基于香豆素与胍的荧光探针的合成及对Co2+、Fe3+的识别研究(英文)

本论文设计合成了基于1,3-二氨基胍盐酸盐、氨基胍盐酸盐的新型香豆素类荧光探针L1、L2。通过紫外-可见、荧光光谱的变化研究探针L1、L2对金属离子的识别效应。利用Job’s plot曲线确定探针L1与Co²⁺形成了1∶2的配合物,探针L2和Fe³⁺形成了3∶1的配合物,且表现为明显的荧光增强。探针L1对Co²⁺的检出限可达到10^-6mol/L,探针L2对Fe³⁺的检出限可达到10^-7mol/L。两种高灵敏度荧光探针有望应用于生物和环境监测领域。     

Turn-on fluorescent probe for Zn2+ ions based on thiazolidine derivative

In this study, simple on–off fluorescent/UV–visible (UV–Vis) probes were easily prepared using 2-(2-hydroxyphenyl)thiazolidine-4-carboxylic acid ( Sen-1 ) and/or 2-(2-hydroxy-5-nitrophenyl)thiazolidine-4-carboxylic acid ( Sen-2 ) for fast detection of Zn²⁺ ions. Their sensing properties towards common metal ions were investigated using UV–Vis and fluorescence spectroscopies. Sen-1 and Sen-2 displayed a significant change with the addition of Zn²⁺ ions in the UV–Vis spectra. The addition of Zn²⁺ ions induced a 104 nm bathochromic shift for Sen-1 . The binding ratio towards Zn²⁺ metal ions was determined to be 1:1 by using Job plot analysis and fluorescence spectroscopy. The association constant and free energy (ΔG) of Sen-1 and Sen-2 towards Zn²⁺ ions were calculated by the Benesi–Hildebrand equation. The limit of detection of Sen-1 towards Zn²⁺ ions is 3.73 × 10⁻⁸ M, which is about 1/100 of the value recommended by the World Health Organization for drinking water. Sen-1 was successfully applied to detect Zn²⁺ ions in water samples and the fluorescence test strip was prepared for visual detection of Zn²⁺ ions. Finally, the quantum chemical parameters of Sen-1 and Sen-2 , such as highest occupied molecular orbital, lowest unoccupied molecular orbital, and chemical hardness, were investigated by the Becke, three-parameter, Lee–Yang–Parr, Hartree–Fock, and M062x methods.     

表面活性剂增溶比率荧光Zn2+检测方法研究

合成了一种新的Zn2+荧光检测试剂8-(2-(十八氨基)乙酰氨基)喹啉(AQZ-18)。通过自发荧光的非离子表面活性剂OP-10增溶AQZ-18,获得了一个与Zn2+结合后在320 nm和505 nm分别有两个荧光发射峰的溶液体系。短波长荧光峰来自OP-10,荧光峰强度不随Zn2+浓度变化;长波长荧光峰来自AQZ-18,荧光峰强度随Zn2+浓度增加而增强。利用上述两个荧光峰强度随Zn2+浓度变化时的比值变化建立了一种新的比率荧光Zn2+检测方法。研究表明,Zn2+与AQZ-18形成1∶1型基态配合物,其表观结合常数为1.1×106L/mol。常见金属离子对Zn2+荧光检测无干扰,Zn2+浓度在0～1.1×10-5mol/L范围内与荧光强度变化的比值呈良好的线性关系,相关系数(r2)为0.996 2,检出限为55 nmol/L。该方法可用于水样中Zn2+的检测。     

Effect of Zn2+ Ions on Upconversion Emission of Er3+ in Zn/Er:LiNbO3 Crystal

The effect of Zn2+ ions codoped on the upconversion emission of Er3+ ions in Er:LiNbO3 crystal under different excitation wavelength was reported.The upconversion emission spectra of Zn/Er:LiNbO3 follo...     

Non-Aqueous Capillary Electrophoresis with Indirect Photometric Detection for Direct Analysis of Pb2+, Zn2+ and Cd2+ Ions

A new approach, based on non-aqueous capillary electrophoresis separation and indirect photometric detection, was established for the determination of the transition metal ions Pb²⁺, Zn²⁺ and Cd²⁺. Under optimized conditions, the method produced baseline separation of these three metal ions. The linear range and detection limits were 1050µM, 1.9µM for Cd²⁺; 1050µM, 2.1µM for Zn²⁺; and 20100µM, 3.8µM for Pb²⁺, respectively.     

