Magnetocaloric-electric combined antibacterial nanoparticles, preparation method and application thereof

Abstract

This application discloses magnetothermal-induced antibacterial nanoparticles, their preparation method, and applications, relating to the field of medical antibacterial nanomaterials. The nanoparticles are prepared by the following method: Co3B and hexadecyltrimethylammonium bromide are weighed, stirred, and centrifuged to obtain uniformly dispersed Co3B particles. Then, the Co3B particles and CoSb3 are added together to a solvent, stirred to dissolve, centrifuged, washed, and dried to obtain Co3B / CoSb3 nanoparticles. The mass ratio of Co3B to hexadecyltrimethylammonium bromide is 1:5–1:8; the mass ratio of Co3B to CoSb3 is 1:3–1:4. This invention's nanocomposite material utilizes the magnetothermal effect to rapidly generate heat for quick sterilization; on the other hand, the magnetothermal effect creates a localized temperature difference, which is converted into a potential difference, thereby exerting a thermoelectric effect to continuously generate reactive oxygen species, thus synergistically enhancing the antibacterial effect against pneumonia pathogens.

Description

Technical Field

[0001] This application relates to the field of medical antibacterial materials, and in particular to magnetothermoelectric combined antibacterial nanoparticles, their preparation methods, and applications. Background Technology

[0002] Bacteria are widely distributed in nature. Some bacteria, once they infect the human body, can induce serious diseases. For example, bacterial pneumonia is the most common type of infectious pneumonia in clinical practice, accounting for 80% of all types of pneumonia caused by pathogens in adults. The main pathogens include Staphylococcus aureus (SA), Pseudomonas aeruginosa, Streptococcus pneumoniae, Klebsiella pneumoniae (Kp), and Haemophilus influenzae. These pathogens can cause lung tissue damage and respiratory dysfunction, and in severe cases, can lead to death.

[0003] Researchers have explored various new strategies to replace traditional antibiotics, including phage therapy, combined use of antibodies and antibiotics, and nanomaterial therapy, and experimental studies have confirmed their effectiveness. Among these, nanomaterials, due to their diverse composition and unique physicochemical properties, show broad application prospects in the field of antibacterial therapy. Nanomaterials with specific physicochemical properties can respond to external stimuli such as light, ultrasound, and alternating magnetic fields (AMF), thereby exerting highly efficient antibacterial activity in specific environments. This has led to the development of novel treatment modalities such as photodynamic therapy (PDT), sonodynamic therapy (SDT), piezoelectric catalytic therapy (PCT), and magnetothermal therapy (MHT).

[0004] Magnetothermic effect refers to the physical phenomenon of temperature change in magnetic materials under the influence of organic metal frameworks (AMFs). Materials with magnetocaloric properties can effectively generate heat in periodic AMFs through mechanisms such as relaxation loss, hysteresis loss, and eddy current loss. As a solid-state thermal effect, magnetocaloric effect can achieve efficient energy conversion of magnetically responsive materials compared to traditional mechanical heat generation techniques. The main antibacterial mechanism of magnetocaloric therapy is the thermal effect: heat can induce thermal stress in bacteria, leading to the loss of function of key proteins, while also damaging the bacterial cell membrane structure and causing leakage of cellular contents. Traditional magnetic nanoparticles (such as oxides, ferrites, elemental metals, and nanoalloys) have been widely studied and used in biomedical treatment due to their good tunability. For example, Chinese patent CN202311761894.1 proposes a method for preparing magnetocaloric and photodynamic synergistic antibacterial nanoparticles, which uses magnetic nanoparticles as the core, forms a metal-organic framework shell on the surface, and includes the preparation, products, and applications of composite nanoparticles containing extracts of the traditional Chinese medicine Tripterygium wilfordii. However, traditional mild magnetothermal therapy (about 45 ℃) has the disadvantage of reducing heat damage but limited bactericidal efficacy. Furthermore, when thermoelectric materials are used alone, they rely on a continuous and stable temperature difference and it is difficult to generate active oxygen efficiently at the site of infection, resulting in unsatisfactory antibacterial effects.

