A metal-organic framework composite material and its preparation method and application

Abstract

The present invention belongs to the field of materials, and discloses a metal organic framework composite material and its preparation method and application, wherein the metal organic framework composite material is a metal organic framework material loaded with a ligand, the metal organic framework material is UiO 67 (Zr), and the ligand is Os (bpy) 2. A hot reflux method is adopted during the preparation process, the preparation method is simple, and the product is easy to obtain. In the present invention, by loading the Os (bpy) 2 ligand into the metal organic framework material UiO 67 (Zr), not only the photosensitivity of the metal organic composite material, especially the photosensitivity under near-infrared irradiation, can be increased, but also its photodynamic antibacterial performance under near-infrared light mediation can be improved, especially for Gram-positive and Gram-negative bacteria, and excellent antibacterial performance can be achieved at extremely low composite material concentrations.

Description

Technical Field

[0001] The present invention belongs to the field of materials and relates to a metal-organic framework composite material and its preparation method and application, and in particular to a metal-organic framework composite material, its preparation method, its application as a photosensitizer, and its application as a photodynamic antibacterial agent mediated by near-infrared light. Background Art

[0002] In recent years, photodynamic therapy (PDT) has been widely studied as an alternative to antibiotics. It is an emerging, highly effective antimicrobial treatment technology. Its antimicrobial effect primarily arises from the generation of reactive oxygen species (ROS) through type I or type II reactions by photosensitizers under light irradiation. These ROS are highly oxidizing and can kill bacteria. The two most critical factors in PDT are the choice of light source and photosensitizer. The most common light sources are ultraviolet (UV) or visible light (50-80 kcal / mol). However, the application of UV-visible light is subject to numerous limitations, including competitive absorption by organic matrices, the difficulty in spatially controlling short-wavelength UV light, and low penetration. Especially in the biomedical field, the harmful effects of UV light on the human body must also be considered. In contrast, near-infrared (NIR) light (λ = 700-1000 nm) offers significant advantages, such as high penetration, good spatial controllability, and minimal tissue damage, thus overcoming the limitations of UV-visible light.

[0003] Osmium (Os)-based complexes are widely used as photosensitizers, exhibiting excellent light absorption properties, with primary absorption peaks located at 454 nm, 578 nm, 649 nm, and 671 nm. However, osmium complexes also have drawbacks, such as aggregation, photobleaching, short excited state or luminescence lifetimes, and concentration quenching, which reduce the generation efficiency of singlet oxygen and other ROS, thereby limiting their performance.

[0004] To address the above problems, the present invention develops a novel metal-organic framework composite material, which can change the photophysical properties of osmium (Os)-based composites while retaining their photosensitivity, thereby broadening their application range. Summary of the Invention

[0005] The purpose of the present invention is to provide a novel metal-organic framework composite material. The composite material is loaded with Os(bpy)2 onto UiO-67(Zr). On the basis of retaining the photosensitivity of the osmium (Os)-based composite, it can also enhance the photosensitization properties of the bare osmium composite under near-infrared light irradiation, and has a good photodynamic antibacterial effect under the mediation of near-infrared light.

[0006] One of the purposes of the present invention is to provide a metal-organic framework composite material, wherein the metal-organic framework composite material is a metal-organic framework material loaded with a ligand, the metal-organic framework material is UiO-67(Zr), and the ligand is Os(bpy)2.

[0007] In the present invention, based on the fact that osmium (Os)-based complexes have good light absorption performance, especially near-infrared absorption performance, but their photophysical properties are poor, the separation of photogenerated carriers is promoted by loading osmium (Os)-based complex ligand molecules onto metal-organic framework materials, thereby improving their photophysical properties.

[0008] In the present invention, a specific Os(bpy)2 ligand (Os-comp for short) and a specific metal-organic framework material UiO-67(Zr) are used. By loading the Os(bpy)2 ligand into the metal-organic framework material UiO-67(Zr), not only the photosensitivity of the metal-organic composite material can be increased, but also its photodynamic antibacterial performance under the mediation of near-infrared light can be improved.

