Bionic pine needle nano antibacterial material as well as preparation method and application thereof

Abstract

The invention belongs to the field of synthesis of nano materials, and particularly relates to a bionic pine needle nano antibacterial material and a preparation method and application thereof, the particle size of the antibacterial material is uniform, and a single particle is of a three-dimensional spine structure composed of 80-300 ZnO nano spines. The preparation method comprises the following steps: weighing raw materials according to a preset proportion: anhydrous zinc acetate powder, a methanol organic solvent and oleylamine, and reacting at a preset temperature to prepare a ZnO bionic nano pine needle solution; and carrying out purification treatment on the ZnO bionic nano pine needle solution to obtain a ZnO bionic nano pine needle solid powder sample. The nano-antibacterial material with a unique three-dimensional spine structure, uniform size, good dispersity and excellent antibacterial performance is prepared, and antibacterial application of the nano-antibacterial material in multiple fields is explored to meet the requirements of the market for efficient, long-acting and safe antibacterial materials.

Description

Technical Field

[0001] The present invention belongs to the field of synthetic nanomaterials, and particularly relates to a bionic pine needle nano antibacterial material, a preparation method thereof and an application thereof. Background Art

[0002] At present, people's living standards are constantly rising, and the concept of health is becoming more and more deeply rooted in people's hearts. This trend has given rise to the booming antibacterial material market. Especially in the medical industry, operating rooms and wards that are related to life and death urgently need antibacterial materials to build a solid safety line for the environment; in the field of food packaging, in order to protect the safety on the tip of the tongue, the demand for antibacterial and fresh-keeping packaging materials is increasing; the textile industry is no exception. Clothing and home textile products that are close to the skin also urgently need the addition of antibacterial materials to add health protection to daily wear and home life. Therefore, the market has an extremely urgent need for high-efficiency, long-lasting and safe antibacterial materials, hoping to effectively inhibit the growth and spread of bacteria, and even efficiently kill bacteria to block their growth.

[0003] At present, metal and metal oxide nano antibacterial materials have been widely studied in recent years. Among many metal elements, gold and silver, as noble metals, have high biological safety and have always been the focus of the biological research field. At the same time, the antibacterial properties of metal nano materials largely depend on the size, shape and composition of their structures. So far, a variety of methods have been developed to synthesize metal nano materials of various shapes, such as rod-shaped, clustered, cubic, spherical, cage-shaped, etc. The main antibacterial mechanism of gold nano antibacterial materials is to affect the change of bacterial membrane potential and the decrease of ATP level, and enter the interior of bacterial cells to generate reactive oxygen species and interfere with the transcription and replication of bacterial DNA. In addition to this, silver nano particle antibacterial materials can also release silver ions, which affect bacterial respiration by directly acting on cell enzymes and proteins and cause cell toxicity from transmembrane operation, resulting in bacterial death. However, these two precious metals are too luxurious and expensive for daily use.

[0004] Zinc oxide has the advantages of environmental friendliness, good biocompatibility, wide sources, and low price, and has been widely used in production and life, especially in the antibacterial field and the cosmetic field. Zinc oxide (ZnO), as a classic light-responsive material, is a rare antibacterial agent approved by the US Food and Drug Administration (FDA). The application history of zinc oxide materials in biosafety protection and medicine has a long history, dating back to even before Christ. Zinc oxide has excellent inhibitory or killing effects on a variety of Gram-negative and Gram-positive bacteria. The photodynamic bactericidal activity of ZnO mainly depends on its wide bandgap (∼3.37 eV). However, traditional ZnO antibacterial materials can only generate reactive oxygen species (such as superoxide anions, hydroxyl radicals, etc.) through photocatalysis to damage bacterial cell membranes and DNA. Therefore, ZnO spiky nanomaterials with spiky structures that can directly bind to bacterial cell membranes and cause cell membrane rupture are urgently needed to be studied and developed. Summary of the Invention

[0005] Aiming at the deficiencies existing in the prior art, the present invention innovatively develops a bionic pine needle nano antibacterial material, its preparation method and application. A nano antibacterial material with a unique three-dimensional spiky structure, uniform size, good dispersibility and excellent antibacterial performance is prepared, and its antibacterial applications in multiple fields are explored to meet the market's demand for efficient, long-lasting and safe antibacterial materials.

[0006] To achieve the above object, the present invention is realized through the following technical solutions: In the first aspect, the present invention provides a bionic pine needle nano antibacterial material, the particle size of the antibacterial material is uniform, and a single particle is a three-dimensional spiky structure composed of 80 - 300 ZnO nano spikes.