[0005] Therefore, how to utilize the synergistic antibacterial effects of magnetocaloric and thermoelectric effects to develop novel nanoparticles remains a key research focus and challenge in this field. Summary of the Invention

[0006] The purpose of this application is to provide antibacterial nanoparticles that can utilize the synergistic effects of magnetothermal and thermoelectric effects.

[0007] To achieve the above objectives, this application employs a magnetothermoelectric combined antibacterial nanoparticle, prepared by the following method: Co3B and hexadecyltrimethylammonium bromide are weighed, stirred, and centrifuged to obtain uniformly dispersed Co3B particles. Then, Co3B and CoSb3 are added together to a solvent, stirred to dissolve, centrifuged, washed, and dried to obtain Co3B / CoSb3 nanoparticles. The mass ratio of Co3B to hexadecyltrimethylammonium bromide is 1:5-1:8; the mass ratio of Co3B to CoSb3 is 1:3-1:4.

[0008] Preferably, the mass ratio of Co3B to hexadecyltrimethylammonium bromide is 1:5; and the mass ratio of Co3B to CoSb3 is 1:4.

[0009] In another aspect, the present invention provides the application of magnetothermoelectric combined antibacterial nanoparticles in the preparation of antibacterial agents against pneumonia pathogens.

[0010] Another aspect of the present invention provides a method for preparing magnetothermoelectric combined antibacterial nanoparticles, comprising the following steps: weighing Co3B and hexadecyltrimethylammonium bromide and dissolving them in ethanol, stirring evenly and then placing them in a constant temperature shaker for shaking; centrifuging with a centrifuge, then washing with distilled water and ethanol and vacuum drying overnight; dissolving the dried mixed solid and CoSb3 in ethanol, stirring and then placing them in a constant temperature shaker for shaking; centrifuging with a centrifuge, washing with distilled water and ethanol and vacuum drying to obtain the Co3B / CoSb3 composite material.

[0011] Preferably, the mass of Co3B is 0.1 g, the mass of hexadecyltrimethylammonium bromide is 0.5 g, and the mass of CoSb3 is 0.4 g.

[0012] Preferably, Co3B is prepared by the following method: Cobalt chloride hexahydrate is weighed and added to water and stirred at room temperature to dissolve it, which is recorded as the first solution; sodium borohydride is weighed and added to water and stirred at room temperature in the dark to dissolve it, and then placed in a refrigerator for pre-cooling, which is recorded as the second solution; the second solution is added dropwise to the first solution under stirring in an ice-water bath in the dark, and then stirred at room temperature, followed by centrifugation and washing, and vacuum drying overnight; the dried solid is placed in a tube furnace for calcination and then cooled to room temperature, centrifuged and washed several times, and vacuum freeze-dried overnight to obtain Co3B.

[0013] Preferably, the mass ratio of CoCl2 to NaBH4 is 1:4.

[0014] Preferably, CoSb3 is prepared by the following method: Cobalt chloride hexahydrate and antimony chloride are weighed and dissolved in ethanol and stirred evenly, and this is recorded as the third solution; sodium borohydride is weighed and dissolved in ethanol, stirred at room temperature in the dark, and then pre-cooled in a refrigerator, and this is recorded as the fourth solution; the fourth solution is slowly added dropwise to the third solution under stirring in an ice-water bath in the dark and stirred at room temperature to obtain a solution. The solution is centrifuged and washed several times, and the solid is vacuum dried overnight. The solid is then calcined in a tube furnace, cooled to room temperature, washed and centrifuged three times, and vacuum freeze-dried overnight to obtain CoSb3 black powder.

[0015] Preferably, the calcination temperature is 500 °C and the calcination time is 4 h. It should be noted that, compared with the traditional solvothermal method, the calcination synthesis scheme of this invention has fewer impurity peaks and lower impurity content in its XRD pattern, and significantly saves the synthesis time.

