BN-loaded MOF antibacterial material as well as preparation method and application thereof

Abstract

The invention relates to the field of biological materials, in particular to a BN-loaded MOF antibacterial material as well as a preparation method and application thereof. The preparation method provided by the invention comprises the following steps: mixing H3BTC, copper chloride and water to obtain a mixed solution, carrying out mixed reaction on the mixed solution and a PVP (Polyvinyl Pyrrolidone) dissolving solution to prepare nano-scale MOF-199, then mixing the nano-scale MOF-199 with water, and carrying out heat treatment etching to obtain the etched nano-scale MOF-199; in addition, h-BN, NaOH, KOH and water are mixed and subjected to a heating reaction to achieve stripping treatment, and h-BN subjected to stripping treatment is obtained; and then mixing the etched nano-scale MOF-199, h-BN subjected to stripping treatment and a buffer solution, and adding dopamine hydrochloride to react, so that the BN-PDA-coated MOF-199 nano-composite antibacterial material is formed. The material obtained by the invention not only can selectively sterilize, but also has high antibacterial activity, and is simple to prepare and easy for expanded production.

Description

Technical Field

[0001] The present invention relates to the field of biomaterials, and in particular to a BN-loaded MOF antibacterial material, a preparation method thereof, and applications thereof. Background Art

[0002] The rise of antibiotic-resistant bacteria has become one of the most pressing challenges facing global public health security, with a particularly severe impact on low-income countries. To this end, a variety of nanomaterials have been developed for antimicrobial applications to circumvent the resistance mechanisms of traditional antibiotics. Based on their antimicrobial mechanisms, these nanomaterials can be broadly categorized into the following categories: oxidative stress damage, such as enzymes that catalyze the production of reactive oxygen species (ROS) to achieve antimicrobial effects; physical contact damage, such as sharp nanopillar structures; ion release, such as silver nanoparticles; and photo- / thermal-mediated multi-mechanism antimicrobial agents, such as molybdenum- and graphene-based composites. These agents possess broad-spectrum antimicrobial activity and modifiability, making them promising alternatives to antibiotics. However, most lack the excellent selectivity of antibiotics and are unable to target specific bacterial structures or metabolic pathways. This results in indiscriminate attacks on both bacteria and mammalian cells, significantly limiting the practical application of nanoantimicrobial agents.

[0003] In recent years, several strategies for imparting selectivity to nanomaterials have been reported, including the following:

[0004] (1) Self-generated oxygen photodynamic therapy:

[0005] By modifying the surface of the nanocomposite with a MnO2 nanolayer, the hydrogen peroxide produced by catalytic decomposition can be provided to the infected area with sufficient oxygen, effectively alleviating the hypoxic environment in the periodontal pocket, improving the efficiency of photodynamic therapy, and having different effects on aerobic and anaerobic bacteria, thus achieving selective antibacterial effect. The photosensitizer in the nanomaterial can produce cytotoxic reactive oxygen species, especially singlet oxygen ( 1 O2), these ROS have toxic effects on bacteria, but have different effects on aerobic bacteria and anaerobic bacteria, thus achieving selective antibacterial effect.

[0006] Through gene fusion technology, silver-binding peptides, bacteria-specific cell wall binding domains and fluorescent proteins were used to construct a hybrid conjugate with silver nanoparticle-amplified fusion protein. This conjugate can selectively bind to target bacteria and locate silver nanoparticles on the cell surface, thereby producing selective bactericidal activity, which is beneficial to reduce the potential toxicity of high-concentration silver nanoparticles and ensure biosafety.

[0007] The above method has the following disadvantages: limited selectivity causes side effects, can only distinguish anaerobic bacteria from aerobic bacteria, and cannot distinguish mammalian cells from bacteria.

[0008] (2) Nanozyme-phage system:

[0009] The existing technology has designed a nanomaterial called phage@Pd. Phage@Pd retains the specific recognition and adhesion ability of phages to host bacteria, ensuring the precise positioning of target bacteria. Secondly, Pd nanozymes have pH-dependent peroxidase-like activity. They are activated in the acidic environment of the infection site and the microenvironment where hydrogen peroxide is overexpressed, producing toxic hydroxyl radicals, thereby producing a strong bactericidal effect locally on the bacterial surface, while remaining inert under physiological conditions, ensuring biosafety. In addition, the filamentous structure of phage@Pd can also improve its bactericidal efficiency against non-host bacteria by randomly winding around non-host bacteria, further expanding the antibacterial spectrum. This design, which combines the specificity of phages and the environmental responsiveness of Pd nanozymes, enables phage@Pd to efficiently eliminate bacteria at the infection site while having little impact on normal tissues, and has good biocompatibility and antibacterial selectivity.

[0010] The above method has the following disadvantages: limited selectivity causes side effects, can only target specific bacteria, cannot distinguish between mammalian cells and bacteria; and is difficult to operate.

[0011] (3) Surface-bound reactive oxygen species strategy:

[0012] The prior art proposes AgPd0.38 silver-palladium bimetallic nanocages, which achieve selective killing of bacteria by generating surface-bound reactive oxygen species (ROS) while maintaining low toxicity to mammalian cells. This selectivity is mainly attributed to two aspects: first, the ROS generated by AgPd0.38 are confined to the surface of the nanocage, which can efficiently destroy the cell wall and cell membrane of bacteria, thereby killing the bacteria; second, mammalian cells encapsulate the nanocages in endocytic vesicles through endocytosis, limiting the contact of ROS with intracellular substances, thereby protecting the cells from damage by ROS. In addition, AgPd0.38 also exhibits efficient killing ability against drug-resistant bacteria and can significantly delay the emergence of bacterial resistance. When used as a coating additive, AgPd0.38 can enable originally inert surfaces to acquire the ability to inhibit biofilm formation and reduce infection-related immune responses, which provides a new strategy for combating genetically encoded and phenotypic drug-resistant bacteria.

[0013] The above method has the following disadvantages: it only combines with the cell wall without actually decomposing the cell wall, and has poor antibacterial performance.

