阅读说明：本技术 一种双配体铕基金属有机框架材料及其制备方法和应用 (Double-ligand europium-based metal organic framework material and preparation method and application thereof ) 是由 杨秀培 胥静 张倩 刘宇航 王亚 于 2020-08-06 设计创作，主要内容包括：本发明提供了一种双配体铕基金属有机框架材料及其制备方法和应用,其制备方法包括以下步骤：将硝酸铕六水合物、1,10-邻菲罗啉和吡啶-3,5-二羧酸加入去离子水中,然后加入2mol/L的氢氧化钠溶液呈碱性,再在80～90℃温度下恒温反应70～75h,冷却至室温,最后依次经洗涤、超声和干燥,得双配体铕基金属有机框架材料。本发明还包括采用上述制备方法制得的双配体铕基金属有机框架材料及其在铜离子检测中的应用。本发明制得了双配体铕基金属有机框架材料,并将其应用于铜离子的荧光检测,有效解决了现有技术中检测设备占用空间大、操作复杂和成本较高等问题。(The invention provides a dual-ligand europium-based metal organic framework material and a preparation method and application thereof, wherein the preparation method comprises the following steps: adding europium nitrate hexahydrate, 1, 10-phenanthroline and pyridine-3, 5-dicarboxylic acid into deionized water, then adding 2mol/L sodium hydroxide solution to be alkaline, reacting at the constant temperature of 80-90 ℃ for 70-75 h, cooling to room temperature, and finally washing, ultrasonically treating and drying in sequence to obtain the dual-ligand europium-based metal organic framework material. The invention also discloses the dual-ligand europium-based metal organic framework material prepared by the preparation method and application thereof in copper ion detection. The invention prepares the dual-ligand europium-based metal organic framework material, and applies the dual-ligand europium-based metal organic framework material to the fluorescence detection of copper ions, thereby effectively solving the problems of large occupied space, complex operation, higher cost and the like of detection equipment in the prior art.)

1. A preparation method of a dual-ligand europium-based metal organic framework material is characterized by comprising the following steps:

adding europium nitrate hexahydrate, 1, 10-phenanthroline and pyridine-3, 5-dicarboxylic acid into deionized water, then adding 2mol/L sodium hydroxide solution to be alkaline, reacting at the constant temperature of 80-90 ℃ for 70-75 h, cooling to room temperature, and finally washing, ultrasonically treating and drying in sequence to obtain the dual-ligand europium-based metal organic framework material;

wherein the mass ratio of the europium nitrate hexahydrate to the 1, 10-phenanthroline to the pyridine-3, 5-dicarboxylic acid is 130-135: 32-38: 30-35, and the mass volume ratio of the 1, 10-phenanthroline to the deionized water is 32-38: 10 g/L.

2. The method of claim 1, wherein the mass ratio of europium nitrate hexahydrate, 1, 10-phenanthroline, and pyridine-3, 5-dicarboxylic acid is 133.8:36: 33.4.

3. The method of claim 1, wherein the mass-to-volume ratio of 1, 10-phenanthroline to deionized water is 36:10 g/L.

4. The method for preparing a bidentate europium-based metal organic framework material as claimed in claim 1, wherein the cooling rate is 1-2 ℃/h during cooling.

5. The dual-ligand europium-based metal organic framework material prepared by the method for preparing the dual-ligand europium-based metal organic framework material as claimed in any one of claims 1 to 4.

6. Use of the dual-ligand europium-based metal-organic framework material of claim 5 in the detection of copper ions.

7. The use of a dual ligand europium-based metal organic framework material according to claim 6, wherein the detection method comprises the following steps:

(1) dissolving the dual-ligand europium-based metal organic framework material in an organic solvent, performing ultrasonic treatment for 20-40 min, standing for 1-3 min, adding a copper ion solution, uniformly mixing, using fluorescence of 310nm as excitation wavelength at room temperature, respectively testing fluorescence spectrograms of copper ions with different concentrations, and calculating to obtain a standard curve;

(2) and (3) filtering the sample to be detected, measuring the blank fluorescence intensity, then respectively adding 5 mu M, 10 mu M and 15 mu M copper ion solutions to test the fluorescence intensity, and calculating the concentration of the copper ions in the sample to be detected by combining the standard curve obtained in the step (1).

