A europium-based metal-organic framework material, a preparation method and application thereof

Abstract

This invention discloses a europium-based metal-organic framework material, its preparation method, and its applications. The invention uses 2,2'-bipyridine-4,4'-dicarboxylic acid (2,4'-H₂BPDC) and furanyl dicarboxylic acid (H₂FDA) as ligands, with europium ions as the metal center, and synthesizes the europium-based metal-organic framework material via a solvothermal method. The material prepared by this invention has a simple preparation method, high purity, and good activity. After filtration and drying at room temperature, it can be used for detection without the need for material pretreatment, making it easy to implement. The europium-based metal-organic framework material of this invention has great potential application value in the preparation of fluorescent probes and the detection of Neo.

Description

Technical Field

[0001] This invention relates to a europium-based metal-organic framework material, its preparation method and application, belonging to the field of porous molecular crystal materials technology. Background Technology

[0002] Neopterin (2-amino-4-hydroxy-6-(D-erythrosyl-1',2',3'-trihydroxyphenyl)-pteridine) is a pteridine compound primarily produced by activated macrophages from guanosine triphosphate (GTP) in a reaction catalyzed by guanosine triphosphate cyclase I. It is an important and sensitive biomarker for cellular immune responses. Studies have shown that the difference in serum and urinary pterin excretion levels between healthy individuals and patients with inflammation is primarily caused by neopterin. Inflammation is involved in almost all normal physiological and psychological / mental processes in the human body. Besides its role in regulating peripheral immunity, cardiovascular function, metabolism, and other activities, it is also crucial for normal central nervous system activity. On the other hand, excessive inflammatory activity can be associated with a range of physical illnesses, including not only infectious and inflammatory diseases but also metabolic, cardiovascular, skeletal, and nutritional disorders. Similarly, in terms of mental and cognitive impairment, abnormal inflammatory states are known to occur in various mental syndromes and adversely affect memory, neuroplasticity, and neurogenesis. Therefore, measuring the level of neopterin in the body can estimate the inflammatory status and prognosis, help monitor disease progression, and contribute to clinical diagnosis and treatment.

[0003] While several chemical and biological research techniques have been developed for the rapid and accurate detection of trace amounts of neopterin, such as high-performance liquid chromatography (HPLC), radioimmunoassay (RIA), and enzyme-linked immunosorbent assay (ELISA), these methods are expensive and labor-intensive, and their effectiveness and quality are often affected by adverse factors. Furthermore, they require skilled operators and time-consuming and complex pretreatment procedures, significantly increasing detection costs and efficiency. Therefore, there is an urgent need to develop a novel, rapid, and on-site detection method to meet the current demand for rapid on-site monitoring of antibiotics. Fluorescent sensors offer advantages such as ease of operation, short response time, high sensitivity, high selectivity, strong anti-interference capabilities, and cost-effectiveness. In the application of fluorescent sensors, molecular recognition and quantitative analysis are crucial challenges. Therefore, developing and implementing methods for the efficient and rapid detection of the inflammatory marker neopterin is essential.

[0004] Metal-organic framework (MOF) fluorescent sensing materials are considered one of the most promising detection methods and are widely used to identify anions, cations, small organic molecules, gases, and markers, etc. (See Jinni Zhao et al., Chemical Communications, 59(36), 5435-5438). Therefore, MOF fluorescent sensing materials can be developed to identify novel pterin. Compared with traditional analytical techniques, MOF-based fluorescent sensing detection has the advantages of high precision, high sensitivity, small size, short response time, and good adaptability. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned problems and obtain a europium-based metal-organic framework material with chemical stability and fluorescence response to the inflammatory marker neopterin. This invention discloses a europium-based metal-organic framework material with neopterin recognition, its preparation method, and its application in fluorescently recognizing the inflammatory marker neopterin.