[0014] In summary, the following points emerge: 1. Because nanomaterials often indiscriminately damage bacteria and mammalian cells, the core problem lies in their inherently nonspecific mechanism of action. Whether through physical contact that disrupts cell membranes, the release of metal ions that interfere with bacterial function, or the generation of reactive oxygen species (ROS) that trigger oxidative stress, they indiscriminately attack both bacteria and mammalian cells. This significantly limits the practical application of nanomaterials. 2. Currently, a limited number of literature reports on several approaches to selective antibacterial nanomaterials, including photodynamic antimicrobial therapy targeting anaerobic bacteria, nanozymes that combine phage recognition with their host Escherichia coli, and a free-rider strategy using modified glucose polymers. However, these selective strategies can only discriminate between different bacteria, not between bacteria and mammalian cells. Additionally, there are reports on selectively binding nanomaterials to bacterial cell walls, but the tough cell wall is difficult to disrupt, limiting the antibacterial efficacy of the materials. These reported selective antibacterial materials suffer from technical challenges such as difficulty distinguishing between bacteria and mammalian cells, low antibacterial efficiency, difficulty in material preparation, and difficulty in industrializing their production. Summary of the Invention

[0015] In view of this, the present invention provides a BN-loaded MOF antibacterial material and its preparation method and application. The antibacterial material provided by the present invention can achieve selective antibacterial properties and has high antibacterial activity.

[0016] The present invention provides a method for preparing a BN-loaded MOF antibacterial material, comprising the following steps:

[0017] (A) H3BTC, copper chloride and water are mixed to obtain a mixture 1;

[0018] (B) mixing PVP with a solvent to obtain a mixed solution 2;

[0019] (C) mixing the mixed solution 1 with the mixed solution 2 for reaction, and then performing solid-liquid separation to obtain nano-scale MOF-199;

[0020] (D) mixing the nano-scale MOF-199 with water, and subjecting the mixture to heat treatment and etching to obtain etched nano-scale MOF-199;

[0021] (E) h-BN, NaOH, KOH, and water are mixed, heated for reaction, and then solid-liquid separation is performed to obtain exfoliated h-BN;

[0022] (F) mixing the etched nanoscale MOF-199 obtained in step (D), the stripped h-BN obtained in step (E), and a buffer solution, adding dopamine hydrochloride to react, and then performing solid-liquid separation to obtain a BN-PDA@MOF-199 nanocomposite antibacterial material;

[0023] Among the above steps, there is no particular restriction on the order of the steps.

[0024] Preferably, in step (C), the reaction temperature is 35-45° C. and the reaction time is 15-120 min.

[0025] Preferably, in step (D), the heat treatment temperature is 130-150° C., and the time is 1-5 hours.

[0026] Preferably, in step (A), the molar ratio of H3BTC to copper chloride is 1: (0.5-1.5).

[0027] Preferably, in step (C), the usage ratio of H3BTC in the mixed solution 1 to PVP in the mixed solution 2 is 1 mmol: (0.05-0.3) g.

[0028] Preferably, in step (E), the mass ratio of h-BN to NaOH is 1:(1.5-4);

[0029] The mass ratio of h-BN to KOH is 1:(0.5-1.6).

[0030] Preferably, in step (F), the mass ratio of the etched nanoscale MOF-199 obtained in step (D) to the stripped h-BN obtained in step (E) is 10:(0.2-5).

[0031] Preferably, in step (F), the buffer is a carbonate buffer;

[0032] The ratio of the etched nano-scale MOF-199 obtained in step (D) to the buffer solution is 10 g: (10-50) mL;

[0033] The reaction of adding dopamine hydrochloride comprises: adding dopamine hydrochloride dropwise until the color of the material in the system changes from blue to gray-green, then stopping the adding dropwise, and then stirring until the mixture in the system turns dark gray.

[0034] The present invention also provides a BN-loaded MOF antibacterial material prepared by the preparation method described in the above technical solution.

[0035] The present invention also provides an application of the BN-loaded MOF antibacterial material described in the above technical solution, comprising: adding the BN-loaded MOF antibacterial material to a solution to be sterilized or coating it on a surface to be sterilized.

[0036] The preparation method provided by the present invention involves reacting a mixture of H3BTC, copper chloride, and water with a PVP solution to prepare nanoscale MOF-199. This mixture is then mixed with water and subjected to heat treatment and etching to obtain etched nanoscale MOF-199. Furthermore, h-BN, NaOH, KOH, and water are mixed and heated to react to achieve exfoliation, obtaining exfoliated h-BN. The etched nanoscale MOF-199, exfoliated h-BN, and buffer are then mixed and dopamine hydrochloride is added to react, thereby forming a BN-PDA@MOF-199 nanocomposite antibacterial material. The resulting material exhibits both selective sterilization and high antibacterial activity, is simple to prepare, and is easily scalable. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0038] Figure 1 The figure is a schematic diagram of the preparation process and product characterization of the antibacterial material BN-PDA@MOF-199 of the present invention; wherein, Figure 1 a is a schematic diagram of the preparation process of the antibacterial material BN-PDA@MOF-199 of the present invention; Figure 1 b is a scanning electron microscope image of the intermediate product nano-scale MOF-199 obtained in step (C) of the preparation method of the present invention; Figure 1 c is a scanning electron microscope image of the etched nanoscale MOF-199 obtained in step (D) of the preparation method of the present invention; Figure 1 d and e are scanning electron micrographs of the final product BN-PDA@MOF-199 nanocomposite obtained by the preparation method of the present invention and its element distribution diagram; Figure 1 f is a transmission electron micrograph of the intermediate product nano-scale MOF-199 obtained in step (C) of the preparation method of the present invention; Figure 1 g is a transmission electron micrograph of the h-BN subjected to exfoliation treatment obtained in step (E) of the preparation method of the present invention; Figure 1 h is a transmission electron microscopy image of the final product BN-PDA@MOF-199 nanocomposite obtained by the preparation method of the present invention;

[0039] Figure 2 This is the effect diagram of the selective antibacterial test of the antibacterial material BN-PDA@MOF-199 of the present invention; wherein, Figure 2 a is the antibacterial activity effect diagram of BN-PDA@MOF-199 against Escherichia coli (E.coli) at different concentrations. Figure 2 b is the antibacterial activity effect diagram of BN-PDA@MOF-199 against methicillin-resistant Staphylococcus aureus (MRSA) at different concentrations. Figure 2 c is the effect diagram of bacterial inactivation rate changing with time, Figure 2 d is a comparison chart of the antibacterial effects of various antibacterial agents. Figure 2 e is the bacterial morphology effect diagram after being treated with BN-PDA@MOF-199. Figure 2 f is a microscopic image of representative mammalian cells L929 cells co-cultured with BN-PDA@MOF-199 and nanosilver;

[0040] Figure 3 This is a diagram showing the mechanism of the antibacterial material BN-PDA@MOF-199 inhibiting bacterial division; Figure 3 a is the effect of BN-PDA@MOF-199 nanocomposite in inhibiting FtsZ polymerization. Figure 3 b is the inhibitory effect of BN-PDA@MOF-199 nanocomplex on FtsZ protein GTP hydrolase activity. Figure 3 c is a diagram showing the detection effect of GTP hydrolysis product GDP. DETAILED DESCRIPTION

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0042] In this article, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0043] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0044] As used herein, when referring to numerical ranges, unless otherwise specified, the numerical ranges are considered continuous and include the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Furthermore, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges subsumed therein.