[0009] The metal-organic framework composite material (Os-comp / MOF for short) obtained by the present invention is active in the entire range from ultraviolet-visible light to near-infrared irradiation, and has particularly excellent photosensitivity under visible light and near-infrared light irradiation.

[0010] The metal-organic framework composite material obtained by the present invention has excellent photodynamic antibacterial properties, especially photodynamic antibacterial properties under the mediation of near-infrared light, especially against Gram-positive and Gram-negative bacteria. Under the action of extremely low concentrations of the metal-organic framework composite material, near-infrared light irradiation for only 5 minutes can achieve high antibacterial properties. Compared with conventional antibiotic therapy, this treatment technology is not only more effective, but also has good biocompatibility.

[0011] Preferably, using Cu-Kα radiation, the metal-organic framework composite material has an X-ray powder diffraction pattern represented by a diffraction angle 2θ with characteristic peaks at 5.7±0.2° and 7.1±0.2°. Figure 1 The X-ray diffraction patterns of simulated UiO-67(Zr) (curve a), synthetic UiO-67(Zr) (curve b) and metal-organic framework composite materials (curve c) were obtained. It was found through the patterns that the simulated UiO-67(Zr), synthetic UiO-67(Zr) and metal-organic framework composite materials all showed characteristic diffraction peaks of UiO-67(Zr) at 2θ of 5.7° (200 crystal plane) and 7.1° (111 crystal plane), indicating that the metal-organic framework composite materials contained UiO-67(Zr).

[0012] Preferably, the XPS spectrum of the metal-organic framework composite material has binding energies at 53.4 eV, 267.7 eV, 285.6 eV, 292.8 eV, and 399.0 eV. Figure 2 UiO-67(Zr)( Figure 2 a curve of A in the middle) and metal organic framework composites ( Figure 2 The XPS spectrum of curve b in A is obtained by Figure 2 It can be seen that compared with the XPS spectrum of UiO-67(Zr), Os-comp / MOF has peaks corresponding to Os4f, Os4d5 and Os4d3 at binding energies of 53.4, 267.7 and 292.8. However, the Os 3d 3 / 2 The peak may overlap with the C1s peak, indicating the presence of Os in Os-comp / MOF. 2+ In addition, the 1s peak of nitrogen in UiO-67(Zr) at 399eV (see Figure 2 A) has a smaller width and is shifted by about 1 eV (400 eV) toward the higher binding energy in Os-comp / MOF (see Figure 2 This indicates that the open N,N'-open coordination sites in UiO-67(Zr) coordinate with Os in the Os-comp / MOF system.

[0013] Preferably, the metal organic framework composite material is -1 、776cm -1 , 1070cm -1 、1105cm -1 、1462cm -1 、1549cm -1 、1654cm -1 、1717cm -1 There are characteristic infrared peaks. Figure 3 The infrared spectra of Os(bpy)2 (curve a), UiO-67(Zr) (curve b) and metal organic framework composites (curve c) are shown. Figure 3 It was found that the three spectra were at 776-927 cm -1 The peaks in the range can be attributed to the binding vibration of CH in the benzene ring. The spectrum of UiO-67(Zr) and metal organic framework composite materials is at 1427-1635 cm -1 The osmium complex shows many absorption peaks in the range of 1550 cm and 1630 cm, which are consistent with the characteristic vibration of the Os(bpy)2 ligand in the photosensitizer (PS). However, in the osmium complex, the C=C and C=N stretching peaks of the pyridine ligand also appear at 1550 cm and 1630 cm -1These peaks appear slightly shifted in the composite (Os-comp / MOF) spectrum, at approximately 1105, 1549, and 1600 cm -1 In addition, the most significant peak in spectrum a (about 1000 cm -1 ) appears as NC vibration, the intensity of which is significantly reduced in the composite (Os-comp / MOF) spectrum.

