Multi-component composite isomerous nanomaterial, and preparation method and application thereof

Abstract

The application discloses a kind of multi-component composite heterostructured nanomaterials, belong to composite nanomaterial technical field, it is characterized in that: its morphology is similar to flying dart, pillar is gold nanobipyramidal structure, one tip of gold nanobipyramid is exposed, AgPd alloy is coated on the other tip of gold nanobipyramid, shell is coated outside AgPd alloy, the shell is ZIF-8 shell or TiO2 shell, Au-AgPd@ZIF-8 and Au-AgPd@TiO2 composite heterostructured nanomaterials prepared by the application, show excellent antibacterial performance and have application prospect in antibacterial field.

Description

Technical Field

[0001] This invention relates to a multi-component composite heterogeneous nanomaterial, its preparation method, and its application, specifically to the preparation method and application of Au-AgPd@ZIF-8 and Au-AgPd@TiO2 composite heterogeneous nanomaterials, which can be widely applied in the field of controllable synthesis of nanomaterials. Background Technology

[0002] Addressing the serious problem of antibiotic resistance in pathogens, the development of multifunctional composite nano-antibacterial agents is of great significance. Traditional antibacterial agents often possess a single antibacterial mechanism, leading to resistance in some bacteria. Composite nanomaterials, however, exhibit structural diversity and multifunctionality, enabling the synergistic effect of multiple materials and mechanisms to enhance antibacterial efficacy and reduce bacterial resistance. Furthermore, composite nano-antibacterial agents can combine the characteristics of both drugs and physical therapies, exerting multiple antibacterial effects simultaneously, such as physical trapping and chemical decomposition. The development of multifunctional composite nano-antibacterial agents will contribute to improving the treatment efficacy against bacterial infectious diseases.

[0003] In recent years, researchers have discovered that metallic nanomaterials possess strong antibacterial activity. They exert their antibacterial effects through multiple pathways, including disrupting bacterial cell membranes, inhibiting cell metabolism, and interacting with microbial DNA. Furthermore, the combined use of metallic nanomaterials and antibiotics can effectively prevent the development of antibiotic resistance in strains. Metallic nanomaterial antibacterial agents have a wide range of applications, including medical devices, the food industry, textiles, and environmental remediation, showing great promise. Metal-organic frameworks (MOFs) are a class of porous crystalline materials composed of metal ions and organic ligands. MOFs can kill bacteria through multiple mechanisms, such as physical sterilization, chemical intervention, and optical sterilization, making them a research hotspot for novel antibacterial agents. Titanium dioxide (TiO2) is a widely used photocatalytic inorganic material, and its antibacterial properties have attracted widespread attention in recent years. It can generate reactive oxygen species under light, thereby disrupting the cell membrane structure and DNA of bacteria and other microorganisms, achieving a bactericidal effect. In addition, TiO2 has advantages such as good biocompatibility and no environmental pollution, making it widely applicable as a bactericide and disinfectant in medical, food, and other fields.

[0004] In this patent, the inventors synthesized two novel composite antibacterial nanomaterials, Au-AgPd@ZIF-8 and Au-AgPd@TiO2, by combining several promising nanomaterials. Highly efficient antibacterial effects were achieved through the rational design of the components and structure of the composite nanomaterials. This preparation method utilizes the adsorption properties of porous structures for molecules, enabling selective growth of specific regions in multi-component composite materials. It breaks the structural symmetry rules of chemically synthesized composite nanomaterials and is also innovative in its preparation method. Summary of the Invention

[0005] The first objective of this invention is to overcome the shortcomings of the prior art and provide a multi-component composite heterogeneous nanomaterial with highly efficient antibacterial properties.

[0006] The technical solution adopted in this invention is as follows:

[0007] A multi-component composite heterogeneous nanomaterial is characterized by: its morphology resembling a dart, with the main support being a gold nanobipyramidal structure, one tip of the gold nanobipyramidal structure being exposed, and the other tip of the gold nanobipyramidal structure being coated with a flower-shaped AgPd alloy, and the AgPd alloy being coated with a shell layer, wherein the shell layer is a ZIF-8 shell layer or a TiO2 shell layer.

[0008] The present invention discloses a multi-component composite heterogeneous nanomaterial, specifically comprising two types: Au-AgPd@ZIF-8 composite heterogeneous nanomaterial and Au-AgPd@TiO2 composite heterogeneous nanomaterial.