[0016] Preferably, the mass ratio of CoCl2:SbCl3:NaBH4 is 1:3:17.

[0017] This application provides a composite nanoparticle that combines magnetocaloric and thermoelectric effects. It is made of a specific ratio of Co3B / CoSb3. Under the action of an alternating magnetic field of AMF, the Co3B / CoSb3 nanocomposite material can rapidly generate heat through the magnetocaloric effect to achieve rapid sterilization. At the same time, the material as a whole forms a local temperature difference due to the magnetocaloric effect, which drives the CoSb3 nanoparticles to exert a thermoelectric effect, converting the temperature difference into an electric potential difference, thereby continuously generating active oxygen and synergistically enhancing the antibacterial effect of pneumonia pathogens. It has potential application prospects in the preparation of antibacterial agents for pneumonia pathogens. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating the preparation process of the Co3B / CoSb3 nanocomposite material in Example 1 of this application.

[0019] Figure 2 The images show the SEM morphology of the Co3B, CoSb3, and Co3B / CoSb3 nanocomposites prepared in Example 1, where a represents Co3B, b represents CoSb3, and c represents the Co3B / CoSb3 nanocomposites.

[0020] Figure 3 Hysteresis loop diagram of Co3B and Co3B / CoSb3 nanocomposite material;

[0021] Figure 4 Co3B / CoSb3 nanocomposites prepared from Co3B powder and CoSb3 powder in different mass ratios produced O2 after 10 min at a temperature difference of 20℃. - The situation;

[0022] Figure 5 Co3B / CoSb3 nanocomposites prepared from Co3B powder and CoSb3 powder in different mass ratios showed the following after 10 min at a temperature difference of 20℃: 1 The case of O2.

[0023] Figure 6 The antibacterial effects of Co3B, CoSb3, and CBCS on MRSA are shown in the graphs, where a is a plate coating image and b is the statistical data on the inhibition rate (n=3, ***p<0.001).

[0024] Figure 7 The antibacterial effects of Co3B, CoSb3, and CBCS on MDR Kp are shown in Figure a, where a is the plate coating diagram and b is the statistical data of inhibition rate (n=3, ***p<0.001).

[0025] Figure 8 SEM images show the antibacterial effects of Co3B, CoSb3, and CBCS, where a represents MRSA and b represents MDR Kp.

[0026] Figure 9 The biofilm inhibition effects and inhibition rates of Co3B, CoSb3 and CBCS are shown in the figure. a) MRSA crystal violet staining; b) MDR Kp crystal violet staining; c) MRSA inhibition rate; d) MDR Kp inhibition rate (n=3, ***p<0.001, **p<0.01). Detailed Implementation

[0027] The following embodiments are only for further illustration of this application and should not be construed as limiting this application.

[0028] Example 1: A method for preparing composite nanomaterials, comprising the following steps:

[0029] Preparation of S101 Co3B: 428 g of cobalt chloride hexahydrate (CoCl2·6H2O) was weighed and added to 20 mL of water under stirring (500 r / min) and stirred at room temperature (25℃) for 30 min to dissolve, and this solution was designated as the first solution. 0.908 g of sodium borohydride (NaBH4) was weighed and added to 20 mL of water under stirring (500 r / min) and stirred at room temperature (25℃) in the dark for 30 min to dissolve, then pre-cooled in a 4℃ refrigerator for 2 h, and this solution was designated as the second solution. The second solution was added dropwise to the first solution under stirring (500 r / min) in an ice-water bath in the dark, and then stirred at room temperature (25℃) for 5 h. The solution was then centrifuged for 10 min at 10000 rpm / min, washed three times with ethanol, and then vacuum dried at 60℃ overnight. The dried solid was placed in a tube furnace and calcined at 500 °C for 4 h (under an argon atmosphere), then cooled to room temperature, washed and centrifuged several times with distilled water, and then freeze-dried under vacuum overnight to obtain a black Co3B powder.

