

Enhanced fluorescence of 3-tryptimino-1-phenyl-butan-1-one–Tb with 1,10-phenanthroline ternary system, and its analytical application

A new Schiff base ligand, 3-tryptimino-1-phenyl-butan-1-one (TPB), was synthesized. The fluorescence intensity of its terbium(III) complex was greatly enhanced by addition of 1,10-phenanthroline to an acetonitrile solution. Spectrofluorimetric determination of trace amounts of Tb³⁺ was performed based on this effect. The excitation and emission wavelengths are 293 and 546 nm, respectively. Under optimal conditions, the fluorescence intensities varied linearly with the concentration of Tb³⁺ in the range of 2.0 × 10⁻⁶ to 7.0 × 10⁻⁶ M with a detection limit of 2.4 × 10⁻⁹ M. Interference by some rare earth ions is described. This method was applied to the determination of trace amounts of terbium(III) in a high purity Y₂O₃ matrix. The mechanism of fluorescence enhancement was also studied.     

Flow Injection Spectrofluorimetric Determination of Terbium (III) Based on Solubilizing its Ternary Complex in Micellar Solution

Abstract

A flow injection spectrofluorimetric method has been developed for the determination of terbium (III) based on solubilizing its ternary complex with pi valoyitrifluoroacetone (PTA) and trioctylphosphine oxide(TOPO) in micellar solution of nona (oxyethylene) dodecyl ether (BL-9EX). Accuracy and reproducibility are good up to 16 ng/ml of terbium (III) and 80 samples per hour can be analyzed. The relative standard deviation was less than 1.0 %. No interferences from 20-fold excesses of 11 rare earth ions were observed.     

Studies on ion transport of some rare earth elements through solvating extractants immobilised on supported liquid membrane

The studies on ion transport of terbium and dysprosium through a porous supported liquid membrane (SLM) containing TOPO (trioctyl phosphine oxide) and TBP (tributyl phosphate) as immobilised carriers have been carried out. The effect of stirring of bulk solutions on permeability coefficient has been investigated. The permeability coefficient increases with increase in pH of source phase from 0–6, and hydrogen ion concentration from 0.01 to 0.1 M of receiving solution. The dependency of permeability coefficient on the carrier concentration has been explored. The effect of ammonium thiocyanate concentration on permeability coefficient has been studied. In order to develop a method for enrichment of rare earth elements, further investigations were carried out by using a hollow fibre membrane extractor. The mechanism of ion transport of terbium and dysprosium in SLM systems has been explained.     

Synergistic effect of 3,5-dichlorophenol and trioctylphosphine oxide on the extraction of vanadium(V) with 2-methyl-8-quinolinol derivatives.

The extraction of vanadium(V) with 2-methyl-8-quinolinol derivatives (HA), such as 2-methyl-8-quinolinol (HMQ), 2-methyl-5-butyloxymethyl-8-quinolinol (HMO4Q), and 2-methyl-5-hexyloxymethyl-8-quinolinol (HMO6Q), from a weakly acidic solution into chloroform was studied in both the absence and presence of 3,5-dichlorophenol (Hdcp) and trioctylphosphine oxide (TOPO) as the synergists. Vanadium(V) was extracted with HA as VO(OH)(A)2 in the absence of synergists, and its extractability increased with an increase in the hydrophobicity of HA. Vanadium(V) was quantitatively extracted from the lower pH region upon the addition of Hdcp and TOPO as VO(OH)(A)2 x Hdcp and VO2(A)(TOPO), respectively. The enhancement of the synergistic effect of Hdcp on the extraction of vanadium(V) with HA increased in the following order: HMQ < HMO4Q < HMO6Q, as opposed to that of TOPO. This result was ascribable to the difference in the mechanisms of the occurrence of the synergistic effect by Hdcp and TOPO.     

Study on the new fluorescence enhancement system of Tb-1,10-bis(2′-carboxylphenyl)-1,4,7,10-tetraoxadecane in silver chloride collosol and its analytical application

A new salicylic-based open-chain crown ether ligand, 1,10-bis(2′-carboxylphenyl)-1,4,7,10-tetraoxadecane (BCPTD) was synthesized. Solutions of its complex with Tb³⁺ can emit the intrinsic fluorescence of Tb³⁺. The fluorescence intensity of the complex in KCl solution was enhanced by the addition of silver(I), leading to a new fluorescence enhancement phenomenon. The spectrofluorimetric determination of traces of silver(I) based on the above phenomenon was carried out. The excitation and emission wavelengths are 298 and 545 nm, respectively. Under optimal conditions, the differential value of fluorescence intensity in the absence and presence of Ag⁺ was proportional to the concentration of silver(I) in the range 0.5-20 μg ml⁻¹. The method was applied to the determination of silver(I) in a standard ore sample. The analytical performance is investigated in detail by using common aromatic carboxylic acids or synthetic analogues of BCPTD as ligands to replace BCPTD. It was found that Tb-aromatic acid complexes did not result in fluorescence enhancement of Tb³⁺ in AgCl collosol. The phenomenon was only observed in Tb(III) with BCPTD or its open-chain crown ether analogues solutions.In addition, the enhancement of the fluorescence intensity of terbium(III) in these complexes depends on the extent of formation of the AgCl collosol.     

环丙沙星铽荧光配合物与DNA的相互作用及染色新方法

合成了环丙沙星铽荧光配合物,并研究其与DNA分子的相互作用.对比DNA分子吸附配合物分子前后的显微红外及荧光光谱发现,以环丙沙星分子为配体的稀土配合物同DNA间存在相互作用,这种作用诱导了DNA二级结构的构象变化.基于这种相互作用,研究了环丙沙星铽配合物对口腔粘膜组织切片的荧光染色,得到了同经典的苏木精-伊红染色法类似的反差效果.