8. The use of the dual-ligand europium-based metal organic framework material in the detection of copper ions according to claim 7, wherein in step (1), the concentration of the dual-ligand europium-based metal organic framework material after being dissolved in an organic solvent is 1-2 g/L.

9. The use of a dual ligand europium-based metal organic framework material according to claim 7, wherein the organic solvent is dichloromethane, acetonitrile, toluene or tetrahydrofuran.

Technical Field

The invention belongs to the technical field of heavy metal detection, and particularly relates to a dual-ligand europium-based metal organic framework material and a preparation method and application thereof.

Background

Heavy goldThe research of the belonging ions is always a hotspot and is also a difficult problem. Sensing and detection of pollutants such as heavy metal ions and organic small molecules play an important role in environmental science, life science, medicine, agriculture and industry. At present, for Fe²⁺、Fe³⁺、Cd²⁺、Hg²⁺、Cr³⁺And Cu²⁺、Al³⁺The detection of such metals is of considerable interest because they exceed certain concentrations which can have a detrimental effect on human health.

Copper is one of the essential inorganic metal elements for human body, and the element content is listed as the third. Copper element can be accumulated in a plurality of organs, the unbalance of copper can be harmful to human health, and excessive intake of Cu²⁺Can be used for treating liver cirrhosis, renal insufficiency, etc. Furthermore, copper is a common contaminant because it is widely used in agricultural, industrial and drinking water systems, with a maximum content of 2ppm (31.5 μ M) of copper in drinking water being recommended by the WHO (world health organization). Although many chemical sensors have been developed to detect Cu²⁺But for Cu²⁺The optimization of the detection method of (2) remains a challenge. Therefore, a simple method is applied to Cu²⁺The selective and efficient detection is of great significance. Traditional copper detection techniques are limited to Inductively Coupled Plasma (ICP), atomic absorption spectroscopy, and atomic emission spectroscopy; these methods require a large laboratory space to accommodate the instruments, and furthermore, the procedures for inspecting the instruments are complicated and the routine maintenance costs are high.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a dual-ligand europium-based metal organic framework material and a preparation method and application thereof, the dual-ligand europium-based metal organic framework material is prepared and applied to the fluorescence detection of copper ions, and the problems of large occupied space, complex operation, high cost and the like of detection equipment in the prior art are effectively solved.

In order to achieve the purpose, the technical scheme adopted by the invention for solving the technical problems is as follows: the preparation method of the double-ligand europium-based metal organic framework material comprises the following steps:

adding europium nitrate hexahydrate, 1, 10-phenanthroline and pyridine-3, 5-dicarboxylic acid into deionized water, then adding 2mol/L sodium hydroxide solution to be alkaline, reacting at the constant temperature of 80-90 ℃ for 70-75 h, cooling to room temperature, and finally washing, ultrasonically treating and drying in sequence to obtain the dual-ligand europium-based metal organic framework material;

wherein the mass ratio of the europium nitrate hexahydrate to the 1, 10-phenanthroline to the pyridine-3, 5-dicarboxylic acid is 130-135: 32-38: 30-35, and the mass volume ratio of the 1, 10-phenanthroline to the deionized water is 32-38: 10 g/L.

Further, the mass ratio of europium nitrate hexahydrate, 1, 10-phenanthroline and pyridine-3, 5-dicarboxylic acid is 133.8:36: 33.4.

Further, the mass-volume ratio of the 1, 10-phenanthroline to the deionized water is 36:10 g/L.

Further, the cooling rate is 1-2 ℃/h during cooling.

Further, washing was performed with pure water and absolute ethanol.