[0045] In this article, when referring to the units of a data range, if the unit is followed only by the right endpoint, it means that the units of the left and right endpoints are the same.

[0046] The present invention provides a method for preparing a BN-loaded MOF antibacterial material, comprising the following steps:

[0047] (A) H3BTC, copper chloride and water are mixed to obtain a mixture 1;

[0048] (B) mixing PVP with a solvent to obtain a mixed solution 2;

[0049] (C) mixing the mixed solution 1 with the mixed solution 2 for reaction, and then performing solid-liquid separation to obtain nano-scale MOF-199;

[0050] (D) mixing the nano-scale MOF-199 with water, and subjecting the mixture to heat treatment and etching to obtain etched nano-scale MOF-199;

[0051] (E) h-BN, NaOH, KOH, and water are mixed, heated for reaction, and then solid-liquid separation is performed to obtain exfoliated h-BN;

[0052] (F) mixing the etched nanoscale MOF-199 obtained in step (D), the stripped h-BN obtained in step (E), and a buffer solution, adding dopamine hydrochloride to react, and then performing solid-liquid separation to obtain a BN-PDA@MOF-199 nanocomposite antibacterial material;

[0053] Among the above steps, there is no particular restriction on the order of the steps.

[0054] In the present invention, among the above steps, the steps with a sequence relationship are performed in a sequence, and the steps without a sequence relationship have no special restrictions on their order. The "steps without a sequence relationship" refer to steps that do not necessarily have a sequence relationship. For example, step (A) and step (C), step (C) uses the mixed solution 1 obtained in step (A), therefore, step (A) must be performed before step (C), that is, there is a sequence relationship, and in this case, they must be performed in a sequence. For example, step (A) and step (B), etc., have no sequence relationship, therefore, their order has no special restrictions; the same applies to other steps, and no further examples are given one by one.

[0055] In the present invention, the numbers 1 and 2 in the "mixed solution 1, mixed solution 2" have no special restrictions on the substances themselves, and are only used as marks to correspond to each step for convenience and intuitiveness.

[0056] The antibacterial material obtained by the present invention is both capable of selective sterilization and has high antibacterial activity. The mechanism is that based on the difference between the division mode of bacteria and mammalian cells, the BN-PDA@MOF-199 nanocomposite inhibits the polymerization process of the FtsZ protein unique to bacterial division, interfering with bacterial division and achieving selective sterilization. It also synergizes with changes in bacterial cell membrane potential and lipid damage pathways to enhance antibacterial activity. The technological advancement of this material lies in its high antibacterial activity based on selective antibacterial properties, simple preparation, and easy scalable production, thus having great practical application prospects.

[0057] Regarding step (A):

[0058] (A) H3BTC, copper chloride and water are mixed to obtain a mixed solution 1.

[0059] In the present invention, the H3BTC, chemically known as trimesic acid, has a structure as shown in formula (1). Its source is not particularly limited and can be a commercial product or prepared according to a preparation method known in the art.

[0060]

[0061] In the present invention, the copper chloride may be anhydrous CuCl2 or hydrate CuCl2·2H2O, more preferably CuCl2·2H2O.

[0062] In the present invention, the water is preferably deionized water.

[0063] In the present invention, the molar ratio of H3BTC to copper chloride is preferably 1: (0.5-1.5), specifically 1: 0.5, 1: 1, 1: 1.5, and more preferably 1: 1. In the present invention, the amount ratio of H3BTC to water is preferably 1 mmol: (15-50) mL, specifically 1 mmol: 15 mL, 1 mmol: 20 mL, 1 mmol: 25 mL, 1 mmol: 30 mL, 1 mmol: 35 mL, 1 mmol: 40 mL, 1 mmol: 45 mL, 1 mmol: 50 mL, and more preferably 1 mmol: 25 mL.

[0064] In the present invention, H3BTC, copper chloride, and water are preferably mixed by ultrasonic treatment. The ultrasonic treatment power is preferably 50 to 500 W, specifically 50 W, 100 W, 150 W, 200 W, 250 W, 300 W, 350 W, 400 W, 450 W, or 500 W. The ultrasonic treatment time is preferably 3 to 30 minutes, specifically 3 minutes, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, or 30 minutes. After mixing, a uniformly mixed solution 1 is obtained.

[0065] Regarding step (B):

[0066] (B) PVP is mixed with a solvent to obtain a mixed solution 2.

[0067] In the present invention, the source of the PVP (polyvinyl pyrrolidone) is not particularly limited, and it can be a commercial product or prepared according to a preparation method known in the art. The present invention introduces PVP, which does not directly participate in the chemical reaction, but assists in promoting the formation of uniform octahedral MOF-199, acting as a nucleating, coordination and template. Specifically: 1. PVP can be used as a nucleating agent, adsorbed on the surface of metal ions and organic ligands, reducing their reactivity, thereby controlling the nucleation rate, making the nucleation process more uniform, avoiding the uneven crystal size and agglomeration caused by excessive local nucleation, and thus facilitating the formation of uniform MOF-199 octahedral crystals; 2. The polar groups such as amide carbonyl in the PVP molecule can coordinate with metal ions, so that the metal ions are evenly distributed in the solution, reducing the disordered aggregation of metal ions and excessive local concentrations. In the subsequent MOF growth process, metal ions can be more evenly coordinated with organic ligands to form a uniform MOF-199 structure; 3. PVP can act as a template, and the aggregation and arrangement of its molecular chains provide a template environment with a specific spatial structure for the growth of MOF-199, guiding the crystallization growth direction and morphology of MOF-199, so that it can be assembled and arranged in a specific manner, thereby obtaining a MOF-199 material with uniform structure and performance.

[0068] In the present invention, the solvent is preferably at least one of DMF (N,N-dimethylformamide), ethanol, ethylene glycol, and DMSO (dimethyl sulfoxide), more preferably DMF (N,N-dimethylformamide). The ethanol is preferably 20% to 100% ethanol, i.e., the mass concentration of ethanol is preferably 20% to 100%, specifically 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100%.

