Visible light driven broad-spectrum bactericidal nanofiber membrane as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of preparation of bactericidal materials, and particularly relates to a visible-light-driven broad-spectrum bactericidal nanofiber membrane and a preparation method and application thereof. The nano-fiber membrane is prepared by covalently grafting photosensitizers on the nano-fiber membrane, and the photosensitizers are vitamin B2 and vitamin K3. The visible-light-driven broad-spectrum bactericidal nanofiber membrane has a stable photosensitive characteristic, and the defect that a photosensitizer is prone to falling off is overcome through covalent grafting.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparation of bactericidal materials, and particularly relates to a visible light-driven broad-spectrum bactericidal nanofiber membrane, a preparation method thereof and an application thereof. Background Art

[0002] Polymer membrane materials (such as cellulose, polyethylene, polypropylene, etc.) are widely used in the food packaging field due to their excellent mechanical properties and chemical stability. In order to endow such materials with bactericidal functions, the prior art mainly modifies them by directly doping bactericides before forming. Although this method has a certain bactericidal effect, due to the dense structure and small specific surface area of traditional thin film materials, it is difficult for bactericides to diffuse to the surface to fully contact with pathogenic bacteria, resulting in low bactericidal efficiency. Electrospun nanofiber membrane technology is a technology that uses a strong electric field to stretch and refine polymer solutions or melts to form nanofibers, and has the characteristics of small fiber diameter, high porosity, large specific surface area, strong adsorption, good filtration performance and good mechanical properties.

[0003] However, when combining traditional bactericides with nanofiber membranes, their bactericidal efficiency will decrease with the consumption of bactericides, and the bactericidal persistence is poor. In recent years, photosensitive bactericides (such as metal oxides such as TiO2, ZnO, etc.) have provided new ideas for solving the above problems because of their characteristics of continuously generating reactive oxygen species (ROS) through photoexcitation, enabling long-term bactericidal effects.

[0004] Existing photosensitive nanofiber membranes are prepared by electrospinning after mixing photosensitizers with electrospinning stock solutions, thereby endowing the fiber membranes with photosensitive properties. However, the photosensitizers mixed in the fiber membranes are prone to falling off, which makes the fiber membranes unable to maintain stable photosensitive characteristics. In addition, such materials have problems of insufficient safety and low bactericidal efficiency, which limit their wide application in the fields of food and agricultural product packaging; the existing covalently grafted vitamin-based photosensitive nanofiber membrane VK3-nanofiber membrane is relatively stable through the chemical bond combination of VK3 and the nanofiber membrane (Patent: CN118461318A, a photosensitive nanofiber membrane and a preparation method and application thereof), but the main light absorption band of VK3 is in the ultraviolet region, which is not conducive to the application of packaging materials under visible light conditions in daily life. Summary of the Invention

[0005] The present invention develops a visible light-driven broad-spectrum bactericidal nanofiber membrane, which is obtained by covalently grafting a nanofiber membrane with photosensitizers vitamin B2 (VB2) and vitamin K3 (VK3) through a chemical reaction. Utilizing the light absorption characteristics of VB2 under visible light, the photoactivity of VK3 under visible light is excited through intermolecular energy transfer. Through experimental verification, this covalently grafted photosensitive bactericidal nanofiber membrane has efficient and stable photosensitive characteristics under visible light.

[0006] To achieve the above object, the present invention may adopt the following technical solutions:

[0007] On the one hand, the present invention provides a visible light-driven broad-spectrum bactericidal nanofiber membrane, which is prepared by covalently grafting a photosensitizer onto the nanofiber membrane. The photosensitizer includes vitamin B2 and vitamin K3.

[0008] Preferably, the above visible light-driven broad-spectrum bactericidal nanofiber membrane is prepared by first covalently grafting vitamin B2 onto the nanofiber membrane and then covalently grafting vitamin K3.

[0009] Preferably, in the above visible light-driven broad-spectrum bactericidal nanofiber membrane, the raw materials for preparing the nanofiber membrane are selected from one or more of cellulose, chitosan, polyacrylonitrile, polyester, polyamide, polyvinylidene fluoride, polymethyl methacrylate, polyvinyl alcohol, polyethylene, polyaniline or polylactic acid.

