Ionically covalent organic framework material, and preparation method and antibacterial application thereof

Abstract

The application discloses an ion covalent organic framework material and a preparation method and antibacterial application thereof. 2+ Zn-BDTD is prepared by coordination in BDTD. The preparation process is simple and the condition is mild; experiments prove that both of the materials have high-efficiency and broad-spectrum antibacterial performance; especially, standard strains (including Escherichia coli and Staphylococcus aureus) and drug-resistant strains (including Staphylococcus aureus and Pseudomonas aeruginosa) with high concentration can be rapidly and completely killed at very low concentration, which is far beyond the prior art level. The application effectively solves the problems of traditional antibiotic drug resistance and low efficiency and high concentration of existing antibacterial materials, and has a wide application prospect in the field of biomedical anti-infection.

Description

Technical Field

[0001] This invention belongs to the field of antibacterial materials technology, specifically relating to an ionic covalent organic framework material, its preparation method, and its antibacterial applications. Background Technology

[0002] Bacterial infections are one of the major threats to human health worldwide. Their harm extends beyond local tissue inflammation and damage; more serious cases can lead to systemic infections such as sepsis, septic shock, and multiple organ failure, even threatening life. Common pathogens such as *Escherichia coli* easily cause gastrointestinal and urinary tract infections, leading to diarrhea, hemorrhagic colitis, and cystitis; *Staphylococcus aureus* easily causes skin and soft tissue infections, pneumonia, and osteomyelitis; while *Pseudomonas aeruginosa*, as an opportunistic pathogen, can invade the human body through multiple routes, causing infections in multiple sites, including the respiratory tract, urinary tract, and middle ear. For a long time, antibiotics have been the core treatment for bacterial infections. Developing novel, highly effective, and non-antibiotic antimicrobial materials that are less likely to induce bacterial resistance has become an urgent need in the fields of biomedicine and materials science.

[0003] To address this challenge, various novel antibacterial strategies, particularly antibacterial materials based on nanotechnology, have been extensively studied. Among these, photocatalytic antibacterial materials have attracted considerable attention due to their ability to generate reactive oxygen species (ROS) for sterilization. However, many materials reported in existing studies still have significant limitations and are difficult to meet practical application requirements. For example, Liu et al. (MaterialsChemistry and Physics 307 (2023) 128158.) reported a COFBDP / CD-S-3 material with ionic covalent organic framework characteristics, which, at a concentration of 63 μg / mL, required 8 min of 420 nm UV irradiation to achieve sterilization at lower concentrations (2 × 10⁻⁶). 5 Achieving a 90% sterilization rate against bacteria at concentrations of CFU / mL is possible, but its sterilization efficiency is highly dependent on the external light source, and its effectiveness against high bacterial concentrations is unknown. While the Er-Co-S composite photocatalyst material developed by Zhang et al. (Chinese Invention Patent, CN116210720A.) is active under visible light, it requires a material concentration as high as 500 μg / mL and an irradiation time as long as 60 min to achieve a sterilization rate against 5 × 10⁵ bacteria. 6 The bacterial sterilization rate reached 90.06% at CFU / mL, but the concentration used was too high, and the efficiency still needs to be improved. Wei et al. (Chinese Invention Patent, CN115886032A.) utilized Ag + Prepared photoresponsive material Ag2TaNb7O21 Even under harsh conditions of high concentration of 200 μg / mL and UV irradiation at 420 nm for 60 min, the antibacterial rate against 1x10 5 CFU / mL bacteria was only 46.2%, far from satisfactory.

[0004] In summary, although researchers have made many progresses in the field of new antibacterial materials, the existing technologies generally have the following common defects: (1) insufficient antibacterial efficiency, especially when facing high concentration of bacteria, the killing effect is significantly reduced; (2) high minimum inhibitory concentration (MIC), a large amount of material is needed to take effect, which may increase the risk of biological safety and cost; (3) single antibacterial spectrum, lack of data on the effect of clinically common drug-resistant strains. Therefore, it is of great significance to develop a new antibacterial material with low concentration, high efficiency, fast and broad-spectrum bactericidal (especially effective against drug-resistant bacteria) to overcome the problem of bacterial drug resistance. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides an ion covalent organic framework material and its preparation method and antibacterial application. The material (BDTD or Zn-BDTD) has high efficient antibacterial performance against standard strains including Escherichia coli and Staphylococcus aureus and drug-resistant strains including Staphylococcus aureus and Pseudomonas aeruginosa, and is a new antibacterial material with high efficiency, broad spectrum, low concentration and fast speed, which effectively overcomes the key technical defects of low efficiency, high concentration, long time and invalidity against drug-resistant bacteria in the existing antibacterial strategies, and provides a highly competitive solution to the global challenge of bacterial drug resistance.