[0069] In the present invention, the usage ratio of the PVP to the solvent is preferably 0.17g:(1-10)mL, specifically 0.17g:1mL, 0.17g:2mL, 0.17g:3mL, 0.17g:4mL, 0.17g:5mL, 0.17g:6mL, 0.17g:7mL, 0.17g:8mL, 0.17g:9mL, 0.17g:10mL, more preferably 0.17g:5mL.

[0070] In the present invention, there is no particular limitation on the manner in which the PVP is mixed with the solvent, as long as the PVP is fully dissolved in the solvent. After mixing, a uniformly dissolved transparent solution, i.e., mixed solution 2, is obtained.

[0071] Regarding step (C):

[0072] (C) Mixing the mixed solution 1 and the mixed solution 2 for reaction, and then performing solid-liquid separation to obtain nano-scale MOF-199.

[0073] In the present invention, the mixing method is preferably: adding the mixed solution 2 dropwise to the mixed solution 1 under stirring. The stirring is preferably magnetic stirring. The speed of the magnetic stirring is preferably 200 to 1000 rpm, specifically 200 rpm, 300 rpm, 400 rpm, 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, or 1000 rpm.

[0074] In the present invention, when the mixed solution 1 and the mixed solution 2 are mixed, the amount ratio of H3BTC in the mixed solution 1 to PVP in the mixed solution 2 is controlled to be 1 mmol: (0.05-0.3) g, specifically 1 mmol: 0.05 g, 1 mmol: 0.10 g, 1 mmol: 0.15 g, 1 mmol: 0.17 g, 1 mmol: 0.20 g, 1 mmol: 0.25 g, 1 mmol: 0.30 g, and more preferably 1 mmol: 0.17 g.

[0075] In the present invention, the reaction temperature is preferably 35-45° C., specifically 35° C., 40° C., 45° C., and more preferably 40° C. The reaction time is preferably 15-120 min, specifically 15 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, 120 min, and more preferably 30 min.

[0076] In the present invention, after the above reaction, a metal organic framework material MOF-199 is formed in the system. Specifically, blue MOF-199 is precipitated in the system to obtain a reaction solution containing MOF-199. Then, solid-liquid separation is performed. In the present invention, the solid-liquid separation method is preferably centrifugal separation. After solid-liquid separation, washing and drying are preferably performed. The detergent used for washing is preferably an organic solvent (such as DMF, ethanol, etc.), and unreacted raw materials, PVP and other impurities are removed by washing. Then, drying is performed to obtain a pure nanoscale MOF-199 material.

[0077] In the present invention, after step (C), the materials in the system undergo the following changes:

[0078] Initial dissolution and dissociation: When H3BTC and CuCl2·2H2O are added to the organic solvent of step (B) respectively, under stirring, the highly polar aprotic solvent of step (B) can dissolve these two substances well. CuCl2·2H2O will dissociate into Cu 2+ and Cl - ions, while H3BTC will partially dissolve and exist in the solution in the form of molecules or ions.

[0079] Coordination reaction occurs: Cu 2+ The ion has an empty d orbital and can coordinate with the carboxylate oxygen atom in the H3BTC molecule. The carboxylate group (-COOH) in the H3BTC molecule loses a proton (H + ), forming carboxylate (-COO - ), and then with Cu 2+ The ions are combined by electrostatic attraction and coordination bonding. As the reaction proceeds, Cu 2+ The ions and H3BTC molecules react in a certain stoichiometric ratio to form a coordination polymer network structure of MOF-199 with a specific structure. 2+ The ions serve as metal central nodes, and the H3BTC molecules serve as organic ligands, which are connected to each other through coordination bonds to build a three-dimensional framework structure.

[0080] Polar groups such as amide carbonyl in PVP molecules can react with Cu 2+ ions have a certain coordination effect, making Cu 2+ ions are more evenly dispersed in the solution, reducing the Cu 2+ The disordered aggregation and localized high concentration of ions allow for more uniform coordination and bonding with H3BTC molecules during the subsequent coordination reaction, forming uniform MOF-199 crystals. Furthermore, PVP can selectively adsorb onto specific crystal faces of MOF-199 crystals, altering the growth rates of each facet, thereby achieving more coordinated growth in all directions and ultimately yielding nanoscale MOF-199 crystals with smaller and more uniform particle sizes. PVP molecules also exhibit a certain steric effect. Their long-chain polymer structure can form a protective layer around MOF-199 crystals, preventing direct collisions and agglomeration between crystals, further ensuring the uniform dispersion and nanoscale formation of MOF-199 crystals.

[0081] Effect of stirring: Under the above reaction temperature and magnetic stirring conditions, stirring makes the reactants in the reaction system fully mixed, accelerates the collision frequency between the reactants, and promotes Cu 2+The contact and coordination reaction rate between ions and H3BTC molecules facilitates the rapid formation of MOF-199. Stirring also prevents side reactions or uneven crystal growth caused by localized excessive concentration or overly vigorous reactions, ensuring a relatively uniform reaction and facilitating the production of nanoscale MOF-199 crystals with uniform size and morphology.

[0082] Reaction endpoint: When the reaction reaches a certain time, the coordination reaction is basically completed, and the Cu 2+ Most of the ions and H3BTC molecules are converted into MOF-199 crystals. At this time, stirring is stopped and the nano-scale MOF-199 product is collected by centrifugation, filtration, etc., and washed with an appropriate solvent (such as DMF, ethanol, etc.) to remove unreacted raw materials, PVP and other impurities. Finally, pure nano-scale MOF-199 material is obtained after drying.

[0083] During the entire reaction, CuCl2·2H2O provides Cu 2+ ions, H3BTC as an organic ligand, PVP as a structure-directing agent and stabilizer, and a strong polar aprotic solvent are used. They interact under certain temperature and stirring conditions and jointly promote the formation of nanoscale MOF-199.

[0084] Compared to commercially available products and existing preparation methods, the method for preparing nanoscale MOF-199 of the present invention has the following advantages: ① The MOF-199 prepared by this method has a size distribution between 800 and 1200 nanometers, with uniform size and complete morphology, without defect collapse; ② The appropriate size maintains sufficient specific surface area for BN loading. Moreover, compared with smaller MOF-199, MOF-199 of this size has good biocompatibility and is less likely to be internalized by cells, causing significant immune reactions or cytotoxicity, which is crucial for applications in the biomedical field. ③ The preparation method is simple, rapid, and low-cost, and can produce MOF-199 of the appropriate size and uniform distribution in the simplest way.

