水杨醛-4-甲氧基苯甲酰腙识别锌离子的研究

设计合成了荧光传感分子水杨醛-4-甲氧基苯甲酰腙(SAMB),通过IR、1HNMR和元素分析确证了其结构,利用紫外-可见吸收光谱和荧光光谱考察了其对不同阳离子的识别作用。结果表明,SAMB的荧光发射对锌离子表现出高选择性响应,且形成1∶1型配合物。乙醇中锌离子的加入导致SAMB的荧光增强328倍,而其他过渡金属离子只引起SAMB的荧光的略微增强。初步探讨了受体分子与锌离子的结合模式与荧光增强机理。     

4′-对二甲氨基苯基-2,2′∶6′,2″-三联吡啶-锌配合物在含水乙醇介质中对磷酸根离子的高选择性识别研究

合成了一种-2,2′∶6′,2″-三联吡啶衍生物,4′-对二甲氨基苯基-2,2′∶6′,2″-三联吡啶(L),利用L与锌离子形成的稳定配合物(ZnL),用紫外可见吸收光谱和荧光光谱研究了在无水乙醇和含水乙醇介质中各种阴离子对该配合物ZnL的吸收光谱和荧光发射光谱的影响,发现该配合物能在含水乙醇介质中选择性的识别磷酸根类离子。磷酸根、磷酸氢根与磷酸二氢根离子分别与ZnL配合物以1∶1、2∶1及2∶1结合模式影响体系的吸收和荧光发射,ZnL配合物对磷酸根类离子的识别作用主要源于配合物多余的结合位点。     

4'-对二甲氨基苯基-2,2':6',2"-三联吡啶-锌配合物在含水乙醇介质中对磷酸根离子的高选择性识别研究

合成了一种-2,2':6',2"-三联吡啶衍生物,4'-对二甲氨基苯基-2,2':6',2"-三联吡啶(L),利用L与锌离子形成的稳定配合物(ZnL),用紫外可见吸收光谱和荧光光谱研究了在无水乙醇和含水乙醇介质中各种阴离子对该配合物ZnL的吸收光谱和荧光发射光谱的影响.发现该配合物能存含水乙醇介质中选择性的识别磷酸根类离子.磷酸根、磷酸氢根与磷酸二氢根离子分别与ZnL配合物以1:1、2:1及2:1结合模式影响体系的吸收和荧光发射,ZnL配合物对磷酸根类离子的识别作用主要源于配合物多余的结合位点.     

多孔硅于甲酸-甲酸钠溶液阳极偏压下的电致发光研究

用荧光分光光度法现场监测了多孔硅于甲酸-甲酸钠溶液阳极偏压下的电致发光行为。发现该体系的电致发光峰值随着阳极偏压增大而发生蓝移;发光峰能量值与阳极偏压呈良好的线性关系,其斜率与多孔硅在阴极偏压下电致发光的结果一致。扫描探针技术研究表明：多孔硅的表面形貌明显地影响其发光性质。提出了多孔硅在甲酸-甲酸钠溶液中阳极偏压下的电致发光与多孔硅表面的Si-H键的氧化作用有关的发光机理。发现了多孔硅于甲酸-甲酸钠溶液中在阳极偏压下电压调制的可见光发射行为,并用量子限制效应对该现象进行了解释。     

锌离子荧光探针研究进展

锌广泛存在于人体内,具有重要生理功能。因此,对游离锌离子的选择性识别和有效检测具有重要意义。荧光探针因其设计简单、易于操作、灵敏度高、可细胞成像等诸多优点而广泛应用于锌离子的识别研究。锌离子荧光探针常见的识别机理包括光致电子转移、分子内电荷转移、荧光共振能量转移、聚集诱导荧光增强、螯合荧光增强等。其中,基于螯合荧光增强机理的锌离子探针,其荧光团通常可同时作为识别基团,因此,相比于其它探针,具有设计较为简单、合成较为便捷的优点。本文综述了近年来文献中报道的基于以上各种识别机理的锌离子荧光探针,并着重介绍了螯合荧光增强机理在锌离子识别中的应用。     