Preparation and Characterization of the Antibacterial Zn2+ or/and Ce3+ Loaded Montmorillonites

A series of modified montmorillonites including Zn²⁺ loaded montmorillonite (Zn/MMT), Ce³⁺ loaded montmorillonite (Ce/MMT) and Zn²⁺‐Ce³⁺ loaded montmorillonites (Zn‐Ce/MMT) were prepared by an ion‐exchange reaction, and characterized using X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction (XRD), and scanning electron microscopy (SEM). The specific surface areas, zeta potentials and antibacterial activity of the modified montmorillonites were also investigated. Zinc and cerium were proved to be present as bivalent zinc state and trivalent cerium state in the modified montmorillonites. For the modified montmorillonites, the d₀₀₁ basal spacings increased and the particles were formed of irregular shapes. The antibacterial activity of the modified montmorillonites was enhanced with the increase of specific surface areas and zeta potentials, and Zn²⁺‐Ce³⁺ loaded montmorillonites displayed obvious synergistic antibacterial effect. When Zn/Ce atomic ratio was 1.24, the Zn‐Ce/MMT showed high antibacterial efficiency and broad‐spectrum antibacterial activity, possessing the MIC against Escherichia coli, Staphylococcus aureus, Candida albicans and Mucor of 1500, 1000, 2000 and 3000 mg·L^?1, respectively.     

A dual-function chemosensor based on coumarin for fluorescent turn-on recognition of Hg2+ and colorimetric detection of Cu2+ in aqueous media

A novel coumarin derivative CTT was synthesized via the condensation of 7-(N,N-diethylamino) coumarin-3-aldehyde with 5-amino-1,3,4-thiadiazole-2-thiol and its structure was characterized using infrared spectroscopy (IR), ¹H NMR, mass spectrometry (MS) techniques, and elemental analysis. The recognition properties of CTT with metal ions were investigated in CH₃CN–H₂O (v/v = 1/1) solution using UV–vis absorption and fluorescence emission spectrum method. The results showed that CTT could monitor Cu²⁺ and Hg²⁺ simultaneously as a dual-function chemosensor in CH₃CN–H₂O (v/v = 1/1). CTT could be used to detect Cu²⁺ colorimetrically; when using CTT, a color change from yellowish-brown to yellowish-green could be readily observed by the naked eye. CTT showed turn-on fluorescent recognition of Hg²⁺, the fluorescence enhancement was attributed to the inhibited C=N isomerization and the obstructed excited state intramolecular proton transfer (ESIPT) of CTT. The recognition mechanism of CTT for Cu²⁺ and Hg²⁺ was studied by experiments and theoretical calculations, respectively. Therefore, CTT has the ability to be a “single chemosensor for dual targets.”     

A bifunctional,colorimetric and fluorescent probe for recognition of Cu2+ and Hg2+ and its application in molecular logic gate

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以三(2-氨基乙基)胺为核的PAMAM与Zn2+的络合作用研究

以三(2-氨基乙基)胺为核,通过发散法合成了不同代数的树状聚酰胺胺(PAMAM),并利用FT-IR、1H NMR等技术对合成的产物进行表征,结果表明所合成产物的分子结构与理论结构相符。合成的PAM-AM具有大量的伯胺、叔胺和酰胺,可以作为Zn2+的络合剂。采用荧光分光光度法研究了PAMAM与Zn2+的络合作用,探讨了PAMAM的代数、Zn2+与PAMAM的摩尔比、溶液pH值、反应时间和温度对络合的影响。结果表明PAMAM的代数越高,所络合的Zn2+数目越多,且与理论值相符;随着Zn2+与PAMAM摩尔比的增加,络合形式发生变化;溶液pH值对络合体系有显著影响,强酸性条件下,PAMAM的伯胺和叔胺被质子化,H+取代Zn2+,Zn2+从络合体系中释放出来,这为PAMAM的循环利用提供了理论依据;另外,反应时间和温度对PAMAM与Zn2+的络合也有一定影响,延长反应时间和升高反应温度均使络合程度增加。     

Pb2+和Zn2+对亲水型光敏热成像材料感光性能和存储稳定性能的影响

分别研究了Pb²⁺和Zn²⁺对以聚乙烯醇(PVA)为粘合剂的亲水型光敏热成像(PTG)材料的感光性能以及老化稳定性能的影响.实验结果表明,涂布液中加入Pb²⁺或Zn²⁺后,PTG材料的热显影灰雾和相对感光度均明显降低,并且随着离子加入量的增加,下降程度更加显著.另外,含有Pb²⁺或Zn²⁺的PTG材料在经过不同时间的老化后,与未老化PTG材料相比,其热显影灰雾缓慢增加,相对感光度也略有上升.     

