Copper-bismuth telluride nanorod antibacterial active material and preparation and application thereof

Abstract

The application belongs to the field of nanomaterials, and particularly relates to a copper-bismuth telluride nanometer short rod antibacterial active material, which is a copper lattice doped bismuth telluride nanometer short rod material, and the length of the nanometer short rod is less than or equal to 250 nm. The application also includes preparation and application of the material. The material has good temperature difference stimulation sensing ability, can effectively promote ROS release, and has good antibacterial performance.

Description

Technical Field

[0001] This invention belongs to the field of materials, specifically relating to the field of antibacterial nanomaterials technology. Background Technology

[0002] There are five main groups of life on Earth: animals, plants, bacteria, fungi, and viruses. Bacteria have existed on Earth for billions of years, exhibiting extremely strong vitality and able to exist in almost every ecological environment worldwide, even in some extreme environments. Bacteria are mainly divided into three major categories: bacilli, cocci, and spirilla. The vast majority of bacteria have developed pathogenicity during evolution. Bacterial pathogenicity refers to the ability of bacteria to cause disease in animals and plants. Most bacterial pathogenicity is conditional pathogenicity. Conditional pathogenicity means that bacteria typically parasitize animal organisms, maintaining a balance with the host's immune system. When the host's immunity is normal, the virulence of the bacteria is insufficient to cause disease; however, when the host's immunity is low, the toxins produced by the bacteria become dominant, causing disease in the organism. Therefore, protection against bacteria has become a major concern. In the context of the COVID-19 pandemic, the importance of masks is self-evident.

[0003] Face masks are wearable protective devices made of non-woven fabric. The antibacterial layer in the middle of the mask plays a crucial role in its protective function, making the search for highly effective antibacterial materials particularly important. Summary of the Invention

[0004] In view of the prior art, the present invention aims to provide a copper-bismuth telluride nanorod antibacterial active material, and to provide a new material with excellent antibacterial activity under temperature difference response.

[0005] The second objective of this invention is to provide a method for preparing the aforementioned copper-bismuth telluride nanorod antibacterial active material.

[0006] A third objective of this invention is to provide the application of the copper-bismuth telluride nanorod antibacterial active material in antibacterial applications.

[0007] The fourth objective of this invention is to provide an antibacterial material comprising the copper-bismuth telluride nanorod antibacterial active material and a method for preparing the same.

[0008] A copper-bismuth telluride nanorod antibacterial active material is a copper lattice-doped bismuth telluride nanorod material, wherein the length of the nanorod is less than or equal to 250 nm.

[0009] The present invention has found that the copper-hybrid bismuth telluride nanorod material has excellent temperature response capability. It can effectively respond to temperature changes in microorganisms and effectively promote ROS release, thereby achieving antibacterial effect. Moreover, the material also has excellent biocompatibility, stability, cell safety and biometabolability.

[0010] In this invention, the combination of copper-hybridized bismuth telluride and short rod-shaped morphology is key to synergistically improving its temperature-responsive ROS release capacity and enhancing its antibacterial ability.

[0011] Preferably, the copper is used to lattice hybridize the bismuth sites of bismuth telluride;

[0012] Preferably, the length of the nanorod is 100–220 nm.

[0013] Preferably, the aspect ratio of the nanorods is 1 to 10.

[0014] This invention also attempts to provide a method for preparing the aforementioned antibacterial active material. However, research has found that to successfully prepare the antibacterial material, it is necessary to solve problems such as the preparation of impurities, easy structural collapse, and difficulty in controlling the morphology of nanorods. To address the preparation challenges of the material described in this invention, the following solutions are provided:

[0015] A method for preparing the copper-bismuth telluride nanorod antibacterial active material involves carrying out a first-stage reaction in a solution A containing a telluric acid source, an alkali, a surfactant, a solvent, and a reducing agent a at a temperature T1; then adding a bismuth source and carrying out a second-stage reaction at T2; finally adding a reducing agent b and a copper source and carrying out a third-stage reaction at T3 to obtain the copper-bismuth telluride nanorod antibacterial active material.

[0016] The temperatures of T1, T2, and T3 are 150–155°C.

[0017] The molar ratio of Te in the telluric acid source, Bi in the bismuth source, and Cu in the copper source is 1:0.35-0.4:0.03-0.04; more preferably, it is 1:0.35-0.4:0.035-0.038.