[0009] in:

[0010] An Au-AgPd@ZIF-8 composite heterogeneous nanoparticle is characterized by: its morphology resembling a dart, the support being a gold nanobipyramidal structure, one tip of the gold nanobipyramidal structure being exposed, the other tip of the gold nanobipyramidal structure being coated with a flower-shaped AgPd alloy, and a ZIF-8 shell being coated on the AgPd alloy.

[0011] An Au-AgPd@TiO2 composite heterogeneous nanoparticle is characterized by: its morphology resembling a dart, with the support being a gold nanobipyramidal structure, one tip of the gold nanobipyramidal structure being exposed, the other tip of the gold nanobipyramidal structure being coated with a flower-shaped AgPd alloy, and a TiO2 shell being coated on the AgPd alloy.

[0012] A second aspect of this invention is to provide a method for preparing the above-mentioned multi-component composite heterogeneous nanomaterials, characterized by comprising the following steps:

[0013] (1) Preparation of gold nanobipyramidal@silver shell nanoparticles

[0014] Silver nitrate solution was added to a solution of gold nanobipyramidal hexadecyltrimethylammonium chloride (CTAC), and ascorbic acid was used as a reducing agent to obtain gold nanobipyramidal / silver core-shell structured nanoparticles.

[0015] (2) Preparation of Au-AgPd composite nanoparticles

[0016] The prepared gold nanobipyramidal@silver shell nanoparticles were dispersed in CTAB solution, and then sodium hydroxide solution, chloropalladic acid solution, and ascorbic acid solution were added. The mixture was shaken and allowed to stand at room temperature to obtain Au-AgPd composite nanoparticles.

[0017] (3) Preparation of multi-component composite heterogeneous nanomaterials

[0018] Then, a mixed solution of dimethylimidazole and zinc nitrate, or a mixed solution of titanium trichloride and sodium bicarbonate, was added to the CTAB solution of Au-AgPd composite nanoparticles. After stirring evenly, the mixture was allowed to grow at room temperature to obtain multi-component composite heterogeneous nanomaterials.

[0019] Preferably:

[0020] In step (1):

[0021] The gold nanoparticles used have an extinction peak at 680–1000 nm and an absorbance of 2–5. The molar ratio of CTAC solution: silver nitrate solution: ascorbic acid solution is 400–800: 3–5: 15–25. The reaction temperature is 60℃–80℃, and the reaction time is 4–8 h.

[0022] In step (2):

[0023] The molar ratio of CTAB solution: sodium hydroxide solution: chloropalladium acid solution: ascorbic acid solution is 30–50: 5–7: 3–5: 3–5. The pH of the reaction solution should be controlled within the range of 7.7–9.8, the reaction temperature should be room temperature, and the reaction time should be 2–24 hours.

[0024] The Au-AgPd composite nanoparticles prepared in step (2) are based on gold nanobipyramidal substrates, with flower-shaped AgPd alloys grown on one tip and the other tip exposed.

[0025] In step (3):

[0026] When the prepared multi-component composite heterogeneous nanomaterial is Au-AgPd@ZIF-8 composite heterogeneous nanomaterial: First, add CTAB to the dimethylimidazole solution and stir for 5-30 minutes to mix evenly. Then, add zinc nitrate solution and Au-AgPd composite nanoparticles to the above solution in sequence and stir evenly. After stirring, let it grow at room temperature to prepare Au-AgPd@ZIF-8 heterogeneous nanoparticles.

[0027] Further: according to the added molar ratio, the aforementioned CTAB: dimethylimidazole: zinc nitrate is 1-5: 1200-4000: 20-70; in the mixed reaction solution, the absorbance of Au-AgPd nanoparticles is 2-12, the optical path is 1 cm, the reaction temperature is room temperature, and the reaction time is 10 min-2 h.

[0028] In step (3): when the prepared multi-component composite heterogeneous nanomaterial is Au-AgPd@TiO2 composite heterogeneous nanomaterial: sodium bicarbonate solution is added dropwise to titanium trichloride solution under continuous stirring. After the solution changes from rose red to light gray, the CTAB solution of Au-AgPd composite nanoparticles is immediately injected at once. Au-AgPd@TiO2 composite heterogeneous nanoparticles are prepared by continuous stirring at room temperature.