[0085] Regarding step (D):

[0086] (D) mixing the nano-scale MOF-199 with water, performing heat treatment and etching, and obtaining etched nano-scale MOF-199.

[0087] In the present invention, the water is preferably deionized water.

[0088] In the present invention, the usage ratio of the water to the H3BTC in step (A) is preferably (10-30) mL:1 mmol, specifically 10 mL:1 mmol, 15 mL:1 mmol, 20 mL:1 mmol, 25 mL:1 mmol, 30 mL:1 mmol, and more preferably 20 mL:1 mmol.

[0089] In the present invention, nano-scale MOF-199 is mixed with water to suspend the nano-scale MOF-199 in the water, and then heat-treated. In the present invention, the temperature of the heat treatment is preferably 130-150°C, specifically 130°C, 135°C, 140°C, 145°C, 150°C, and more preferably 140°C. The time of the heat treatment is preferably 1-5h, specifically 1h, 2h, 3h, 4h, 5h, and more preferably 3h. The present invention etches the nano-scale MOF-199 through the above-mentioned heat treatment, and after etching, uniform holes appear on the octahedron surface, which is beneficial to the loading of BN (such as Figure 1 c).

[0090] In the present invention, after the heat treatment, the product is preferably washed. The washing is preferably performed with water. The water is preferably deionized water. The washing may be repeated multiple times. After the above treatment, etched nano-scale MOF-199 is obtained.

[0091] Regarding step (E):

[0092] (E) h-BN, NaOH, KOH, and water are mixed, heated for reaction, and then solid-liquid separation is performed to obtain exfoliated h-BN.

[0093] In the present invention, the source of the h-BN (i.e., hexagonal boron nitride) is not particularly limited and can be a commercial product.

[0094] In the present invention, the mass ratio of h-BN to NaOH is preferably 1:(1.5-4), specifically 1:1.5, 1:2.0, 1:2.5, 1:2.84, 1:3.0, 1:3.5, 1:4.0, and more preferably 1:2.84. In the present invention, the mass ratio of h-BN to KOH is preferably 1:(0.5-1.6), specifically 1:0.5, 1:0.8, 1:1.0, 1:1.08, 1:1.2, 1:1.5, 1:1.6, and more preferably 1:1.08.

[0095] In the present invention, the water is preferably deionized water. In the present invention, the ratio of h-BN to water is preferably 1 g: (15-50) mL, specifically 1 g: 15 mL, 1 g: 20 mL, 1 g: 25 mL, 1 g: 30 mL, 1 g: 35 mL, 1 g: 40 mL, 1 g: 45 mL, 1 g: 50 mL, and more preferably 1 g: 30 mL.

[0096] In the present invention, the temperature of the heating reaction is preferably 160-200° C., specifically 160° C., 165° C., 170° C., 175° C., 180° C., 185° C., 190° C., 195° C., 200° C., more preferably 180° C. The heating reaction time is preferably 0.5-4 h, specifically 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, more preferably 2 h.

[0097] In the present invention, after the above-mentioned heating reaction, washing is preferably performed. The washing is preferably performed sequentially by water washing and ethanol washing. The water washing is preferably performed with deionized water. The water washing can be repeated multiple times. The ethanol washing is preferably performed with anhydrous ethanol. The ethanol washing can be repeated multiple times.

[0098] Commercially available h-BN is in block form. In step (E) of the present invention, h-BN, NaOH, KOH and water are mixed and heated to react to achieve exfoliation. Specifically, under strong alkaline conditions, NaOH and KOH will dissociate into a large amount of Na + , K + and OH - These ions can penetrate into the interlayers of h-BN under the high temperature and high pressure environment of the hydrothermal reaction. The ions inserted into the interlayers interact with the atoms in the h-BN layers, breaking the original van der Waals forces and other forces between the h-BN layers, thereby weakening the binding energy between the layers and making the h-BN layers easier to separate. In addition, strong alkali may react chemically with h-BN, corroding the surface or edge of h-BN, changing its surface structure and chemical properties, further promoting the peeling of the interlayers, and generating some soluble boron-containing compounds, which are beneficial to the dispersion and peeling of h-BN nanosheets. At the same time, OH- can form hydrogen bonds with the h-BN surface. This hydrogen bonding can further shorten the distance between water molecules and the h-BN surface, enhance the ability of water molecules to insert into the h-BN interlayers, and also destroy the layered structure of h-BN to a certain extent, which is beneficial to the peeling process.

[0099] Regarding step (F):

[0100] (F) The etched nanoscale MOF-199 obtained in step (D), the stripped h-BN obtained in step (E), and a buffer solution are mixed, and then dopamine hydrochloride is added to react, followed by solid-liquid separation to obtain a BN-PDA@MOF-199 nanocomposite antibacterial material.

[0101] In the present invention, the mass ratio of the etched nanoscale MOF-199 obtained in step (D) to the stripped h-BN obtained in step (E) is preferably 10:(0.2-5), specifically 10:0.2, 10:0.5, 10:1, 10:2, 10:3, 10:4, 10:5, and more preferably 10:1.

[0102] In the present invention, the buffer solution is preferably a carbonate buffer solution. The concentration of the carbonate buffer solution is preferably 0.1 to 0.5 mol / L, specifically 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, or 0.5 mol / L; the pH value of the carbonate buffer solution is preferably 7.8 to 9.2, specifically 7.8, 8.0, 8.5, 9.0, or 9.2, and more preferably 8.5. In the present invention, the ratio of the etched nanoscale MOF-199 obtained in step (D) to the buffer solution is preferably 10 g: (10 to 50) mL, specifically 10 g: 10 mL, 10 g: 20 mL, 10 g: 30 mL, 10 g: 40 mL, or 10 g: 50 mL, and more preferably 10 g: 30 mL.

[0103] In the present invention, the mixing method is preferably ultrasonic treatment. The power of the ultrasonic treatment is preferably 50 to 500 W, specifically 50 W, 100 W, 150 W, 200 W, 250 W, 300 W, 350 W, 400 W, 450 W, or 500 W; the time of the ultrasonic treatment is preferably 3 to 30 minutes, specifically 3 minutes, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, or 30 minutes.