[0018] This invention innovatively discovers that by combining the aforementioned material and ratio control, and further coordinating the aforementioned three-stage reaction approach and the combined control of temperatures T1 to T3, the purity and lattice stability of copper-hybridized bismuth telluride phase can be improved. It also facilitates the preparation of materials with short rod-shaped structures. More importantly, the combined control of the aforementioned preparation process and parameters enables the preparation of new materials with excellent temperature-stimulated response and antibacterial properties.

[0019] In this invention, the telluric acid source material, combined with other processes, facilitates the preparation of a material with the characteristics described in this invention and possessing excellent antibacterial properties. In this invention, the telluric acid source is an oxyacid salt of tellurium, metallic tellurium, or a telluride. Preferably, it is at least one of sodium tellurite, tellurium powder, or sodium telluride.

[0020] Preferably, the alkali is at least one of sodium hydroxide and potassium hydroxide;

[0021] Preferably, the surfactant is at least one of polyvinylpyrrolidone and polyethylene glycol;

[0022] Preferably, solution A is at least one of ethylene glycol and vicinal diol;

[0023] Preferably, the reducing agent a is one of hydrazine hydrate, ascorbic acid, or sodium borohydride;

[0024] Preferably, the weight ratio of telluric acid source, alkali, reducing agent a, and surfactant is 1:0.8-1:4-5:0.6-1;

[0025] Preferably, the reaction time for the first stage is 2 to 5 hours; more preferably, it is 3 to 4 hours.

[0026] Preferably, the bismuth source is bismuth nitrate or bismuth hydrochloride; more preferably, it is at least one of bismuth pentahydrate and anhydrous bismuth chloride.

[0027] Preferably, the bismuth source is added in the form of a solution, and the solvent therein is solvent A;

[0028] Preferably, the reaction time for the second stage is 1 to 3 hours.

[0029] Preferably, the reducing agent b is the same as the reducing agent a;

[0030] Preferably, the copper source is at least one of cuprous chloride, copper sulfate, and copper nitrate;

[0031] Preferably, the reducing agent b and the copper source are added in the form of a solution, and the solvent therein is the same as that of solvent A;

[0032] Preferably, the reaction time for the third stage is 1 to 3 hours.

[0033] Preferably, the first to third stage reaction processes are carried out under stirring, and there are no special requirements for the stirring speed, for example, 400 to 800 rpm, and more preferably 500 to 600 rpm.

[0034] In this invention, after the third stage reaction, a solid is separated, washed, and dried to obtain the antibacterial active material. The solvent in the washing process is, for example, at least one of acetone, water, or ethanol. The drying method is, for example, vacuum drying, and the temperature is, for example, 60-80°C, preferably 70-80°C.

[0035] The present invention also provides an application of the copper-bismuth telluride nanorod antibacterial active material described above, using it as an antibacterial active material for the preparation of antibacterial materials.

[0036] In this invention, the antibacterial active material described herein can be used to prepare any material, device, or equipment that requires antibacterial properties.

[0037] Preferably, the antibacterial material is an external antibacterial material; more preferably, it is at least one of antibacterial dressings, antibacterial fiber membranes, and antibacterial masks.

[0038] The present invention also provides an antibacterial fiber, comprising a polymer fiber and the aforementioned copper-bismuth telluride nanorod antibacterial active material composited on the polymer fiber.

[0039] Preferably, the polymer is at least one of polycaprolactone, polyethylene glycol, and polyvinyl alcohol. The molecular weight of polycaprolactone is, for example, 6w to 10w, more preferably 7w to 8w. The molecular weight of polyethylene glycol is, for example, 5000 to 8000, more preferably 6000 to 6500, and the polyvinyl alcohol is of type 1788 or 1799.

[0040] The present invention also provides an antibacterial fiber membrane, woven from antibacterial fibers containing the antibacterial active material described in the present invention;

[0041] Preferably, it is an electrospun membrane made of the antibacterial fiber.

[0042] The present invention also provides a method for preparing the antibacterial fiber membrane, wherein the spinning solution containing the polymer and the copper-bismuth telluride nanorod antibacterial active material is subjected to electrospinning treatment to obtain the antibacterial fiber membrane.

[0043] The polymer in the spinning solution is, for example, at least one of polycaprolactone and polyethylene glycol; preferably, a mixture of polycaprolactone and polyethylene glycol in a mass ratio of 2 to 4:1. The solvent in the spinning solution is, for example, one of tetrahydrofuran and ethanol, more preferably tetrahydrofuran.

[0044] Preferably, the polymer mass fraction in the spinning solution is 5% to 15%, more preferably 5% to 6%.