[0029] Further: according to the added molar ratio of titanium trichloride: sodium bicarbonate: CTAB, it is 3-16: 9-50: 1-5. The absorbance of the Au-AgPd nanoparticle solution in the mixed reaction solution is 3-10, the optical path is 1 cm, the reaction temperature is room temperature, and the reaction time is 10 min-2 h.

[0030] The gold bipyramidal nanoparticles described in this invention can be selected from commercially available products or prepared using methods already reported in the prior art. A preferred method for preparing the gold bipyramidal nanoparticles can be found in the literature (Sánchez-Iglesias, A.; Winckelmans, N.; Altantzis, T.; Bals, S.; Grzelczak, M.; Liz-Marzán, LM High-Yield Seeded Growth of Monodisperse Pentatwinned Gold Nanoparticles through Thermally Induced Seed Twinning. J. Am. Chem. Soc. 2017, 139, 107–110.).

[0031] The third objective of this invention is to provide an application of the multi-component composite heterogeneous nanomaterial prepared above in the preparation of antibacterial materials. Experiments have confirmed that the multi-component composite heterogeneous nanomaterial prepared by this invention has significant antibacterial effects against Staphylococcus aureus (a representative of Gram-positive bacteria) and Escherichia coli (a representative of Gram-negative bacteria).

[0032] Compared with the prior art, the beneficial effects of the present invention include:

[0033] (1) The two Au-AgPd@ZIF-8 and Au-AgPd@TiO2 composite heterogeneous nanomaterials prepared in this invention have not been reported before, and both belong to innovative structures.

[0034] (2) The innovative point of the preparation method of composite heterogeneous nanoparticles in this invention is to utilize the adsorption properties of porous structures for molecules and design a specific region selective growth of multi-component composite materials to achieve the growth of ZIF-8 and TiO2 only on the flower-like AgPd alloy at one end of the gold nanoparticle bipyramidal structure. This preparation method has not been reported and belongs to an innovative chemical preparation method.

[0035] (3) The two Au-AgPd@ZIF-8 and Au-AgPd@TiO2 composite heterogeneous nanomaterials in this patent have high-efficiency antibacterial properties, making them suitable for the treatment of bacterial infection diseases.

[0036] (4) The present invention has low requirements for experimental instruments, the method is simple and easy to operate, and the obtained composite nanoparticles have high yield, uniform size, and good dispersibility, and can be used for antibacterial applications. Attached Figure Description

[0037] Figure 1 The images shown are schematic diagrams and transmission electron microscope (TEM) images of the product obtained in Example 1, Example 2, and Example 3.

[0038] Figure 2 The image shown is a transmission electron microscope (TEM) elemental scanning image of the product obtained in Example 2 of this invention, with a scale bar of 50 nm.

[0039] Figure 3 The image shown is a transmission electron microscope (TEM) elemental scanning image of the product obtained in Example 3 of this invention, with a scale bar of 50 nm.

[0040] Figure 4 This is a transmission electron microscope image of the product obtained in Comparative Example 1 of the present invention.

[0041] Figure 5 This invention demonstrates the antibacterial effect of Au-AgPd@ZIF-8 composite heterogeneous nanoparticles against Staphylococcus aureus and Escherichia coli in Example 2.

[0042] Figure 6 The EPR spectra of Au-AgPd@TiO2 composite heterogeneous nanoparticles in Example 3 of this invention under laser irradiation at 633 nm and 1064 nm are shown.

[0043] Figure 7 This demonstrates the photoantibacterial effect of Au-AgPd@TiO2 composite heterogeneous nanoparticles against Staphylococcus aureus and Escherichia coli in Example 3 of this invention. Detailed Implementation

[0044] The following embodiments provide those skilled in the art with guidance on how to manufacture and evaluate the present invention. These embodiments are merely illustrative of the present disclosure and do not limit the scope of the invention. While every effort has been made to ensure accuracy regarding numerical values ​​(e.g., quantities, temperatures, etc.), some errors and deviations should be considered. Unless otherwise stated, temperatures are expressed in °C or at ambient temperature.