[0007] As a further optimized scheme of the present invention, the overall particle size of the single particle is 300 - 600 nm.

[0008] In the second aspect, the present invention provides a preparation method of the bionic pine needle nano antibacterial material as described above, including the following steps: Weigh raw materials according to a preset ratio: anhydrous zinc acetate powder, methanol-based organic solvent and oleylamine, and react at a preset temperature to prepare a ZnO bionic nano pine needle solution; Purify the ZnO bionic nano pine needle solution to obtain a ZnO bionic nano pine needle solid powder sample.

[0009] As a further optimized scheme of the present invention, the molar ratio of the anhydrous zinc acetate powder, methanol-based organic solvent and oleylamine is 1 : (10 - 15) : (4 - 6).

[0010] As a further optimized solution of the present invention, the methanol-based organic solvent is a mixed solvent of methanol, methyl formate and benzyl alcohol with a volume ratio of 3:1:1.

[0011] As a further optimized solution of the present invention, the preset temperature is 130-160 °C and the reaction time is 10-14 hours.

[0012] As a further optimized solution of the present invention, the purification steps of the ZnO biomimetic nanoneedle solution include: adding isopropanol and acetone to the ZnO biomimetic nanoneedle solution, fully mixing and then centrifuging at high speed for phase separation, discarding the upper clear liquid, dissolving the lower precipitate with chloroform, then rotary evaporating the solution to dryness, dispersing and centrifuging the precipitate with isopropanol and acetone, and finally dissolving the precipitate product in tert-butanol, freezing with liquid nitrogen and drying in vacuum to obtain the ZnO biomimetic nanoneedle solid powder sample.

[0013] As a further optimized solution of the present invention, the volume of the added isopropanol and acetone is 4-6 times the volume of the ZnO biomimetic nanoneedle solution.

[0014] The reaction mechanism for synthesizing ZnO biomimetic nanoneedles is as follows: 1. The raw materials react to form zinc oxide crystal nuclei: Anhydrous zinc acetate serves as a zinc source and an oxygen source. In an oil bath environment at 130-160 °C, zinc acetate thermally decomposes into zinc ions and oxygen ions to form zinc oxide (ZnO) crystal nuclei. The methanol-based organic solvent plays a role in regulating the reaction rate and controlling the crystal growth direction. As the reaction proceeds, more zinc oxide binds to the crystal nuclei, promoting the continuous growth of the crystal nuclei.

[0015] 2. The regulation of crystal growth by oleylamine: Oleylamine acts as a ligand in the reaction. On the one hand, it coordinates with zinc ions, affects the reactivity of zinc ions and the surrounding electron cloud distribution, and thus controls the growth rate and direction of zinc oxide crystals. On the other hand, the steric hindrance effect of oleylamine molecules restricts the growth of zinc oxide crystals in certain directions, promoting their development towards a three-dimensional spike-like structure similar to pine needles. For example, oleylamine molecules may preferentially adsorb on certain crystal planes of the crystal, hindering the growth of these crystal planes, while the other unadsorbed crystal planes continue to grow, eventually forming a special morphology with spike-like shapes. The disappearance of the thiol characteristic peak at 2500-2600 in the Fourier transform infrared spectrum proves that oleylamine acts as a ligand to protect and participate in the entire reaction process, playing a key role in the final formation of the unique ZnO biomimetic nanoneedle structure.

[0016] 3. Reaction conditions promoting structure formation: An oil bath temperature of 130 - 160 °C and a reaction time of 10 - 14 hours provide suitable kinetic conditions for the above reaction. The appropriate temperature enables the raw materials to react fully, with intense enough molecular thermal motion, which is conducive to the combination of ions and the growth of crystals; while a long enough reaction time ensures that the crystal nuclei have sufficient time to grow and develop into ZnO biomimetic nanoneedle structures with specific sizes and morphologies. If the temperature is too low or the reaction time is too short, the reaction may be incomplete, unable to form a complete three-dimensional spike structure similar to a pine needle, or the generated particles may have smaller sizes and unstable structures.

[0017] In a third aspect, the present invention provides an application of the biomimetic nano antibacterial material in the antibacterial field, and the antibacterial field includes the medical industry, the food packaging field, and the textile industry.

[0018] As a further optimized solution of the present invention, the antibacterial material is applied to the surface of the environment and articles to be antibacterial by spraying.