[0045] Preferably, the concentration of the antibacterial active material in the spinning solution is 1 mg / mL to 8 mg / mL, and more preferably 3 mg / mL to 5 mg / mL.

[0046] Preferably, the flow rate during electrospinning is 0.5 mg / mL to 2 mg / mL, and more preferably 1.5 to 1.8 mg / mL.

[0047] Preferably, the inner diameter of the electrospinning needle is G10-G25, more preferably G15-G19. Preferably, the electrostatic field voltage for electrospinning is 15-18kV, more preferably 15-16kV.

[0048] Preferably, the electrospinning receiving distance is 12-18 cm, and more preferably 14-16 cm.

[0049] This invention also includes the application of the aforementioned antibacterial fiber membrane to prepare any antibacterial product, such as antibacterial dressings, antibacterial masks, etc.

[0050] The copper-bismuth telluride nanorod antibacterial active material of this invention can efficiently generate reactive oxygen species under temperature difference. Therefore, the antibacterial active material of this invention can respond to the environmental conditions in the bacterial microenvironment and specifically achieve antibacterial effect under the action of temperature difference, while also possessing a certain degree of biosafety.

[0051] The mechanism is as follows:

[0052] O2+e - ––>·O2 - (1)

[0053] ·O2 - +2H + ––>H2O2(2)

[0054] The first step of the reaction is the catalysis of oxygen to generate superoxide anion free radicals by the antibacterial active material described in this invention. The second step is the catalysis of superoxide anion free radicals to generate hydrogen peroxide by the antibacterial active material described in this invention. Under temperature difference stimulation, the antibacterial active material can generate reactive oxygen species to kill bacteria based on temperature stimulation response.

[0055] Beneficial effects

[0056] (1) This invention provides a novel antibacterial material of copper-bismuth telluride nanorods. This material has excellent temperature stimulus response capability, can sense temperature difference changes and promote ROS release, thereby achieving antibacterial effect. Moreover, the material also has excellent biocompatibility, stability, non-cytotoxicity, biometabolizability, and good polymer compatibility, and can be compounded with polymers to form any desired composite material.

[0057] (2) In this invention, the combination of the preparation process and parameters provided can prepare the novel antibacterial material of copper-bismuth telluride nanorods and enable it to have better antibacterial ability.

[0058] (3) The preparation method of the present invention is relatively simple, the preparation and application conditions are relatively mild, the cost is low, and it is easy to prepare on a large scale. In addition, the material has high biocompatibility, is easy to be metabolized by organisms, has no obvious toxicity, and is conducive to exerting its efficient temperature difference stimulus response performance. Attached Figure Description

[0059] To make the objectives, content, and beneficial effects of this invention clearer, the invention will now be described in further detail with reference to the accompanying drawings, wherein:

[0060] Figure 1 Bi2Te3-Cu prepared by Example 1 1.6 Scanning electron microscope (SEM) image of Te nanorods;

[0061] Figure 2 Bi2Te3-Cu prepared in Example 1 1.6 Elemental distribution (Mapping) of Te nanorods;

[0062] Figure 3 Bi2Te3-Cu prepared in Example 1 1.6 X-ray photoelectron spectroscopy (XPS) of Te nanorods;

[0063] Figure 4 Bi2Te3-Cu prepared in Example 1 1.6 X-ray diffraction (XRD) pattern of Te nanorods.

[0064] Figure 5 Bi2Te3-Cu prepared by the steps of Example 1 1.6 Transmission electron microscopy (TEM) image of Te nanorods.

[0065] Figure 6 Bi2Te3-Cu prepared by the steps of Example 1 1.6 (a) Hydrated particle size and (b) Surface Zeta potential of Te nanorods.

[0066] Figure 7 To obtain Bi2Te3-Cu through the steps of Example 1 1.6 Comparison of Seebeck coefficients between Te nanorods and pure Bi2Te3.

[0067] Figure 8 (a) To obtain Bi2Te3-Cu through the steps of Example 11.6 The UV-Vis absorption spectrum of the Te nanorods generating superoxide anion radicals (b) is the fluorescence emission spectrum of the generated hydrogen peroxide.

[0068] Figure 9 (a) Bi2Te3-Cu prepared by the steps of Example 1 1.6 Photographs of Te nanorods against methicillin-resistant Staphylococcus aureus and Escherichia coli on plate and comparison with (b) airborne bacteria count;

[0069] Figure 10 Bi2Te3-Fe prepared for Comparative Example 2 2-x Comparison of (b) antimicrobial plate photos of Te against methicillin-resistant Staphylococcus aureus and Escherichia coli with the count of airborne bacteria.

