A zinc-based metal-organic framework material with fluorescent recognition of anthrax bacillus biomarker and preparation method thereof

Abstract

A zinc-based metal-organic framework material with fluorescent recognition of anthrax bacillus biomarker and a preparation method thereof, wherein 2,6-naphthalene dicarboxylic acid and 1.2-di(4-pyridyl)ethylene are used as ligands, zinc ions are used as metal centers, and the zinc-based metal-organic framework material is synthesized by a solvothermal method. The material preparation method prepared by the present invention is simple, high in purity, and good in activity. After drying at room temperature, the material can be used for detection without pre-treatment of the material, and is easy to implement. At the same time, the material has the advantages of being fast, simple, selective, highly sensitive, and having a low detection limit in detecting 2,6-pyridine dicarboxylic acid (DPA), so the material has great potential application value in the preparation of fluorescent probe solid-state devices and the detection of DPA.

Description

Technical Field

[0001] The invention relates to a zinc-based metal-organic framework material with fluorescence recognition of anthrax bacillus biomarkers and a preparation method thereof, belonging to the technical field of porous molecular crystal materials. Background Art

[0002] Anthrax is a serious infectious disease caused by Bacillus anthracis. It can infect humans through the respiratory tract, digestive tract and skin contact. Skin infection is the most common. It has acute destructive effects on the skin, lungs and intestines of animals and humans, and seriously threatens human health. Since anthrax spores have extremely strong resistance in the environment, they have always been listed as the number one biological warfare agent. 2,6-pyridinedicarboxylic acid (DPA) is a major component of the shell layer of Bacillus anthracis, accounting for about 5-15% of the mass of dry Bacillus anthracis. Therefore, Bacillus anthracis can be indirectly detected by quantitatively detecting the content of DPA.

[0003] Although some chemical and biological research techniques have been developed to detect trace amounts of DPA instantly and accurately, such as polymerase chain reaction immunoassay, surface-enhanced Raman spectroscopy, and photoluminescence, most of these methods take a long time and require relatively expensive instruments and reagents. Fluorescent sensors have the advantages of simple operation, short time, high sensitivity, high selectivity, and high cost-effectiveness. In the application of fluorescent sensors, molecular recognition and quantitative analysis are crucial challenges. Therefore, it is necessary to develop and develop methods that can efficiently and quickly detect anthrax bacteria.

[0004] Metal-organic framework fluorescent sensing materials are considered to be one of the most promising detection methods and are widely used to identify harmful substances such as anions, cations, and small molecule organic matter. See Qiuzheng Du et al. Coordination Chemistry Reviews, 2020, 404, 213113. Therefore, metal-organic framework fluorescent sensing materials can be developed to identify 2,6-pyridinedicarboxylic acid (DPA). Compared with traditional analytical techniques, fluorescence sensing detection based on metal-organic frameworks has the characteristics of high precision, high sensitivity, small size, short response time, and good adaptability. In recent years, metal-organic frameworks have also been used to detect anthrax bacteria, but most of them are based on ratio-type rare earth fluorescent probes to detect anthrax bacteria. See, Publication No. CN106959290A. A ratio-type rare earth fluorescent probe Tb / DPA@SiO2-Eu / GMP is disclosed, which can visualize the detection of DPA molecules. Summary of the invention

[0005] The purpose of the present invention is to solve the problem of detecting anthrax bacillus using metal-organic framework fluorescent sensing materials, and to propose a zinc-based metal-organic framework material with fluorescent recognition of anthrax bacillus biomarkers and a preparation method.

[0006] The technical scheme for implementing the present invention is as follows: a zinc-based metal-organic framework material with anthrax bacillus biomarker recognition, the chemical formula of which is: {[Zn2(2,6-NBC)2(vlpy)·Zn(2,6-NBC)(vlpy) 0.5 ]·0.8(2,6-H2NBC)·H2O} n ; Where: n is a natural number from 1 to positive infinity; (2,6-NBC) 2- It is obtained by deprotonation of 2,6-naphthalene dicarboxylic acid; vlpy is 1,2-di(4-pyridyl)ethylene.

[0007] The zinc-based metal-organic framework material belongs to the triclinic system, the space group is P-1, and the unit cell parameters are: α=97.934(2)°; β=95.154(2)°; γ=92.056(2)°.

[0008] The smallest asymmetric unit of the zinc-based metal-organic framework material contains three crystallographically independent zinc ions, three 2,6-NBC ligands, 1.5 vlpy ligands and one free water molecule and a free 2,6-NBC molecule; a Zn2(COO)4 secondary structural unit is formed between the zinc ions, and the secondary structural unit is further connected into a two-dimensional planar structure through 2,6-NBC, and the two-dimensional planar structure is further connected into a three-dimensional layered columnar structure through vlpy.