[0006] The present application is realized by the following technical solutions:

[0007] A preparation method of an ion covalent organic framework material, comprising the following steps:

[0008] Step 1) 2,2'-dipyridyl-5,5'-diformaldehyde, triaminoguanidine hydrochloride, 1,4-dioxane, deionized water and acetic acid solution are sequentially added to a reaction container, and then ultrasonic treatment is performed for 15 min to obtain a uniformly dispersed solution;

[0009] Step 2) The reaction container is quickly frozen to 77 K in a liquid nitrogen bath, and degassing treatment is performed by three cycles of freezing-vacuumizing-thawing; the tube opening is sealed, and the reaction is heated at 120°C for 3 days;

[0010] Step 3) After the reaction is completed, the obtained precipitate is collected by filtration and washed with anhydrous ethanol and 1,4-dioxane several times; the obtained solid is dried at 60°C under vacuum conditions overnight, and the obtained product is named as BDTD;

[0011] Step 4) Dissolve BDTD and ZnCl2 in anhydrous ethanol, then ultrasonic treatment for 15 min to obtain a uniform dispersion system; the obtained reaction solution is refluxed at 70℃ for 12 h;

[0012] Step 5) After the reaction is completed, the solution is cooled to room temperature, the solid product is separated by filtration, and washed with anhydrous ethanol for several times to remove impurities; the obtained solid is dried at 60℃ under vacuum overnight, and the obtained product is named as Zn-BDTD.

[0013] Preferably, the concentration of 2,2'-bipyridine-5,5'-diformaldehyde in step 1) is 0.24 mmol, and the amount is 50.9 mg; the concentration of triaminoguanidine hydrochloride is 0.36 mmol, and the amount is 50.6 mg; the amount of 1,4-dioxane is 2.0 mL; the amount of deionized water is 1.0 mL; the concentration of acetic acid solution is 3 M, and the amount is 0.5 mL.

[0014] Preferably, the amount of BDTD in step 4) is 50 mg; the amount of ZnCl2 is 25 mg; the amount of anhydrous ethanol is 25 mL.

[0015] The ionically covalent organic framework material prepared by the above preparation method, the material is BDTD or Zn-BDTD; wherein, the BDTD has a structural formula as shown in formula II:

[0016]

[0017] Formula II;

[0018] The Zn-BDTD has a structural formula as shown in formula III:

[0019]

[0020] Formula III.

[0021] The ionically covalent organic framework material is used in antibiosis.

[0022] Preferably, the bacteria for antibiosis include standard strains and drug-resistant strains; the standard strains include Escherichia coli and Staphylococcus aureus; the drug-resistant strains include Staphylococcus aureus and Pseudomonas aeruginosa.

[0023] Preferably, under light conditions, when the bacteria are standard strains, the amount of BDTD is ≥50 μg / mL, and the amount of Zn-BDTD is ≥50 μg / mL; when the bacteria are drug-resistant strains, the amount of BDTD is ≥200 μg / mL, and the amount of Zn-BDTD is ≥10 μg / mL.

[0024] Preferably, the application can be carried out under light or non-light conditions.

[0025] Preferably, the light condition is formed by 405 nm wavelength ultraviolet light irradiation, the light intensity is 50 mW / cm 2 , and the light time is 30 min.

[0026] The ion covalent organic framework material is applied to preparation of an antibacterial product.

[0027] The beneficial effects of the present application are as follows:

[0028] (1) The preparation method of the material (BDTD or Zn-BDTD) of the present application is simple, convenient to operate, and mild in reaction conditions, without the need for complex and expensive equipment, which is conducive to large-scale production and practical application.