[0019] As a further optimized solution of the present invention, the preparation method of the spray containing the antibacterial material includes: dissolving the ZnO biomimetic nanoneedle solid powder sample obtained by vacuum drying in a mixed solvent of ultrapure water and ethanol, and ultrasonicating to obtain the ZnO biomimetic nanoneedle spray.

[0020] As a further optimized solution of the present invention, the volume ratio of ultrapure water to ethanol is 1 : (5 - 10), and the ultrasonic time is 5 - 10 minutes.

[0021] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present invention first uses a hydrothermal one-step method to prepare biomimetic ZnO nanoparticles with a three-dimensional spike structure similar to a pine needle. There are various synthesis methods for existing metal and metal oxide nano antibacterial materials, but most of them have high synthesis temperatures, complex processes, or high costs. For example, the synthesis of gold and silver nano antibacterial materials often requires special equipment and complex processes, while the hydrothermal one-step method of the present invention is relatively simple to operate and can complete the transformation from raw materials to target products in the same reaction system, reducing intermediate steps, and lowering the synthesis difficulty and production cost.

[0022] The raw materials used in the preparation process, such as zinc acetate anhydrous, methanol-based organic solvents, and oleylamine, are widely sourced and relatively environmentally friendly. Compared with some traditional antibacterial materials that use toxic, harmful, or expensive raw materials in the synthesis process, the present invention is more in line with the concept of green chemistry, reducing the negative impact on the environment and at the same time reducing the safety risks in the production process.

[0023] The ZnO biomimetic nanoneedles prepared by the present invention have a three-dimensional spiky structure, which is a key feature distinguishing them from traditional ZnO antibacterial materials. Traditional ZnO antibacterial materials mainly rely on photocatalysis to generate reactive oxygen species to destroy the bacterial structure, while the materials of the present invention can not only utilize photocatalysis, but also their spiky structure can directly bind to the bacterial cell membrane, physically pierce the cell membrane, causing the leakage of bacterial contents and resulting in bacterial death. It can be clearly seen from the scanning electron microscope images that after culturing with Escherichia coli and Staphylococcus aureus, the bacterial cell membranes are pierced. This multi-mechanism antibacterial method greatly improves the antibacterial efficiency.

[0024] The ZnO biomimetic nanoneedles have uniform particle sizes and are composed of 80 - 300 ZnO nanospikes, with an overall particle size of 300 - 600 nm. This uniform size distribution ensures the stability of the material properties. In practical applications, the antibacterial effects will not vary unevenly due to particle size differences. At the same time, the particles can be uniformly and stably dispersed in ethanol or water and can be directly sprayed with a spray bottle, which is convenient to use. In contrast, some traditional antibacterial materials have problems with dispersibility and are prone to agglomeration, affecting the exertion of their antibacterial properties.

[0025] The materials of the present invention exhibit high-efficiency and broad-spectrum antibacterial properties against a variety of bacteria and fungi, and the antibacterial efficiency is higher than 99.99%. From the MIC data and the statistical charts of antibacterial efficiency, it can be seen that they have significant inhibitory effects on 7 kinds of bacteria and fungi. Existing antibacterial materials may only be effective against specific types of bacteria and do not have broad-spectrum antibacterial properties, or have low antibacterial efficiency and cannot meet the actual needs.

[0026] With its excellent antibacterial properties and good dispersibility, it has broad application prospects in many industries such as medical treatment, food packaging, and textiles. In the medical industry, it can be used for the disinfection of operating rooms and ward environments to reduce the risk of cross-infection; in the food packaging field, it can extend the shelf life of food and ensure food safety; in the textile industry, it can endow clothing and home textiles with antibacterial functions and improve the quality of life. In contrast, some traditional antibacterial materials are restricted in application fields due to issues such as safety and cost. Description of the Drawings

[0027] Figure 1 It is a schematic diagram of the synthesis process of the ZnO biomimetic nanoneedles in Example 1 of the present invention.

[0028] Figure 2 It is a transmission electron microscope image (0.5 μm) of the ZnO biomimetic nanoneedles in Example 1 of the present invention.

[0029] Figure 3 It is a transmission electron microscope image (200 nm) of the ZnO biomimetic nanoneedles in Example 1 of the present invention.

[0030] Figure 4Transmission electron microscope image of the ZnO biomimetic nanoneedles of Example 1 of the present invention.

[0031] Figure 5 Scanning electron microscope image of the ZnO biomimetic nanoneedles of Example 1 of the present invention.

[0032] Figure 6 Secondary electron microscope image of the ZnO biomimetic nanoneedles of Example 1 of the present invention.

