Carbazole derivative-metal oxide nanoparticles, their preparation methods and applications

Abstract

This invention discloses a method for preparing carbazole derivative-metal oxide nanoparticles, comprising: 1) mixing and stirring carbazole derivatives and metal salts in different proportions until uniformly dispersed in a polar solvent to obtain a dispersion; 2) transferring the dispersion to a reaction vessel and reacting at 150–250°C for 2–20 h; 3) after the reaction is complete, centrifuging, washing, and drying to obtain carbazole derivative-metal oxide nanoparticles. This invention coordinates and assembles carbazole derivatives containing antibacterial fragments with metal oxides to obtain carbazole derivative-metal oxide nanoparticles, which can synergistically kill bacteria through a combination of chemikinetic and photothermal effects, greatly improving antibacterial efficiency. This invention determines the optimal reaction conditions for achieving peroxidase-like activity by changing the feed ratio of carbazole derivatives to metal salts, reaction time, and reaction temperature, thereby determining the optimal reaction conditions for antibacterial effect.

Description

Technical Field

[0001] This invention relates to the field of antibacterial nanomaterials technology, and particularly to carbazole derivative-metal oxide nanoparticles, their preparation methods, and applications. Background Technology

[0002] Bacterial infections are a growing health problem, posing a serious threat to global public health. Traditional treatments primarily rely on antibiotics. However, antibiotic use leads to the emergence of drug-resistant bacteria and "superbugs," posing a significant threat to the treatment of various bacterial infections. The rapid development and application of nanotechnology has brought new ideas for exploring novel antibacterial pathways. Existing research shows that the excellent antibacterial properties of nanomaterials in chemokinetic therapy and photothermal therapy have been extensively studied. Carbazole groups are a common antibacterial segment, and carbazole and its derivatives are important nitrogen-containing aromatic heterocyclic compounds with advantages such as large rigid planar structures and relatively stable free radical cations. Their antibacterial properties are often enhanced by introducing active functional groups on C and N. Introducing an acetic acid group on the N of carbazole enhances its electrostatic adsorption and hydrogen bonding, thereby promoting its assembly and mating with metal oxides. However, most existing technologies study the catalytic and photoelectric properties of carbazole metal complexes. For example, CN105732593A discloses a novel carbazole dipyrrolemethane metal complex with unique structure and oxidation catalytic activity, but does not mention its antibacterial properties. Furthermore, a search revealed that existing technologies have not disclosed any metal oxide nanomaterials based on carbazole derivatives and their application in antibacterial applications, resulting in limited research on the peroxidase-like activity and antibacterial properties of such materials. To obtain a non-antibiotic-dependent nanomaterial with excellent antibacterial properties, this invention is proposed, providing a carbazole derivative-metal oxide nanomaterial for antibacterial purposes. Summary of the Invention

[0003] To achieve the above-mentioned objectives, the present invention provides the following technical solution after research:

[0004] The first aspect of the present invention provides a method for preparing carbazole derivative-metal oxide nanoparticles, comprising the following steps:

[0005] 1) Mix carbazole derivatives and metal salts in different proportions and stir until uniformly dispersed in a polar solvent to obtain a dispersion;

[0006] 2) Transfer the dispersion to a reaction vessel and react at 150–250°C for 2–20 hours;

[0007] 3) After the reaction is complete, the carbazole derivative-metal oxide nanoparticles are obtained by centrifugation, washing and drying.

[0008] Preferably, in step 1), the carbazole derivative is N-carbazole acetic acid (CAA) or carbofen (CPF), with N-carbazole acetic acid (CAA) being more preferred.

[0009] Preferably, in step 1), the metal salt can be selected from at least one of copper salt, iron salt, manganese salt, and zinc salt. More preferably, the metal salt is copper acetate, zinc nitrate, or ferric chloride, with copper acetate being the most preferred.

[0010] Preferably, in step 1), the mass ratio of the carbazole derivative to the metal salt is 1:0.4 to 3.0, more preferably 1:1 to 2.0, and even more preferably 1:1.7 to 2.0.