[0029] (2) The material (BDTD or Zn-BDTD) of the present application breaks through the bottleneck that existing antibacterial materials are usually only effective for standard strains but ineffective for clinically drug-resistant strains, and exhibits high-efficiency broad-spectrum antibacterial activity, especially for drug-resistant bacteria. Experiments prove that the material not only has extremely strong killing effect on standard strains (such as Escherichia coli and Staphylococcus aureus), but also exhibits ultra-high sterilization rate on multi-drug-resistant strains (such as drug-resistant Staphylococcus aureus and drug-resistant Pseudomonas aeruginosa), solving the treatment problem of drug-resistant bacterial infection.

[0030] (3) The material (BDTD or Zn-BDTD) of the present application can achieve complete sterilization at very low concentration, with extremely low minimum antibacterial concentration (MIC). Among them, Zn-BDTD can completely kill standard strains at a concentration of only 50 μg / mL for high-concentration bacteria (1×10 6 CFU / mL), and can completely kill drug-resistant strains at a concentration of only 10 μg / mL. The concentration is much lower than the similar materials mentioned in the background art, and the efficiency is much higher than the prior art, significantly reducing the use cost and potential biological toxicity of the material.

[0031] (4) The material (BDTD or Zn-BDTD) of the present application can be efficiently activated under the condition of 405 nm ultraviolet lamp (50 mW / cm 2 ) irradiation for only 30 min, achieving the best sterilization effect and realizing rapid photocatalytic response. Compared with the existing similar materials that need long-time irradiation (60 min), the treatment time is greatly shortened, the dependence on light energy is reduced, the treatment efficiency is improved, and the material is more feasible and convenient in practical application.

[0032] (5) The material (BDTD or Zn-BDTD) of the present application simultaneously solves the problem of efficient killing of standard bacteria and drug-resistant bacteria, gram-negative bacteria (such as Escherichia coli and Pseudomonas aeruginosa) and gram-positive bacteria (such as Staphylococcus aureus), and exhibits the outstanding feature of "one material with multiple functions". Due to its excellent performance, the material has great application potential in many anti-infection fields such as medical device coating, wound dressing, water treatment, food packaging, etc. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 The infrared spectrum of BDTD in Example 1 and two raw materials thereof 13 C solid-state nuclear magnetic resonance spectrum;

[0034] Figure 2 The infrared spectrum of BDTD in Example 1 and two raw materials thereof

[0035] Figure 3 The infrared spectrum of BDTD in Example 1 and two raw materials thereof

[0036] Figure 4 The scanning electron microscope images of BDTD (a) and Zn-BDTD (b) in Example 1;

[0037] Figure 5 The Zeta potential diagram of BDTD and Zn-BDTD in Example 1;

[0038] Figure 6 The antibacterial performance of BDTD and Zn-BDTD of different concentrations under different sterilization conditions (with light or without light) on 1x10 6 CFU / mL standard Staphylococcus aureus in Example 2;

[0039] Figure 7 The survival rate diagram of standard Staphylococcus aureus under different concentrations of BDTD and Zn-BDTD in Example 2;

[0040] Figure 8 The antibacterial performance of BDTD and Zn-BDTD of different concentrations under different sterilization conditions (with light or without light) on 1x10 6 CFU / mL standard Escherichia coli in Example 2;

[0041] Figure 9 The survival rate diagram of standard Escherichia coli under different concentrations of BDTD and Zn-BDTD in Example 2;

[0042] Figure 10 The antibacterial performance of BDTD and Zn-BDTD of different concentrations under different sterilization conditions (with light or without light) on 1x10 6Antibacterial performance of BDTD and Zn-BDTD against 1 x 105 CFU / mL resistant Staphylococcus aureus;

[0043] Figure 11 Survival rate of resistant Staphylococcus aureus in different concentrations of BDTD and Zn-BDTD in Example 3.