[0030] Preparation of S102CoSb3: 0.238 g of cobalt chloride hexahydrate (CoCl2·6H2O) and 0.684 g of antimony chloride (SbCl3) were dissolved in 20 mL of ethanol under stirring (500 r / min) for 30 min at room temperature, and this solution was designated as the third solution. 0.643 g of sodium borohydride (NaBH4) was dissolved in 20 mL of ethanol under stirring (500 r / min) for 30 min at room temperature in the dark, and then pre-cooled in a 4 ℃ refrigerator for 2 h, designated as the fourth solution. The fourth solution was added dropwise to the third solution under stirring in an ice-water bath in the dark, and stirred at room temperature for 5 h. The resulting solution was centrifuged for 10 min at 10000 rpm / min, then washed several times with ethanol and dried under vacuum at 60 ℃ overnight. The dried solid was placed in a tube furnace and calcined at 500 ℃ under an argon atmosphere for 4 hours. After cooling to room temperature, the mixture was washed and centrifuged three times with distilled water, and then freeze-dried under vacuum overnight to obtain a black CoSb3 powder.

[0031] Preparation of S103 Co3B / CoSb3 nanocomposite materials:

[0032] 0.1 g Co3B and 0.5 g hexadecyltrimethylammonium bromide (CTAB) were dissolved in 40 mL of ethanol under stirring. After stirring for 30 min, the solution was placed in a shaker at 180 r / min for 12 h at a constant temperature (37 °C). The solution was centrifuged for 10 min at 10000 rpm, then washed several times with distilled water and ethanol, and dried under vacuum at 60 °C overnight. The dried mixed solid and 0.4 g CoSb3 were dissolved in 40 mL of ethanol under stirring. After stirring for 30 min, the solution was placed in a shaker at 180 r / min for 12 h at a constant temperature (37 °C). The solution was centrifuged for 10 min at 10000 rpm, then washed three times with distilled water and ethanol, and dried under vacuum at 60 °C for 12 h to obtain the Co3B / CoSb3 (CBCS) composite material. In this embodiment, the mass ratio of Co3B black powder to CoSb3 black powder is 1:4, and the mass ratio of Co3B to CTAB is 1:5.

[0033] Examples 2 to 6: The difference between Examples 2 to 6 and Example 1 is that the mass ratio of Co3B powder to CoSb3 powder is 1:1, 1:2, 1:3, 1:5 and 1:6, respectively.

[0034] Examples 7 to 10: The difference between Examples 7 to 10 and Example 1 is that the amount of CTAB added in step S103 is different, so that the mass ratio of Co3B to CTAB is 1:1, 1:3, 1:7 and 1:8 respectively.

[0035] (1) The morphology of the Co3B, CoSb3 and Co3B / CoSb3 nanocomposites prepared in Example 1 was characterized, such as... Figure 2 As shown in section a, Co3B is a cluster of nanoparticles, each with a diameter between 100 and 200 nm; as Figure 2 As shown in section b, the obtained CoSb3 is a cluster of nanoparticles, with each particle having a diameter between 10 nm and 100 nm; Figure 2 As shown in section c, CoSb3 nanoparticles are attached to the surface of larger Co3B nanoparticles, forming clusters with a diameter of about 1000 nm, thus forming a stable composite material.

[0036] (2) The hysteresis loops of the Co3B, CoSb3 and Co3B / CoSb3 nanocomposites prepared in Example 1 were measured.

[0037] The hysteresis loops of Co3B and Co3B / CoSb3 nanocomposites were measured, and the results are as follows: Figure 3 As shown, the saturation magnetization of Co3B is 53.7 emu / g, and the coercivity is 330 Oe. Under the premise that CoSb3 itself is not ferromagnetic, the coercivity of Co3B / CoSb3 is 478 Oe, and the saturation magnetization reaches 57.1 emu / g, indicating that the ferromagnetism of the composite Co3B / CoSb3 nanocomposite is significantly enhanced.