[0033] Figure 7 High-angle annular dark-field image of the ZnO biomimetic nanoneedles of Example 1 of the present invention.

[0034] Figure 8 EDS mapping image of zinc element of the ZnO biomimetic nanoneedles of Example 1 of the present invention.

[0035] Figure 9 EDS mapping image of oxygen element of the ZnO biomimetic nanoneedles of Example 1 of the present invention.

[0036] Figure 10 High-resolution transmission electron microscope image of the ZnO biomimetic nanoneedles of Example 1 of the present invention and the diagram for measuring the crystal plane spacing, where a is the high-resolution transmission electron microscope image and b is the diagram for measuring the crystal plane spacing.

[0037] Figure 11 Ultraviolet-visible light spectrum diagram of the ZnO biomimetic nanoneedles of Example 1 of the present invention.

[0038] Figure 12 Fourier infrared spectrum diagram of the ZnO biomimetic nanoneedles of Example 1 of the present invention.

[0039] Figure 13 X-ray diffraction pattern of the ZnO biomimetic nanoneedles of Example 1 of the present invention.

[0040] Figure 14 X-ray photoelectron spectroscopy full spectrum diagram of the ZnO biomimetic nanoneedles of Example 1 of the present invention.

[0041] Figure 15 X-ray photoelectron spectroscopy zinc fine spectrum diagram of the ZnO biomimetic nanoneedles of Example 1 of the present invention.

[0042] Figure 16 MIC diagram of the ZnO biomimetic nanoneedles of Example 1 of the present invention against 7 kinds of bacteria and fungi.

[0043] Figure 17 Antibacterial efficiency statistical chart of the ZnO biomimetic nanoneedles of Example 1 of the present invention.

[0044] Figure 18 Scanning electron microscope image after culturing ZnO biomimetic nanoneedles and Escherichia coli in Example 1 of the present invention.

[0045] Figure 19 Scanning electron microscope image after culturing ZnO biomimetic nanoneedles and Staphylococcus aureus in Example 1 of the present invention.

[0046] Figure 20 Transmission electron microscope image of ZnO biomimetic nanoneedles in Comparative Example 1 of the present invention.

[0047] Figure 21 MIC graph of ZnO biomimetic nanoneedles against 7 kinds of bacteria and fungi in Comparative Example 1 of the present invention.

[0048] Figure 22 Statistical chart of antibacterial efficiency of ZnO biomimetic nanoneedles in Comparative Example 1 of the present invention.

[0049] Figure 23 Transmission electron microscope image of ZnO biomimetic nanoneedles in Comparative Example 2 of the present invention.

[0050] Figure 24 MIC graph of ZnO biomimetic nanoneedles against 7 kinds of bacteria and fungi in Comparative Example 2 of the present invention.

[0051] Figure 25 Statistical chart of antibacterial efficiency of ZnO biomimetic nanoneedles in Comparative Example 2 of the present invention. Detailed implementation manners

[0052] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the preferred implementation manners of the present invention are described below in conjunction with specific embodiments, but it should not be construed as a limitation of the present invention, and only for example.

[0053] Example 1

[0054] This example provides a preparation method of a biomimetic nanoneedle antibacterial material, including the following steps: Step 1: Synthesis of ZnO biomimetic nanoneedles: Weigh anhydrous zinc acetate powder, methanol-based organic solvents (methanol, methyl formate, and benzyl alcohol with a volume ratio of 3:1:1), and oleylamine and react them in an oil bath at 145°C for 12 hours according to a molar ratio of 1:12.5:5 to obtain a ZnO biomimetic nanoneedle solution.

[0055] Step 2: Purification of ZnO biomimetic nanoneedles: Purification of ZnO biomimetic nanoneedles: Add isopropanol and acetone with a volume 5 times that of the ZnO biomimetic nanoneedle solution in the second step above. After thorough mixing, perform high-speed centrifugation for phase separation. Discard the upper clear liquid, dissolve the lower precipitate with chloroform, then rotary evaporate the solution to dryness. Disperse and centrifuge the precipitate with isopropanol and acetone, repeat three times. Finally, dissolve the precipitate product in tert-butanol, freeze it with liquid nitrogen, and vacuum dry for 3 days to obtain a solid powder sample.

[0056] Step 3. Preparation of ZnO biomimetic nanoneedle spray: Dissolve the ZnO biomimetic nanoneedle solid powder sample obtained by vacuum drying in a mixed solvent with a volume ratio of ultrapure water to ethanol of 1:8, and ultrasonicate for 8 minutes to obtain ZnO biomimetic nanoneedle spray.