[0044] Figure 12 Antibacterial performance of BDTD and Zn-BDTD against 1 x 105 CFU / mL resistant Pseudomonas aeruginosa; 6 Antibacterial performance of BDTD and Zn-BDTD against 1 x 105 CFU / mL resistant Pseudomonas aeruginosa;

[0045] Figure 13 Survival rate of resistant Pseudomonas aeruginosa in different concentrations of BDTD and Zn-BDTD in Example 3. DETAILED DESCRIPTION

[0046] The application will be further described below in conjunction with the accompanying drawings and specific examples.

[0047] Unless otherwise specified, the technical means used in the following examples are conventional means known to those skilled in the art. The experimental methods not specified in the specific conditions are conventional methods in the art.

[0048] The materials and reagents used in the following examples can be obtained from commercial sources unless otherwise specified.

[0049] The standard strains of Escherichia coli and Staphylococcus aureus used in the following examples were obtained from Wenzhou Micro-King Microbial Technology Co., Ltd., wherein the Escherichia coli had a product number of HC-16007 and a strain number of CMCC(B)44102; the Staphylococcus aureus had a product number of HC-16005 and a strain number of CMCC(B)26003. The resistant strains of Staphylococcus aureus and Pseudomonas aeruginosa used were obtained from clinical samples of the Fourth Hospital of Suzhou University.

[0050] Example 1 Preparation of Zn-BDTD

[0051] A method for preparing an ion-covalent organic framework material Zn-BDTD, the synthesis reaction formula is shown in the following formula I, and the specific steps are as follows:

[0052]

[0053] Formula I

[0054] (1) 2,2'-Bipyridine-5,5'-dicarboxaldehyde (50.9 mg, 0.24 mmol), triaminoguanidine hydrochloride (50.6 mg, 0.36 mmol), 1,4-dioxane (2.0 mL), deionized water (1.0 mL), and 3 M acetic acid solution (0.5 mL) were sequentially added into a 10 mL Pyrex glass tube, which was then treated in an ultrasonic cleaner for 15 min to obtain a homogeneous dispersion. After that, the reaction tube was rapidly frozen to 77 K in a liquid nitrogen bath and degassed by three freeze-pump-thaw cycles. After degassing was completed, the tube was sealed and heated at 120 °C for 3 days. After the reaction was completed, the resulting precipitate was collected by filtration and washed with anhydrous ethanol and 1,4-dioxane (5.0 mL each) sequentially. Finally, the resulting solid was dried in a vacuum oven at 60 °C overnight to obtain a bright yellow powder, which was named as BDTD and its structure is shown in Formula II.

[0055]

[0056] Formula II

[0057] (2) BDTD (50 mg) and metal chloride ZnCl2(25 mg) were dissolved in 25 mL of anhydrous ethanol, which was then treated under ultrasonic conditions for 15 min to obtain a homogeneous dispersion system. The resulting reaction solution was refluxed at 70 °C for 12 h. After the reaction was completed, the solution was cooled to room temperature, and the solid product was separated by filtration and washed with anhydrous ethanol to remove impurities. Finally, the resulting solid was dried in a vacuum oven at 60 °C overnight to obtain the product, which was named as Zn-BDTD and its structure is shown in Formula III.

[0058]

[0059] Formula III

[0060] From Figure 1 the infrared spectrum shown in 13 C solid-state nuclear magnetic resonance spectrum, different types of carbon in the BDTD material can be analyzed, as shown in Figure 2 the infrared spectrum shown in Figure 3 Zn-BDTD infrared spectrum is basically consistent with the characteristic peaks of BDTD, confirming the reasonable geometric configuration described in Formula II and Formula III. Scanning electron microscope images (SEM) Figure 4 ) show that both BDTD and Zn-BDTD have porous characteristics. The above results prove the successful preparation of two ionic covalent organic framework materials, BDTD and Zn-BDTD. Zeta potential (Figure 5 Tests showed that the surface potential of Zn-BDTD was significantly higher than that of BDTD, which could effectively electrostatically adsorb onto the negatively charged bacterial surface, making it easier for ROS and metal ions to enter the bacteria and enhancing the bactericidal effect.