[0070] Figure 11 To obtain Bi2Te3-Cu through the steps of Example 1 1.6 Bacterial liveness / death staining images after Te nanorods interacted with methicillin-resistant Staphylococcus aureus and Escherichia coli.

[0071] Figure 12 This is an electron microscope image of the nanomaterial-mixed electrospun fabric prepared by the steps of Example 1.

[0072] Figure 13 To obtain Bi2Te3-Cu through the steps of Example 1 1.6 (a) Photograph of bacteria plate on wound under temperature difference stimulation by Te nanorods (b) Comparison of bacterial counts.

[0073] Figure 14 To obtain Bi2Te3-Cu through the steps of Example 1 1.6 Figure 1 shows the cytotoxicity experiment of Te nanorods as antibacterial drugs. Detailed Implementation

[0074] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be understood that these preferred embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. After reading this description, any modifications or alterations made to the present invention based on its principles also fall within the scope defined by the claims.

[0075] Part 1: Bi2Te3-Cu 1.6 Preparation of Te nanorods

[0076] Example 1

[0077] Step (1):

[0078] Step (1-a):

[0079] Sodium tellurite (Na2TeO3, 0.220 g), sodium hydroxide (NaOH, 0.18 g), and polyvinylpyrrolidone (PVP, 0.15 g) were mixed and added to a 24 mL three-necked flask of ethylene glycol equipped with a polytetrafluoroethylene magnetic stir bar. The mixture was stirred thoroughly at 155 °C until dissolved. Then, under vigorous stirring, 1 mL of hydrazine hydrate (80% by volume) was added, and stirring continued until the color of the mixture gradually deepened from dark yellow to brownish-black. The mixture was then stirred at 155 °C (marked as T1) for 1 h.

[0080] Step (1-b):

[0081] Continue adding 24 mL of ethylene glycol solution containing 0.123 g of anhydrous bismuth chloride, and continue stirring at 155 °C (labeled T2) for 1 h;

[0082] Step (1-c):

[0083] Subsequently, 500 μL of hydrated hydrazine (volume fraction, 80%) was added for etching, followed by the addition of 3.5 mg of anhydrous cuprous chloride containing 6 mL of ethylene glycol. The reaction was then continued with stirring at 155 °C (labeled T3) for 1 h. The stirring speed was 600 rpm throughout the entire process.

[0084] Step (2): The product from step 1 was centrifuged at high speed with acetone to remove excess solvent, and then dried using a vacuum dryer for 10 hours to obtain Bi2Te3-Cu. 1.6 Te short rod clusters.

[0085] Figures 1-4 Bi2Te3-Cu prepared by the steps of Example 1 1.6 Basic characterization diagrams of Te nanorods.

[0086] Depend on Figure 1 It can be seen that the Bi2Te3-Cu 1.6 Te nanorods exhibit a short rod-shaped microstructure, with a length of approximately 220 nm and a diameter of approximately 30 nm, both exhibiting a short rod shape, and an aspect ratio of approximately 10.

[0087] Depend on Figure 2 It can be seen that the Bi2Te3-Cu 1.6 The Te nanorods are composed of tellurium, bismuth, and copper, which are uniformly distributed and contain no other impurity elements.

[0088] Depend on Figure 3 It can be seen that the Bi2Te3-Cu 1.6 The peak positions and intensities of the tellurium, bismuth, and copper elements in the Te nanorods conform to the literature values.

[0089] Depend on Figure 4 It can be seen that the Bi2Te3-Cu 1.6 The X-ray diffraction peaks of the Te nanorods at various angles match those in the standard X-ray diffraction card for bismuth telluride (JCPDSPDF#82-0358). The intensity of the two diffraction peaks at 37.8 and 41.2 decreases, possibly due to the incorporation of copper. The product has a short rod-shaped structure, and the short rods contain a large number of interconnects composed of nanoparticles, which leads to a decrease in crystallinity. This is due to the addition of sodium hydroxide.

[0090] Figure 5 As can be seen under a transmission electron microscope, this Bi2Te3-Cu 1.6 Te nanorods exhibit a clear short rod-like structure with a length ranging from 200 to 220 nm and a diameter ranging from 25 to 30 nm, which is basically consistent with the results of scanning electron microscopy, showing the same short rod-like morphology.

[0091] Depend on Figure 6 It can be seen that Bi2Te3-Cu 1.6 The hydrated particle size of Te nanorods is about 250-300 nm. The zeta potential of pure bismuth telluride is +20 mV, which becomes -17 mV after copper doping. The reversal of the surface potential proves the incorporation of copper.

