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

Abstract

A zinc-based metal organic framework material and a preparation method and application thereof, with 1,4-bis(2-ethyl imidazole-1-yl) terephthalic acid as an organic ligand, and transition metal zinc as a forming body, the zinc-based metal organic framework material is synthesized through a solvothermal method.The zinc-based metal organic framework material, after being combined with calcium ions, is used as a fluorescence probe for a ratio fluorescence probe of doxycycline hydrochlorate in a water system, and rapid detection of the content of doxycycline hydrochlorate can be realized.The method has the characteristics of rapid response, high selectivity, high sensitivity, high accuracy and the like in the determination of doxycycline hydrochlorate in water, and compared with existing doxycycline hydrochlorate detection technologies, the method has good market application potential due to low cost, high efficiency, high sensitivity, high selectivity and simple operation.

Description

Technical Field

[0001] This invention relates to the field of doxycycline hydrochloride detection, and particularly to a zinc-based metal-organic framework material, its preparation method, and its application. Background Technology

[0002] Doxycycline hydrochloride, a tetracycline antibiotic, is widely used in aquaculture due to its excellent antibacterial properties. This drug is effective in treating Gram-negative bacteria and infections caused by Chlamydia or Mycoplasma, increasing aquatic product yields. However, its overuse has led to serious environmental problems. Excessive use of doxycycline hydrochloride can inhibit biological growth, affect steroid production, cause endocrine disorders in aquatic organisms, and ultimately damage the entire ecosystem. Furthermore, the accumulation of this drug in aquatic animals can enter the human body through the food chain, damaging the digestive, central nervous, and hematopoietic systems, seriously threatening human health. Currently, methods for detecting doxycycline hydrochloride mainly include high-performance liquid chromatography (HPLC), high-performance liquid chromatography-mass spectrometry (HPLC-MS), ultra-high-performance liquid chromatography-mass spectrometry, thin-layer chromatography, electrochemical voltammetry, and enzyme-linked immunosorbent assay (ELISA). However, these methods typically suffer from drawbacks such as high cost, poor selectivity, low sensitivity, and complex operation. Therefore, finding a rapid and effective method for detecting doxycycline hydrochloride is urgently needed.

[0003] Metal-organic frameworks (MOFs) are a novel type of porous material that exhibits great potential in luminescent sensing due to their unique three-dimensional framework structure and tunable pore size. By rationally optimizing the pore size and morphology of MOF materials, rapid and sensitive detection of target analytes can be achieved. When metal ions, as analytical reagents, are absorbed by the pores of MOF materials, they come into contact with metal ions or ligands within the organic framework, resulting in electron or energy transfer, leading to enhancement or reduction of fluorescence properties, thereby enabling the identification and detection of target analytes. In recent years, fluorescence sensing technology using luminescent MOF materials has developed rapidly due to its advantages of short response time, low cost, high sensitivity, and high efficiency. Researchers in various fields have successively established a variety of fluorescent sensors based on MOF materials with different functions. Zinc ions are d... 10 Transition metal ions with electronic configurations can promote radiation emission and are suitable for constructing luminescent metal-organic framework materials. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a zinc-based metal-organic framework material that can rapidly detect the content of doxycycline hydrochloride in water, and has rapid response, high selectivity and high sensitivity, as well as its preparation method and application.

[0005] To solve the above problems, the technical solution of the present invention is:

[0006] A zinc-based metal-organic framework material, the molecular formula of which is as follows:

[0007] Zn[C 18 H 16 O4N4]·C2H6SO·2H2O.

[0008] A method for preparing a zinc-based metal-organic framework material, the specific steps of which are as follows:

[0009] S1: Preparation of organic ligand-metal salt solution

[0010] The organic ligand {1,4-bis(2-ethylimidazol-1-yl)-2,5-terephthalic acid} and the metal salt (Zn(NO3)2·6H2O) were weighed and added to a mixed solvent of DMF, DMSO and ethanol at a mass ratio of 1:3. The mass-volume ratio of the organic ligand to DMSO was 4 g / L. The mixture was stirred until homogeneous to obtain the prepared organic ligand-metal salt solution.

[0011] S2: Solvothermal preparation of zinc-based metal-organic framework materials

[0012] The organic ligand-metal salt solution was poured into a glass bottle and heated in an oven at 80°C for 3 days to obtain white, transparent rhomboid crystals. The crystals were washed, filtered, dried, and ground to obtain zinc-based metal-organic framework powder (denoted as Zn-MOF).

[0013] Furthermore, the volume ratio of DMF, DMSO and ethanol is 1:1:1.

[0014] Application of a zinc-based metal-organic framework material in the rapid detection of doxycycline hydrochloride in water.