[0011] Preferably, in step 1), the polar solvent is methanol, ethanol, or water; preferably, the polar solvent is methanol.

[0012] Preferably, in step 1), the mass fraction of the carbazole derivative in the dispersion is 1-30%. More preferably, the mass fraction is 1-20%, and more preferably 1-15%.

[0013] Preferably, in step 2), the reaction vessel is a polytetrafluoroethylene (PTFE) vessel.

[0014] Preferably, in step 2), the reaction temperature is 150–250°C, more preferably 180–220°C.

[0015] Preferably, in step 2), the reaction time is 2 to 20 hours, more preferably 4 to 12 hours.

[0016] The centrifugation step according to the present invention is for separating carbazole derivative-metal oxide nanoparticles from the reaction solution, and can be performed according to conventional centrifugation parameters. In a typical embodiment, the centrifugation speed is 9000 r / min and the centrifugation time is 6 min.

[0017] A second aspect of the present invention provides carbazole derivative-metal oxide nanoparticles prepared according to the above preparation method, preferably, the carbazole derivative-metal oxide nanoparticles have a particle size of 200-500 nm and a spherical morphology.

[0018] A third aspect of the present invention provides the use of carbazole derivative-metal oxide nanoparticles in the preparation of medical devices and in vivo / in vitro antibacterial products.

[0019] Preferably, the in vitro antibacterial product is an antibacterial dressing.

[0020] Preferably, the antibacterial dressing is a dressing for treating infections caused by drug-resistant pathogens, wherein the drug-resistant pathogens are selected from one or more of Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Escherichia coli, Proteus, Shigella dysenteriae, and Salmonella typhi.

[0021] Compared with the prior art, the beneficial effects of the present invention include at least the following:

[0022] 1. This invention is the first to prepare antibacterial nanoparticles based on the coordination assembly of carbazole derivatives and metal oxides. The nanoparticles possess peroxidase-like activity, killing bacteria by generating hydroxyl radicals (·OH); simultaneously, this nanomaterial exhibits high photothermal conversion efficiency in the near-infrared region, enabling sterilization through the generated excessive heat. Therefore, the carbazole derivative-metal oxide nanoparticles prepared in this invention can achieve synergistic sterilization through a dual action of chemodynamics and photothermal action, significantly improving antibacterial efficiency.

[0023] 2. In order to obtain the best antibacterial effect, the present invention optimizes the reaction conditions for preparing nanoparticles by using different feed ratios and different reaction times through solvothermal methods, which can produce the best peroxidase-like activity and inhibit and kill bacteria in the near-infrared region.

[0024] 3. The carbazole derivative-metal oxide nanoparticles of the present invention have good biocompatibility and are expected to be used in clinical antibacterial applications, thereby providing more efficient and safe methods for clinical antimicrobial therapy and helping to solve clinical treatment problems such as increasingly serious drug resistance, stubborn pathogenic microorganisms and newly emerging harmful microorganisms.

[0025] 4. The carbazole derivative-metal oxide nanoparticles of this invention are simple to operate and easy to mass-produce as antibacterial materials. Attached Figure Description

[0026] Figure 1 This is a scanning electron microscope image and particle size distribution diagram of CAA-Cu2O-11NPs obtained in Example 8 of the present invention.

[0027] Figure 2 This is the X-ray diffraction pattern of CAA-Cu2O-11NPs obtained in Example 8 of the present invention.

[0028] Figure 3 This is a photothermal change curve of CAA-Cu2O-11NPs obtained in Example 8 of the present invention.

[0029] Figure 4 This is the UV-Vis absorption spectrum of CAA-Cu2O-11NPs obtained in Example 8 of the present invention.

[0030] Figure 5This is a graph showing the in vitro inhibitory effect of CAA-Cu2O-11NPs obtained in Example 8 of the present invention on Staphylococcus aureus.