[0038] (3) Study the magnetocaloric and thermoelectric properties of Co3B / CoSb3 nanocomposites prepared with different mass ratios of Co3B powder and CoSb3 powder.

[0039] As shown in Table 1, when the Co3B:CoSb3 ratio is 1:1 to 1:5, the temperature of Co3B / CoSb3 in 20 A A increases, while it decreases when the Co3B:CoSb3 ratio is 1:6, indicating that Co3B / CoSb3 with a composite ratio of 1:2 to 1:5 has better magnetocaloric properties.

[0040] Furthermore, due to the relationship between absorbance and reactive oxygen species (ROS) production, the indicator (nitrotetrazolium chloride (NBT) or 9,10-anthratrium-bis(methylene)dimalonic acid (ABDA)) itself has a specific UV absorption peak, the intensity of which is recorded as 100%. The indicator will bind with specific types of ROS, thus losing its UV absorption peak. The weaker the absorption peak intensity, the more indicator binds with ROS, indicating a higher ROS production. If the indicator has no peak at all, it means that the indicator has been completely consumed by ROS (out of range). A water bath heating method was used to create a temperature difference (20 °C) to test whether Co3B / CoSb3 could effectively generate ROS (·O2) under these conditions. - ),like Figure 4 , Figure 5 As shown in Table 1, Co3B / CoSb3 can generate a large amount of O2 at this temperature difference. - and 1 O2 is generated, and the ability to generate it increases significantly with the increase of the proportion of CoSb3 in the composite material. The above experiments confirm that Co3B / CoSb3 can generate two types of ROS under temperature difference, indicating that Co3B / CoSb3 has thermoelectric properties. Considering the combined effects of magnetothermoelectricity, the preferred ratio of Co3B:CoSb3 is 1:3 to 1:4.

[0041] Table 1. Test results of magnetocaloric and thermoelectric properties of Co3B / CoSb3 nanocomposites prepared with different mass ratios of Co3B powder and CoSb3 powder.

[0042]

[0043] (4) Investigate the effect of different CTAB dosages on the magnetocaloric properties of Co3B / CoSb3 nanocomposites.

[0044] The temperature change of Co3B in an alternating magnetic field (AMF) was measured using an infrared thermometer, such as... Figure 7 The results show that Co3B can increase temperature under the influence of AMF, and the presence of CTAB enables Co3B to be fully dispersed, enhancing its heating capacity. The heat generation effect gradually increases and tends to stabilize when Co3B:CTAB = 1:1-1:5. Therefore, the preferred ratio is Co3B:CTAB = 1:5-1:8.

[0045] Table 2. Effects of different CTAB dosages on the magnetocaloric properties of Co3B / CoSb3 nanocomposites.

[0046]

[0047] (5) Testing of the combined magnetothermoelectric antibacterial properties of Co3B / CoSb3 nanocomposites in Examples 1 and 2

[0048] Since multidrug-resistant Klebsiella pneumoniae (MDR Kp) and methicillin-resistant Staphylococcus aureus (MRSA) are the most common pathogens causing pneumonia, and are Gram-negative and Gram-positive bacteria respectively, we selected these two bacteria to test their antibacterial effect on CBCS. The experimental groups are as follows:

[0049] PBS: bacteria + buffer, without magnetic field stimulation or added antibacterial materials;

[0050] PBS+AMF: Bacteria + Buffer + Alternating Magnetic Field Stimulation;

[0051] CBCS: Bacteria + Co3B / CoSb3 composite material;

[0052] CS+AMF: Bacteria + CoSb3 + alternating magnetic field stimulation;

[0053] CB+AMF: Bacteria + Co3B + alternating magnetic field stimulation;

[0054] CBCS+AMF: Bacteria + Co3B / CoSb3 composite material + alternating magnetic field stimulation.