[0104] In the present invention, after the above mixing, dopamine hydrochloride is added. The method of adding dopamine hydrochloride is preferably dropwise addition of dopamine hydrochloride. In the present invention, this step specifically includes: adding dopamine hydrochloride dropwise until the color of the material in the system changes from blue to gray-green, stopping the dropwise addition, and then stirring until the mixture in the system turns dark gray to obtain the final product. The stirring is preferably magnetic stirring.

[0105] In the present invention, after the above reaction, washing and drying are preferably performed. The washing is preferably performed with water. The water is preferably deionized water. The washing may be repeated multiple times. The drying is preferably performed under vacuum. The drying temperature is preferably 25-85°C, specifically 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, and more preferably 60°C. The drying time is preferably 4-12 hours, specifically 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, and more preferably 8 hours. After the above treatment, a dark gray BN-PDA@MOF-199 nanocomposite, i.e., a BN-loaded MOF antibacterial material, is obtained.

[0106] In the preamble of the present invention, MOF-199 is etched to form pores on its surface, increasing its specific surface area and surface active sites, providing more active sites for the subsequent adsorption and polymerization of dopamine, which is beneficial to improving the subsequent amount of BN loaded and the performance of the composite. The etched MOF-199 is placed in a dopamine solution. Under alkaline conditions, the amino groups in the dopamine molecules are oxidized to imino groups, which then interact with the catechol structure to cause the dopamine molecules to adsorb on the surface and in the pores of MOF-199. Over time, the dopamine molecules continue to undergo self-polymerization reactions to form a polydopamine (PDA) layer. The hydroxyl and amino groups in the dopamine molecules can form hydrogen bonds with certain groups on the surface of MOF-199, enhancing the adsorption stability of the dopamine molecules on the MOF-199 surface. The benzene rings in the dopamine molecules can also undergo π-π stacking with MOF-199, further promoting the aggregation and adsorption of dopamine molecules on the MOF-199 surface. On the other hand, active groups such as hydroxyl groups in the PDA layer can chemically bond with the exfoliated BN, thereby anchoring the BN to the PDA layer on the MOF-199 surface. Furthermore, BN nanosheets may be charged, and through electrostatic adsorption, they attract the oppositely charged PDA layer, further enabling the loading of BN on the MOF-199 surface.

[0107] The BN-PDA@MOF-199 nanocomposite consists of hexagonal boron nitride, polydopamine layer and MOF-199 substrate ( Figure 1 d, e, h), which still retains the octahedral morphology of MOF-199, but the h-BN component is obviously loaded on the surface.

[0108] The present invention also provides a BN-loaded MOF antibacterial material prepared by the preparation method described in the above technical solution. The antibacterial material obtained by the present invention can inhibit bacterial division by utilizing the difference between bacterial and mammalian cell division, thereby achieving selective antibacterial properties and high antibacterial activity.

[0109] The present invention also provides an application of the BN-loaded MOF antibacterial material described in the above technical solution, comprising: adding the BN-loaded MOF antibacterial material to a solution to be sterilized or coating it on a surface to be sterilized.

[0110] The BN-PDA@MOF-199 nanocomposite provided by the present invention has the following beneficial effects:

[0111] (1) It can achieve selective sterilization, specifically selective sterilization between bacteria and mammalian cells. The mechanism by which the material achieves selective antibacterial effect is that it inhibits the unique binary fission of bacteria, which does not occur in mammalian cells. The BN-PDA@MOF-199 nanocomposite inhibits the GTP hydrolase activity of the bacterial FtsZ protein, preventing the FtsZ monomers from polymerizing into the Z ring, making it difficult for bacteria to divide, thus achieving a selective antibacterial effect.

[0112] (2) Good antibacterial properties. It can completely inactivate 10 6 Order of magnitude of methicillin-resistant Staphylococcus aureus.

[0113] (3) The material is simple to prepare and easy to scale up production, and has good application prospects.

[0114] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0115] Example 1

[0116] 1. Preparation of BN-PDA@MOF-199 nanocomposites

[0117] (A) H3BTC (1 mmol), CuCl2·2H2O (1 mmol), and deionized water (25 mL) were added to a beaker and then sonicated at 200 W for 10 min to obtain a homogeneous mixed solution 1.

[0118] (B) PVP (0.17 g) was dissolved in DMF solvent (5 mL) to obtain a transparent mixed solution 2.

[0119] (C) Under continuous magnetic stirring, the mixture 2 obtained in step (B) was added dropwise to the mixture 1 obtained in step (A), and the mixture was reacted at 40° C. for 30 min to precipitate a blue MOF-199 product, which was then centrifuged, washed, and dried to obtain nano-scale MOF-199.

[0120] (D) The nanoscale MOF-199 obtained in step (C) was suspended in 20 mL of deionized water and heated in a reactor at 140° C. for 3 h. The product was then washed five times with deionized water to obtain etched nanoscale MOF-199.

[0121] (E) h-BN (1 g), NaOH (2.84 g), and KOH (1.08 g) were introduced into a high-pressure reactor filled with deionized water (30 mL) and reacted at 180°C for 2 h. The white h-BN product was centrifuged. The product was then washed five times with deionized water and three times with anhydrous ethanol to obtain exfoliated h-BN.

[0122] (F) The etched nanoscale MOF-199 obtained in step (D) and the exfoliated h-BN obtained in step (E) were suspended in a carbonate buffer solution (30 mL, 0.2 mol / L, pH 8.5) at a mass ratio of 10:1 and ultrasonically mixed. Dopamine hydrochloride was then added dropwise until the color of the mixture changed from blue to gray-green. The mixture was then stirred until it turned dark gray. The solid product was then isolated by centrifugation, washed five times with deionized water, and dried under vacuum at 60°C for 8 h to yield a dark gray BN-PDA@MOF-199 nanocomposite.