[0092] Comparative Example 1

[0093] Compared with Example 1, the only difference is that steps 1-c and subsequent steps are omitted to obtain Bi2Te3 nanomaterials.

[0094] Comparative Example 2

[0095] Compared with Example 1, the main difference is that ferrous chloride is used to replace cuprous chloride in an equimolar amount. Other operations and parameters are the same as in Example 1, and the resulting product is labeled as Bi2Te3-Fe. 2-x Te.

[0096] Part Two: Bi2Te3-Cu 1.6 Performance characterization and testing of Te nanorods

[0097] Depend on Figure 7 It can be seen that Bi2Te3-Cu 1.6 Compared to bismuth telluride nanorods, the Seebeck coefficient of Te nanorods is significantly increased. Since the material is an N-type semiconductor, its Seebeck coefficient is negative. The increase proves that the incorporation of copper is beneficial to improving the temperature-induced response capability of nano-bismuth telluride.

[0098] Superoxide anion radical assay: Nanomaterials were dispersed in dimethyl sulfoxide (DMSO), and 1 mg / mL of NBT in DMSO solution was added to make the final concentration of the material 200 μg / mL. The system was subjected to a cold and hot cycle from 4℃ to 37℃. After the cycle, the supernatant was removed by centrifugation, and the supernatant was detected by UV-Vis absorption spectroscopy at 530 nm.

[0099] Hydrogen peroxide test: The material was dispersed in deionized water, and a 25 μg / mL AmplexRed (red probe) detection solution was prepared to achieve a final concentration of 12.5 μg / mL. HRP (horseradish peroxidase) was dissolved in PBS solution at pH 5.8. After the test, the mixture was subjected to a cold and hot cycle. After the test, the supernatant was removed by centrifugation, and the fluorescence emission spectrum was measured. The excitation wavelength was 530 nm, and the emission range was 560–750 nm. A characteristic emission spectrum appeared near 590 nm.

[0100] Reference test

[0101] Experiments conducted under different experimental conditions were labeled as follows: control group (only ultrapure water was added, no other operations were performed), thermal cycling group (ΔT, only ultrapure water was added and temperature changes occurred; the heat source was a 37°C constant temperature water bath, and the cold source was a 4°C ice box), and nanomaterial group (Bi2Te3-Cu). 1.6 Te, only Bi2Te3-Cu added 1.6 Te nanorods (prepared in Example 1), experimental group (Bi2Te3-Cu) 1.6 Te+ΔT, adding Bi2Te3-Cu 1.6 Te nanorods (prepared in Example 1) were subjected to a temperature difference, with the source being a 37°C constant temperature water bath and the cold source being a 4°C ice box.

[0102] Figure 8 (a) Bi2Te3-Cu prepared in Example 1 under different reference tests 1.6 UV-Vis absorption spectrum of superoxide anion radical production by Te nanorods Figure 8 (b) To test Bi2Te3-Cu under different reference conditions 1.6 Fluorescence emission spectrum of hydrogen peroxide generated by Te nanorods.

[0103] Depend on Figure 8 As can be seen, the Bi2Te3-Cu prepared in Example 1 1.6Te nanorods can catalyze the formation of oxygen superoxide anion radicals, which can bind protons to convert into hydrogen peroxide. Conversely, when subjected to hot and cold stimuli, the solutions in the control group (without any other operations) and the hot and cold stimulation group (group ΔT) did not produce significant signals. This confirms the effectiveness of the Bi₂Te₃-Cu prepared in Example 1. 1.6 Te nanorods possess the ability to catalyze the generation of superoxide anion radicals from oxygen in response to temperature differences, and then convert them into hydrogen peroxide.

[0104] Part Three: Bi2Te3-Cu 1.6 Te nanorod antibacterial effect test

[0105] Using methicillin-resistant Staphylococcus aureus (ATCC43330) and Escherichia coli (ATCC8739) as samples to investigate Bi2Te3-Cu 1.6 The antibacterial ability of Te nanorods (prepared in Example 1). Methicillin-resistant Staphylococcus aureus and Escherichia coli were obtained by incubation in tryptic soy peptone liquid medium (TSB) at 37°C for 16 h. The medium was removed, and the obtained bacterial strains were carefully washed 1-2 times with physiological saline and then dispersed in physiological saline.

[0106] The Bi2Te3-Cu prepared in Example 1 1.6 Te nanorods were dissolved in physiological saline (0.9% NaCl) to prepare a solution with a concentration of 200 μg / mL.