[0061] Example 2: Antibacterial experiment of BDTD and Zn-BDTD against standard strains

[0062] 1. Experimental Procedure

[0063] (1) Take 0.1 mL of revived standard Escherichia coli or Staphylococcus aureus bacterial solution and measure the transmittance (OD) at a wavelength of 600 nm. 600 =1), resulting in a bacterial concentration of 1×10⁻⁶. 9 CFU / mL, take a certain amount of bacterial suspension and mix it with sterile PBS solution to reduce the bacterial concentration to 1×10⁻⁶. 8 CFU / mL.

[0064] (2) Weigh out the antibacterial materials BDTD and Zn-BDTD, and add them to sterile PBS solution to prepare a suspension with a concentration of 1 mg / mL.

[0065] (3) Select a sterile 24-well plate and add 1 mL of 1×10⁻⁶ solution. 6 Add 0, 10, 20, and 50 μg of BDTD or Zn-BDTD to standard Escherichia coli or Staphylococcus aureus suspensions at CFU / mL, respectively. (For example, for a 100 μg / mL concentration, first add 0.89 mL of PBS solution to each well, then add 0.1 mL of the suspension, and finally add 0.01 mL of diluted bacterial solution, ensuring a total liquid volume of 1 mL in each well. At this point, the bacterial count in each well is 1 × 10⁻⁶.) 6 CFU), each concentration of material was tested in triplicate to eliminate errors. After spotting, the non-light group (-light) was placed directly in a 37°C incubator under air atmosphere to co-culture bacteria and antibacterial material for 24 h; the light group (+light) was incubated under a 405 nm wavelength ultraviolet lamp (50 mW / cm²). 2 Irradiate for 30 minutes, then place the well plate in a 37°C incubator with air atmosphere to co-culture the bacteria and antibacterial material for 24 hours. The control group (control / ctrl) for each concentration is the same concentration of bacterial solution without the addition of this antibacterial material.

[0066] (4) Take out the hole plate of the end of co-culture. After the concentration of the solution in the hole plate is diluted to 1 / 10 of the original, take 10 μL of the diluted liquid and drop it on the LB-medium in the culture dish, and smear it evenly with a smearing rod. Then invert the coated culture dish and place it in a 37°C constant temperature box under air atmosphere, and wait for bacterial growth for 24 h.

[0067] (5) Take out the culture dish, take a photo of the growth condition of the colonies, count the number of colonies, and calculate the bactericidal rate.

[0068] The formula for calculating the bactericidal rate is as follows:

[0069]

[0070] In the formula, the number of colonies refers to the number of bacterial colonies on the LB-medium after the culture is completed.

[0071] 2. Experimental results

[0072] (1) The antibacterial performance of BDTD and Zn-BDTD of different concentrations under light and without light against 1×10 6 CFU / mL standard Staphylococcus aureus is shown in FIGS. Figure 6 , 7 As can be seen from the figure, when the dosage of BDTD and Zn-BDTD is 50 μg / mL, the bactericidal rate of both under light conditions can reach 99%, and the bactericidal rate of both under non-light conditions is only about 20%.

[0073] (2) The antibacterial performance of BDTD and Zn-BDTD of different concentrations under light and without light against 1×10 6 CFU / mL standard Escherichia coli is shown in FIGS. Figure 8 , 9 When the dosage of BDTD and Zn-BDTD is 50 μg / mL, the bactericidal rate of BDTD under light conditions is about 80%, and the bactericidal rate of Zn-BDTD can reach 99%; the bactericidal rate of both under non-light conditions is only about 60%.

[0074] Example 3 Antibacterial experiment of BDTD and Zn-BDTD on drug-resistant strains

[0075] 1. Experimental steps

[0076] (1) Take 0.1 mL of the recovered drug-resistant Staphylococcus aureus or Pseudomonas aeruginosa bacterial liquid to measure the light transmittance (OD 600 =1) at 600 nm wavelength, obtain the bacterial liquid concentration of 1×10 9 CFU / mL, and mix a certain amount of bacterial liquid with sterile PBS solution to reduce the bacterial liquid concentration to 1×10 8 CFU / mL.

[0077] (2) Take the antibacterial material BDTD and Zn-BDTD, and add them into sterile PBS solution respectively to prepare a suspension with a concentration of 1 mg / mL.