基于羟苯基苯并咪唑的Zn2+比率荧光探针

通过羰基将两分子2-(4-氨基-2-羟苯基)苯并咪唑(4-AHBI)连接,合成了结构高度对称的新化合物N,N′-二-[3-羟基-4-(2-苯并咪唑)苯基]脲(C27H20N6O3,1),测试了不同溶剂条件下1的紫外吸收和荧光发射光谱,研究了1对Zn2+的选择性识别作用。结果表明,随着溶剂极性的增大,1的紫外吸收峰发生蓝移,激发态分子内质子转移(ESIPT)荧光发射峰明显增强。与4-AHBI相比,1在乙腈溶液中的紫外吸收强度增强约3.5倍,最大吸收峰红移8 nm,荧光发射增强8倍多。1在乙腈溶液中的Zn2+荧光响应行为表明1与Zn2+的结合将导致1在445 nm处的荧光强度不断降低,而在395 nm处出现的新峰的荧光强度不断增强,具有比率荧光探针的特点,而且检测范围较宽,可达1×10-6-1×10-2 mol.L-1。     

Er3+、In3+等金属离子对多孔硅光致发光性质的影响

用阳极腐蚀的方法制备了多孔硅样品,用电化学方法在多孔硅中注入Er3+、In3+等金属离子,并对注入离子后多孔硅的光致荧光光谱进行了研究,结果表明：注入Er3+及In3+后的多孔硅在588nm处的发光峰强度大大增加,同时发光峰稍有展宽。随着离子注入时间的增长,强度继续增加,但当离子溶液浓度一定时,这种增强对时间具有饱和性。     

以3, 5-二甲基-1-羧甲基-4-吡唑甲酸为配体的两个锌的配合物的合成、晶体结构和荧光性能

以3,5-二甲基-1-羧甲基-4-吡唑甲酸和4,4′-联吡啶为配体,合成了1个单核锌(Ⅱ)配合物[Zn(4,4′-bpy)(Hcmdpca)2(H2O)3]·2H2O(1)和1个锌(Ⅱ)的一维配位聚合物[Zn(4,4′-bpy)(Hcmdpca)2(H2O)]·3H2O(2)(H2cmdpca=3,5-二甲基-1-羧甲基-4-吡唑甲酸;4,4′-bpy=4,4′-联吡啶),并用元素分析、红外光谱、X-射线单晶衍射结构分析、热重分析等对其进行了表征。配合物1和2都属于单斜晶系,空间群为P21/c。配合物1的锌离子都位于一个畸变的八面体构型中。配合物1中的独立结构单元间通过分子间氢键作用构成一个三维的超分子结构。而在2中,锌离子位于一个畸变的四方锥构型中,每个4,4′-联吡啶分子桥联2个相邻的锌(Ⅱ)离子,形成一个一维链;这些一维链和水分子通过分子间氢键进一步形成一个三维的结构。此外还考察了1和2的热稳定性和固体荧光性质。     

一种高灵敏度高选择性的荧光素基比色荧光锌传感器

本文报道了一种基于荧光素的锌离子传感器FN1,其在甲醇溶液中显示了对锌离子极高的灵敏度和选择性。随着锌离子的滴加,紫外-可见光谱中最初在371 nm处的吸收峰消失,在437 nm处出现了一个新峰。当在混合金属离子的甲醇溶液中滴加了相对于二价金属离子的等物质的量浓度的锌离子或相对于一价金属离子0.5倍物质的量浓度的锌离子后,锌离子积分荧光强度增强了近37倍（Φ=0.48,λ_max(em)=513 nm）,估算的锌离子检测限为7 μg·L^-1。基于紫外-可见光、荧光和质谱的结果,讨论了1∶1的FN1/Zn²⁺配合物的结合机理。     

基于水杨醛席夫碱结构的锌离子选择性荧光探针

设计并合成了一种新型锌离子荧光探针——4-N,N-二乙胺基水杨醛-2-吡啶肼席夫碱(1).在pH为7.0的50%水/乙醇(体积比)体系中,1对锌离子表现出显著的荧光增强响应.提高体系中的乙醇含量有利于获得更高的荧光放大倍数,在纯乙醇中,1对锌离子的荧光增强可达100倍.1对锌离子的荧光检测表现出良好的选择性,尤其可以区分锌离子的常见干扰离子镉离子.其线性范围为0.1~1.0μmol/L,检测限达到35 nmol/L.同时,1被成功用于实际水样中锌离子的定量检测.     