[0009] The smallest asymmetric unit of the zinc-based metal-organic framework material has two crystallographically independent structures: Zn2(2,6-NBC)2(vlpy) and Zn(2,6-NBC)(vlpy) 0.5 ; These two structures intersect with each other, further forming an interpenetrating three-dimensional structure in space.

[0010] The zinc-based metal-organic framework material can stably exist in water, methanol, ethanol, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, acetonitrile and 1,4-dioxane solvents.

[0011] The zinc-based metal-organic framework material can detect DPA through fluorescence changes; the fluorescence of the zinc-based metal-organic framework material increases with the increase of DPA concentration, and at low concentrations (0-0.3mmol·L -1The fluorescence curve of DPA ethanol solution was linearly related to the DPA concentration, and the detection limit was 128 nmol·L -1 .

[0012] The invention discloses a method for preparing a zinc-based metal-organic framework material with fluorescent recognition of anthrax bacillus biomarker. The method is as follows: the method uses 2,6-naphthalene dicarboxylic acid and 1.2-di(4-pyridyl)ethylene as ligands and zinc ions as metal centers to synthesize the zinc-based metal-organic framework material by a solvent thermal method.

[0013] The organic ligands 2,6-NBC and vlpy are dissolved in N,N-dimethylformamide solvent, and ZnCl2 is dissolved in water respectively. The two solutions are mixed and put into a closed hydrothermal reactor. The mixture is reacted at a constant temperature of 90°C for 3 days, and then cooled to room temperature after 1 day. A light yellow solid is taken out. The solid is washed with N,N-dimethylformamide for multiple times to obtain a light yellow block crystal.

[0014] The concentration of the N,N-dimethylformamide solution of the 2,6-NBC is 0.01-1 mol / L; the concentration of the N,N-dimethylformamide solution of the vlpy is 0.01-1 mol / L; the concentration of the ZnCl2 aqueous solution is 0.01-1 mol / L.

[0015] The beneficial effects of the present invention are that the zinc-based metal-organic framework material prepared by the present invention is simple, high in purity, good in activity, can be used for detection after drying at room temperature, does not require pretreatment of the material, and is easy to implement; and has the advantages of rapidity, simplicity, good selectivity, high sensitivity, and low detection limit in detecting antibiotics. Therefore, it has great potential application value in the preparation of fluorescent probe solid-state devices and the detection of anthrax bacillus biomarkers. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a coordination environment diagram of the zinc-based metal-organic framework material of the present invention;

[0017] Figure 2 is a unit cell diagram of the zinc-based metal-organic framework material of the present invention;

[0018] Figure 3 is a three-dimensional structural diagram of the zinc-based metal-organic framework material of the present invention;

[0019] Figure 4 The fluorescence spectra of the zinc-based metal-organic framework material of the present invention in different solvents;

[0020] Figure 5 It is the fluorescence spectrum of the zinc-based metal organic framework material in the embodiment of the present invention to DPA and different interference solutions;

[0021] Figure 6 The fluorescence spectra of the zinc-based metal-organic framework material in the embodiment of the present invention to DPA solutions of different concentrations;

[0022] Figure 7 is a curve diagram of the DPA concentration of the present invention versus the fluorescence intensity I0 / I of the zinc-based metal-organic framework material in the embodiment;

[0023] Figure 8 is a Stern-Volmer linear plot of DPA concentration versus the fluorescence intensity I0 / I of the zinc-based metal-organic framework material in the embodiment ([DPA]≤0.3mmol / L);

[0024] Fig. 9 It is a flowchart of a method for preparing a zinc-based metal-organic framework material with fluorescent recognition of anthrax bacillus biomarkers according to the present invention. DETAILED DESCRIPTION

[0025] This embodiment provides a zinc-based metal-organic framework material with anthrax Bacillus biomarker recognition, and the chemical formula of the zinc-based metal-organic framework material is: {[Zn2(2,6-NBC)2(vlpy)·Zn(2,6-NBC)(vlpy) 0.5 ]·0.8(2,6-H2NBC)·H2O} n ;

[0026] Where: n is a natural number from 1 to positive infinity; (2,6-NBC) 2- It is obtained by deprotonation of 2,6-naphthalene dicarboxylic acid; vlpy is 1,2-di(4-pyridyl)ethylene.

[0027] The zinc-based metal-organic framework material of this embodiment belongs to the triclinic system, the space group is P-1, and the unit cell parameters are: α=97.934(2)°; β=95.154(2)°; γ=92.056(2)°.

[0028] The minimum asymmetric unit of the zinc-based metal-organic framework material of this embodiment contains three crystallographically independent zinc ions, three 2,6-NBC ligands, 1.5 vlpy ligands, and one free water molecule and free 2,6-H2NBC. The zinc ions form a Zn2(COO)4 secondary structural unit, which is further connected to a two-dimensional planar structure through 2,6-NBC, and the two-dimensional planar structure is further connected to a three-dimensional columnar structure through vlpy.