[0031] Figure 6 This refers to the hemolysis rate of CAA-Cu2O-11NPs obtained in Example 8 of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Examples of the embodiments are shown in the accompanying drawings. It should be understood that the specific embodiments described in the following embodiments of the invention are merely illustrative examples of specific implementations of the invention and are intended to explain the invention, but do not constitute a limitation thereof.

[0033] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. In the description of this application, unless otherwise stated, the terms "an," "a plurality of," and similar terms mean two or more.

[0034] The first aspect of the present invention provides a method for preparing carbazole derivative-metal oxide nanoparticles, comprising the following steps:

[0035] 1) Mix carbazole derivatives and metal salts in different proportions and stir until uniformly dispersed in a polar solvent to obtain a dispersion;

[0036] 2) Transfer the dispersion to a reaction vessel and react at 150–250°C for 2–20 hours;

[0037] 3) After the reaction is complete, the carbazole derivative-metal oxide nanoparticles are obtained by centrifugation, washing and drying.

[0038] According to the present invention, the carbazole derivative contains a carboxylic acid group and has the potential for coordination self-assembly with metal oxides, such as N-carbazole acetic acid (CAA) and carbofen (CPF). In step 1), the carbazole derivative is CAA or CPF, preferably CAA.

[0039] According to the present invention, a metal salt refers to a compound composed of a metal ion with a +1 or higher valence and an anion, having the ability to coordinate with carbazole derivatives. The metal ion may be a transition metal ion, including at least one selected from zinc ions, copper ions, iron ions, manganese ions, cobalt ions, nickel ions, or silver ions. The anion may be, for example, acetate ions, nitrate ions, sulfate ions, or chloride ions. Preferably, in step 1), the metal salt may be selected from at least one selected from copper salts, iron salts, manganese salts, and zinc salts. More preferably, the metal salt is copper acetate, zinc nitrate, or ferric chloride, with copper acetate being the most preferred.

[0040] Preferably, in step 1), the mass ratio of the carbazole derivative to the metal salt is 1:0.4 to 3.0, more preferably 1:1 to 2.0, and even more preferably 1:1.7 to 2.0.

[0041] According to the present invention, the polar solvent is a solvent that does not participate in the reaction, specifically, it can be methanol, ethanol, or water, preferably methanol. Preferably, in step 1), the polar solvent is methanol.

[0042] According to the present invention, in step 1), considering the influence on obtaining nanoparticles with the ideal morphology, if the mass fraction of the carbazole derivative in the dispersion is too high or too low, it will result in nanoparticles with the undesirable morphology. Preferably, in step 1), the mass fraction of the carbazole derivative in the dispersion is 1-30%. More preferably, the mass fraction is 1-20%, and more preferably 1-15%.

[0043] According to the present invention, the reaction vessel described herein is a commonly used reaction vessel, such as a polytetrafluoroethylene (PTFE) vessel.

[0044] According to the present invention, the reaction temperature refers to the preset temperature of the instrument and the temperature that can be maintained for a corresponding time, while there is no limitation on the time for reaching the preset temperature. Preferably, in step 2), the reaction temperature is 150-250°C, more preferably 180-220°C.

[0045] According to the present invention, the different reaction times are started when a preset temperature is reached. Preferably, in step 2), the reaction time is 2 to 20 hours, more preferably 4 to 12 hours.

[0046] The centrifugation step according to the present invention is for separating carbazole derivative-metal oxide nanoparticles from the reaction solution, and can be performed according to conventional centrifugation parameters. In a typical embodiment, the centrifugation speed is 9000 r / min and the centrifugation time is 6 min.

[0047] A second aspect of the present invention provides carbazole derivative-metal oxide nanoparticles prepared according to the above-described preparation method. According to preferred preparation parameters, the particle size of the carbazole derivative-metal oxide nanoparticles is 200–500 nm, and the morphology is spherical. Typical carbazole derivative-metal oxide nanoparticles are CAA-M... x O y NPs (N-carbazoleacetic acid-metal oxide nanoparticles) or CPF-M x O y NPs (carbofen-metal oxide nanoparticles).