A fluorescent probe for both pH and Zn2+ based on 2-(1-phenyl-1H-benzo[d]imidazol-2-yl)phenol

A sensitive fluorescent probe 2-(1-phenyl-1H-benzo[d]imidazol-2-yl)phenol (HBIZ) for pH and Zn2+ has been developed. Great changes have taken place in the UV-vis absorption and fluorescence spectra for HBIZ upon increasing pH of its aqueous solution, acting as a pH-induced emission "off-on-off" switch with large enhancement factors of ～290 and ～75 over the pH range of 1.00-5.40 and 5.20-10.40. A over 100-fold fluorescence enhancement was also observed after complexation of HBIZ to Zn2+ in N,N-dimethylformamide.     

Ratiometric and water-soluble fluorescent zinc sensor of carboxamidoquinoline with an alkoxyethylamino chain as receptor

A novel "naked-eye" and ratiometric fluorescent zinc sensor (AQZ) of carboxamidoquinoline with an alkoxyethylamino chain as receptor was designed and synthesized. AQZ shows good water solubility and high selectivity for sensing; about an 8-fold increase in fluorescence quantum yield and a 75 nm red-shift of fluorescence emission upon binding Zn2+ in buffer aqueous solution are observed. Moreover, AQZ can enter yeast cells and signal the presence of Zn2+.     

1-乙酰基-3-(2-羟基-4,6-二甲氧基苯基)-5-苯基-2-吡唑啉的合成及锌离子探针的研究

设计合成了1-乙酰基-3-(2-羟基-4,6-二甲氧基苯基)-5-苯基-2-吡唑啉(4), 测试了其紫外光谱和荧光光谱, 研究了其对锌离子的选择性识别作用. 结果表明, 化合物4作为锌离子荧光探针, 受常见离子的干扰较小, 对于锌离子有着较高的选择性和较低的检出限.     

Esterase-activated two-fluorophore system for ratiometric sensing of biological zinc(II)

Intracellular ester hydrolysis by cytosolic esterases is a common strategy used to trap fluorescent sensors within the cell. We have prepared analogues of Zinpyr-1 (ZP1), an intensity-based fluorescent sensor for Zn2+, that are linked via an amido-ester or diester moiety to a calibrating fluorophore, coumarin 343. These compounds, designated Coumazin-1 and -2, are nonpolar and are quenched by intramolecular interactions between the two fluorophores. Esterase-catalyzed hydrolysis generates a Zn2+-sensitive ZP1-like fluorophore and a Zn2+-insensitive coumarin as a calibrating fluorophore. Upon excitation of the fluorophores, coumarin 343 emission relays information concerning sensor concentration whereas ZP1 emission indicates the relative concentration of Zn2+-bound sensor. This approach enables intracellular monitoring of total sensor concentration and provides a ratiometric system for sensing biological zinc ion.     

Turn-on fluorescence sensing of nucleoside polyphosphates using a xanthene-based Zn(II) complex chemosensor

Fluorescence sensing with small molecular chemosensors is a versatile technique for elucidation of function of various biological substances. We now report a new fluorescent chemosensor for nucleoside polyphosphates such as ATP using metal-anion coordination chemistry. The chemosensor 1-2Zn(II) is comprised of the two sites of 2,2'-dipicolylamine (Dpa)-Zn(II) as the binding motifs and xanthene as a fluorescent sensing unit for nucleoside polyphosphates. The chemosensor 1-2Zn(II) selectively senses nucleoside polyphosphates with a large fluorescence enhancement (F/F(o) > 15) and strong binding affinity (K(app) approximately = 1 x 10(6) M(-1)), whereas no detectable fluorescence change was induced by monophosphate species and various other anions. The 'turn-on,' fluorescence of 1-2Zn(II) is based on a new mechanism, which involves the binding-induced recovery of the conjugated form of the xanthene ring from its nonfluorescent deconjugated state which was formed by an unprecedented nucleophilic attack of zinc-bound water. The selective and highly sensitive ability of 1-2Zn(II) to detect nucleoside polyphosphates enables its bioanalytical applications in fluorescence visualization of ATP particulate stores in living cells, demonstrating the potential utility of 1-2Zn(II).     

8-Hydroxyquinoline derivative as a fluorescent chemosensor for zinc ion.