[0029] The smallest asymmetric unit of the zinc-based metal-organic framework material has two crystallographically independent structures: Zn2(2,6-NBC)2(vlpy) and Zn(2,6-NBC)(vlpy) 0.5 ; The intersection between these two structures further forms an interpenetrating three-dimensional structure in space.

[0030] The present embodiment provides a method for preparing a zinc-based metal-organic framework material with fluorescent recognition of anthrax biomarker. Fig. 9 As shown, the synthesis steps include the following:

[0031] 43.2 mg of the organic ligand 2,6-NBC and 18.2 mg of the vlpy ligand were dissolved in 4 mL of N, N-dimethylformamide solvent respectively; 27.2 mg of ZnCl2 was dissolved in 4 mL of water; the two solutions were mixed and then put into a closed hydrothermal reactor and then into an electric blower drying oven. The temperature was raised to 90°C after two hours and kept constant for 3 days, then cooled to room temperature after 1 day, and a light yellow solid was taken out; after taking out the solid, the solid was washed 3 times with N, N-dimethylformamide and water to obtain a light yellow block crystal, and the yield was 80% based on metallic zinc.

[0032] The properties of the zinc-based metal-organic framework material with fluorescent recognition of anthrax bacillus biomarkers prepared in this example are characterized as follows:

[0033] (1) Structural determination of a zinc-based metal-organic framework material with fluorescent recognition of anthrax biomarker in this embodiment:

[0034] The crystal structure was determined using a Supernova single crystal X-ray diffractometer using graphite monochromatized Mo-Kα radiation. is the incident radiation source, Diffraction points were collected by scanning, and the unit cell parameters were obtained by least squares correction. The crystal structure was solved by SHELXL-97 direct method from the difference Fourier electron density map and corrected by Lorentz and polarization effects. All H atoms were synthesized by difference Fourier and determined by ideal position calculation. The exact number of solvent molecules was determined by thermogravimetric and elemental analysis tests. Detailed crystal determination data are shown in Table 1.

[0035] Table 1 Crystallographic data of zinc-based metal-organic framework materials

[0036]

[0037] (2) Characterization of the fluorescence properties of the zinc-based metal-organic framework material of this example

[0038] Figure 1The figure shows the coordination environment diagram of the zinc-based metal-organic framework material of the present invention. In the figure, the smallest asymmetric unit of the zinc-based metal-organic framework material has three crystallographically independent zinc ions, and the smallest asymmetric unit of the zinc-based metal-organic framework material has two crystallographically independent structures: Zn2(2,6-NBC)2(vlpy) and Zn(2,6-NBC)(vlpy) 0.5 The zinc ion, four O atoms from the 2,6-NBC ligand and one N atom from the vlpy ligand form a 5-coordinated [ZnO4N] secondary structural unit.

[0039] Figure 2 The figure shows a unit cell diagram of the zinc-based metal-organic framework material of the present invention. In the figure, the smallest asymmetric unit of the zinc-based metal-organic framework material contains three crystallographically independent zinc ions, three 2,6-NBC ligands, 1.5 vlpy ligands, one free water molecule and free 2,6-H2NBC. The smallest asymmetric unit of the zinc-based metal-organic framework material contains two crystallographically independent structures: Zn2(2,6-NBC)2(vlpy) and Zn(2,6-NBC)(vlpy) 0.5 .

[0040] Figure 3 The figure shows the three-dimensional structure of the zinc-based metal-organic framework material of this embodiment. In the formula, n is a natural number from 1 to positive infinity, indicating that the material is a polymer. From the figure, it can be seen that there are two crystallographically independent structures of the minimum asymmetric unit of the zinc-based metal-organic framework material: Zn2(2,6-NBC)2(vlpy) and Zn(2,6-NBC)(vlpy) 0.5 The mutual intersection between them further forms an interpenetrating three-dimensional structure in space.

[0041] Figure 4 The figure shows the fluorescence spectra of the zinc-based metal-organic framework material in different solvents in this embodiment of the invention. The vertical axis in the figure is the fluorescence intensity, and the horizontal axis is the fluorescence wavelength; it can be seen from the figure that the zinc-based metal-organic framework material exhibits different fluorescence intensities in different solvents, and the fluorescence intensity of the zinc-based metal-organic framework material in the DMF solvent is enhanced.

[0042] Figure 5 The figure shows the detection of DPA and different interferents by the zinc-based metal-organic framework material in an embodiment of the present invention. The vertical axis in the figure is the fluorescence intensity and the horizontal axis is the fluorescence wavelength. It can be seen from the figure that the addition of PDA significantly enhances the fluorescence intensity of the material.