[0055] like Figure 5 As shown, the antibacterial experiment results of the CBCS composite material prepared in Example 1 on the experimental strain MRSA by plate coating showed that CBCS itself had a slight bactericidal effect without any irritant conditions. When AMF was added externally, the CBCS composite material generated effective heat on the one hand, achieving a significant bactericidal effect through high temperature; on the other hand, it could effectively utilize the temperature difference between the magnetothermal high temperature and the ambient room temperature to generate ROS through thermoelectric effect, thereby further significantly improving the antibacterial effect (p < 0.001). This is consistent with the antibacterial effect of the CBCS+AMF group, which reached over 97%. Figure 6 The antibacterial experiment of the CBCS composite material against MDR Kp showed that the bactericidal effect of CBCS was similar to that of MRSA. The CBCS composite material of the present invention was equally effective against Gram-negative and Gram-positive bacteria, and also exhibited a combined magnetothermal-thermoelectric inhibitory effect. The antibacterial properties of Co3B / CoSb3 nanocomposites prepared with different mass ratios of Co3B powder and CoSb3 powder were tested, and the results in Table 3 show that when the Co3B:CoSb3 ratio was 1:1 to 1:4, the antibacterial properties of the Co3B / CoSb3 nanocomposites against Klebsiella pneumoniae (MDR Kp) and methicillin-resistant Staphylococcus aureus (MRSA) gradually increased, and the Co3B / CoSb3 nanocomposites prepared in Example 1 showed the best antibacterial properties.

[0056] Furthermore, the bacteria from the diluted mixed solution used in the above antibacterial experiment were subjected to SEM testing, and the results are as follows: Figure 8 The results showed that the magnetocaloric effect of Co3B could induce bacterial thermal stress, leading to the death of some bacteria and cell membrane rupture. In the CBCS group, the thermoelectric effect of the nanomaterials utilized the temperature difference of the magnetocaloric effect to generate a large amount of reactive oxygen species, causing bacterial oxidative stress, which resulted in cell membrane rupture in almost all bacteria. This indicates that the antibacterial ability of CBCS nanomaterials is significantly enhanced compared to Co3B.

[0057] Table 3. Test results of Co3B / CoSb3 nanocomposites prepared from Co3B powder and CoSb3 powder with different mass ratios.

[0058]

[0059] (6) Biofilms are one of the key reasons for bacterial resistance. Further experiments were conducted on MRSA and MDR Kp biofilms. First, bacteria were allowed to grow biofilms under the same conditions. Then, materials were added or stimuli were applied according to the groups. After that, crystal violet was used for staining. Crystal violet will bind to the biofilm to form purple. Then, acetic acid was used to wash off this specifically bound purple and the absorbance was measured. The experimental groups are as follows:

[0060] PBS: biofilm + buffer, no irritants or added antibacterial materials;

[0061] PBS+AMF: biological membrane + buffer + alternating magnetic field stimulation;

[0062] CBCS: Biomembrane + Co3B / CoSb3 composite material;

[0063] CS+AMF: Biomembrane + CoSb3 + alternating magnetic field stimulation;

[0064] CB+AMF: Biomembrane + Co3B + alternating magnetic field stimulation;

[0065] CBCS+AMF: Biomembrane + Co3B / CoSb3 composite material + alternating magnetic field stimulation.

[0066] The results are as follows Figure 9 As shown, the Co3B / CoSb3 nanocomposite material itself has limited inhibitory effect on biofilms. However, when AMF is added externally, the Co3B component can effectively reduce the biomass in the biofilm through the magnetocaloric effect, and the thermoelectric effect of CoSb3 can further inhibit biofilm formation. This confirms that the Co3B / CoSb3 nanocomposite material has the ability to effectively inhibit biofilm formation.

[0067] The above results indicate that CBCS nanoparticles possess excellent antibacterial properties through the combined effects of magnetocaloric and thermoelectric effects, enabling their application in inhibiting pneumonia pathogens.

[0068] The above description, in conjunction with specific embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. Those skilled in the art to which this application pertains can make several simple deductions or substitutions without departing from the concept of this application.