[0015] Application of a zinc-based metal-organic framework material in the rapid detection of doxycycline hydrochloride in water, wherein the zinc-based metal-organic framework material is related to Ca 2+ A ratiometric fluorescent probe for rapid detection of doxycycline hydrochloride in water was prepared by mixing.

[0016] The application of a zinc-based metal-organic framework material in the rapid detection of doxycycline hydrochloride in water, wherein the specific steps of the ratiometric fluorescent probe for the rapid detection of doxycycline hydrochloride in water are as follows:

[0017] Zinc-based metal-organic framework (MOF) powder was added to deionized water and ultrasonically dispersed to prepare a 1 g / L MOF dispersion. The MOF dispersion was then mixed with 0.02 mol·L⁻¹ water. -1 A calcium chloride solution was mixed at a volume ratio of 1:1 to obtain a ratiometric fluorescent probe for doxycycline hydrochloride.

[0018] The beneficial effects of this invention are:

[0019] (1) Zn-MOF and Ca 2+ In the preparation of fluorescent probes, when doxycycline hydrochloride is present in the liquid, doxycycline hydrochloride can react with the CaO in the fluorescent probe via intramolecular oxygen from the ketone and hydroxyl groups. 2+ This combination forms a stable six-membered ring chelate. At this point, the conformational rotation of the doxycycline hydrochloride molecule is restricted, the rigidity of the plane increases, and the radiative energy increases, leading to the reaction of doxycycline hydrochloride with Ca... 2+ The complex forms a new and obvious fluorescence peak at 550 nm, resulting in a decrease in fluorescence at 430 nm and an increase in fluorescence at 550 nm, which enables the ratio fluorescence detection of doxycycline hydrochloride.

[0020] (2) Simple operation and low cost. It can quickly detect the content of doxycycline hydrochloride in water, and has the characteristics of rapid response, high selectivity and high sensitivity. It can achieve rapid visual detection of doxycycline hydrochloride through changes in fluorescence intensity. Compared with existing doxycycline hydrochloride detection technologies, this doxycycline hydrochloride detection reagent is low in cost, effective and easy to operate, and has a good market application prospect. Attached Figure Description

[0021] Figure 1 This is a diagram of the ligand structure used in the zinc-based metal-organic framework powder (Zn-MOF) prepared in this invention;

[0022] Figure 2 This is a diagram of the Zn(II) coordination environment of the zinc-based metal-organic framework material powder (Zn-MOF) prepared by this invention;

[0023] Figure 3 This is a three-dimensional structural diagram of the zinc-based metal-organic framework material powder (Zn-MOF) prepared in this invention;

[0024] Figure 4 This is a topological structure diagram of the zinc-based metal-organic framework material powder (Zn-MOF) prepared in this invention;

[0025] Figure 5 This is the XRD diffraction pattern of the zinc-based metal-organic framework material powder (Zn-MOF) prepared in this invention;

[0026] Figure 6 This is a graph showing the fluorescence intensity variation of the ratiometric fluorescent probe of the zinc-based metal-organic framework material powder (Zn-MOF) prepared in this invention at different concentrations of doxycycline hydrochloride.

[0027] Figure 7This is a linear relationship graph of the ratiometric fluorescent probe of the present invention under different concentrations of doxycycline hydrochloride;

[0028] Figure 8 This is an experimental diagram illustrating the anti-interference capabilities of the ratiometric fluorescent probe of this invention.

[0029] Figure 9 This is a graph showing the effect of the zinc-based metal-organic framework material powder (Zn-MOF) prepared in this invention on the detection of tetracycline antibiotics. Detailed Implementation

[0030] Example 1

[0031] S1: Solvothermal preparation of zinc-based metal-organic framework materials

[0032] Weigh the organic ligand 1,4-bis(2-ethylimidazol-1-yl)-2,5-terephthalic acid ( 40 mg of DMF and 120 mg of Zn(NO3)2·6H2O were completely dissolved in 30 mL of a mixed solvent of DMF, DMSO and ethanol in a volume ratio of 1:1:1. The mixture was stirred until homogeneous to obtain a mixed solution. The mixed solution was poured into a thick-walled, pressure-resistant glass bottle and then placed in an oven and heated continuously at 80°C for 3 days to obtain white, transparent rhombic crystals. The crystals were washed, filtered, dried and ground to obtain zinc-based metal-organic framework (Zn-MOF) powder.

[0033] S2: Preparation of a ratiometric fluorescent probe for doxycycline

[0034] (1) Weigh 10 mg of zinc-based metal-organic framework material powder, put it into 10 mL of deionized water, and disperse it evenly by ultrasonication to obtain a zinc-based metal-organic framework material dispersion.

[0035] (2) Weigh 22 mg of anhydrous calcium chloride and add 10 mL of distilled water to prepare 0.02 mol·L⁻¹ calcium chloride solution. -1 Calcium chloride solution;

[0036] (3) Mix 0.9 mL of the zinc-based metal-organic framework material dispersion prepared in step (1) with 0.9 mL of the calcium chloride solution prepared in step (2) to obtain the ratio fluorescent probe of doxycycline hydrochloride.