[0014] Preferably, the metal-organic framework composite material has an ultraviolet absorption peak at 376-850 nm. Figure 4 UV-visible diffuse reflectance spectra of UiO-67(Zr) (curve a), the osmium complex [Os(bpy)2Cl2] (curve b), and Os-comp / MOF (curve c). The diffuse reflectance spectrum of UiO-67(Zr) reveals a band associated with the benzene ring around 324 nm. This band shifts to 376 nm upon addition of Os(bpy)2Cl2. Os(bpy)2Cl2 exhibits panchromatic absorbance, and the intensity of this broadband absorption increases upon coordination of Os(bpy)2Cl2 with the MOF (Os-comp / MOF). The metal-to-ligand charge transfer (MLCT) band is visible at approximately 493 nm and extends into the near-infrared region at 850 nm, resulting in strong absorption of Os-comp / MOF in the 376-850 nm region.

[0015] Figure 5 Figure 3 is the H-NMR nuclear magnetic resonance spectrum of Os-comp and Os-comp / MOF, where A is the H-NMR nuclear magnetic resonance spectrum of Os-comp and B is the H-NMR nuclear magnetic resonance spectrum of Os-comp / MOF. It can be seen that the Os-comp / MOF spectrum has all the peaks of the Os-comp spectrum, further proving the appropriate chemical combination of Os-comp and UiO-67(Zr) structure to form a new photosensitizer, and during the synthesis of Os-comp / MOF, the Os(bpy)2Cl2 complex remains intact.

[0016] The second object of the present invention is to provide a method for preparing a metal-organic framework composite material as described in one of the objects, comprising: refluxing an organic solution containing Os(bpy)2X2 with an organic solution containing UiO-67(Zr) at 50-85°C (for example, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, etc.) for 5-32h (for example, 5h, 10h, 15h, 20h, 25h, 30h, 32h, etc.) to obtain the metal-organic framework composite material.

[0017] In the present invention, a mixed solution containing Os(bpy)2X2 and UiO-67(Zr) is subjected to a reflux reaction, during which the two undergo a redox reaction to form a metal organic framework composite material.

[0018] Preferably, in the organic solution containing Os(bpy)2X2, the solvent is any one of DMF, methanol or ethanol or a combination of at least two thereof, and the solute is any one of Os(bpy)2Cl2, Os(bpy)2Br2 or Os(bpy)2I2.

[0019] Preferably, in the organic solution containing Os(bpy)2X2, the concentration of Os(bpy)2X2 is 0.001-0.005 mol / L, for example, 0.001 mol / L, 0.002 mol / L, 0.003 mol / L, 0.004 mol / L, 0.005 mol / L, etc.

[0020] Preferably, when Os(bpy)2X2 is Os(bpy)2Cl2, the preparation method of Os(bpy)2Cl2 comprises:

[0021] (1) mixing 2,2-bipyridine and K2OsCl6 in N,N-dimethylformamide, stirring and refluxing at 50-85°C (e.g., 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C) for 5-24 hours (e.g., 5 hours, 10 hours, 15 hours, 20 hours, 24 hours), and then adding diethyl ether to the filtrate after solid-liquid separation to obtain a precipitate;

[0022] (2) The precipitate obtained in step (1) was placed in a mixture of N,N-dimethylformamide and methanol, and NaS2O4 was added in an ice bath to react until the mixture changed from orange to dark gray-purple to obtain Os(bpy)2Cl2.

[0023] As a preferred technical solution of the present invention, the preparation method of Os(bpy)2Cl2 comprises:

[0024] (1) 100 mmol / L 2,2-bipyridine and 50 mmol / L K2OsCl6 were mixed in 20 mL of N,N-dimethylformamide and refluxed at 50-85°C for 5-24 h. After the reaction, the mixture was cooled to room temperature and the potassium chloride precipitate was removed by vacuum filtration. 250 mL of diethyl ether was then added to the filtrate and the mixture was placed in a refrigerator overnight for complete precipitation. The mixture was then filtered to obtain a dark orange precipitate.