[0006] The technical solution for achieving the present invention is as follows: a europium-based metal-organic framework material with the chemical formula: {[Eu(BPDC)(μ3-OH)(H2O)]·H2O·DMF} n In the formula: n is a natural number from 1 to positive infinity; BPDC 2- It is obtained by deprotonating 2,2'-bipyridine-4,4'-dicarboxylic acid.

[0007] Specifically, the europium-based metal-organic framework material belongs to the triclinic crystal system, with space group P-1 and cell parameters as follows: α=106.136(7)°, β=95.362(6)°, γ=99.319(6)°;

[0008] Specifically, the smallest asymmetric unit of the europium-based metal-organic framework material contains one crystallographically independent europium ion and one BPDC. 2- The ligand consists of a μ3-OH ion and a bound water molecule; europium ions form a one-dimensional chain structure through the μ3-OH ions, and the one-dimensional chain structure is further connected into a three-dimensional planar structure by the organic ligand 2,4'-H2BPDC.

[0009] A method for preparing europium-based metal-organic framework materials includes the following synthesis steps: weighing 24.42 mg of organic ligand 2,4'-H2BPDC and 15.61 mg of H2FDA ligand and placing them into a sealed hydrothermal reactor; then adding an alkaline solution for acid-base neutralization; then adding an aqueous europium salt solution; finally adding N,N-dimethylformamide solvent and water; under hydrothermal conditions, heating to 60-180℃ and reacting at a constant temperature; after the reaction is complete, cooling to room temperature and removing the red solid; washing to obtain red blocky crystals.

[0010] Specifically, the alkaline solution has a concentration of 0.01%. -1 A mol / L aqueous solution of NaOH.

[0011] Specifically, the europium salt aqueous solution has a concentration of 0.01%. -1 A mol / L aqueous solution of Eu(NO3)3·6H2O.

[0012] Specifically, during the hydrothermal reaction, the temperature is raised to 130°C in an electric heating drying oven for two hours and kept constant for three days, and then cooled to room temperature for one day.

[0013] Specifically, the red solid was washed multiple times with the original solution and N,N-dimethylformamide to obtain red blocky crystals.

[0014] This invention provides the application of europium-based metal-organic framework materials in fluorescence detection.

[0015] More specifically, the present invention provides the application of europium-based metal-organic framework materials as fluorescent probes for recognizing the inflammatory marker neopterin.

[0016] The beneficial effects of this invention are that the material prepared by this invention is simple to prepare, has high purity and good activity, and can be used for detection after being dried at room temperature without the need for material pretreatment, making it easy to implement. At the same time, it has the advantages of being rapid, simple, selective, sensitive and low detection limit in the detection of antibiotics (especially neopterin). Therefore, it has great potential application value in the preparation of fluorescent probes and the detection of inflammatory markers. Attached Figure Description

[0017] Figure 1 This is a coordination environment diagram of the europium-based metal-organic framework material of the present invention;

[0018] Figure 2 This is a one-dimensional chain structure diagram of the europium-based metal-organic framework material of the present invention;

[0019] Figure 3 This is a three-dimensional structural diagram of the europium-based metal-organic framework material of the present invention;

[0020] Figure 4The fluorescence spectra of europium-based metal-organic framework materials against Neo and solutions of different interfering substances are shown in the embodiments of the present invention.

[0021] Figure 5 The images show the fluorescence spectra of europium-based metal-organic framework materials in Neo solutions of different concentrations in embodiments of the present invention.

[0022] Figure 6 The fluorescence intensity I of the europium-based metal-organic framework material in the Neo concentration example is... 443 / I 614 Stern-Volmer linear plot ([Neo]≤32μM). Detailed Implementation

[0023] The present invention will be further explained in detail below with reference to the embodiments.

[0024] This embodiment provides a europium-based metal-organic framework material, the chemical formula of which is: {[Eu(BPDC)(μ3-OH)(H2O)]·H2O·DMF} n In the formula: n is a natural number from 1 to positive infinity; BPDC 2- It is obtained by deprotonating 2,2'-bipyridine-4,4'-dicarboxylic acid.