8-Hydroxyquinoline derivative 1 as a fluorescent chemosensor for Zn2+ was synthesized. Because Cd2+ is often found with Zn2+ in the environment and can form fluorescent complexes with chelating fluorophores, a potentially important property of chemosensors for Zn2+ is their selectivity for Zn2+ over Cd2+. The Zn2+ or Cd2+ complexes of 1 gave an emission band from the 1:1 complex, but the fluorescence intensity for Cd2+ was a half of that for Zn2+. Ligand 1 is suited for use as a fluorescent chemosensor for Zn2+.     

A ratiometric fluorescence probe for selective visual sensing of Zn2+

A simple ratiometric fluorescence probe based on vinylpyrrole end-capped bipyridine for the visual sensing of Zn2+ under aqueous physiological pH (6.8-7.4) is described. The fluorophores 3a-c showed strong emission around 537 nm in acetonitrile with a quantum yield of 0.4. In buffered (HEPES, pH 7.2) acetonitrile-water mixture (9:1 v/v), titration of transition metal salts to 3c showed strong quenching of the emission at 547 nm except in the case of Zn2+, which resulted in a red-shifted emission at 637 nm. Alkali and alkaline earth metal salts could not induce any considerable changes to the emission behavior of 3a-c. The binding of Zn2+ was highly selective in the presence of a variety of other metal ions. Though Cu2+ quenches the emission of 3c, in the presence of Zn2+, a red emission prevails, indicating the preference of 3c toward Zn2+. Job plot and Benesi-Hildebrand analysis revealed a 1:1 complexation between the probe and the metal ion. The selective visual sensing of Zn2+ with a red emission is ideally suited for the imaging of biological specimens.     

铝,镁,锌—氟哌酸配合物的荧光特性及其脂溶性研究

探讨了介质ＰＨ值及Ａｌ＾３－，Ｍｇ＾２＋，Ｚｎ＾２＋离子对喹诺酮类药物氟哌酸荧光特性的影响。发现铝，镁及锌离子在不同ＰＨ值条件下与氟哌酸形成配合物而增强荧光，据此建立了用铝离子增强荧光测定氟哌酸含量的新方法。     

Selective fluorescence zinc ion sensing and binding behavior of 4-methyl-2,6-bis(((phenylmethyl)imino)methyl)phenol: biological application

Zinc ion fluorescence sensing and the binding properties of 4-methyl-2,6-bis(((phenylmethyl)imino)methyl)phenol (HL) have been investigated. It displays high selectivity for Zn2+ and can be used as zinc ion-selective luminescent probe for biological application under physiological conditions. The increase in emission in the presence of Zn2+ is accounted for by the formation of hexanuclear complex [Zn6(L)2(OH)2(CH3COO)8] characterized by X-ray crystallography. An approximately 6-fold Zn2+-selective chelation-enhanced fluorescence response in HEPES buffer (pH 7.4) is attributed due to the strong coordination of Zn(II) that would impose rigidity and hence decrease the nonradiative decay of the excited state. By incubation of cultured living cells (B16F10 mouse melanoma and A375 human melanoma) with HL, intracellular Zn2+ concentration could be monitored.     

Development of an iminocoumarin-based zinc sensor suitable for ratiometric fluorescence imaging of neuronal zinc

Ratiometric imaging is a technique to reduce artifacts by minimizing the influence of extraneous factors on the fluorescence of a sensor and is particularly useful for cellular imaging studies. Here we characterized the iminocoumarin fluorophore as a new scaffold for sensors for ratiometric imaging. The iminocoumarin 4 showed a high quantum yield in aqueous media on excitation in the visible wavelength region, while its coumarin analogue showed little fluorescence. We therefore developed a novel fluorescence probe, ZnIC, for ratiometric imaging of Zn2+, using iminocoumarin as a fluorophore and (ethylamino)dipicolylamine as a Zn2+ chelator. ZnIC exhibited almost the same fluorescence properties as 4, and the emission spectrum of this probe was red-shifted on addition of Zn2+ under physiological conditions. ZnIC is selective for Zn2+ over other biologically important metal ions, such as Ca2+ and Mg2+, and has high affinity for Zn2+. To confirm the suitability of ZnIC for biological applications, we employed it for the ratiometric detection of changes in intracellular Zn2+ in cultured cells and in rat hippocampal slices. The results indicate that iminocoumarin is a useful fluorophore for fluorescence microscopic imaging and that ZnIC should be useful for studies on the biological functions of Zn2+.