[0025] (2) The dark orange precipitate obtained in step (1) was resuspended in 15 mL of a mixture of N,N-dimethylformamide and methanol in a volume ratio of 2:1. NaS2O4 at a concentration of 57 mmol / L was added dropwise in an ice bath and stirred until the reaction mixture changed from orange to dark gray-purple. The solid was obtained by vacuum filtration, washed with N,N-dimethylformamide and ethanol 3-5 times, and vacuum dried at 60-80°C for 24-48 h to obtain Os(bpy)2Cl2.

[0026] Preferably, the solvent in the organic solution containing UiO-67(Zr) is ethanol, DMF, a mixture of DMF and methanol, or a mixture of DMF and ethanol;

[0027] Preferably, in the organic solution containing UiO-67(Zr), the concentration of UiO-67(Zr) is 0.003-0.007 mol / L, for example, 0.003 mol / L, 0.004 mol / L, 0.005 mol / L, 0.006 mol / L, 0.007 mol / L, etc.

[0028] Preferably, the preparation further comprises: sequentially performing solid-liquid separation, washing, and drying on the mixture obtained after the reflux reaction.

[0029] Preferably, the solid-liquid separation method is filtration;

[0030] Preferably, the drying is vacuum drying, wherein the vacuum degree of the vacuum drying is 10 -8 -10 -3 torr (e.g. 10 - 8 torr, 10 -7 torr, 10 -6 torr, 10 -5 torr, 10 -4 torr, 10 -3 torr, etc.), the vacuum drying temperature is 60-100°C (for example, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, etc.), and the vacuum drying time is 4-12h (for example, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, etc.).

[0031] A third object of the present invention is to provide an application of the metal organic framework composite material as described in the first object in the preparation of a photosensitizer.

[0032] In the present invention, the metal organic framework composite material has activity in the entire range from ultraviolet-visible light to near infrared irradiation, and in particular has good visible light and near infrared light photosensitivity.

[0033] A fourth object of the present invention is to provide a use of the metal-organic framework composite material as described in the first object in the preparation of a near-infrared light-mediated photodynamic antibacterial agent.

[0034] The metal organic framework composite material of the present invention has good photodynamic antibacterial performance under the mediation of infrared light, especially against Gram-positive and Gram-negative bacteria.

[0035] The technical features and beneficial effects of the present invention are as follows:

[0036] In the present invention, a specific Os(bpy)2 ligand and a specific metal-organic framework material UiO-67(Zr) are used. By loading the Os(bpy)2 ligand into the metal-organic framework material UiO-67(Zr), not only the photosensitivity of the metal-organic composite material can be increased, but also its photodynamic antibacterial performance under near-infrared light mediation can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 X-ray diffraction patterns of simulated UiO-67(Zr), synthesized UiO-67(Zr), and metal-organic framework composites;

[0038] Figure 2 XPS spectra of UiO-67(Zr) and metal-organic framework composites;

[0039] Figure 3 The infrared spectra of Os(bpy)2, UiO-67(Zr) and metal-organic framework composites;

[0040] Figure 4 UV-visible diffuse reflectance spectra of UiO-67(Zr), osmium complex [Os(bpy)2Cl2] (b) and Os-comp / MOF (c);

[0041] Figure 5 H-NMR spectra of Os-comp and Os-comp / MOF;

[0042] Figure 6 Schematic diagram of photodynamic antibacterial effect of the metal-organic framework composite material obtained in Example 1 under near-infrared light irradiation. DETAILED DESCRIPTION

[0043] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are only provided to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0044] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the technical solution of the present application will be described in detail below with reference to specific examples. If the specific experimental conditions are not specified in the examples, they are usually based on conventional conditions or the conditions recommended by the reagent company; the raw materials, reagents, consumables, etc. used in the following examples, unless otherwise specified, can be obtained through commercial channels.