[0025] The europium-based metal-organic framework material belongs to the triclinic crystal system, space group P-1, and its unit cell parameters are: α=106.136(7)°, β=95.362(6)°, γ=99.319(6)°;

[0026] The smallest asymmetric unit of the europium-based metal-organic framework material contains one crystallographically independent europium ion and one BPDC. 2- The ligand consists of a μ3-OH group and a bound water molecule. The europium ion is separated from the carboxylate ion by the (μ3-OH) group. 1- Ions form a one-dimensional chain structure, which is further connected into a three-dimensional planar structure by ligand 2,4'-H2BPDC.

[0027] The preparation method of europium-based metal-organic framework material in this embodiment includes the following synthesis steps: 24.42 mg of organic ligand 2,4'-H2BPDC and 15.61 mg of H2FDA ligand are weighed and placed in a sealed hydrothermal reactor; then 8 mg of NaOH is dissolved in 2 mL of deionized water and added for acid-base neutralization; next, 89.20 mg of Eu(NO3)3·6H2O is dissolved in 2 mL of deionized water and added; finally, 1 mL of N,N-dimethylformamide solvent and 9 mL of deionized water are added; the mixture is placed in an electrically heated drying oven, heated to 130°C for two hours and held at that temperature for three days, then cooled to room temperature for one day, and the red solid is removed; after removing the solid, it is washed multiple times with the original solution and N,N-dimethylformamide to obtain red blocky crystals. The yield is calculated to be 81% based on the amount of europium.

[0028] The properties of the europium-based metal-organic framework material prepared in this embodiment are characterized as follows:

[0029] (1) Structural determination of europium-based metal-organic framework materials:

[0030] Crystal structure determination was performed using a Supernova X-ray single-crystal diffractometer, employing Mo-Kα rays monochromated with graphite. As the incident radiation source, with Diffraction points were collected using a scanning method, and the unit cell parameters were obtained after least squares correction. The crystal structure was then derived from the difference Fourier electron density map using the SHELXL-97 direct method, and corrected for Lorentz and polarization effects. All H atoms were synthesized using the difference Fourier method and their positions were calculated from ideal positions. The exact number of solvent molecules was determined by thermogravimetric and elemental analysis. Detailed crystal measurement data are shown in Table 1.

[0031] Table 1 Crystallographic data of europium-based metal-organic framework materials

[0032]

[0033] (2) Characterization of fluorescence properties of europium-based metal-organic framework materials

[0034] Figure 1 This is a coordination environment diagram of the europium-based metal-organic framework material of the present invention; Figure 1 The smallest asymmetric unit of europium-based metal-organic frameworks contains a crystallographically independent europium ion, and the smallest asymmetric unit of europium-based metal-organic frameworks contains a crystallographically independent structure: the europium ion and six ions from BPDC. 2- The O atom of the ligand, one O atom from the coordinated H2O and one O atom from the μ3-OH ion form an 8-coordinate structure.

[0035] Figure 2 This is a unit cell diagram of the europium-based metal-organic framework material of the present invention; the smallest asymmetric unit of the europium-based metal-organic framework material in the diagram contains one crystallographically independent europium ion, one 2,4'-H2BPDC ligand, one coordinated water molecule and one μ3-OH ion.

[0036] Figure 3 The diagram shown is a three-dimensional structural diagram of the europium-based metal-organic framework material of this embodiment, where n is a natural number from 1 to positive infinity, indicating that the material is a polymer. From Figure 3 It can be seen that the smallest asymmetric unit of europium-based metal-organic framework materials has a crystallographically independent one-dimensional chain structure, which is further connected into a three-dimensional planar structure by ligand 2,4'-H2BPDC.

[0037] Figure 4 For the detection of Neo and different interfering substances by europium-based metal-organic framework materials in this embodiment, from Figure 4 It can be seen from this that the addition of Neo affects the fluorescence intensity (I) of the material. 614 It has a significant quenching effect.