[0043] Figure 6The figure shows the fluorescence spectra of the zinc-based metal-organic framework material in the embodiment of the present invention to different concentrations of DPA solution. The vertical coordinate in the figure is the fluorescence intensity, and the horizontal coordinate is the fluorescence wavelength; it can be seen from the figure that when DPA is gradually added to the ethanol solution of the zinc-based metal-organic framework material, its fluorescence intensity shows an upward trend with the increase of the amount of DPA, and the change is obvious, indicating that the zinc-based metal-organic framework material has a good fluorescence response to DPA and can be used as a DPA fluorescent probe.

[0044] Figure 7 The graph shown is a curve of the DPA concentration of the present invention versus the fluorescence intensity I0 / I of the zinc-based metal-organic framework material in the embodiment, and the curve equation is y=0.1895+0.825*exp(-4.24x); in the figure, the vertical axis is the fluorescence intensity I0 / I, and the horizontal axis is the DPA concentration value.

[0045] Figure 8 The figure shows the Stern-Volmer linear plot of DPA concentration versus the fluorescence intensity I0 / I of the zinc-based metal-organic framework material in the embodiment ([DPA]≤0.3m mol / L), and the linear equation is y=0.9629-1.9523*x. In the figure, the ordinate is the fluorescence intensity I0 / I, and the abscissa is the DPA concentration value.

[0046] It can be seen from the figure that when the DPA concentration is low (0-0.3mmol / L), the fluorescence intensity I0 / I of the zinc-based metal-organic framework material is linearly related to the DPA concentration, and its detection limit is 128nmol·L -1 ,When the DPA concentration is high, the fluorescence intensity I0 / I of the Zn-based metal-organic framework material is no longer linearly related to the DPA concentration.

Claims

1. A zinc-based metal-organic framework material with anthrax biomarker recognition, characterized in that: The chemical formula of the zinc-based metal-organic framework material is: {[Zn2(2,6-NBC)2(vlpy)·Zn(2,6-NBC)(vlpy) 0.5 ]·0.8(2,6-H2NBC)·H2O} n ; Where: n is a natural number from 1 to positive infinity; (2,6-NBC) 2- It is obtained by deprotonation of 2,6-naphthalenedicarboxylic acid; vlpy is 1,2-di(4-pyridyl)ethylene; The zinc-based metal-organic framework material belongs to the triclinic system, the space group is P-1, and the unit cell parameters are: α=97.934(2)°; β=95.154(2)°; γ=92.056(2)°; The minimum asymmetric unit of the zinc-based metal-organic framework material contains three crystallographically independent zinc ions, three 2,6-NBC ligands, 1.5 vlpy ligands, and one free water molecule and a free 2,6-NBC molecule; a Zn2(COO)4 secondary structural unit is formed between the zinc ions, and the secondary structural unit is further connected to form a two-dimensional planar structure through 2,6-NBC, and the two-dimensional planar structure is further connected to form a three-dimensional layered columnar structure through vlpy; The smallest asymmetric unit of the zinc-based metal-organic framework material has two crystallographically independent structures: Zn2(2,6-NBC)2(vlpy) and Zn(2,6-NBC)(vlpy) 0.5 ; These two structures intersect with each other, further forming an interpenetrating three-dimensional structure in space; The zinc-based metal-organic framework material can stably exist in water, methanol, ethanol, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, acetonitrile, and 1,4-dioxane solvents; The zinc-based metal-organic framework material can detect 2,6-pyridinedicarboxylic acid DPA through fluorescence changes; the fluorescence of the zinc-based metal-organic framework material increases with the increase of DPA concentration, and at a low concentration of 0-0.3 mmol·L -1 The fluorescence curve of DPA ethanol solution was linearly related to DPA concentration, and the detection limit was 128 nmol·L -1 .

2. The method for preparing a zinc-based metal-organic framework material having anthrax biomarker recognition according to claim 1, characterized in that: The method is as follows: The organic ligands 2,6-NBC and vlpy are dissolved in N,N-dimethylformamide solvent, and ZnCl2 is dissolved in water respectively. The two solutions are mixed and put into a closed hydrothermal reactor. The mixture is reacted at a constant temperature of 90°C for 3 days, and then cooled to room temperature after 1 day. A light yellow solid is taken out. The solid is washed with N,N-dimethylformamide for multiple times to obtain a light yellow block crystal.

3. The method for preparing a zinc-based metal-organic framework material with anthrax bacillus biomarker recognition according to claim 2, characterized in that: The concentration of the N,N-dimethylformamide solution of the 2,6-NBC is 0.01-1 mol / L; the concentration of the N,N-dimethylformamide solution of the vlpy is 0.01-1 mol / L; the concentration of the aqueous solution of ZnCl2 is 0.01-1 mol / L.

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