[0045] Preparation Example

[0046] (1) 100 mmol / L 2,2-bipyridine and 50 mmol / L K2OsCl6 were mixed in 20 mL of N,N-dimethylformamide and refluxed at 85°C for 24 h. After the reaction, the mixture was cooled to room temperature and the potassium chloride precipitate was removed by vacuum filtration. 250 mL of diethyl ether was then added to the filtrate and the mixture was placed in a refrigerator overnight for complete precipitation. The mixture was then filtered to obtain a dark orange precipitate.

[0047] (2) The dark orange precipitate obtained in step (1) was resuspended in 15 mL of a mixture of N,N-dimethylformamide and methanol in a volume ratio of 2:1. NaS2O4 at a concentration of 57 mmol / L was added dropwise under ice bath and stirring to react until the reaction mixture changed from orange to dark gray-purple. The solid was obtained by vacuum filtration, washed with N,N-dimethylformamide and ethanol 3-5 times, and dried in a vacuum oven at 70°C overnight to obtain Os(bpy)2Cl2.

[0048] It should be noted that the Os(bpy)2Cl2 used in the following examples were all prepared according to the preparation examples.

[0049] Example 1

[0050] This embodiment provides a method for preparing a metal-organic framework composite material, comprising:

[0051] (1) 57 mg of Os(bpy)2Cl2 was dissolved in 20 mL of DMF to form a solution 1 with a concentration of 0.004 mol / L, and 300 mg of UiO-67(Zr) was dissolved in 20 mL of ethanol to form a solution 2 with a concentration of 0.006 mol / L;

[0052] (2) Solution 1 and solution 2 in step (1) were mixed in a round-bottom flask, and refluxed at 70° C. for 24 h. After the reflux reaction was completed, the mixture was filtered, washed, and vacuum-dried overnight to obtain a metal-organic framework composite material.

[0053] Figure 1The X-ray diffraction patterns of simulated UiO-67(Zr) (curve a), synthetic UiO-67(Zr) (curve b) and metal-organic framework composite materials (curve c) were found through the patterns. It was found that the simulated UiO-67(Zr), synthetic UiO-67(Zr) and metal-organic framework composite materials all showed characteristic diffraction peaks of UiO-67(Zr) at 2θ of 5.7° (200 crystal plane) and 7.1° (111 crystal plane), indicating that the metal-organic framework composite materials contained UiO-67.

[0054] Figure 2 UiO-67( Figure 2 a curve of A in the middle) and metal organic framework composites ( Figure 2 The XPS spectrum of curve b in A is obtained by Figure 2 It can be seen that compared with the XPS spectrum of UiO-67(Zr), Os-comp / MOF has peaks corresponding to Os4f, Os4d5 and Os4d3 at binding energies of 53.4, 267.7 and 292.8. However, the peaks of Os3d with a binding energy of about 285.6 eV are 3 / 2 The peak may overlap with the C1s peak, indicating the presence of Os in Os-comp / MOF. 2+ In addition, the 1s peak of nitrogen in UiO-67(Zr) at 399eV (see Figure 2 A) has a smaller width and is shifted by about 1 eV (400 eV) toward the higher binding energy in Os-comp / MOF (see Figure 2 This indicates that the open N,N'-open coordination sites in UiO-67(Zr) coordinate with Os in the Os-comp / MOF system.

[0055] Figure 3 The infrared spectra of Os(bpy)2 (curve a), UiO-67(Zr) (curve b) and metal organic framework composites (curve c) are shown. Figure 3 It was found that the three spectra were at 776-927 cm -1 The peaks in the range can be attributed to the binding vibration of CH in the benzene ring. The spectrum of UiO-67(Zr) and metal organic framework composite materials is at 1427-1635 cm -1 The osmium complex shows many absorption peaks in the range of 1550 cm and 1630 cm, which are consistent with the characteristic vibration of the Os(bpy)2 ligand in the photosensitizer (PS). However, in the osmium complex, the C=C and C=N stretching peaks of the pyridine ligand also appear at 1550 cm and 1630 cm -1 These peaks appear slightly shifted in the composite (Os-comp / MOF) spectrum, at approximately 1105, 1549, and 1600 cm -1In addition, the most significant peak in spectrum a (about 1000 cm -1 ) is manifested as NC vibration, the intensity of which is significantly reduced in the composite (Os-comp / MOF) spectrum. Infrared spectroscopy shows that Os-comp / MOF has good near-infrared photosensitivity.