[0045] Example 1: Preparation of Au-AgPd composite nanoparticles

[0046] (1) Preparation of gold nanobipyramidal@silver shell nanoparticles

[0047] A 1 mL solution of gold nanobipyramidal nanoparticles with an absorbance of 3 (the extinction peak of the gold nanobipyramidal nanoparticles is located at 800 nm) was centrifuged at 6500 rpm for 10 min, concentrated, and dispersed in 1 mL of 0.08 M CTAC solution. 45 μL of 0.01 M silver nitrate solution and 22.5 μL of 0.1 M ascorbic acid solution were added, shaken well, and incubated at 60 °C for 6 h. After centrifugation and concentration, gold nanobipyramidal nanoparticles@silver shell nanoparticles were obtained.

[0048] (2) Preparation of Au-AgPd composite nanoparticles

[0049] The prepared gold nanobipyramidal@silver shell nanoparticles were centrifuged at 6500 rpm for 10 min, concentrated, and dispersed in 0.004 M CTAB solution. Then, 5 μL of 0.1 M sodium hydroxide solution, 30 μL of 0.01 M chloropalladic acid solution, and 30 μL of 0.01 M ascorbic acid solution were added, shaken well, and allowed to stand at room temperature for 12 h. After centrifugation, Au-AgPd composite nanoparticle precipitate was obtained.

[0050] Product structure confirmed:

[0051] like Figure 1 As shown, Au-AgPd composite nanoparticles are based on gold nanobipyramidal substrates, with flower-shaped AgPd alloys growing at one end and the other tip exposed.

[0052] Example 2: Preparation of Au-AgPd@ZIF-8 composite heterogeneous nanoparticles

[0053] The Au-AgPd composite nanoparticles prepared in Example 1 were redispersed in water. CTAB (1 mM, 144 μL) was added to a dimethylimidazole solution (0.79 M, 1 mL), and the mixture was stirred for 10 minutes. Then, CTAB (5 mM, 100 μL), zinc nitrate solution (14.4 mM, 1 mL), and Au-AgPd nanoparticle solution (maximum absorbance 20, optical path length 1 cm, 1 mL) were added sequentially to the reaction solution. After mixing, the maximum absorbance of the Au-AgPd nanoparticles in the reaction solution was 6, and the optical path length was 1 cm. After stirring thoroughly, the reaction solution was allowed to stand at room temperature for 20 minutes to prepare Au-AgPd@ZIF-8 composite heterogeneous nanoparticles.

[0054] Product structure confirmed:

[0055] The obtained Au-AgPd@ZIF-8 composite isomeric nanoparticles were centrifuged and redispersed in methanol. SEM samples were prepared to observe their morphology (see [link]). Figure 1 ),like Figure 1 As shown, one end of the Au-AgPd@ZIF-8 composite heterogeneous nanoparticle is a tip (exposed) of a gold nanobipyramidal structure, while the other end is covered with a ZIF-8 shell encapsulated by a flower-like AgPd alloy. Figure 2 This is an elemental surface scan of Au-AgPd@ZIF-8 composite heterogeneous nanoparticles, from... Figure 2 The elemental composition and spatial distribution of Au-AgPd@ZIF-8 composite heterogeneous nanoparticles can be observed.

[0056] Replacement Example 2:

[0057] The preparation method is the same as in Example 2, except that the reaction time of Example 2 is changed to test its effect on the performance of nanoparticles, as shown in Table 1.

[0058] Table 1: Effect of reaction time on product performance

[0059] Serial Number Example 2 Reaction Time Performance indicators Example 2-1 5min AgPd nanoflowers are not coated with a ZIF-8 shell. Example 2-2 30min Target product Example 2-3 1h Target product Examples 2-4 2h Target product Examples 2-5 3h ZIF-8 completely encapsulates Au-AgPd composite nanoparticles.

[0060] analyze:

[0061] As shown in Table 1, when the reaction time is less than 10 min, ZIF-8 has not yet grown on the outer layer of the AgPd nanoflowers due to insufficient reaction time. When the reaction time exceeds 2 h, ZIF-8 extensively coats the Au-AgPd composite nanoparticles due to the excessive reaction time, eventually becoming a fully encapsulated structure and losing its heterogeneous structure. The optimal reaction time is 10 min to 2 h.