Claims

1. A magnetocalorically and electrically combined antibacterial nanoparticle, characterized by, The nanoparticles were prepared by the following method: Co3B and hexadecyltrimethylammonium bromide were weighed, stirred, and centrifuged to dry to obtain Co3B particles. Then, the Co3B particles and CoSb3 were added together to a solvent, stirred evenly, centrifuged, washed, and dried to obtain Co3B / CoSb3 nanoparticles. The mass ratio of Co3B to hexadecyltrimethylammonium bromide was 1:5-1:8; the mass ratio of Co3B to CoSb3 was 1:3-1:

4.

2. The magneto-caloric and electrically combined antibacterial nanoparticle according to claim 1, characterized in that, The mass ratio of Co3B to hexadecyltrimethylammonium bromide is 1:5; the mass ratio of Co3B to CoSb3 is 1:

4.

3. The application of the magnetothermoelectric combined antibacterial nanoparticles as described in claim 1 or 2 in the preparation of antibacterial agents against pneumonia pathogens.

4. The method of claim 1 or 2, wherein the method of preparing a magnetocaloric-electricity combined antibacterial nanoparticle is characterized by The process includes the following steps: weighing Co3B and hexadecyltrimethylammonium bromide, dissolving them in ethanol, stirring until homogeneous, and then shaking in a shaker; centrifuging with a centrifuge, then washing with distilled water and ethanol and vacuum drying overnight; dissolving the dried mixed solid and CoSb3 in ethanol, stirring, and then shaking in a shaker; centrifuging with a centrifuge, washing with distilled water and ethanol, and then vacuum drying to obtain the Co3B / CoSb3 composite material.

5. The method for preparing magnetothermoelectric combined antibacterial nanoparticles according to claim 4, characterized in that, The mass of Co3B is 0.1 g, the mass of hexadecyltrimethylammonium bromide is 0.5 g, and the mass of CoSb3 is 0.4 g.

6. The method for preparing magnetothermoelectric combined antibacterial nanoparticles according to claim 5, characterized in that, The Co3B was prepared by the following method: Cobalt chloride hexahydrate was weighed and added to water and stirred at room temperature to dissolve it, which was recorded as the first solution; sodium borohydride was weighed and added to water and stirred at room temperature in the dark to dissolve it, and then placed in a refrigerator for pre-cooling, which was recorded as the second solution; the second solution was added dropwise to the first solution under stirring in an ice-water bath in the dark, and then stirred at room temperature. After centrifugation and washing, it was vacuum dried overnight. The dried solid was placed in a tube furnace for calcination and then cooled to room temperature. After centrifugation and washing several times, it was freeze-dried in a vacuum overnight to obtain Co3B.

7. The method for preparing magnetothermoelectric combined antibacterial nanoparticles according to claim 6, characterized in that, The mass ratio of cobalt chloride hexahydrate to sodium borohydride is 1:

4.

8. The method for preparing magnetothermoelectric combined antibacterial nanoparticles according to claim 5, characterized in that, The CoSb3 was prepared by the following method: Cobalt chloride hexahydrate and antimony chloride were weighed and dissolved in ethanol and stirred evenly, and this was recorded as the third solution; sodium borohydride was weighed and dissolved in ethanol, stirred at room temperature in the dark, and then pre-cooled in a refrigerator, and this was recorded as the fourth solution; the fourth solution was slowly added dropwise to the third solution under stirring in an ice-water bath in the dark, and stirred, centrifuged and washed several times at room temperature, and then vacuum dried overnight. The resulting solid was placed in a tube furnace for calcination, cooled to room temperature, washed and centrifuged three times, and then vacuum freeze-dried overnight to obtain CoSb3 black powder.

9. The method for preparing magnetothermoelectric combined antibacterial nanoparticles according to claim 8, characterized in that, The calcination temperature was 500 ℃ and the calcination time was 4 h.

10. The method for preparing magnetothermoelectric combined antibacterial nanoparticles according to claim 8, characterized in that, The mass ratio of cobalt chloride hexahydrate: antimony chloride: sodium borohydride is 1:3:17.

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