[0056] Figure 4 UV-visible diffuse reflectance spectra of UiO-67(Zr) (curve a), the osmium complex [Os(bpy)2Cl2] (curve b), and Os-comp / MOF (curve c). The diffuse reflectance spectrum of UiO-67(Zr) reveals a band associated with the benzene ring around 324 nm. This band shifts to 376 nm upon addition of Os(bpy)2Cl2. Os(bpy)2Cl2 exhibits panchromatic absorbance, and the intensity of this broadband absorption increases upon coordination of Os(bpy)2Cl2 with the MOF (Os-comp / MOF). The metal-to-ligand charge transfer (MLCT) band is visible at approximately 493 nm and extends into the near-infrared region at 850 nm, resulting in strong absorption of Os-comp / MOF in the 376-850 nm region. Ultraviolet-visible diffuse reflectance spectroscopy shows that Os-comp / MOF has good broad-spectrum absorption properties, especially good visible light and near-infrared light photosensitivity.

[0057] Figure 5 Figure 3 is the H-NMR nuclear magnetic resonance spectrum of Os-comp and Os-comp / MOF, where A is the H-NMR nuclear magnetic resonance spectrum of Os-comp and B is the H-NMR nuclear magnetic resonance spectrum of Os-comp / MOF. It can be seen that the Os-comp / MOF spectrum has all the peaks of the Os-comp spectrum, further proving the appropriate chemical combination of Os-comp and UiO-67(Zr) structure to form a new photosensitizer, and during the synthesis of Os-comp / MOF, the Os(bpy)2Cl2 complex remains intact.

[0058] The metal organic framework composite material obtained in this embodiment was used to test the photodynamic antibacterial performance of Gram-positive bacteria (G+) Staphylococcus aureus and Gram-negative bacteria (G-) Escherichia coli. Figure 6 As shown, the following steps were performed: fresh strains were cultured in nutrient broth at 37°C for 16 hours and diluted with nutrient broth to an optical density (OD) of 0.1. The bacterial cell count was further diluted to 5 x 10 6CFU / mL. Synthetic photosensitizers at varying concentrations (10, 20, 30, 40, 50, and 60 μM) were incubated with bacterial solutions in a 96-well plate for 20 minutes. The solution was then irradiated with near-infrared light (800-810 nm / 100 W) for 5 minutes and incubated in the 96-well plate for an additional 15 hours and 40 minutes. The optical density of the sterilized bacterial solution was measured at 600 nm using a microplate reader.

[0059] Gentamycin (10 μg / mL) was used as a positive control, and DMSO (no more than 1%) was used as a solvent control. Each experiment was repeated three times.

[0060] Through testing, we found that:

[0061] When irradiated with near-infrared light of 800-810 nm for 5 minutes, the antibacterial effect of the composite material increased accordingly with increasing Os(bpy)2 / UiO-67(Zr) concentration in the range of 10-60 μM. For example, when the Os(bpy)2 / UiO-67(Zr) concentration was 10 μM, the minimum survival rate of Staphylococcus aureus was 48%, and the minimum survival rate of Escherichia coli was 65%; when the Os(bpy)2 / UiO-67(Zr) concentration was 30 μM, the minimum survival rate of Staphylococcus aureus was 34%, and the minimum survival rate of Escherichia coli was 54%; when the Os(bpy)2 / UiO-67(Zr) concentration was 60 μM, the minimum survival rate of Staphylococcus aureus was 12.9%, and the minimum survival rate of Escherichia coli was 33.4%, indicating that the optimal dose of Os(bpy)2 / UiO-67(Zr) is 60 μM.