[0078] (3) Select a sterile 24-well plate, and add 1 mL of drug-resistant Staphylococcus aureus or Pseudomonas aeruginosa liquid with a concentration of 1×10 6 CFU / mL, and add 0, 50, 100, 200 μg of BDTD or 0, 2, 5, 10 μg of Zn-BDTD respectively, and repeat the experiment three times for each concentration of the material to eliminate errors. After the plate is spotted, the non-illumination group (-light) is directly placed into an air atmosphere 37°C incubator to allow the bacteria to be co-cultured with the antibacterial material for 24 h; the illumination group (+light) is irradiated with a 405 nm wavelength ultraviolet lamp (50 mW / cm 2 ) for 30 min, and then the well plate is placed into an air atmosphere 37°C incubator to allow the bacteria to be co-cultured with the antibacterial material for 24 h. The control group (ctrl) for each concentration is the same concentration of bacteria liquid without the addition of the antibacterial material.

[0079] (4) Take out the well plate after the co-culture is completed. Dilute the solution in the well plate to 1 / 10 of the original concentration, take 10 μL of the diluted liquid, and drop it on the LB-culture medium in a culture dish, and evenly spread it with a spreader. Then, the spread culture dish is inverted and placed in an air atmosphere 37°C incubator in an air atmosphere, and bacteria growth is waited for 24 h.

[0080] (5) Take out the culture dish, take a photo of the growth condition of the bacterial colonies, count the number of bacterial colonies, and calculate the sterilization rate (the calculation formula is the same as that in Example 2).

[0081] 2, Experimental results

[0082] (1) The antibacterial performance of different concentrations of BDTD and Zn-BDTD on 1×10 6 CFU / mL drug-resistant Staphylococcus aureus with / without illumination is shown in Figure 10 , 11 From the figure, when the dosage of BDTD is 200 μg / mL and the dosage of Zn-BDTD is 10 μg / mL, the sterilization rate of both under illumination conditions can reach 99%; and the sterilization rate of both under non-illumination conditions is only about 60%.

[0083] (2) The antibacterial performance of different concentrations of BDTD and Zn-BDTD on 1×10 6 CFU / mL drug-resistant Pseudomonas aeruginosa with / without illumination is shown in Figure 12 , 13As shown in the figure, when the dosage of BDTD is 200 μg / mL and the dosage of Zn-BDTD is 10 μg / mL, the sterilization rate of BDTD under light conditions can reach about 90%, and the sterilization rate of Zn-BDTD can reach 99%; the sterilization rates of the two under dark conditions are only about 10%.

[0084] The experimental results of the above examples show that the present application realizes high-efficiency antibiosis of standard strains of Escherichia coli and Staphylococcus aureus and drug-resistant strains of Staphylococcus aureus and Pseudomonas aeruginosa by preparing ion-covalent organic framework materials. Moreover, the material of the present application can realize high-efficiency antibiosis of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa at a lower concentration under light conditions. The final result is that both BDTD and Zn-BDTD ion-covalent organic framework materials have certain antibacterial effect. Among them, the antibacterial performance of Zn-BDTD on standard Escherichia coli and Staphylococcus aureus and drug-resistant Staphylococcus aureus and Pseudomonas aeruginosa is particularly outstanding. When Zn-BDTD is 50 μg / mL (non-illumination), the sterilization rate of 1×10 6 CFU / mL standard Escherichia coli and Staphylococcus aureus is more than 50%. It is worth noting that under the condition of irradiation of a 405 nm wavelength ultraviolet lamp (50 mW / cm 2 ) for 30 min, the sterilization performance of Zn-BDTD on higher concentrations of Escherichia coli and Staphylococcus aureus is greatly improved. 20 μg / mL of Zn-BDTD has a sterilization rate of more than 99.99% on 1×10 6 CFU / mL standard Escherichia coli and Staphylococcus aureus. When Zn-BDTD is 10 μg / mL (non-illumination), the sterilization rate of 1×10 6 CFU / mL drug-resistant Staphylococcus aureus and Pseudomonas aeruginosa is more than 50%. It is worth noting that under the condition of irradiation of a 405 nm wavelength ultraviolet lamp (50 mW / cm 2 ) for 30 min, the sterilization performance of Zn-BDTD on higher concentrations of drug-resistant Staphylococcus aureus and Pseudomonas aeruginosa is greatly improved. 10 μg / mL of Zn-BDTD has a sterilization rate of more than 99.99% on 1×10 6 CFU / mL drug-resistant Staphylococcus aureus and Pseudomonas aeruginosa. The high-efficiency antibacterial performance of the ion-covalent organic framework material of the present application on Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa solves the problems of poor antibacterial effect on Escherichia coli and Staphylococcus aureus at a low material concentration and the problem of drug-resistant Staphylococcus aureus and Pseudomonas aeruginosa at a low material concentration.