[0048] A third aspect of the present invention provides the use of carbazole derivative-metal oxide nanoparticles in the preparation of medical devices and in vivo / in vitro antibacterial products.

[0049] Preferably, the in vitro antibacterial product is an antibacterial dressing.

[0050] Preferably, the antibacterial dressing is a dressing for treating infections caused by drug-resistant pathogens, wherein the drug-resistant pathogens are selected from one or more of Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Escherichia coli, Proteus, Shigella dysenteriae, and Salmonella typhi.

[0051] Example 1: Preparation of CAA-Cu2O-1NPs

[0052] 40 mg of CAA and 16 mg of copper acetate were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor and reacted at 150 °C for 20 h. After the reaction was complete, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 20 mg of brownish-red CAA-Cu₂O₁NPs, with a yield of 50.0% and a photothermal conversion efficiency of 30.1%.

[0053] Example 2: Preparation of CAA-Cu2O-2NPs

[0054] 200 mg CAA and 80 mg copper acetate were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor and reacted at 210 °C for 8 h. After the reaction was complete, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 115 mg of black CAA-Cu₂O₂NPs, with a yield of 57.5% and a photothermal conversion efficiency of 35.9%.

[0055] Example 3: Preparation of CAA-Cu2O-3NPs

[0056] 200 mg CAA and 80 mg copper acetate were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor and reacted at 220 °C for 12 h. After the reaction was complete, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 105 mg of brownish-red CAA-Cu₂O₃NPs, with a yield of 52.5% and a photothermal conversion efficiency of 32.6%.

[0057] Example 4: Preparation of CAA-Cu2O-4NPs

[0058] 600 mg of CAA and 240 mg of copper acetate were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor and reacted at 250 °C for 2 h. After the reaction was complete, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 210 mg of yellowish-brown CAA-Cu₂O₄NPs, with a yield of 35.0% and a photothermal conversion efficiency of 25.4%.

[0059] Example 5: Preparation of CAA-Cu2O-5NPs

[0060] 200 mg CAA and 130 mg copper acetate were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor and reacted at 220 °C for 8 h. After the reaction was complete, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 121 mg of brownish-red CAA-Cu₂O₅NPs, with a yield of 60.5% and a photothermal conversion efficiency of 36.4%.

[0061] Example 6: Preparation of CAA-Cu2O-6NPs

[0062] 800 mg CAA and 520 mg copper acetate were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor. The temperature was set at 180 °C, and the reaction was carried out for 12 h. After the reaction was completed, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 338 mg of light brown CAA-Cu₂O₃-6NPs, with a yield of 42.3% and a photothermal conversion efficiency of 28.1%.

[0063] Example 7: Preparation of CAA-Cu2O-7NPs

[0064] 200 mg CAA and 176 mg copper acetate were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor and reacted at 250 °C for 4 h. After the reaction was complete, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 94 mg of yellowish-brown CAA-Cu₂O₇NPs, with a yield of 47.0% and a photothermal conversion efficiency of 27.2%.

[0065] Example 8: Preparation of CAA-ZnO-8NPs

[0066] 400 mg CAA and 352 mg zinc nitrate were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor. The temperature was set at 160 °C, and the reaction was carried out for 15 h. After the reaction was completed, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 172 mg of brownish-red CAA-ZnO-8NPs, with a yield of 43.0% and a photothermal conversion efficiency of 32.6%.

[0067] Example 9: Preparation of CAA-Fe2O3-9 NPs

[0068] 80 mg of CAA and 80 mg of ferric chloride were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor and reacted at 220 °C for 6 h. After the reaction was complete, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 55 mg of brownish-red CAA-Fe₂O₃⁻⁹ NPs, with a yield of 68.8% and a photothermal conversion efficiency of 34.3%.

[0069] Example 10: Preparation of CAA-Cu2O-10NPs

[0070] 200 mg of CAA and 200 mg of copper acetate were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor. The temperature was set at 180 °C, and the reaction was carried out for 12 h. After the reaction was completed, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 117 mg of brownish-red CAA-Cu₂O₃-10NPs, with a yield of 58.5% and a photothermal conversion efficiency of 32.3%.