[0123] 2. Product characterization

[0124] The preparation process and product characterization of the antibacterial material BN-PDA@MOF-199 obtained in Example 1 are as follows Figure 1 shown; among them, Figure 1 b is a scanning electron microscope image of the intermediate product nano-scale MOF-199 obtained in step (c); Figure 1 c is a scanning electron microscope image of the etched nanoscale MOF-199 obtained in step (D); Figure 1 d, e are scanning electron microscopy images of the final product BN-PDA@MOF-199 nanocomposite and its element distribution map; Figure 1 f is a transmission electron microscopy image of the intermediate product nano-scale MOF-199 obtained in step (C); Figure 1 g is a transmission electron micrograph of the exfoliated h-BN obtained in step (E); Figure 1 h is the transmission electron microscopy image of the final product BN-PDA@MOF-199 nanocomposite. It can be seen that with the assistance of PVP, a uniform nanoscale octahedral MOF-199 precursor ( Figure 1 b, 1f). In order to provide sites for uniform loading of BN, MOF-199 was etched at 140 degrees Celsius ( Figure 1 c). Using dopamine polymerization to remove the h-BN ( Figure 1g) was bonded to the etched MOF-199, and finally the BN-PDA@MOF-199 nanocomposite was obtained ( Figure 1 d, e, h). The size of the BN-PDA@MOF-199 nanocomposite is slightly larger than that of MOF-199, which is due to the h-BN loading layer. EDS characterization of BPM shows that the Cu, B, and N elements are uniformly distributed in BPM ( Figure 1 e). These results demonstrate that h-BN was successfully loaded onto the MOF-199 surface.

[0125] 3. Selective antimicrobial testing

[0126] Escherichia coli (ATCC25922) and methicillin-resistant Staphylococcus aureus (MRSA, ATCC43300) are used as typical Gram-negative and Gram-positive bacteria; commercial nanosilver and typical antibiotics are used as control materials; L929 cells are used as typical mammalian cells, which can be purchased and passaged for long-term use.

[0127] Bacterial culture and its interaction with BN-PDA@MOF-199 nanocomplexes: Single bacterial colonies were cultured in Luria-Bertani (LB) broth at 37°C with continuous shaking for 12 hours. The bacteria were then harvested by centrifugation, washed three times with phosphate-buffered saline (PBS), and resuspended to 3.3×10 7 The bacterial suspension was then treated with different concentrations of the nanoparticles to adjust the final bacterial concentration to 3.3 × 10 6 CFU / mL. The mixture was further diluted with PBS to a bacterial concentration of 10 3 CFU / mL, and then use the spread plate technique to evenly spread it onto nutrient agar plates. After incubation at 37°C for 24 hours, the colonies were counted. The bacteria were collected and fixed with glutaraldehyde (2.5%) for 4 hours, and then dehydrated with ethanol graded (30%, 50%, 70%, 80%, 90%, 95% and 100%). The samples were then examined using an electron microscope.

[0128] L929 cell culture and its interaction with the BN-PDA@MOF-199 nanocomplex: Remove the cryovial from the liquid nitrogen tank and quickly place it in a 37°C water bath. Once completely thawed, transfer it to a clean bench. Transfer the cell suspension to a centrifuge tube, then add twice the volume of culture medium. Centrifuge at 1000 rpm for 3 minutes. After centrifugation, discard the supernatant, add an appropriate amount of culture medium, and pipette repeatedly to evenly disperse the cells. Next, inoculate an appropriate amount of the cell suspension into a culture flask, top up with culture medium, and gently shake to ensure even cell distribution. The flask is then placed in an incubator for incubation. The next day, observe cell growth under a microscope. Based on the cell growth, decide whether to change the medium or perform a subculture. Subculture can be performed when the cell density reaches 80% to 90% as observed under a microscope. First, discard the culture medium from the flask and add phosphate-buffered saline (PBS). Gently shake the flask 1-2 times to wash the cells, then discard the buffer. Add trypsin containing EDTA to the flask, ensuring that it covers the bottom of the flask. Place the flask in a 37°C CO2 incubator and digest for 3 minutes. Remove the flask and immediately observe the cells under a microscope. When approximately 80% of the cells have shrunk and become rounded, with increased spacing between them, gently tap the bottom of the flask to dislodge the remaining cells. Immediately add twice the volume of culture medium as the trypsin volume to terminate the digestion process. Gently pipette the cells to mix them evenly and prevent overdigestion. Transfer the entire cell suspension to a centrifuge tube and centrifuge at 1000 rpm for 3 minutes. Discard the supernatant, add culture medium, and resuspend the cells by pipetting. Aspirate an appropriate amount of the cell suspension based on the desired cell density and inoculate it into a new culture flask. Gently shake the flask to ensure that the cells are evenly distributed. Then, continue culturing the flask in a 37°C CO2 incubator. After the cells had grown to a certain number, they were exposed to a BN-PDA@MOF-199 nanocomposite at a concentration of 1 mg / mL. All other culture conditions were the same as those for the bacterial experiment. After a period of incubation, the cells were observed under a microscope and the experimental results were recorded.

[0129] Analysis of the result records: as attached Figure 2 As shown, Figure 2 a is the antibacterial activity effect diagram of BN-PDA@MOF-199 against Escherichia coli (E.coli) at different concentrations. Figure 2 b is the antibacterial activity effect diagram of BN-PDA@MOF-199 against methicillin-resistant Staphylococcus aureus (MRSA) at different concentrations. Figure 2 c is the effect diagram of bacterial inactivation rate changing with time, Figure 2d is a comparison chart of the antibacterial effects of various antimicrobial agents (each antimicrobial agent was tested according to the bacterial experiment shown above, with the antimicrobial agent concentration being 10 μg / mL for Escherichia coli and 0.5 μg / mL for methicillin-resistant Staphylococcus aureus). Figure 2 e is the bacterial morphology effect diagram after treatment with BN-PDA@MOF-199 (wherein, the left picture in the first row is the morphology effect diagram of Escherichia coli in the blank control group, the right picture in the first row is the morphology effect diagram of Escherichia coli after treatment with BN-PDA@MOF-199, the left picture in the second row is the morphology effect diagram of methicillin-resistant Staphylococcus aureus in the blank control group, and the right picture in the second row is the morphology effect diagram of methicillin-resistant Staphylococcus aureus after treatment with BN-PDA@MOF-199). Figure 2 f is a microscopic image of representative mammalian cells L929 cells after co-culture with BN-PDA@MOF-199 and nanosilver (from left to right are microscopic images of blank group mammalian cells L929 cells, mammalian cells L929 cells + BN-PDA@MOF-199 co-culture, and mammalian cells L929 cells + nanosilver co-culture).

[0130] Depend on Figure 2 Microscope images of E. coli, a typical bacterium, and L929 cells, a typical mammalian cell, show that 3 μg / mL of the BN-PDA@MOF-199 nanocomposite completely inactivated 3.3×106 E. coli in a neutral environment, while the minimum inhibitory concentration (MIC) for MRSA was as low as 0.35 μg / mL. The BN-PDA@MOF-199 nanocomposite rapidly inactivated bacteria within 30 minutes, exhibiting antibacterial activity superior to that of nanosilver and common antibiotics. After co-culture with L929 cells, the BN-PDA@MOF-199 nanocomposite did not significantly affect cell division and proliferation, while nanosilver, in contrast, significantly altered cell morphology, demonstrating the cell selectivity of the BN-PDA@MOF-199 nanocomposite, thus exhibiting good cytocompatibility.