[0057] Example 2

[0058] This example provides a preparation method of a biomimetic nanoneedle antibacterial material, including the following steps: Step 1. Synthesis of ZnO biomimetic nanoneedles: Weigh anhydrous zinc acetate powder, methanol-based organic solvents (methanol, methyl formate, and benzyl alcohol with a volume ratio of 3:1:1), and oleylamine in a molar ratio of 1:10:4, and react in an oil bath at 130 °C for 10 hours to obtain a ZnO biomimetic nanoneedle solution.

[0059] Step 2. Purification of ZnO biomimetic nanoneedles: Purification of ZnO biomimetic nanoneedles: Add isopropanol and acetone with a volume 4 times that of the ZnO biomimetic nanoneedle solution in the second step above. After thorough mixing, perform high-speed centrifugation for phase separation. Discard the upper clear liquid, dissolve the lower precipitate with chloroform, then rotary evaporate the solution to dryness. Disperse and centrifuge the precipitate with isopropanol and acetone, repeat three times. Finally, dissolve the precipitate product in tert-butanol, freeze it with liquid nitrogen, and vacuum dry for 2 days to obtain a solid powder sample.

[0060] Step 3. Preparation of ZnO biomimetic nanoneedle spray: Dissolve the ZnO biomimetic nanoneedle solid powder sample obtained by vacuum drying in a mixed solvent with a volume ratio of ultrapure water to ethanol of 1:5, and ultrasonicate for 5 minutes to obtain ZnO biomimetic nanoneedle spray.

[0061] Example 3

[0062] This example provides a preparation method of a biomimetic nanoneedle antibacterial material, including the following steps: Step 1. Synthesis of ZnO biomimetic nanoneedles: Anhydrous zinc acetate powder, methanol organic solvent (methanol, methyl formate and benzyl alcohol in a volume ratio of 3:1:1) and oleylamine in a molar ratio of 1:15:6 were weighed and reacted in an oil bath at 160° C. for 14 hours to obtain a ZnO bionic nano pine needle solution.

[0063] Step 2: Purification of ZnO bionic nano pine needles: Purification of ZnO bionic nano pine needles: add 6 times the volume of isopropanol and acetone to the ZnO bionic nano pine needle solution in the above step 2, mix thoroughly and then centrifuge to separate the phases, discard the upper clear layer, dissolve the lower precipitate with chloroform, then evaporate the solution to dryness, use isopropanol and acetone to disperse and centrifuge, repeat three times, finally dissolve the precipitated product in tert-butanol, freeze with liquid nitrogen and vacuum dry for 3 days to obtain a solid powder sample.

[0064] Step 3: Preparation of ZnO bionic nano pine needle spray: The ZnO bionic nano-pine needle solid powder sample obtained by vacuum drying was dissolved in a mixed solvent of ultrapure water and ethanol in a volume ratio of 1:10, and ultrasonicated for 10 minutes to obtain a ZnO bionic nano-pine needle spray.

[0065] Comparative Example 1 The difference from Example 1 is that the anhydrous zinc acetate powder, methanol organic solvent (methanol, methyl formate and benzyl alcohol in a volume ratio of 3:1:1) and oleylamine are selected in a molar ratio of 0.5:12.5:5, and the other conditions are the same. The number of ZnO bionic nano pine needles obtained is reduced to 40-100, and the size is about 250nm.

[0066] Comparative Example 2 The difference from Example 1 is that anhydrous zinc acetate powder, methanol organic solvent (methanol, methyl formate and benzyl alcohol in a volume ratio of 3:1:1) and oleylamine are weighed in a molar ratio of 1:12.5:5 and reacted in an oil bath at 145°C for 6 hours. The other conditions are the same, and the number of ZnO bionic nano pine needles obtained is reduced to about 6, and the size is about 220nm.

[0067] Antimicrobial testing MIC determination: Inoculate the strain to be tested on the corresponding solid culture plate in advance and incubate it overnight in a bacterial incubator at 37°C. According to the experimental requirements, dilute the stock solution with LB liquid medium to the highest drug concentration to be tested. Take a sterile 96-well plate and perform drug dilution in a biosafety cabinet. The specific operation is as follows: Add 200 μL of the highest drug concentration to be tested to the first well (A1), add 100 μL of LB liquid medium to wells A2 - A12. Then, aspirate 100 μL from well A1 and add it to well A2. After mixing, aspirate 100 μL from well A2 and add it to well A3, and so on, diluting in a gradient to well A12, and discard the last 100 μL of the diluted liquid; Add 1 mL of PBS to a transparent plastic test tube; Zero the turbidity meter, then pick the strain to be tested and dissolve it thoroughly in normal saline, shake and mix well, adjust the turbidity to between 0.4 and 0.6, and continue to dilute it 20 times with PBS for standby; Add 10 μL of the diluted bacterial suspension to each well of the drug at each concentration (A1 - A12) in turn; Place the 96-well plate in a bacterial incubator at 37°C and incubate for 16 - 18 h; Read the lowest drug concentration at which no bacteria grow, which is the minimum inhibitory concentration of the bionic nanopine needles against this bacterium.