[0071] Example 11: Preparation of CAA-Cu2O-11NPs

[0072] 200 mg CAA and 340 mg copper acetate were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor and reacted at 210 °C for 8 h. After the reaction was complete, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 177 mg of black CAA-Cu₂O₁₁NPs, with a yield of 88.5% and a photothermal conversion efficiency of 43.9%.

[0073] Example 12: Preparation of CAA-Cu2O-12NPs

[0074] 200 mg CAA and 370 mg zinc nitrate were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor. The temperature was set at 200 °C, and the reaction was carried out for 15 h. After the reaction was completed, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 132 mg of brownish-red CAA-Cu₂O₁₂NPs, with a yield of 66.0% and a photothermal conversion efficiency of 37.7%.

[0075] Example 13: Preparation of CAA-Cu2O-13NPs

[0076] 200 mg CAA and 400 mg copper acetate were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor. The temperature was set at 220 °C, and the reaction was carried out for 12 h. After the reaction was completed, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 124 mg of brownish-red CAA-Cu₂O₁₃NPs, with a yield of 62.0% and a photothermal conversion efficiency of 31.1%.

[0077] Example 14: Preparation of CAA-Cu2O-14NPs

[0078] 400 mg of CAA and 800 mg of copper acetate were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor and reacted at 240 °C for 4 h. After the reaction was complete, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 182 mg of light brown CAA-Cu₂O₁₄NPs, with a yield of 45.5% and a photothermal conversion efficiency of 28.2%.

[0079] Example 15: Preparation of CAA-Cu2O-15NPs

[0080] 200 mg of CAA and 500 mg of copper acetate were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor and reacted at 220 °C for 8 h. After the reaction was complete, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 142 mg of brownish-red CAA-Cu₂O₁₅NPs, with a yield of 71.0% and a photothermal conversion efficiency of 36.2%.

[0081] Example 16: Preparation of CAA-Cu2O-16NPs

[0082] 200 mg of CAA and 600 mg of copper acetate were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor and reacted at 180 °C for 10 h. After the reaction was complete, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 123 mg of brownish-red CAA-Cu₂O₁₆NPs, with a yield of 61.5% and a photothermal conversion efficiency of 33.6%.

[0083] Example 17: Preparation of CAA-Fe2O3-17 NPs

[0084] 400 mg of CAA and 1200 mg of ferric chloride were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor and reacted at 250 °C for 6 h. After the reaction was complete, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 183 mg of yellowish-brown CAA-Cu₂O₁₇NPs, with a yield of 45.8% and a photothermal conversion efficiency of 30.2%.

[0085] Example 18: Preparation of CPF-ZnO-18NPs

[0086] 40 mg of CPF and 40 mg of zinc nitrate were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor and reacted at 220 °C for 10 h. After the reaction was complete, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 24.6 mg of light brown CAA-Cu₂O₁₈NPs, with a yield of 61.5% and a photothermal conversion efficiency of 32.7%.

[0087] Example 19: Preparation of CPF-Cu2O-19NPs

[0088] 200 mg CPF and 400 mg copper acetate were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor and reacted at 150 °C for 18 h. After the reaction was complete, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 123 mg of light brown CAA-Cu₂O₁₉NPs, with a yield of 45.8% and a photothermal conversion efficiency of 30.2%.

[0089] Example 20: Preparation of CPF-Fe2O3-20 NPs

[0090] 400 mg CPF and 1200 mg ferric chloride were placed in a 100 mL beaker, and 40 mL of methanol was added. After stirring and dispersing evenly, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor and reacted at 250 °C for 6 h. After the reaction was complete, the mixture was centrifuged (9000 r / min) for 6 min, and the supernatant was discarded. The resulting precipitate was washed successively with methanol, deionized water, and anhydrous ethanol, and then dried under vacuum to obtain 169 mg of yellowish-brown CAA-Cu₂O₂₀NPs, with a yield of 42.3% and a photothermal conversion efficiency of 29.8%.