[0010] On the other hand, the present invention provides a method for preparing the visible light-driven broad-spectrum bactericidal nanofiber membrane in the present invention, which includes: (1) soaking the nanofiber membrane in a crosslinking agent for treatment; (2) soaking the treated nanofiber membrane in an aqueous solution of vitamin B2 to obtain a VB2 nanofiber membrane; (3) preparing vitamin K3 into VK3O with an epoxy structure, and soaking the VB2 nanofiber membrane in an aqueous solution of VK3O with an epoxy structure to obtain a visible light-driven broad-spectrum bactericidal nanofiber membrane.

[0011] Preferably, in the above preparation method, the crosslinking agent is selected from one or more of glutaraldehyde, formaldehyde, bis(heterocyclic methyl)hexamethylenediamine, butanetetracarboxylic acid, cyanuric chloride, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, copper sulfate or lignin methacrylate.

[0012] Preferably, in the above preparation method, the method for preparing vitamin K3 into VK3O with an epoxy structure includes: mixing vitamin K3, 2-methylimidazolyl zinc salt, acetonitrile and hydrogen peroxide, stirring and reacting, and then removing the 2-methylimidazolyl zinc salt to obtain VK3O with an epoxy structure.

[0013] More preferably, in the above preparation method, the nanofiber membrane is prepared by electrospinning the spinning dope, and the spinning dope is obtained by dissolving the raw materials for preparing the nanofiber membrane in a mixed solvent of isopropanol and water.

[0014] More preferably, in the above preparation method, the mass fraction of the raw materials for preparing the nanofiber membrane in the mixed solvent is 5%-9%; and / or in the mixed solvent, the volume ratio of isopropanol to water is 8:(1-3).

[0015] On yet another aspect, the present invention provides the use of the visible light-driven broad-spectrum bactericidal nanofiber membrane in the present invention for sterilization.

[0016] Preferably, in the above application, the bacterium is a pathogenic bacterium on the food contact surface and / or the medical device surface.

[0017] The beneficial effects of the present invention include:

[0018] (1) The visible light-driven broad-spectrum bactericidal nanofiber membrane provided by the present invention is obtained by covalently grafting the nanofiber membrane with photosensitizers VB2 and VK3 through a chemical reaction. It has been experimentally verified that this covalently grafted visible light-driven broad-spectrum bactericidal nanofiber membrane has stable photosensitive properties, and covalent grafting solves the drawback of easy shedding of photosensitizers.

[0019] (2) Under light illumination conditions, the visible light-driven broad-spectrum bactericidal nanofiber membrane provided by the present invention can generate a large amount of ROS, can effectively kill foodborne pathogenic bacteria, and can be widely applied to the packaging of food and agricultural products; it has the advantages of good application versatility, high bactericidal efficiency, and strong safety; it realizes the purpose of having stable photosensitive properties, good application versatility, high bactericidal efficiency, and strong safety. Description of the Drawings

[0020] Figure 1 It is the morphology and fiber thickness distribution diagrams of nanofiber membranes PVA-co-PE, VB2-PVA-co-PE, and VK3-VB2-PVA-co-PE;

[0021] Figure 2 It is the Fourier transform infrared spectroscopy analysis diagrams of nanofiber membranes PVA-co-PE, VB2-PVA-co-PE, and VK3-VB2-PVA-co-PE;

[0022] Figure 3 It is the XPS analysis spectra of nanofiber membranes PVA-co-PE, VB2-PVA-co-PE, and VK3-VB2-PVA-co-PE;

[0023] Figure 4 It is the DRS diffuse reflection curves of VB2 and VK3 dissolved in aqueous solution, VB2 / VK3 / PVA-co-PE blended, and VK3-VB2-PVA-co-PE under different light illumination conditions;

[0024] Figure 5 It is the water contact angles of nanofiber membranes PVA-co-PE, VB2-PVA-co-PE, and VK3-VB2-PVA-co-PE;

[0025] Figure 6AQuantitative determination results of ROS (hydrogen peroxide) generated by nanofiber membranes PVA-co-PE, VB2-PVA-co-PE, VK3-PVA-co-PE, and VK3-VB2-PVA-co-PE under D65 light illumination;

[0026] Figure 6B Quantitative determination results of ROS (hydroxyl radical) generated by nanofiber membranes PVA-co-PE, VB2-PVA-co-PE, VK3-PVA-co-PE, and VK3-VB2-PVA-co-PE under D65 light illumination;