[0062] Example 3: Preparation of Au-AgPd@TiO2 composite heterogeneous nanoparticles

[0063] The Au-AgPd composite nanoparticles prepared in Example 1 were redispersed in water. A titanium trichloride solution (200 μL, 1.5 M) and water (4 mL) were mixed thoroughly, followed by the dropwise addition of sodium bicarbonate solution (0.9 M, 1 mL). When the mixed solution changed from rose-red to light gray, the Au-AgPd composite nanoparticle solution (0.5 mL, maximum absorbance 36, optical path 1 cm), 0.5 mL of 0.2 M CTAB, and 1.3 mL of H2O were immediately added under continuous stirring. After mixing, the maximum absorbance of the Au-AgPd nanoparticles in the reaction solution was 5, and the optical path was 1 cm. After stirring at room temperature for 10 minutes, Au-AgPd@TiO2 composite heterogeneous nanoparticles were prepared.

[0064] Product structure confirmed:

[0065] The prepared Au-AgPd@TiO2 composite heterogeneous nanoparticles were washed twice by centrifugation at 5000 rpm for 8 min, and then redispersed in water. TEM samples were prepared and their morphology was observed (see...). Figure 1 ),like Figure 1 As shown, one end of the Au-AgPd@TiO2 composite heterogeneous nanoparticle is a pointed tip (exposed) of a gold nanobipyramidal structure, while the other end has a flower-like AgPd alloy outer layer encapsulated by a TiO2 shell. Figure 3 This is an elemental surface scan of Au-AgPd@TiO2 composite heterogeneous nanoparticles, from... Figure 3 The elemental composition and spatial distribution of Au-AgPd@TiO2 composite heterogeneous nanoparticles can be observed.

[0066] Replacement Example 3:

[0067] The preparation method is the same as in Example 3, except that the maximum absorbance of Au-AgPd composite nanoparticles in the mixed reaction solution is changed to test its effect on the nanoparticle performance.

[0068] Table 2. Effect of the maximum absorbance of Au-AgPd composite nanoparticles in the mixed reaction solution on product performance

[0069]

[0070]

[0071] analyze:

[0072] As shown in Table 2, when the maximum absorbance of the Au-AgPd composite nanoparticle solution in the mixed reaction solution is less than 3, the insufficient number of Au-AgPd composite nanoparticles leads to TiO2 completely encapsulating the Au-AgPd composite nanoparticles. As the maximum absorbance of the particles increases, the target product can be observed. However, when the maximum absorbance of the Au-AgPd composite nanoparticle solution in the mixed reaction solution is greater than 10, the excessive amount of Au-AgPd composite nanoparticles results in insufficient TiO2 to completely encapsulate the outer layer of the AgPd nanoflowers. Therefore, the optimal maximum absorbance of the Au-AgPd composite nanoparticle solution in the mixed reaction solution is 3 to 10.

[0073] Comparative Example 1: Selective growth of TiO2 by different particles

[0074] To demonstrate the significant impact of the adsorption properties of the AgPd-terminal porous structure of Au-AgPd composite nanoparticles on the selective growth of ZIF-8 and TiO2, we conducted the following control experiment using the selective growth of TiO2 as an example:

[0075] Prepared aqueous solutions of gold nanobipyramidal nanoparticles (250 μL, maximum absorbance 36, optical path 1 cm), gold nanobipyramidal nanoparticles@silver shell nanoparticles (250 μL, maximum absorbance 36, optical path 1 cm), and Au-AgPd composite nanoparticles in CTAB solution (0.5 mL Au-AgPd composite nanoparticle aqueous solution (maximum absorbance 36, optical path 1 cm) + 0.5 mL 0.2 M... CTAB + 1.3 mL H₂O was added to a solution of titanium trichloride (200 μL, 17.1 wt%, containing 20-30 wt% HCl) and water (4 mL). The mixture was then added dropwise with sodium bicarbonate solution (0.9 M, 1 mL). When the solution changed from rose-red to light gray, CTAB solutions of gold nanoparticles (bipyramidal), gold nanoparticles@silver shell nanoparticles, and Au-AgPd composite nanoparticles were added immediately under continuous stirring. After stirring at room temperature for 10 minutes, the resulting products were washed twice by centrifugation at 5000 rpm for 8 minutes and redispersed in water. TEM samples were prepared and their morphology observed (see Appendix). Figure 4 .from Figure 4 As can be seen, TiO2 selectively grows only on the AgPd end of Au-AgPd composite nanoparticles, confirming that our method for preparing multi-component heterogeneous composite nanoparticles is based on the adsorption properties of porous structures, a point that has not been reported before and is innovative.