[0068] Calculation of antibacterial rate: On Luria-Bertani (LB) agar plates, using Escherichia coli (Gram-negative bacterium), Staphylococcus aureus (Gram-positive bacterium), and methicillin-resistant Staphylococcus aureus as representative bacteria, the antibacterial activity of the bionic nanopine needles was studied by the colony-forming unit (CFU) method. Escherichia coli, Staphylococcus aureus, or methicillin-resistant Staphylococcus aureus was cultured in LB medium. The original bacterial suspension was incubated overnight in a shaking incubator at 37°C. Then, the bacterial suspension was diluted with PBS (pH 7.4), and Escherichia coli, Staphylococcus aureus, or methicillin-resistant Staphylococcus aureus (1×10 7 CFU / mL -1 ) bacterial suspension was incubated with control (PBS) or bionic nanopine needles at 37°C for 24 h. For the colony counting experiment, the bacterial suspension was spread on agar plates and incubated for another 24 h to evaluate its antibacterial ability. The formula for calculating the bacterial lethality rate is as follows: .

[0069] Next, taking the products prepared in Example 1, Comparative Example 1, and Comparative Example 2 of the present invention as examples, their synthesis results and performance characterizations are described: Figure 1 This is a schematic diagram of the synthesis process of ZnO bionic nanopine needles in Example 1 of the present invention. This figure shows the preparation process of ZnO bionic nanopine needle particles. The whole reaction process system is single, and the synthesis process is simple, green, and efficient.

[0070] Figure 2This is the transmission electron microscope image of the ZnO biomimetic nanoneedles of Example 1 of the present invention. This image shows the overall display of the synthesized ZnO biomimetic nanoneedle particles, indicating that the synthesized ZnO biomimetic nanoneedle particles have good dispersibility, uniform size, and the overall particle size is 300 - 600 nm.

[0071] Figure 3 This is the transmission electron microscope image of the ZnO biomimetic nanoneedles of Example 1 of the present invention. This image is the front view of a single ZnO biomimetic nanoneedle particle, indicating that the synthesized ZnO biomimetic nanoneedles are composed of 80 - 300 ZnO nanospines, and the overall particle size is 300 - 600 nm.

[0072] Figure 4 This is the transmission electron microscope image of the ZnO biomimetic nanoneedles of Example 1 of the present invention. This image is the top view of a single ZnO biomimetic nanoneedle particle, indicating that the synthesized ZnO biomimetic nanoneedles have a three - dimensional spine structure similar to pine needles.

[0073] Figure 5 This is the scanning electron microscope image of the ZnO biomimetic nanoneedles of Example 1 of the present invention. This image and Figure 2 show that the synthesized ZnO biomimetic nanoneedle particles have uniform size, and the overall particle size is 300 - 600 nm.

[0074] Figure 6 This is the secondary electron microscope image of the ZnO biomimetic nanoneedles of Example 1 of the present invention. This image indicates that the synthesized ZnO biomimetic nanoneedles have a three - dimensional spiky structure.

[0075] Figure 7 This is the high - angle annular dark - field image of the ZnO biomimetic nanoneedles of Example 1 of the present invention. This image indicates that the synthesized ZnO biomimetic nanoneedle particles have uniform size, and the overall particle size is 300 - 600 nm.

[0076] Figure 8 This is the EDS mapping image of zinc element of the ZnO biomimetic nanoneedles of Example 1 of the present invention. This image indicates that the synthesized ZnO biomimetic nanoneedle particles contain zinc element in their composition.

[0077] Figure 9 This is the EDS mapping image of oxygen element of the ZnO biomimetic nanoneedles of Example 1 of the present invention. This image indicates that the synthesized ZnO biomimetic nanoneedle particles contain oxygen element in their composition.

[0078] Figure 7 、 Figure 8 and Figure 9 prove that the composition of the ZnO biomimetic nanoneedles of Example 1 of the present invention is zinc oxide.