[0027] Figure 6C Quantitative determination results of ROS (singlet oxygen) generated by nanofiber membranes PVA-co-PE, VB2-PVA-co-PE, and VK3-VB2-PVA-co-PE under D65 light illumination;

[0028] Figure 7A Bactericidal effects of nanofiber membranes PVA-co-PE, VB2-PVA-co-PE, and VK3-VB2-PVA-co-PE against Escherichia coli;

[0029] Figure 7B Bactericidal effects of nanofiber membranes PVA-co-PE, VB2-PVA-co-PE, and VK3-VB2-PVA-co-PE against Listeria monocytogenes;

[0030] Figure 7C Bactericidal cycle diagrams of nanofiber membranes PVA-co-PE, VB2-PVA-co-PE, and VK3-VB2-PVA-co-PE against Escherichia coli;

[0031] Figure 7D Bactericidal cycle diagrams of nanofiber membranes PVA-co-PE, VB2-PVA-co-PE, and VK3-VB2-PVA-co-PE against Listeria monocytogenes. Detailed implementation manners

[0032] The examples are given to better illustrate the present invention, but the content of the present invention is not limited only to the given examples. Therefore, those skilled in the art who make non-essential improvements and adjustments to the implementation manners based on the above invention content still fall within the protection scope of the present invention.

[0033] The terms used in this document are only for describing specific embodiments and are not intended to limit the present disclosure. Unless there is an obviously different meaning in the context, the expressions in the singular form include those in the plural form. As used herein, it should be understood that terms such as "including", "having", "containing" are intended to indicate the existence of features, numbers, operations, components, parts, elements, materials or combinations. The terms of the present invention are disclosed in the specification and are not intended to exclude the possibility that one or more other features, numbers, operations, components, parts, elements, materials or their combinations may exist or can be added. As used herein, depending on the circumstances, " / " can be interpreted as "and" or "or".

[0034] To better understand the present invention, the content of the present invention will be further clarified below in conjunction with specific examples, but the content of the present invention is not limited to the following examples only.

[0035] I. Preparation of visible light-driven broad-spectrum bactericidal nanofiber membrane

[0036] (I) Preparation of PVA-co-PE nanofiber membrane

[0037] (1) Mix isopropanol and water in a volume ratio of 8:2 to obtain a mixed solvent;

[0038] (2) Dissolve polyvinyl alcohol copolymer (PVA-co-PE) in the mixed solvent to obtain a copolymer solution. In the copolymer solution, the mass fraction of PVA-co-PE is 7% (7% is the mass fraction of polyvinyl alcohol copolymer (PVA-co-PE) dissolved in the mixed solvent, 7 g of PVA-co-PE is dissolved in 100 mL (80 mL isopropanol, 20 mL water) of the mixed solvent);

[0039] (3) Place the copolymer solution in an electrospinning machine to prepare nanofiber membrane PVA-co-PE. Among them, the parameters of the electrospinning machine are: voltage: 28 kV, feeding speed: 2 mL / h, spinning distance: 20 cm;

[0040] (4) Dissolve vitamin B2 (VB2) in water (concentration: 10 g / L), adjust the pH to 12.5 with triethylamine, and let it stand for several minutes until it is completely dissolved and clarified to obtain a VB2 aqueous solution;

[0041] (5) Put the nanofiber membrane PVA-co-PE into 3M NaOH solution and react for half an hour under ice bath conditions;

[0042] (6) Under ice bath conditions, put the nanofiber membrane PVA-co-PE treated in step (5) into a 10% crosslinking agent CC (cyanuric chloride) solution (for example, 10% means 5 g of cyanuric chloride is dissolved in 50 mL of 1,4-dioxane) and react for two hours;

[0043] (7) Place the nanofiber membrane PVA-co-PE processed in step (6) into the VB2 aqueous solution completely dissolved in step (4) and react at room temperature for one hour to obtain the nanofiber membrane VB2-PVA-co-PE (also known as EVOH).

[0044] (8) Wash the VB2-PVA-co-PE solution prepared in step (7) with a large amount of water and 1,4-dioxane (1,4-D), and dry it at room temperature to obtain the dried nanofiber membrane VB2-PVA-co-PE (also known as VB2-EVOH).