[0076] Product performance testing:

[0077] 1. Antibacterial performance test of Au-AgPd@ZIF-8 composite heterogeneous nanoparticles

[0078] Au-AgPd@ZIF-8 composite heterogeneous nanoparticles were co-cultured with Staphylococcus aureus and Escherichia coli, respectively, to observe their antibacterial properties. Specific experimental procedures: Different concentrations of Au-AgPd@ZIF-8 composite heterogeneous nanoparticle solutions (100 μL) were co-cultured with Staphylococcus aureus (10 μL) and Escherichia coli (10 μL) and Escherichia coli (10 μL) and Escherichia coli, respectively. 6 CFU mL -1 100 μL) and Escherichia coli (10 6 CFU mL -1 100 μL of the sample was co-cultured in 96-well plates at 37°C for 6 hours. Four parallel experiments were performed for each well. After 6 hours, the bacterial turbidity of each sample was measured using a microplate reader, and colony analysis was conducted to determine the minimum inhibitory concentration (MIC) of the Au-AgPd@ZIF-8 composite heterogeneous nanoparticles against Staphylococcus aureus and Escherichia coli. The experimental results are as follows: Figure 5 As shown: Appendix Figure 5 a represents the minimum inhibitory concentration (MIC) of Au-AgPd@ZIF-8 composite heterogeneous nanoparticles against Staphylococcus aureus and Escherichia coli. Figure 5 b shows the colony count results of Au-AgPd@ZIF-8 composite heterogeneous nanoparticles against Staphylococcus aureus and Escherichia coli, which proves the strong bactericidal performance of Au-AgPd@ZIF-8 composite heterogeneous nanoparticles at low concentrations.

[0079] 2. Antibacterial performance test of Au-AgPd@TiO2 composite heterogeneous nanoparticles

[0080] Au-AgPd@TiO2 composite heterogeneous nanoparticles, by combining semiconductor TiO2 and noble metal nanomaterials, exhibit a redshift in the effective range of photothermal carriers from the ultraviolet region to the visible-near-infrared region. We used electron paramagnetic resonance (EPR) spectroscopy to investigate the effects of Au-AgPd@TiO2 composite heterogeneous nanoparticle solutions under 633 nm and 1064 nm laser irradiation (1W cm⁻¹). -2 The ability to generate reactive oxygen species (see appendix) Figure 6 From the appendix Figure 6 In the EPR spectrum, the characteristic peaks of reactive oxygen species generated in the Au-AgPd@TiO2 composite heterogeneous nanoparticle solution under laser irradiation are clearly visible. In contrast, no reactive oxygen species characteristic peaks were observed in a dark environment.

[0081] We further investigated the sterilization effects of Au-AgPd@TiO2 composite heterogeneous nanoparticles on Staphylococcus aureus and Escherichia coli under 633 nm and 1064 nm laser irradiation, respectively. Specific experimental procedures: Different concentrations of Au-AgPd@TiO2 composite heterogeneous nanoparticle solutions (100 μL) were respectively reacted with Staphylococcus aureus (10⁶ CFU / mL). -1100 μL) and Escherichia coli (106 CFU / mL) -1 100 μL of Au-AgPd@TiO2 composite heterogeneous nanoparticles were co-cultured in 96-well plates and irradiated with lasers at 633 nm and 1064 nm for 10 min, respectively. The plates were then co-cultured at 37°C for 6 h. Four parallel experiments were performed for each group. After 6 h, the turbidity of each sample was measured using a microplate reader to determine the minimum inhibitory concentration (MIC) of Au-AgPd@TiO2 composite heterogeneous nanoparticles against Staphylococcus aureus and Escherichia coli under 633 nm and 1064 nm laser irradiation, respectively. The experimental results are as follows: Figure 7 As shown: Figure 7 The results show that Au-AgPd@TiO2 composite heterogeneous nanoparticles possess strong photo-antibacterial properties.