[0037] I. Structure and Characterization of Zinc-Based Metal-Organic Frameworks

[0038] (1) Structural Analysis

[0039] To analyze the structure of Zn-MOF, measurements were performed at room temperature using a Bruker D8VENTURE X-ray single-crystal diffractometer. Monochromatic microfocused Cu Kα radiation was used at an incident angle λ = 0.71073°. Diffraction data can be obtained using multi-scan absorption correction. To analyze single-crystal diffraction data and obtain the crystal structure, the software Olex2 was used for analysis, and the obtained unit cell parameter data are as follows.

[0040]

[0041]

[0042] Figure 1 The structure of the ligands used in the preparation of Zn-MOF; Figure 2 To define the coordination environment of Zn(II) in the prepared Zn-MOF, each Zn 2+ It is coordinated with 2 nitrogen atoms and 2 oxygen atoms, wherein the two nitrogen atoms are derived from the imidazole functional group in the ligand and the two oxygen atoms are derived from the carboxyl functional group in the ligand; Figure 3 The image shows the three-dimensional structure of Zn-MOF. Figure 4 Topology diagram of Zn-MOF.

[0043] (2) Powder diffraction characterization

[0044] Figure 5 The powder line diffraction pattern of the prepared Zn-MOF is shown below. Figure 5 As shown, the diffraction peaks in the simulated PXRD and the actual measured PXRD correspond well, indicating that Zn-MOF was successfully synthesized and the complexes are all pure phases.

[0045] II. Calculation of the detection limit

[0046] 1.8 mL of the ratiometric fluorescent probe of doxycycline hydrochloride prepared in Example 1 was mixed evenly with 0.2 mL of the sample to be tested. The mixture was then excited under a 313 nm UV lamp. The content of doxycycline hydrochloride in the water was detected based on the change in fluorescence intensity of the sample. A linear relationship model was constructed with doxycycline hydrochloride concentration as the x-axis and fluorescence intensity as the y-axis, and the detection limit was calculated.

[0047] The specific steps are as follows:

[0048] (1) Prepare a series of doxycycline hydrochloride standard solutions of known concentrations (concentrations of 0, 0.2mM, 0.4mM, 0.6mM, 0.8mM, 1mM, 1.2mM, 1.4mM, 1.6mM, 1.8mM, 2mM, 2.2mM, 2.4mM, 2.6mM, 2.8mM, 3mM);

[0049] (2) Take 1.8 mL of the ratioographic fluorescent probe of doxycycline hydrochloride prepared in Example 1, add 0.2 mL of the above-mentioned standard solution of doxycycline hydrochloride of known concentration, mix well, and measure its fluorescence intensity at an excitation wavelength of 313 nm.

[0050] Figure 6 This is a graph showing the change in fluorescence intensity after adding 0.2 mL of doxycycline hydrochloride standard solution of different concentrations to a doxycycline hydrochloride fluorescent probe. From... Figure 6 It is evident that as the concentration of doxycycline hydrochloride increases, the fluorescence intensity of the doxycycline hydrochloride fluorescent probe gradually quenches at 430 nm and gradually increases at 550 nm. For example... Figure 7 As shown, a linear relationship exists between the fluorescence intensity ratio of the doxycycline hydrochloride fluorescent probe and the concentration of doxycycline hydrochloride in the range of 0-160 μM. The linear equation is F0. 550 / F 430 =0.00799C-0.03472, R 2 = 0.98135, where C represents the concentration of doxycycline hydrochloride in μmol / L. The limit of detection (LOD) is calculated using the formula: LOD = 3σ / K sv The detection limit of this doxycycline hydrochloride fluorescent probe was calculated to be 1.43 μM. Within the 180-300 μM range, the linear equation between the fluorescence intensity ratio of the doxycycline hydrochloride fluorescent probe and the concentration of doxycycline hydrochloride is F. 550 / F 430 =0.02821C-3.73046, R 2 =0.97388 (where σ is the standard deviation of the fluorescence intensity of 11 blank experiments without any added ions for testing the doxycycline hydrochloride fluorescent probe; in this experiment, σ = 0.003337). K sv Represents the quenching constant (μM) -1 )).