[0045] (II) Preparation of VK3O with epoxy structure

[0046] Mix 170 mg of VK3 (vitamin K3), 33 mg of ZIF-8 (2-methylimidazolyl zinc salt), 10 mL of MeCN (acetonitrile), and 270 mg of H2O2 (hydrogen peroxide), and then react at a reaction temperature of 70 °C, add a rotor and adjust the rotation speed to 500 rpm / min for 1.5 h; after the reaction, centrifuge at 5000 x g for 1 min (the recovered ZIF-8 can be recycled), and take the supernatant as the VK3O solution with epoxy structure; dry the VK3O solution to obtain VK3O powder.

[0047] (III) Preparation of visible light-driven broad-spectrum bactericidal nanofiber membrane and preparation of VK3-PVA-co-PE nanofiber membrane

[0048] Add the completely dried VK3O powder to water and adjust the pH to 12 until the solution is light red to obtain the VK3O aqueous solution (10 g / L); place the dried nanofiber membrane VB2-PVA-co-PE prepared above into the VK3O aqueous solution and react at 60 °C for one hour; after the reaction, wash the fiber membrane with a large amount of water and dry it at room temperature to obtain the final reaction product nanofiber membrane VK3-VB2-PVA-co-PE (also known as VK3-VB2-EVOH), which is the visible light-driven broad-spectrum bactericidal nanofiber membrane. At the same time, in order to prove the ROS generation advantage of the visible light-driven spectral bactericidal nanofiber membrane grafted with two photosensitizers, VK3-PVA-co-PE grafted with VK3 alone was prepared. Among them, as described above, xylitol with a structure similar to VB2 was grafted by the grafting method of VB2 on PVA-co-PE to control the grafting amount of VK3. The obtained xylitol-PVA-co-PE membrane was placed in the VK3O aqueous solution, reacted at 60 °C for one hour, washed with water, and dried to obtain VK3-PVA-co-PE.

[0049] II. Characterization of Visible Light-Driven Broad-Spectrum Bactericidal Nanofiber Membrane

[0050] The nanofiber membranes PVA-co-PE, VB2-PVA-co-PE, and VK3-VB2-PVA-co-PE in Example 1 were respectively subjected to morphological characterization analysis by SEM, and the results are as follows Figure 1 shown ( Figure 1 from left to right are nanofiber membrane PVA-co-PE, nanofiber membrane VB2-PVA-co-PE, and nanofiber membrane VK3-VB2-PVA-co-PE), and it can be observed that due to the swelling effect of the solvent, the fiber diameter gradually becomes thicker.

[0051] The nanofiber membranes PVA-co-PE, VB2-PVA-co-PE, and VK3-VB2-PVA-co-PE in Example 1 were respectively subjected to Fourier transform infrared spectroscopy (FT-IR) analysis, and the results are as follows Figure 2 shown, and the results show that a new peak appears at 1003 cm -1 for the ether bond C-O-C, 1556 cm -1 and 1607 cm -1 are for C═C stretching vibration, and 1419 cm -1 is for C-H bending vibration; it can be proved that VB2 is covalently grafted onto the nanofiber membrane PVA-co-PE through an ether bond.

[0052] The nanofiber membranes PVA-co-PE, VB2-PVA-co-PE, and VK3-VB2-PVA-co-PE in Example 1 were respectively subjected to XPS analysis, and the results are as follows Figure 3 shown, and the results show that due to the presence of VB2 and crosslinking agent CC in VB2-PVA-co-PE, N1s and Cl2p newly appear, and the disappearance of Cl2p in VK3-VB2-PVA-co-PE is due to the Cl on CC being replaced by VK3.

[0053] VB2 and VK3 in Example 1 were dissolved in aqueous solution, VB2 / VK3 / PVA-co-PE was blended, and VK3-VB2-PVA-co-PE were respectively subjected to DRS diffuse reflection spectroscopy analysis, and the results are as follows Figure 4 shown ( Figure 4Among them, the aqueous solution of VB2 or VK3 refers to an aqueous solution in which 100 mg of VB2 or 100 mg of VK3 is dissolved in 10 mL of water. The blending of VB2, VK3, and PVA-co-PE means dissolving 322 mg of VB2, 84 mg of VK3, and 7 g of PVA-co-PE in a mixed solution of 20 mL of water and 80 mL of isopropanol respectively, and directly spinning using the electrospinning technology with the above parameters. The results show that after covalent grafting, its photosensitive stability is significantly improved.