The dual-ligand europium-based metal organic framework material is prepared by the preparation method of the dual-ligand europium-based metal organic framework material.

The application of the double-ligand europium-based metal organic framework material in copper ion detection.

Further, the detection method comprises the following steps:

(1) dissolving the dual-ligand europium-based metal organic framework material in an organic solvent, performing ultrasonic treatment for 20-40 min, standing for 1-3 min, adding a copper ion solution, uniformly mixing, using fluorescence of 310nm as excitation wavelength at room temperature, respectively testing fluorescence spectrograms of copper ions with different concentrations, and calculating to obtain a standard curve;

(2) and (3) filtering the sample to be detected, measuring the blank fluorescence intensity, then respectively adding 5 mu M, 10 mu M and 15 mu M copper ion solutions to test the fluorescence intensity, and calculating the concentration of the copper ions in the sample to be detected by combining the standard curve obtained in the step (1).

Further, in the step (1), the concentration of the dual-ligand europium-based metal organic framework material after being dissolved in an organic solvent is 1-2 g/L.

Further, the organic solvent is dichloromethane, acetonitrile, toluene or tetrahydrofuran.

In summary, the invention has the following advantages:

1. the double-ligand europium-based metal organic framework material formed by lanthanide is prepared by a hydrothermal method, has unique optical characteristics including high color purity, larger Stokes shift value, macroscopic luminescent color and relatively longer fluorescence life, is applied to fluorescence detection of copper ions, is simple to operate, occupies small area, reduces detection cost, and effectively solves the problems of large occupied space, complex operation, higher cost and the like of detection equipment in the prior art.

2. The ligand is cheap, economical and practical; the method for synthesis is simple and easy to operate, and the synthesis conditions are easy to control; the obtained dual-ligand europium-based metal organic framework material (Eu-MOF) has good stability in an organic solvent, good thermal stability, stability in a pH value range of 2-12 and wide application scenes.

Drawings

FIG. 1 is a TEM image of a dual-ligand europium-based metal-organic framework material;

FIG. 2 is an EDS-Mapping diagram of a dual-ligand europium-based metal-organic framework material;

FIG. 3 is a structural diagram (A) of Eu-MOF in different directions and a two-dimensional structural diagram (B) of Eu-MOF;

FIG. 4 is a simulated XRD spectrum of single crystal data and an XRD spectrum of Eu-MOF;

FIG. 5 is a FT-IR diagram of Eu-MOF and ligands 1, 10-phenanthroline and 3, 5-pyridinedicarboxylic acid;

FIG. 6 is pH stability and solvent stability of Eu-MOF at room temperature;

FIG. 7 is a thermogravimetric plot of Eu-MOF;

FIG. 8 is a graph of UV-VIS spectra, solid excitation and emission spectra and fluorescence emission spectra in aqueous solution at room temperature for Eu-MOF;

FIG. 9 shows fluorescence emission spectra of Eu-MOF dispersed in various organic solvents (3mL acetonitrile, 3mg Eu-MOF) and fluorescence intensity value at 613 nm;

FIG. 10 is a Eu-MOF fluorescence emission spectrum in the presence of acetone in an organic solvent and an emission intensity at 613 nm;

FIG. 11 shows the luminescence spectrum (1g/L) of Eu-MOF dispersed in acetonitrile-acetone solution at different volume contents of acetone and the I of Eu-MOF at 613nm with increasing volume contents of acetone in acetonitrile-acetone solution₀I-1 strength;

FIG. 12 shows Cu in 0-30 min²⁺Graph (A) of the intensity of Eu-MOF at 613nm as a function of time when present; cu of different concentrations²⁺Emission spectrum (B) of Eu-MOF when present; i of Eu-MOF at 613nm₀I-1 (C); fluorescence quenching I₀I-1 and Cu²⁺The concentration is in a linear relation (D);

FIG. 13 shows the luminescence intensity of Eu-MOF in different metal ions (A) and the luminescence intensity of mixed metal cations (λ)_ex＝310nm)(B)。

Detailed Description