[0079] Figure 10 This is the high-resolution transmission electron microscope image of ZnO biomimetic nanoneedles in Example 1 of the present invention and the diagram for measuring the crystal plane spacing. This image shows that the crystal plane of the synthesized ZnO biomimetic nanoneedle particles is (002).

[0080] Figure 11 This is the ultraviolet-visible light spectrum diagram of ZnO biomimetic nanoneedles in Example 1 of the present invention. This image shows that the synthesized ZnO biomimetic nanoneedle particles have a zinc oxide characteristic peak at 360 nm, proving that zinc oxide is included in the composition of the biomimetic nanoneedle particles.

[0081] Figure 12 This is the Fourier transform infrared spectrum diagram of ZnO biomimetic nanoneedles in Example 1 of the present invention. This image shows that the characteristic peak of mercapto group at 2500 - 2600 disappears for the synthesized ZnO biomimetic nanoneedle particles, proving that oleylamine acts as a ligand to protect the biomimetic nanoneedle particles.

[0082] Figure 13 This is the X-ray diffraction pattern of ZnO biomimetic nanoneedles in Example 1 of the present invention. The characteristic peaks of ZnO biomimetic nanoneedles can correspond one by one to those of the ZnO standard card #79 - 2205, proving that its crystal structure is the same as that of the ZnO standard card #79 - 2205, which is a hexagonal wurtzite structure.

[0083] Figure 14 This is the full spectrum diagram of X-ray photoelectron spectroscopy of ZnO biomimetic nanoneedles in Example 1 of the present invention, proving that it contains elements such as zinc, oxygen, carbon, and nitrogen.

[0084] Figure 15 This is the fine spectrum diagram of zinc in the X-ray photoelectron spectroscopy of ZnO biomimetic nanoneedles in Example 1 of the present invention, proving that the zinc in the synthesized ZnO biomimetic nanoneedles is +2 valence.

[0085] Figure 16 This is the MIC diagram of ZnO biomimetic nanoneedles in Example 1 of the present invention against 7 kinds of bacteria and fungi. Among them, it has strong antibacterial properties against Pseudomonas fluorescens and Candida albicans, and the MIC is only 2 μg / mL. The MIC against Bacillus cereus is 4 μg / mL, and the MIC against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis is 16 μg / mL, proving its high-efficiency and broad-spectrum antibacterial properties.

[0086] Figure 17 This is the antibacterial efficiency statistical chart of 16 μg / mL ZnO biomimetic nanoneedles in Example 1 of the present invention against Escherichia coli, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus; proving that it has good antibacterial properties against various bacteria, all higher than 99.99%.

[0087] Figure 18 Scanning electron microscope image after culturing ZnO biomimetic nanoneedles of Example 1 of the present invention and Escherichia coli; it can be clearly seen that there is obvious contact between the ZnO biomimetic nanoneedles and the bacterial cell wall, and the bacterial cell wall has obvious shrinkage and rupture, proving that it can physically pierce bacteria and achieve a bactericidal effect.

[0088] Figure 19 Scanning electron microscope image after culturing ZnO biomimetic nanoneedles of Example 1 of the present invention and Staphylococcus aureus; it can be clearly seen that there is obvious contact between the ZnO biomimetic nanoneedles and the bacterial cell wall, and the bacterial cell wall has obvious shrinkage and rupture, proving that it can physically pierce bacteria and achieve a bactericidal effect.

[0089] Figure 20 Transmission electron microscope image of ZnO biomimetic nanoneedles of Comparative Example 1 of the present invention. This image shows that the number of ZnO rods in the synthesized ZnO biomimetic nanoneedles by reducing the proportion of zinc acetate anhydrous is reduced to 40 - 200, and the overall particle size is reduced to about 250 nm, indicating that reducing the zinc source will cause the synthesized ZnO biomimetic nanoneedles to become smaller and have no obvious three-dimensional structure of pine needles.

[0090] Figure 21 MIC diagram of ZnO biomimetic nanoneedles of Comparative Example 1 of the present invention against 7 kinds of bacteria and fungi. The MIC against Pseudomonas fluorescens and Bacillus cereus is 16 μg / mL, the MIC against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis is 16 μg / mL, and the MIC against Candida albicans is 128 μg / mL, proving that the antibacterial performance is worse than that of the ZnO biomimetic nanoneedles in Example 1 of the invention.