[0131] 4. Exploration of the mechanism of inhibiting bacterial division

[0132] Mechanistic Exploration of the BN-PDA@MOF-199 Nanocomplex (BPM) Inhibition of Bacterial Division: FtsZ Aggregation Detected by Protein Filament Precipitation. A buffer containing 60 mM Hepes-KOH (pH 7.5), 120 mM potassium glutamate, 200 mM potassium acetate, 5 mM magnesium acetate, and 20% Ficoll (70K) was prepared. FtsZ (0.5 mg / mL) diluted in the buffer was added to an ultracentrifuge tube, followed by 10 mM GTP and the BN-PDA@MOF-199 nanocomplex. The mixture was transferred to a 24°C incubator for 2 hours and then centrifuged at 100,000 rpm for 30 minutes to precipitate the FtsZ aggregates formed during the reaction. The supernatant was transferred to a new ultracentrifuge tube, and the GTP hydrolysis product (inorganic phosphate, Pi) in the supernatant was detected using a malachite green phosphate assay kit. The supernatant was resuspended in double-distilled water and quantified using a Bradford protein concentration assay kit.

[0133] The results are as follows Figure 3 As shown, Figure 3 a is the effect of BN-PDA@MOF-199 nanocomposite in inhibiting FtsZ polymerization (where Sed represents precipitate and Sup represents supernatant). Figure 3 b is the inhibitory effect of BN-PDA@MOF-199 nanocomplex on FtsZ protein GTP hydrolase activity. Figure 3 c is the detection effect diagram of GTP hydrolysis product GDP. Figure 3 a It can be seen that when the BN-PDA@MOF-199 nanocomplex is not added to the system, a large amount of polymer protein is detected in the sediment at the bottom of the centrifuge tube after high-speed centrifugation, which corresponds to the normal occurrence of FtsZ polymerization. When the BN-PDA@MOF-199 nanocomplex is added, the protein concentration detected at the bottom of the centrifuge tube is significantly reduced, indicating that the polymerization of FtsZ is inhibited, resulting in insufficient FtsZ monomers to form aggregates and thus sedimentation. Figure 3 b It can be seen that when the hydrolysis product inorganic phosphate (Pi) is detected using the Malachite Green Phosphate Detection Kit, after adding the BN-PDA@MOF-199 nanocomplex to the system in advance to react with FtsZ, and then adding GTP to start the reaction, almost no Pi is produced. When the BN-PDA@MOF-199 nanocomplex is added at the start of the reaction and 50 minutes after the reaction, the reaction activity of FtsZ in hydrolyzing GTP is inhibited to varying degrees. This proves that the BN-PDA@MOF-199 nanocomplex can inhibit the GTPase activity of FtsZ, resulting in the inability of FtsZ monomers to polymerize, thereby preventing the bacteria from completing division and achieving selective bacterial disinfecting. Figure 3 c As can be seen, when the changes in GTP in the supernatant of the system were characterized by NMR phosphorus spectroscopy, the product detected in the system after adding the BN-PDA@MOF-199 nanocomplex was still the GTP initially added, and it was difficult to react normally to form the GDP product. This indicates that the BN-PDA@MOF-199 nanocomplex inhibited the GTPase activity of FtsZ, making the process of GTP hydrolysis to GDP difficult to occur.

[0134] Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enable any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal description of the claims, or if they include equivalent structural elements that are not substantially different from the literal description of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A method for preparing a BN-loaded MOF antibacterial material, characterized in that: The following steps are involved: (A) H3BTC, copper chloride and water are mixed to obtain a mixture 1; (B) mixing PVP with a solvent to obtain a mixed solution 2; (C) mixing the mixed solution 1 with the mixed solution 2 for reaction, and then performing solid-liquid separation to obtain nano-scale MOF-199; (D) mixing the nano-scale MOF-199 with water, and subjecting the mixture to heat treatment and etching to obtain etched nano-scale MOF-199; (E) h-BN, NaOH, KOH, and water are mixed, heated for reaction, and then solid-liquid separation is performed to obtain exfoliated h-BN; (F) mixing the etched nanoscale MOF-199 obtained in step (D), the stripped h-BN obtained in step (E), and a buffer solution, adding dopamine hydrochloride to react, and then performing solid-liquid separation to obtain a BN-PDA@MOF-199 nanocomposite antibacterial material; Among the above steps, there is no particular restriction on the order of the steps.

2. The preparation method according to claim 1, characterized in that In step (C), the reaction temperature is 35-45° C. and the reaction time is 15-120 min.

3. The preparation method according to claim 1, characterized in that In step (D), the heat treatment temperature is 130-150° C., and the time is 1-5 hours.

4. The preparation method according to claim 1, characterized in that In step (A), the molar ratio of H3BTC to copper chloride is 1: (0.5-1.5).

5. The preparation method according to claim 1, characterized in that In step (C), the usage ratio of H3BTC in the mixed solution 1 to PVP in the mixed solution 2 is 1 mmol: (0.05-0.3) g.

6. The preparation method according to claim 1, characterized in that In step (E), the mass ratio of h-BN to NaOH is 1:(1.5-4); The mass ratio of h-BN to KOH is 1:(0.5-1.6).

7. The preparation method according to claim 1, characterized in that In step (F), the mass ratio of the etched nano-scale MOF-199 obtained in step (D) to the stripped h-BN obtained in step (E) is 10:(0.2-5).

8. The preparation method according to claim 1, characterized in that In step (F), the buffer is a carbonate buffer; The ratio of the etched nano-scale MOF-199 obtained in step (D) to the buffer solution is 10 g: (10-50) mL; The reaction of adding dopamine hydrochloride comprises: adding dopamine hydrochloride dropwise until the color of the material in the system changes from blue to gray-green, then stopping the adding dropwise, and then stirring until the mixture in the system turns dark gray.

9. A BN-loaded MOF antibacterial material prepared by the preparation method according to any one of claims 1 to 8.

10. An application of the BN-loaded MOF antibacterial material according to claim 9, comprising: The BN-loaded MOF antibacterial material is added to a solution to be sterilized or coated on a surface to be sterilized.

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