A rhodamine-based fluorescent and colorimetric chemodosimeter for the rapid detection of Hg2+ ions in aqueous media

A rhodamine-based fluorescent and colorimetric chemodosimeter for the rapid detection of Hg2+ ions in aqueous media was developed. The system, which utilizes an irreversible Hg2+-promoted oxadiazole forming reaction, responds instantaneously at room temperature in a 1:1 stoichiometric manner to the amount of Hg2+. The selectivity of this system for Hg2+ over other metal ions is remarkably high, and its sensitivity is below 2 ppb in aqueous solutions.     

Anthracylmethyl Benzoazacrown Ether as Selective Fluorescence Sensors for Zn^2＋

A new benzoazacrown ether fluorescence sensor was synthesized with 9-anthrylmethyl chloride and benzoaza-15-crown-5 in CH3CN, which particularly shows a strong affinity for Zn^2 .Its fluorescence quantum yield increase more than one order of magnitude and a red shift could be noticed when passing from the apolar to the polar solvent.     

Ratiometric chemosensor for fluorescent determination of Zn2+ in aqueous ethanol

A new ratiometric and selective fluorescent chemosensor (1) for quantification of zinc ions in aqueous ethanol has been synthesized and investigated in this work. In an environmentally friendly media of 30% (v/v) water/ethanol and 10 mM Tris-HCl neutral buffer (pH 7.03), 1 displayed selective Zn²⁺ ratiometric fluorescence response, with a dynamic working range of 1.0-8.0 μM and a detection limit of 0.5 μM Zn²⁺. The determination of Zn²⁺ in synthesized water sample was also successful.     

3-(2-Pyridyl)-2-pyrazoline derivatives: novel fluorescent probes for Zn ion

Spectroscopic studies revealed that 3-(2-pyridyl)-2-pyrazoline derivatives have rather strong affinity toward divalent transition metal ions, but have almost no interaction with alkali and alkaline-earth metal ions. In the case of the 5-(4-cyanophenyl) derivative, enhancement of the fluorescence intensity was observed upon addition of the Zn²⁺ ion, while most of other transition metal ions caused complete quenching.     

Novel naphthalene-based fluorescent chemosensors for Cu2+ and Fe3+ in aqueous media

Three novel compounds bearing 2,7-dihydroxylnaphthalene capable of detecting Cu²⁺ or Fe³⁺ have been synthesised based on photoinduced electron transfer. The ability of these compounds for complex transition metal ions has been studied, and complex stoichiometry for Cu²⁺ and Fe³⁺ complex has been determined in the Tris–HCl (0.01 M DMSO/H₂O (v/v) 1:1, buffer, pH 7.4) solution system by fluorescence titration experiments. These chemosensors form a 1:1 complex with Cu²⁺ or Fe³⁺ and show a fluorescent quenching with a binding constant of (4.46 ± 0.29) × 10³ and (8.04 ± 0.26) × 10⁴, respectively.     

Oligonucleotide‐mediated aggregation of a cationic conjugated polymer for fluorescent detection of mercury ions in an aqueous medium

A cationically charged conjugated polymer ( P2 ) functionalized with quaternary ammonium salt was newly synthesized via Suzuki cross‐coupling polymerization. The functionalized P2 features different fluorescence colors according to its phases (blue emission in solution and green emission as asolid) which is caused by intramolecular and intermolecular exciton migration, respectively. The use of P2 as a novel fluorescent sensing platform is demonstrated for mercury ion detection. The detection of mercury ions is accomplished in two steps: (1) the cationic, blue‐emitting P2 absorbs an anionic oligonucleotide, polythymidine ( PT ) via electrostatic interaction to form a complex with green emission due to aggregation between the two species; (2) the addition of mercury ions to the complex produces a new complex of PT ‐Hg²⁺ via more favorable specific interaction, resulting in the isolation of P2 and the consequent recovery of blue fluorescence of P2 . It suggests that this detection system has high selectivity and sensitivity down to the ～10^?7 M level, even in mixtures of metal ions. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2393–2400