[0107] Antibacterial test: The above-mentioned sample containing 200 μg / mL Bi2Te3-Cu was tested. 1.6 A physiological saline solution (or pure physiological saline) of Te nanorods was added dropwise to physiological saline containing bacterial culture for a hot-cold cycling process. After the experiment, the bacterial culture was serially diluted, spread onto plate, and incubated overnight at 37°C. The number of colonies on the plates was observed and counted.

[0108] As an alternative experiment, Bi2Te3-Fe 2-x Bi2Te3-Cu prepared by Te (comparative Example 2) 1.6 Te nanorods were dissolved in physiological saline (0.9% NaCl) to prepare a solution with a concentration of 200 μg / mL. The above solution containing 200 μg / mL Bi₂Te₃-Fe 2- x A physiological saline solution (or pure physiological saline) of Te nanorods was added dropwise to physiological saline containing bacterial culture for a hot-cold cycling process. After the experiment, the bacterial culture was serially diluted, spread onto plate, and incubated overnight at 37°C. The number of colonies on the plates was observed and counted.

[0109] Antibacterial live / dead staining test: After the experiment, the bacterial culture was centrifuged at 10,000 rpm. SYTO9 (green fluorescent nucleic acid staining agent) and PI (propidium iodide) were added, with 3 μL of the mixed dye added to every 1 mL of physiological saline (1:1 ratio). The prepared mixed dye was added to the treated bacteria, mixed thoroughly, and stained in the dark for 15 minutes. The staining solution was then transferred to a glass plate, and fluorescence images were taken using a laser confocal microscope. SYTO9 stained both dead and live bacteria green, while PI only stained dead bacteria red. It could be observed that only Bi2Te3-Cu... 1.6 Te nanorods can only generate reactive oxygen species to kill bacteria under temperature difference stimulation; this phenomenon was not observed in other groups.

[0110] Reference test

[0111] Experiments conducted under different experimental conditions were labeled as follows: control group (only pure physiological saline was added, no other operations were performed), hot and cold cycling group (only ultrapure water was added and the temperature was changed, the heat source was a 37°C constant temperature water bath, and the cold source was a 4°C ice box), and nanomaterial group (Bi2Te3-Cu). 1.6 Te, only Bi2Te3-Cu added 1.6 Te nanorods (prepared in Example 1), experimental group (Bi2Te3-Cu) 1.6 Te+ΔT, with the addition of Bi2Te3-Cu 1.6 Te nanorods (prepared in Example 1) were subjected to a temperature difference, with the source being a 37°C constant temperature water bath and the cold source being a 4°C ice box.

[0112] Figure 9 and Figure 10 Bi2Te3-Cu prepared by the steps of Example 1 1.6 Te nanorod temperature-stimulated bacterial growth plate Figure 9 a) and survival rate plot ( Figure 9 b) with Bi2Te3-Fe 2-x Te nanorods on temperature-stimulated bacterial growth plates Figure 10 a) and survival plot ( Figure 10 b).

[0113] Depend on Figures 9-10 It is evident that the control group and the hot-cold group had the highest bacterial count, while the experimental group had the lowest. The number of bacterial colonies decreased in both the nanomaterial group and the experimental group. This indicates that simply adding Bi₂Te₃-Cu... 1.6 Co-incubation with Te nanorods showed some antibacterial effect, but the removal effect was not ideal. When Bi2Te3-Cu was added... 1.6When Te nanorods are co-incubated and subjected to hot and cold stimulation, a relatively ideal antibacterial effect can be achieved. As a replacement group, Bi2Te3-Fe... 2-x Te has almost no obvious antibacterial effect, proving that copper doping with Bi2Te3 significantly improves the response to temperature difference stimulation, while iron does not.

[0114] Figure 11 Bi2Te3-Cu prepared by the steps of Example 1 1.6 Images showing the liveness and death of Te nanorods after interaction with methicillin-resistant Staphylococcus aureus and Escherichia coli.

[0115] Depend on Figure 11 It is evident that only the experimental group exhibited a superposition of red and green fluorescence, while the other groups only showed green fluorescence, indicating that Bi2Te3-Cu 1.6 Te nanorods generate reactive oxygen species that kill bacteria when stimulated by temperature differences.

[0116] Part 4: Bi2Te3-Cu 1.6 Te nanorods were combined with electrospinning to prepare wound dressings and conduct antibacterial tests.