[0091] Example 21: Characterization of CAA-Cu2O-11NPs

[0092] (1) Electron microscopy (SEM) analysis and particle size distribution map

[0093] The morphology of the CAA-Cu2O-11NPs prepared in this invention was observed and analyzed using a scanning electron microscope (JSM7500F). The results are shown in the appendix. Figure 1 : Figure 1 a and Figure 1 b is a scanning electron microscope image of the morphology of CAA-Cu2O-11NPs, which shows that CAA-Cu2O-11NPs has a spherical structure. Figure 1 c is the particle size distribution diagram of CAA-Cu2O-11NPs, showing that the particle size of the nanoparticles is about 300 nm, further proving the morphology of CAA-Cu2O-11NPs.

[0094] (2) X-ray diffraction (XRD) analysis

[0095] The crystal structure of the CAA-Cu2O-11NPs prepared in this invention was observed and analyzed using an X-ray diffractometer (ULTIMALV). The results are shown in the appendix. Figure 2 :from Figure 2It can be seen that the XRD patterns of CAA-Cu2O-11NPs and CAA show significant differences in diffraction peaks, indicating different crystal forms, thus demonstrating the successful preparation of CAA-Cu2O-11NPs. Furthermore, the XRD pattern of CAA-Cu2O-11NPs shows that the diffraction peaks at 29.7°, 36.2°, 42.3°, 52.4°, 61.9°, 69.8°, 74.1°, and 77.5° are consistent with those of Cu2O (JCPDF No: 99-0041), which are (7.3), (100), (32.2), (1.4), (23.1), (0.4), (14.5), and (2.7).

[0096] Example 22: Investigation of the photothermal activity of CAA-Cu2O-11NPs

[0097] Using 808nm (0.5W·cm) -2 The photothermal activity of the CAA-Cu2O-11NPs prepared in this invention was detected by near-infrared light, and the results are shown in the appendix. Figure 3 : Figure 3 a shows the temperature change curves of CAA-Cu2O-11NPs aqueous solutions with different concentrations. It was found that after irradiation with an 808nm laser for 600s, the temperature of the CAA-Cu2O-11NPs aqueous solution increased significantly compared with the control group, indicating that CAA-Cu2O-11NPs has good photothermal performance and a photothermal conversion efficiency of 40.3%. Figure 3 b is an 808 nm laser irradiation (1.0 W·cm⁻¹) of a 0.25 mg / mL CAA-Cu₂O₁₁NPs aqueous solution. -2 Heating and cooling cycle curves during the process revealed that CAA-Cu2O-11NPs exhibit photothermal stability.

[0098] Example 23: Peroxidase activity analysis of CAA-Cu2O-11NPs using UV-Vis absorption spectroscopy

[0099] The CAA-Cu2ONPs prepared in this invention were analyzed for reactive oxygen species (ROS) using a UV-Vis spectrophotometer (PEERSEE TU-1810). The CAA-Cu2O-8NPs prepared in Preparation Example 11, which exhibited the best activity, were selected for further study. The results are shown in the appendix. Figure 4 : Figure 4The UV-Vis absorption spectra of CAA, Cu2O, CAA-Cu2O-11NPs, and 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2 are shown. The figures reveal characteristic peaks at 652 nm for CAA, Cu2O, and CAA-Cu2O-11NPs, with CAA-Cu2O-11NPs exhibiting the highest absorption peak, significantly higher than that of the CAA and Cu2O groups. This indicates that CAA-Cu2O-11NPs can generate a substantial amount of ROS in the presence of H2O2, far exceeding that of the other groups.