[0054] The water contact angles of the nanofiber membranes PVA-co-PE, VB2-PVA-co-PE, and VK3-VB2-PVA-co-PE in Example 1 were measured respectively, and the results are as Figure 5 shown. The results show that with the grafting of photosensitizers, the water contact angle gradually decreases and the hydrophilicity increases.

[0055] III. Effect test of visible light-driven broad-spectrum bactericidal nanofiber membrane

[0056] (I) ROS generation test

[0057] The nanofiber membranes PVA-co-PE, VB2-PVA-co-PE, and VK3-VB2-PVA-co-PE in Example 1 were respectively tested for the generation of ROS, and the ROS of VK3-PVA-co-PE which was not grafted with VB2 but only grafted with VK3 was quantitatively tested, including the determination of the yields of hydrogen peroxide, hydroxyl radicals, and singlet oxygen.

[0058] (1) Determination of hydrogen peroxide: First, immerse 10 mg of the nanofiber membrane in 10 mL of deionized water and treat it for a period of time under the condition of alternating D65 light and darkness (the dark condition and the light condition are intermittent. 0-20 min is the light condition, 20-40 min is the dark condition, and so on in a cycle until 140 min); after treatment, take 1 mL of deionized water and add 1 mL of reagent I (reagent I is an aqueous solution containing 66 g / L potassium iodide, 2 g / L NaOH, and 0.2 g / L ammonium molybdate tetrahydrate) and 1 mL of reagent II (20 g / L aqueous solution of potassium hydrogen phthalate), stir for 5 min, vortex for 10 s, react under the dark condition for 5 min, and then measure the absorbance at 351 nm using UV-Vis. And use the established standard curve equation c (mol / L) = (abs - 0.0942) / 13.014, where abs is the absorbance and c is the concentration of the H2O2 solution, so as to calculate the hydrogen peroxide yield.

[0059] (2) Hydroxyl radical determination: 10 mg of the nanofiber membrane was placed into 10 mL of a 50 μM p-NDA aqueous solution (p-nitroso-N,N-dimethylaniline aqueous solution). After irradiation with D65 light, the absorbance at 440 nm was measured. The standard curve was established as c (mol / L) = (abs - 0.0065) / 25577, where abs is the absorbance and c is the concentration of the p-NDA solution. Subsequently, the production of hydroxyl radicals was calculated according to the formula OH· (μg / g) = 34 × 10 -6 × Δc × 10 mL / 10 mg.

[0060] (3) Singlet oxygen test: The p-DNA and L-histidine quantitative test system was used to measure the production of 1 O2 (refer to "Photochemical Study of Vitamin K and Vitamin B Derivatives and Their Applications as Photo-induced Antimicrobial Agents"). 10 mg of the nanofiber membrane was placed into 10 mL of a p-NDA solution without histidine as a control, and 10 mL of a 1.5615 mg / mL p-NDA solution was used as the experimental group. According to the formula 1 O2 (μg / g) = 34 × 10 -6 × Δc × 10 mL / 10 mg, and thus the production of singlet oxygen was obtained.

[0061] The measurement results are as shown in Figure 6A 、 6B and 6C. The results show that only under light illumination can the visible light-driven broad-spectrum bactericidal nanofiber membrane generate ROS, and the production is higher than that of the nanofiber membranes grafted with VB2 and VK3 alone.

[0062] (II) Bactericidal effect test

[0063] The nanofiber membranes PVA-co-PE, VB2-PVA-co-PE, and VK3-VB2-PVA-co-PE in Example 1 were respectively tested for their bactericidal effects against Escherichia coli (ATCC 25922) and Listeria monocytogenes (ATCC 19111). The specific steps are as follows:

[0064] Take 100 μl of 7Log 10CFU / mL of Escherichia coli and Listeria monocytogenes were dropped onto a 1×1 cm nanofiber membrane and irradiated under D65 conditions. To prevent bacterial dehydration and death from affecting the experimental results, 10 μL of sterilized saline was added to the nanofiber membrane every 5 minutes in both the experimental group and the control group (the control group included nanofiber membranes of PVA-co-PE, VB2-PVA-co-PE, and VK3-VB2-PVA-co-PE under dark conditions) to maintain the physiological activity of the bacteria. Additionally, samples were taken at 0, 10 minutes, 20 minutes, 30 minutes, and 60 minutes within the 1-hour test time and placed into 1 mL of 1×PBS solution (composed of disodium hydrogen phosphate, sodium dihydrogen phosphate, and sodium chloride, without calcium and magnesium ions; this reagent is a 20× concentrate and is diluted to 1× for use, with a pH value of approximately 7.2 - 7.4 after dilution), and vortexed for 1 minute to evenly disperse the bacteria on the membrane in the PBS solution, followed by drop plate counting.

[0065] The results are as Figures 7A to 7D shown. The results show that under D65 conditions, the bactericidal rate was 5 Log 10 CFU / mL - 6 Log 10 CFU / mL within 30 minutes. Among them, the bactericidal rate against Escherichia coli was faster. After five cycles (a cycle refers to inoculating 10 μL of 7 Log 10 pathogenic bacteria onto the same VB2-VK3-nanofiber membrane, sterilizing for one hour (during which 10 μL of saline was added every 5 minutes), vortex-washing with saline, then inoculating and sterilizing Listeria monocytogenes or Escherichia coli for one hour, and repeating this cycle five times, with bactericidal counting performed every hour), this visible light-driven broad-spectrum bactericidal nanofiber membrane still had good bactericidal properties.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A visible light-driven broad-spectrum bactericidal nanofiber membrane, characterized in that, It is prepared by covalently grafting a photosensitizer onto a nanofiber membrane, and the photosensitizer includes riboflavin and vitamin K3.

2. The visible light-driven broad-spectrum bactericidal nanofiber membrane according to claim 1, wherein It is prepared by first covalently grafting riboflavin onto the nanofiber membrane and then covalently grafting vitamin K3.

3. The visible light-driven broad-spectrum bactericidal nanofiber membrane according to claim 1 or 2, characterized in that, The raw materials for preparing the nanofiber membrane are selected from one or more of cellulose, chitosan, polyacrylonitrile, polyester, polyamide, polyvinylidene fluoride, polymethyl methacrylate, polyvinyl alcohol, polyethylene, polyaniline or polylactic acid.

4. The preparation method of the visible light-driven broad-spectrum bactericidal nanofiber membrane according to claim 2 or 3, characterized in that, It includes: (1) Immerse the nanofiber membrane in a crosslinking agent for treatment; (2) Immerse the treated nanofiber membrane in an aqueous riboflavin solution to obtain a VB2 nanofiber membrane; (3) Prepare vitamin K3 into VK3O with an epoxy structure, and immerse the VB2 nanofiber membrane in an aqueous solution of VK3O with an epoxy structure to obtain a visible light-driven broad-spectrum bactericidal nanofiber membrane.

5. The preparation method according to claim 3, characterized in that, The crosslinking agent is selected from one or more of cyanuric chloride, glutaraldehyde, formaldehyde, bis(heterocyclic methyl)n-hexanediamine, butanetetracarboxylic acid, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, copper sulfate or lignin methacrylate.

6. The preparation method according to claim 4 or 5, characterized in that, The preparation method for preparing vitamin K3 into VK3O with an epoxy structure includes: mixing vitamin K3, 2-methylimidazolyl zinc salt, acetonitrile and hydrogen peroxide, stirring and reacting, and then removing the 2-methylimidazolyl zinc salt to obtain VK3O with an epoxy structure.

7. The preparation method according to claim 4 or 5, characterized in that The nanofiber membrane is prepared by electrospinning the spinning dope, and the spinning dope is obtained by dissolving the raw materials for preparing the nanofiber membrane in a mixed solvent of isopropanol and water.

8. The preparation method according to claim 7, characterized in that, The mass fraction of the raw materials for preparing the nanofiber membrane in the mixed solvent is 5%-9%; and / or in the mixed solvent, the volume ratio of isopropanol to water is 8:(1-3).

9. Use of the visible light-driven broad-spectrum bactericidal nanofiber membrane according to any one of claims 1 to 3 in sterilization.

10. The use according to claim 9, wherein The bacteria are pathogenic bacteria on the surface of food contact surfaces and / or medical devices.

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