[0117] Example 2

[0118] 1.26 g of poly(ε-caprolactone) was dissolved in 30 mL of tetrahydrofuran and magnetically stirred until dissolved. Then, 0.54 g of polyethylene glycol was added, and stirring continued until completely dissolved. The prepared spinning solution was divided into two portions: one containing only the spinning solution, and the other containing the Bi₂Te₃-Cu prepared in step 1 of Example 1. 1.6 Te nanorods were stirred evenly and then loaded into 5mL disposable syringes. A microfluidic pump was used as the driving device to push the syringes inward. The syringes were replaced with flat-headed stainless steel needles. The voltage was adjusted to 16kV and the flow rate to 2mL / h. The receiving device was aluminum foil with a receiving distance of 16cm. Finally, two kinds of spun fabrics were obtained.

[0119] Antibacterial test of spun fabric: The prepared spun fabric was cut into pieces of 1.5*1.5cm in size. Physiological saline solutions of methicillin-resistant Staphylococcus aureus (ATCC43330) and Escherichia coli (ATCC8739) were added to the pieces. The pieces were subjected to hot and cold cycles. After the cycle, the bacterial solutions were serially diluted and inoculated onto tryptic soy agar (TSA) plates. The plates were incubated at 37°C for 16 hours. The plates were photographed and bacteria were counted.

[0120] Biosafety test: Three different cell lines were prepared: HUVEC (human umbilical vein endothelial cells), L929 (mouse epithelioid fibroblasts), and L02 (human normal hepatocytes). The cells were cultured in a CO2 incubator at 37°C until they reached dense growth. After digestion with trypsin, the cells were collected by centrifugation, dispersed in fresh culture medium, and added to 96-well plates. After 48 hours of adherent growth, different concentrations of Bi2Te3-Cu1.6Te nanorods (0, 10, 25, 50, 100, 200, and 300 μg / mL) were added. After 24 hours of growth, the culture medium was discarded, and CCK-8 solution was added to fresh culture medium at a ratio of 10:1. 100 μL of the detection solution was added to each well, and the plates were incubated at 37°C for 30 minutes. The absorbance was measured at 450 nm using a microplate reader. Cells were divided into a control group, an experimental group, and a blank group. The control group contained only cells and CCK-8, the experimental group contained cells, nanomaterials, and CCK-8, and the blank group contained only nanomaterials and CCK-8. The formula for calculating cytotoxicity is (A... 实验组 -A 空白 / A 对照 -A 空白 )*100, where A is the absorbance.

[0121] Reference test

[0122] The experiments conducted under different experimental conditions were labeled as follows: Control group (physiological saline and temperature changes, heat source: 37℃ constant temperature water bath, cold source: 4℃ ice box), Hot and cold cycling group (ΔT, only physiological saline and temperature changes, heat source: 37℃ constant temperature water bath, cold source: 4℃ ice box), Pp group (pure spun fabric group, (prepared in Example 2)), P-p+ΔT group (P-p+ΔT, applying temperature difference, heat source: 37℃ constant temperature water bath, cold source: 4℃ ice box), Pp-Bi2Te3-Cu 1.6 Te group (Pp-Bi2Te3-Cu) 1.6 Te, with the addition of Bi2Te3-Cu 1.6 Te nanorods (prepared in Example 2), experimental group (Bi2Te3-Cu) 1.6 Te+ΔT, adding Bi2Te3-Cu 1.6 Te nanorods (prepared in Example 2) were subjected to a temperature difference, with the source being a 37°C constant temperature water bath and the cold source being a 4°C ice box. Pp refers to a blend of poly(ε-caprolactone) (PCL) and polyethylene glycol (PEG) spun fabric.

[0123] Figure 12 Spinned fabric prepared by electrospinning.

[0124] Depend on Figure 12As can be seen, the fibers of the spun fabric are uniformly dispersed and exhibit a random stacking pattern. Figure a shows the undoped polymer spun fabric Pp, and Figure b shows the doped polymer spun fabric Pp-Bi2Te3-Cu. 1.6 Te and Pp refer to blended fabrics of poly(ε-caprolactone) (PCL) and polyethylene glycol (PEG). There is no significant difference between the two, possibly due to the Bi2Te3-Cu... 1.6 Te's hydrophilicity causes it to be encapsulated in the spinning process.

[0125] Figure 13 To achieve antibacterial properties through spun fabric ( Figure 13 a) Photographs of bacterial agar plates and ( Figure 13 b) Bacterial survival rate graph

[0126] Depend on Figure 13 It is evident that the experimental group exhibited good antibacterial effects, indicating that under given conditions, Bi2Te3-Cu... 1.6 Te nanorods can activate ROS under temperature difference stimulation to achieve effective antibacterial effects, and can be used as highly efficient antibacterial dressings.