[0038] Figure 5 The images show the fluorescence spectra of europium-based metal-organic framework materials in Neo solutions of different concentrations, as described in this embodiment of the invention. Figure 5 As can be seen from this, when Neo is gradually added to an aqueous solution of europium-based metal-organic framework materials, its fluorescence intensity (IL) decreases. 614 The fluorescence response of the europium-based metal-organic framework material to Neo decreased significantly with increasing Neo content, indicating that the material has a good fluorescence response to Neo and can be used as a Neo fluorescent probe.

[0039] Figure 6 The fluorescence intensity I of the europium-based metal-organic framework material in the Neo concentration example is... 443 / I 614 The Stern-Volmer linear plot ([Neo]≤32μM) shows the linear equation y=0.0225x+0.0544. From... Figure 6 It can be seen that at low Neo concentrations (0-32 μM), the fluorescence intensity I of europium-based metal-organic framework materials is... 443 / I 614 The fluorescence intensity of europium-based metal-organic framework materials (I) showed a linear relationship with Neo concentration, with a detection limit of 13.52 nM. At higher Neo concentrations, the fluorescence intensity I... 443 / I 614 The relationship with Neo concentration is no longer linear.

[0040] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A europium-based metal-organic framework material, characterized in that: The chemical formula of the europium-based metal-organic framework material is: {[Eu(μ3-OH)(BPDC)(H2O)]•H2O•DMF} n ; wherein: n is a natural number from 1 to positive infinity; BPDC 2- is the deprotonated form of 2,2'-bipyridine-4,4'-dicarboxylic acid; The europium-based metal-organic framework material belongs to the triclinic crystal system, space group P-1, and has the following cell parameters: a = 4.5269(3)Å, b = 12.5366(10)Å, c = 15.7023(13)Å, α = 106.136(7)°, β = 95.362(6)°, γ = 99.319(6)°.

2. The europium-based metal-organic framework material according to claim 1, characterized in that: The smallest asymmetric unit of the europium-based metal-organic framework material contains 1 crystallographically independent europium ion, 1 BPDC 2- ligands, one μ3-OH ion and 1 bound water molecule; the europium ions form one-dimensional chain structures via the μ3-OH ions, which are further connected into a three-dimensional planar structure by the organic ligands 2,4'-H2BPDC.

3. The application of europium-based metal-organic framework materials as described in claim 1 or 2 in fluorescence detection.

4. The application of europium-based metal-organic framework materials as described in claim 1 or 2 as fluorescent probes for recognizing the inflammatory marker neopterin.

5. The method for preparing europium-based metal-organic framework materials as described in any one of claims 1 or 2, characterized in that, Weigh 24.42 mg of the organic ligand 2,4'-H2BPDC and 15.61 mg of the 2,5-furandicarboxylic acid ligand and place them in a sealed hydrothermal reactor. Then, add an alkaline solution for acid-base neutralization. Next, add europium salt aqueous solution. Finally, add N,N-dimethylformamide solvent and water. Under hydrothermal conditions, raise the temperature to 60-180℃ and keep the temperature constant. After the reaction is complete, cool to room temperature and take out the red solid. Wash to obtain red blocky crystals.

6. The method for preparing a europium-based metal-organic framework material according to claim 5, characterized in that, The alkaline solution has a concentration of 0.01%. -1 A mol / L aqueous solution of NaOH.

7. The method for preparing a europium-based metal-organic framework material according to claim 5, characterized in that, The europium salt aqueous solution has a concentration of 0.01%. -1 A mol / L aqueous solution of Eu(NO3)3•6H2O.

8. The method for preparing a europium-based metal-organic framework material according to claim 5, characterized in that, During the hydrothermal reaction, the temperature is raised to 130°C in an electric heating drying oven for two hours and kept constant for three days, and then cooled to room temperature for one day.

9. The method for preparing a europium-based metal-organic framework material according to claim 5, characterized in that, The red solid was washed repeatedly with N,N-dimethylformamide to obtain red blocky crystals.

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