[0051] III. Interference Experiment

[0052] Considering the complex and diverse conditions of real water bodies, to evaluate the selectivity of a ratiometric fluorescent probe for rapid detection of doxycycline hydrochloride in water, several common antibiotics were selected for anti-interference experiments, such as... Figure 8As shown, 10 mM solutions of doxycycline hydrochloride, oxytetracycline, chloramphenicol, roxithromycin, tetracycline, thiamphenicol, azithromycin, and chlortetracycline hydrochloride were prepared at the same concentration. Using doxycycline hydrochloride ratiometric fluorescent probes as blank samples, the intensity of the ratiometric fluorescent probes significantly increased after adding 50 μL of doxycycline hydrochloride, indicating that the doxycycline hydrochloride ratiometric fluorescent probes have high sensitivity to doxycycline hydrochloride. However, after adding 50 μL of the other antibiotics mentioned above, the intensity of the ratiometric fluorescent probes for rapid detection of doxycycline hydrochloride in water did not change significantly; only when similar tetracycline antibiotics were added did the ratiometric fluorescence intensity increase slightly. However, compared with the ratiometric fluorescence intensity of the added doxycycline hydrochloride, the ratiometric fluorescence intensity of tetracycline antibiotics was relatively weak, thus the effect of tetracycline antibiotics on the doxycycline hydrochloride ratiometric fluorescent probes can be ignored, indicating that the doxycycline hydrochloride ratiometric fluorescent probes are selective.

[0053] IV. Comparison of the detection effects of the Zn-MOF organic framework material of the present invention and the ratio fluorescence probe of the present invention for doxycycline hydrochloride.

[0054] To explore the advantages of the doxycycline hydrochloride ratio fluorescent probe, the zinc-based metal-organic framework material powder of this invention was subjected to separate tetracycline antibiotic efficacy testing.

[0055] 10 mM solutions of oxytetracycline, tetracycline, chlortetracycline hydrochloride, and doxycycline hydrochloride were prepared at the same concentration. After adding 50 μL of each solution, their effects on Zn-MOF organic framework materials and doxycycline hydrochloride ratio fluorescent probes were investigated.

[0056] Among the findings, the quenching rate of Zn-MOF organic framework materials reached 28.23% after the addition of chlortetracycline hydrochloride, while the quenching rate reached 76.93% after the addition of doxycycline hydrochloride, demonstrating a response effect 2.72 times that of chlortetracycline hydrochloride. When using a doxycycline hydrochloride ratiometric fluorescent probe, the fluorescence intensity was 2.15 after the addition of chlortetracycline hydrochloride, and 36.93 after the addition of doxycycline hydrochloride, showing a response effect 17.2 times that of chlortetracycline hydrochloride. Therefore, compared with the separate detection of zinc-based metal-organic framework material powders, the method using a doxycycline hydrochloride ratiometric fluorescent probe can significantly increase the detection effect and improve the accuracy of doxycycline hydrochloride.

[0057] The above are merely specific embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A zinc-based metal organic framework material, characterized in that: The molecular formula of the material is as follows: Zn[C 18 H 16 O4N4]·C2H6SO·2H2O. 2.A method for preparing the zinc-based metal organic framework material according to claim 1, comprising the following steps: S1: preparing an organic ligand-metal salt solution An organic ligand 1, 4-bis (2-ethyl imidazole-1-yl) -2, 5-p-phenylenedimethylene and a metal salt (Zn (NO3) 2·6H2O) are weighed according to a mass ratio of 1:3 and added to a mixed solvent of DMF, DMSO and ethanol, the mass-volume ratio of the organic ligand to DMSO is 4 g / L, and the mixture is stirred uniformly to obtain the prepared organic ligand-metal salt solution; S2: preparing the zinc-based metal organic framework material by a solvent thermal method The organic ligand-metal salt solution is poured into a glass bottle and heated in an oven at 80℃ for 3 days to obtain white transparent rhombic crystals, which are washed, filtered, dried, ground and obtained as zinc-based metal organic framework material powder.

3. The method for preparing the zinc-based metal-organic framework material according to claim 2, characterized in that: The volume ratio of the DMF, DMSO and ethanol is 1:1:

1. 4.The zinc-based metal organic framework material according to claim 1 is used for rapid detection of doxycycline hydrochloride in water.

5. The use of zinc-based metal-organic framework material according to claim 4 for rapid detection of doxycycline hydrochloride in water, characterized in that: The zinc-based metal organic framework material and Ca 2+ Mixed preparation of ratio fluorescent probe for rapid detection of doxycycline hydrochloride in water.

6. The use of zinc-based metal-organic framework material according to claim 4 for rapid detection of doxycycline hydrochloride in water, characterized in that: The specific steps of the ratio fluorescent probe for rapid detection of doxycycline hydrochloride in water are as follows: The zinc-based metal organic framework material powder is added into deionized water, and after ultrasonic dispersion, a zinc-based metal organic framework material dispersion liquid with a mass-volume ratio of 1 g / L is prepared; the zinc-based metal organic framework material dispersion liquid and 0.02 mol·L -1 of the calcium chloride solution are mixed according to a volume ratio of 1:1 to obtain a doxycycline hydrochloride ratiometric fluorescent probe.

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