[0085] The embodiments described above are only some of the embodiments of the present application, not all the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the claimed application, but only to represent selected embodiments of the present application. The scope of protection of the present application is subject to the scope of claims, and all other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

Claims

1. A method of preparing an ion-covalent organic framework material, characterized in that, Comprising the following steps: Step 1) 2,2'-bipyridine-5,5'-dicarboxaldehyde, triaminoguanidine hydrochloride, 1,4-dioxane, deionized water and acetic acid solution were sequentially added into a reaction vessel, followed by ultrasonic treatment for 15 min to obtain a uniform dispersion solution; Step 2) The reaction vessel was rapidly frozen to 77 K in a liquid nitrogen bath and degassed by three freeze-pump-thaw cycles; the tube was sealed and heated at 120°C for 3 days; Step 3) After the reaction was completed, the obtained precipitate was collected by filtration and washed with anhydrous ethanol and 1,4-dioxane several times; the obtained solid was dried at 60°C under vacuum overnight, and the obtained product was named as BDTD; Step 4) BDTD and ZnCl2 were dissolved in anhydrous ethanol, followed by ultrasonic treatment for 15 min to obtain a uniform dispersion system; the obtained reaction solution was refluxed at 70°C for 12 h; Step 5) After the reaction was completed, the solid product was separated by filtration and washed with anhydrous ethanol several times to remove impurities; the obtained solid was dried at 60°C under vacuum overnight, and the obtained product was named as Zn-BDTD.

2. The method of claim 1, wherein the ion-covalent organic framework material is prepared by the method comprising: Step 1) The concentration of 2,2'-bipyridine-5,5'-dicarboxaldehyde was 0.24 mmol, and the amount was 50.9 mg; the concentration of triaminoguanidine hydrochloride was 0.36 mmol, and the amount was 50.6 mg; the amount of 1,4-dioxane was 2.0 mL; the amount of deionized water was 1.0 mL; the concentration of acetic acid solution was 3 M, and the amount was 0.5 mL. ​ 3. The method for preparing an ionovalent organic framework material according to claim 1, characterized in that, Step 4) The amount of BDTD was 50 mg; the amount of ZnCl2 was 25 mg; the amount of anhydrous ethanol was 25 mL.

4. The ion-covalent organic framework material prepared according to the method of any one of claims 1-3, wherein, The material is BDTD or Zn-BDTD; The BDTD has a structural formula as shown in formula II: Formula II; The Zn-BDTD has a structural formula as shown in formula III: Formula III.

5. The use of the ion-covalent organic framework material of claim 4 in antibiosis.

6. Use according to claim 5, characterized in that, The bacteria for antibiosis include standard strains and drug-resistant strains; the standard strains include Escherichia coli and Staphylococcus aureus; the drug-resistant strains include Staphylococcus aureus and Pseudomonas aeruginosa.

7. Use according to claim 6, characterized in that, Under light conditions, when the bacteria are standard strains, the amount of BDTD is ≥50 μg / mL, and the amount of Zn-BDTD is ≥50 μg / mL; when the bacteria are drug-resistant strains, the amount of BDTD is ≥200 μg / mL, and the amount of Zn-BDTD is ≥10 μg / mL.

8. Use according to claim 5, characterized in that, The use can be carried out under light or non-light conditions.

9. Use according to claim 7 or 8, characterized in that, The light condition is formed by irradiation of 405 nm wavelength ultraviolet light, the light intensity is 50 mW / cm 2 , and the light time is 30 min.

10. The use of the ion-covalent organic framework material of claim 4 in the preparation of an antibacterial product.

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