[0062] Similarly, the antibacterial properties of UiO-67(Zr) and Os(bpy)2Cl2 at different concentrations in the range of 10-60 μM were tested using near-infrared light with a wavelength of 800-810 nm for 5 minutes. It was also found that the antibacterial effect increased accordingly with increasing concentration, and the best antibacterial effect was achieved at 60 μM.

[0063] The test results of UiO-67(Zr) with a concentration of 60μM: the minimum survival rate of Staphylococcus aureus was 53%, and that of Escherichia coli was 65%; the test results of Os(bpy)2Cl2 with a concentration of 60μM: the minimum survival rate of Staphylococcus aureus was 37%, and that of Escherichia coli was 50%; through comparison, it can be shown that the metal-organic framework composite material obtained by loading Os(bpy)2 onto UiO-67(Zr) can significantly improve its antibacterial performance under near-infrared mediation.

[0064] Example 2

[0065] (1) Os(bpy)2Cl2 was dissolved in 20 mL of DMF to form a solution 1 with a concentration of 0.001 mol / L, and UiO-67(Zr) was dissolved in 20 mL of ethanol to form a solution 2 with a concentration of 0.003 mol / L;

[0066] (2) Solution 1 and solution 2 in step (1) were mixed in a round-bottom flask, and refluxed at 50° C. for 32 h. After the reflux reaction was completed, the mixture was filtered, washed, and vacuum-dried overnight to obtain a metal-organic framework composite material.

[0067] The composite material obtained in Example 2 was characterized in the same manner as in Example 1, and the characterization results were similar to those in Example 1.

[0068] The composite material obtained in Example 2 was subjected to the same antibacterial performance test as in Example 1. It was found that when the concentration of Os(bpy)2 / UiO-67(Zr) was 60 μM, the minimum survival rate of Staphylococcus aureus was 16.2%, and the minimum survival rate of Escherichia coli was 38.1%.

[0069] Example 3

[0070] (1) Os(bpy)2Cl2 was dissolved in 20 mL of DMF to form a solution 1 with a concentration of 0.005 mol / L, and UiO-67(Zr) was dissolved in 20 mL of ethanol to form a solution 2 with a concentration of 0.007 mol / L;

[0071] (2) Solution 1 and solution 2 in step (1) were mixed in a round-bottom flask, and refluxed at 85° C. for 5 h. After the reflux reaction was completed, the mixture was filtered, washed, and vacuum-dried overnight to obtain a metal-organic framework composite material.

[0072] The composite material obtained in Example 3 was characterized in the same manner as in Example 1, and the characterization results were similar to those in Example 1.

[0073] The composite material obtained in Example 3 was subjected to the same antibacterial performance test as in Example 1. It was found that when the concentration of Os(bpy)2 / UiO-67(Zr) was 60 μM, the minimum survival rate of Staphylococcus aureus was 16.7%, and the minimum survival rate of Escherichia coli was 35.4%.

[0074] Example 4

[0075] (1) Os(bpy)2Cl2 was dissolved in 20 mL of DMF to form a solution 1 with a concentration of 0.002 mol / L, and UiO-67(Zr) was dissolved in 20 mL of ethanol to form a solution 2 with a concentration of 0.006 mol / L;

[0076] (2) Solution 1 and solution 2 in step (1) were mixed in a round-bottom flask, and refluxed at 85° C. for 5 h. After the reflux reaction was completed, the mixture was filtered, washed, and vacuum-dried overnight to obtain a metal-organic framework composite material.

[0077] The composite material obtained in Example 3 was characterized in the same manner as in Example 1, and the characterization results were similar to those in Example 1.

[0078] The composite material obtained in Example 3 was subjected to the same antibacterial performance test as in Example 1. It was found that when the concentration of Os(bpy)2 / UiO-67(Zr) was 60 μM, the minimum survival rate of Staphylococcus aureus was 14.9%, and the minimum survival rate of Escherichia coli was 35.7%.