[0127] Figure 14 Bi2Te3-Cu prepared and modified by the steps of Example 1 1.6 Cytotoxicity assays of Te nanorods.

[0128] Depend on Figure 14 It can be seen that when Bi2Te3-Cu in the drug 1.6 When the Te nanorods reached 300 μg / mL, the survival rate of three different cell types was higher than 50%, demonstrating excellent biocompatibility.

[0129] III. Data

[0130] Through the above embodiments, the applicant has demonstrated, by way of example, that Bi2Te3-Cu 1.6 Preparation of Te nanorods and their application in temperature-sensitive antibacterial treatment and in the preparation of highly efficient antibacterial dressings using combined electrospinning technology. The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above-described embodiments. All equivalent variations and modifications made within the scope of the claims of this invention should be considered within the scope of the present invention. The scope of protection claimed in this application is as shown in the claims.

Claims

1. An application of a copper-bismuth telluride nanorod antibacterial active material, characterized in that, It can be used as an antibacterial active material to prepare antibacterial materials with temperature-stimulated response capabilities; The copper-bismuth telluride nanorod antibacterial active material is a copper lattice-doped bismuth telluride nanorod material, and the length of the nanorod is less than or equal to 250 nm. The copper described herein performs lattice hybridization on the bismuth sites of bismuth telluride; The aspect ratio of the nanorods is 1 to 10; The preparation method of the copper-bismuth telluride nanorod antibacterial active material is as follows: a solution A containing telluric acid source, alkali, surfactant, solvent and reducing agent a is subjected to a first stage reaction at temperature T1; then a bismuth source is added and a second stage reaction is carried out at T2; then a reducing agent b and a copper source are added and a third stage reaction is carried out at T3 to obtain the copper-bismuth telluride nanorod antibacterial active material. The temperatures of T1, T2, and T3 are 150~155℃; The molar ratio of Te in the telluric acid source, Bi in the bismuth source, and Cu in the copper source is 1:0.35~0.4:0.03~0.04; The weight ratio of telluric acid source, alkali, reducing agent a, and surfactant is 1:0.8~1:4~5:0.6~1; The first stage of the reaction takes 2-5 hours; The second stage of the reaction takes 1-3 hours; The third reaction takes 1 to 3 hours.

2. The application as described in claim 1, characterized in that, The telluric acid source is at least one of sodium tellurite, tellurium powder, or sodium telluride; The alkali is at least one of sodium hydroxide and potassium hydroxide; The surfactant is at least one of polyvinylpyrrolidone and polyethylene glycol; Solution A is at least one of ethylene glycol and vicinal diol; The reducing agent a is one of hydrazine hydrate, ascorbic acid, or sodium borohydride.

3. The application as described in claim 1, characterized in that, The bismuth source is bismuth nitrate or bismuth hydrochloride; The bismuth source is added in the form of a solution, and the solvent therein is solvent A.

4. The application as described in claim 1, characterized in that, The reducing agent b is the same as the reducing agent a; The copper source is at least one of cuprous chloride, copper sulfate, and copper nitrate; The reducing agent b and the copper source are added in the form of a solution, and the solvent in the solution is the same as that in solvent A.

5. The application as described in claim 1, characterized in that, The antibacterial material mentioned is an external antibacterial material.

6. The application as described in claim 5, characterized in that, The antibacterial material is at least one of antibacterial dressings, antibacterial fiber membranes, and antibacterial masks.

7. An antibacterial fiber, characterized in that, The antibacterial active material of copper-bismuth telluride nanorods as described in any one of claims 1 to 6, including polymer fibers and copper-bismuth telluride nanorods composited on polymer fibers.

8. The antibacterial fiber as described in claim 7, characterized in that, The polymer is at least one of poly(ε-caprolactone), polyethylene glycol, and polyvinyl alcohol.

9. An antibacterial fiber membrane, characterized in that, It is woven from the antibacterial fiber as described in claim 7 or 8.

10. The antibacterial fiber membrane as described in claim 9, characterized in that, It is an electrospun membrane made of the aforementioned antibacterial fibers.

11. A method for preparing the antibacterial fiber membrane according to claim 9 or 10, characterized in that, The antibacterial fiber membrane is prepared by electrospinning a spinning solution containing the polymer and the copper-bismuth telluride nanorod antibacterial active material.

Images