[0091] Figure 22 Statistical chart of antibacterial efficiency of 64 μg / mL ZnO biomimetic nanoneedles of Comparative Example 1 of the present invention against Escherichia coli, Staphylococcus aureus and methicillin-resistant Staphylococcus aureus; proving that its antibacterial performance is worse than that of the ZnO biomimetic nanoneedles in Example 1 of the invention.

[0092] Figure 23 Transmission electron microscope image of ZnO biomimetic nanoneedles of Comparative Example 2 of the present invention. This image shows that the number of ZnO rods in the synthesized ZnO biomimetic nanoneedles by reducing the reaction time is reduced to about 6, and the overall particle size is reduced to about 220 nm, indicating that reducing the reaction time will cause the synthesized ZnO biomimetic nanoneedles to become smaller and have no obvious three-dimensional structure of pine needles.

[0093] Figure 24MIC diagram of ZnO biomimetic nanopine needles of Comparative Example 2 of the present invention against 7 kinds of bacteria and fungi. The MIC against Pseudomonas fluorescens and Bacillus cereus is 128 μg / mL, the MIC against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis is 256 μg / mL, and the MIC against Candida albicans is 512 μg / mL, proving that the antibacterial performance is worse than that of the ZnO biomimetic nanopine needles in Example 1 of the invention.

[0094] Figure 25 Statistical chart of antibacterial efficiency of 512 μg / mL ZnO biomimetic nanopine needles of Comparative Example 2 of the present invention against Escherichia coli, Staphylococcus aureus and methicillin-resistant Staphylococcus aureus; it is proved that its antibacterial performance is worse than that of the ZnO biomimetic nanopine needles in Example 1 of the invention.

[0095] The above are only the preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be subject to the scope defined by the claims. For those of ordinary skill in the art, without departing from the spirit and scope of the present invention, several improvements and retouches can be made, and these improvements and retouches should also be regarded as the protection scope of the present invention.

Claims

1. A bionic pine needle nano antibacterial material, characterized in that, The particle size of the antibacterial material is uniform, and each single particle is a three-dimensional spike structure composed of 80 - 300 ZnO nanospikes.

2. The bionic pine needle nano antibacterial material according to claim 1, wherein The overall particle size of each single particle is 300 - 600 nm.

3. A method for preparing the bionic pine needle nano antibacterial material as described in claim 1 or 2, characterized in that, It includes the following steps: Weigh raw materials according to a preset ratio: anhydrous zinc acetate powder, methanol-based organic solvent, and oleylamine, and react at a preset temperature to prepare a ZnO biomimetic nanoneedle solution. Purify the ZnO biomimetic nanoneedle solution to obtain a ZnO biomimetic nanoneedle solid powder sample.

4. The preparation method of the bionic pine needle nano antibacterial material according to claim 3, characterized in that The molar ratio of the anhydrous zinc acetate powder, methanol-based organic solvent, and oleylamine is 1 : (10 - 15) : (4 - 6).

5. The preparation method of the bionic pine needle nano antibacterial material according to claim 3, characterized in that, The preset temperature is 130 - 160 °C, and the reaction time is 10 - 14 hours.

6. The preparation method of the bionic pine needle nano antibacterial material according to claim 3, characterized in that, The purification steps for the ZnO biomimetic nanoneedle solution include: adding isopropanol and acetone to the ZnO biomimetic nanoneedle solution, fully mixing and then centrifuging at high speed for phase separation, discarding the upper clear liquid, dissolving the lower precipitate with chloroform, then rotary evaporating the solution to dryness, dispersing and centrifuging the precipitate with isopropanol and acetone, and finally dissolving the precipitate product in tert-butanol, freezing with liquid nitrogen and drying in vacuum to obtain the ZnO biomimetic nanoneedle solid powder sample.

7. The preparation method of the bionic pine needle nano antibacterial material according to claim 6, characterized in that, The volume of the added isopropanol and acetone is 4 - 6 times the volume of the ZnO biomimetic nanoneedle solution.

8. Use of the bionic nano antibacterial material as described in claim 1 or 2 in the field of antibacterial, characterized in that, The antibacterial field includes the medical industry, the food packaging field, and the textile industry.

9. The application according to claim 8, characterized in that, The antibacterial material is applied to the surface of the environment and items to be antibacterial by spraying.

10. The application according to claim 8 or 9, characterized in that, The preparation method of the spray containing the antibacterial material includes: dissolving the ZnO biomimetic nanoneedle solid powder sample obtained by vacuum drying in a mixed solvent of ultrapure water and ethanol, and ultrasonically obtaining a ZnO biomimetic nanoneedle spray.

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