[0079] Comparative Example 1

[0080] This comparative example discloses a composite material comprising directly physically mixing 57 mg of Os(bpy)2Cl2 and 300 mg of UiO-67(Zr).

[0081] By testing the composite material obtained in the comparative example, it was found that its antibacterial effect was significantly worse than the antibacterial performance of the metal-organic framework composite material of the present application.

[0082] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A metal-organic framework composite material, characterized in that: The metal organic framework composite material is a metal organic framework material loaded with a ligand, the metal organic framework material is UiO-67(Zr), and the ligand is Os(bpy)2.

2. The metal-organic framework composite material according to claim 1, characterized in that Using Cu-Kα radiation, the metal-organic framework composite material has an X-ray powder diffraction pattern represented by a diffraction angle 2θ with characteristic peaks at 5.7±0.2° and 7.1±0.2°; The XPS spectrum of the metal-organic framework composite material has binding energies at 53.4 eV, 267.7 eV, 285.6 eV, 292.8 eV, and 399.0 eV.

3. The metal-organic framework composite material according to claim 1, characterized in that The metal organic framework composite material is at 650 cm -1 、776cm -1 , 1070cm -1 、1105cm -1 、1462cm -1 、1549cm -1 、1654cm -1 、1717cm -1 There are infrared characteristic peaks at The metal organic framework composite material has an ultraviolet absorption peak at 376-850nm.

4. The method for preparing the metal-organic framework composite material according to any one of claims 1 to 3, characterized in that: The preparation method comprises: subjecting an organic solution containing Os(bpy)2X2 and an organic solution containing UiO-67(Zr) to reflux reaction at 50-85° C. for 5-32 hours to obtain the metal-organic framework composite material.

5. The preparation method according to claim 4, characterized in that In the organic solution containing Os(bpy)2X2, the solvent is any one of DMF, methanol or ethanol or a combination of at least two thereof, and the solute is any one of Os(bpy)2Cl2, Os(bpy)2Br2 or Os(bpy)2I2; In the organic solution containing Os(bpy)2X2, the concentration of Os(bpy)2X2 is 0.001-0.005 mol / L.

6. The preparation method according to claim 5, characterized in that When Os(bpy)2X2 is Os(bpy)2Cl2, the preparation method of Os(bpy)2Cl2 comprises: (1) Mixing 2,2-bipyridine and K2OsCl6 in N,N-dimethylformamide, stirring and refluxing at 50-85°C for 5-24 hours, and then separating the solid and liquid. Then, adding diethyl ether to the filtrate after solid-liquid separation to obtain a precipitate; (2) The precipitate obtained in step (1) was placed in a mixture of N,N-dimethylformamide and methanol, and NaS2O4 was added under ice bath and stirring to react until the mixture changed from orange to dark gray-purple to obtain Os(bpy)2Cl2.

7. The preparation method according to claim 4, characterized in that In the organic solution containing UiO-67(Zr), the solvent is ethanol, DMF, a mixture of DMF and methanol, or a mixture of DMF and ethanol; In the organic solution containing UiO-67(Zr), the concentration of UiO-67(Zr) is 0.003-0.007 mol / L.

8. The preparation method according to claim 4, characterized in that The preparation further comprises: sequentially performing solid-liquid separation, washing, and drying on the mixture obtained after the reflux reaction; The solid-liquid separation method is filtration; The drying is vacuum drying, wherein the vacuum degree of the vacuum drying is 10 -8 -10 -3 torr, the vacuum drying temperature is 60-100℃, and the vacuum drying time is 4-12h.

9. Use of the metal organic framework composite material according to any one of claims 1 to 3 in the preparation of a photosensitizer.

10. Use of the metal-organic framework composite material according to any one of claims 1 to 3 in the preparation of a near-infrared light-mediated photodynamic antibacterial agent.

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