[0100] Example 24: Antibacterial Experiment of CAA-Cu2O-11NPs

[0101] 1) Preparation of primary seed culture: 100 μL of laboratory-frozen Gram-positive bacteria - Staphylococcus aureus (ATCC6538) was added to 100 mL of LB liquid medium (Haibo Biotechnology) and cultured at constant temperature with shaking for 14 h (37℃, 100 rpm) to obtain primary seed culture;

[0102] 2) Preparation of secondary seed culture: Take 100 μL of the primary seed culture obtained in 1) and transfer it to a new 100 mL LB liquid medium. The culture is then inoculated based on the absorbance (OD) of the bacterial culture at 600 nm. 600 The optimal absorbance range for bacterial concentration determination is generally between 0.6 and 0.8. This yields a secondary seed culture.

[0103] 3) Preparation of antibacterial mother liquor: Weigh an appropriate amount of hydrogen peroxide and the prepared CAA-Cu2O-11NPs and add them to the secondary seed liquor obtained in step 2). The concentration of CAA-Cu2O-11NPs is 1 μg / mL, and the concentration of hydrogen peroxide is 5 mmol. The experiment was divided into two groups: one group was not treated with light, and the other group was treated with an 808 nm laser lamp (1.0 W·cm). -2 Irradiate for 5 min, then co-culture both groups with bacteria, and incubate at a constant temperature with shaking for 30 min (37℃, 100 rpm) to obtain antibacterial stock solution. Blank control and raw material control are also set up.

[0104] 4) Observe bacterial survival using the plate count method: The bacterial suspension containing CAA-Cu2O-11NPs added in step 3) was serially diluted. The bacterial suspension containing Staphylococcus aureus was serially diluted to six concentrations, 10-10 -3 Up to 10 -8 Spread 100 μL of the diluted solution onto nutrient agar plates, with three replicates for each concentration gradient. Then, invert the plates and incubate at 37°C for 18 hours. Observe the bacterial colonies and compare their antibacterial activity. Figure 5 As shown, the CAA-Cu2O-11 material in the light-irradiated group exhibits the strongest bactericidal ability, with a bactericidal rate exceeding 90%.

[0105] Example 25, CAA-Cu2O-11NPs hemolysis experiment

[0106] The biocompatibility of CAA-Cu2O-11NPs was characterized by co-culturing erythrocytes with the prepared CAA-Cu2O-11NPs to determine whether the erythrocytes ruptured. The results are shown in the appendix. Figure 6 : Figure 6 The hemolysis rate of different concentrations of CAA-Cu2O-11NPs in physiological saline solution was measured. It was found that when the concentration of CAA-Cu2O-11NPs reached 20 μg / mL, the hemolysis rate was 4.3%. Compared with the 0.1% Triton group, the hemolysis rate was within a controllable range, indicating that CAA-Cu2O-11NPs has good biocompatibility.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and do not constitute a limitation on the content of the present invention. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including combining various technical features in any other suitable manner. These simple modifications and combinations should also be regarded as the content disclosed in the present invention and all fall within the protection scope of the present invention.

Claims

1. A method for preparing carbazole derivative-metal oxide nanoparticles, characterized in that, Includes the following steps: 1) N - Carbazole acetic acid and copper acetate were mixed and stirred at a mass ratio of 1:1.7 until uniformly dispersed in methanol to obtain a dispersion. 2) Transfer the dispersion to a reaction vessel and react at 210 °C for 8 h; 3) After the reaction is complete, the carbazole derivative-metal oxide nanoparticles are obtained by centrifugation, washing and drying.

2. The preparation method according to claim 1, characterized in that, In step 1), the mass fraction of the carbazole derivative in the dispersion is 1-15%.

3. Carbazole derivative-metal oxide nanoparticles prepared by the preparation method according to claim 1 or 2.

4. The carbazole derivative-metal oxide nanoparticles as described in claim 3, characterized in that, The particle size of the carbazole derivative-metal oxide nanoparticles is 200~500 nm.

5. The use of carbazole derivative-metal oxide nanoparticles as described in claim 3 or 4 in the preparation of in vitro antibacterial products, characterized in that, The in vitro antibacterial product is a dressing used to treat infections caused by drug-resistant pathogens, the drug-resistant pathogen being Staphylococcus aureus.

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