[0082] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. Those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for preparing a multi-component composite heterogeneous nanomaterial, characterized in that, The multi-component composite heterogeneous nanomaterial has a morphology similar to a flying dart, the pillar is a gold nanobipyramid structure, one tip of the gold nanobipyramid is exposed, a flower-shaped AgPd alloy is coated on the other tip of the gold nanobipyramid, and a shell layer is coated outside the AgPd alloy, the shell layer is a ZIF-8 shell layer or a TiO2 shell layer; The preparation method of the multi-component composite heterogeneous nanomaterial comprises the following steps: (1) preparing gold nanobipyramid@silver shell nanoparticles Silver nitrate solution is added to the cetyltrimethylammonium chloride (CTAC) solution of the gold nanobipyramid, ascorbic acid is used as a reducing agent, and gold nanobipyramid / silver core-shell structure nanoparticles are obtained; In step (1), the gold nanobipyramid used has an extinction peak at 680-1000 nm and an absorbance of 2-5, the molar ratio of the added CTAC solution, silver nitrate solution and ascorbic acid solution is 400-800:3-5:15-25, the reaction temperature is 60-80 DEG C, and the reaction time is 4-8 h; (2) preparing Au-AgPd composite nanoparticles The prepared gold nanobipyramid@silver shell nanoparticles are dispersed in a CTAB solution, sodium hydroxide solution, chloropalladic acid solution and ascorbic acid solution are added, the mixture is shaken and left to stand at room temperature, and Au-AgPd composite nanoparticles are obtained; In the mixture of step (2), the molar ratio of the added CTAB solution, sodium hydroxide solution, chloropalladic acid solution and ascorbic acid solution is 30-50:5-7:3-5:3-5, the pH of the reaction solution is controlled at 7.7-9.8, the reaction temperature is room temperature, and the reaction time is 2-24 h; The Au-AgPd composite nanoparticles obtained in step (2) have gold nanobipyramids as a substrate, a flower-shaped AgPd alloy grows on one tip of the gold nanobipyramid, and the other tip is exposed; (3) preparing multi-component composite heterogeneous nanomaterials When the prepared multi-component composite heterogeneous nanomaterial is Au-AgPd@ZIF-8 composite heterogeneous nanomaterial, CTAB is added to a dimethylimidazole solution, stirred for 5-30 minutes to mix uniformly, and then zinc nitrate solution and Au-AgPd composite nanoparticles are sequentially and quickly added to the above solution, the mixture is stirred uniformly, left to stand at room temperature, and Au-AgPd@ZIF-8 composite heterogeneous nanoparticles are prepared; When the prepared multi-component composite heterogeneous nanomaterial is Au-AgPd@TiO2 composite heterogeneous nanomaterial, sodium bicarbonate solution is added dropwise to titanium trichloride solution under continuous stirring, the solution changes from magenta to light gray, and then Au-AgPd composite nanoparticle CTAB solution is injected at one time, and the mixture is continuously stirred at room temperature to prepare Au-AgPd@TiO2 composite heterogeneous nanoparticles.

2. The method according to claim 1, wherein: In step (3), when the prepared multi-component composite isomerism nanometer material is Au-AgPd@ZIF-8 composite isomerism nanometer material: according to the molar ratio of the added CTAB: dimethyl imidazole: zinc nitrate is 1-5: 1200-4000: 20-70; in the mixed reaction solution, the Au-AgPd nanoparticle absorbance is 2-12, the optical path is 1 cm, the reaction temperature is room temperature, and the reaction time is 10 min-2 h.

3. The method for preparing a multi-component composite heterogeneous nanomaterial according to claim 1, characterized in that: In step (3), when the prepared multi-component composite isomerism nanometer material is Au-AgPd@TiO2 composite isomerism nanometer material: according to the molar ratio of the added titanium trichloride: sodium bicarbonate: CTAB is 3-16: 9-50: 1-5, the Au-AgPd nanoparticle absorbance in the mixed reaction solution is 3-10, the optical path is 1 cm, the reaction temperature is room temperature, and the reaction time is 10 min-2 h.

4. The multi-component composite hetero-nano-material prepared by the method of claim 1, wherein: The morphology is similar to a flying dart, the support is a gold nanometer bipyramid structure, one tip of the gold nanometer bipyramid is exposed, a flower-shaped AgPd alloy is coated on the other tip of the gold nanometer bipyramid, and a shell layer is coated outside the AgPd alloy, the shell layer is a ZIF-8 shell layer or a TiO2 shell layer.

5. Application of the multi-component composite isomerism nanometer material prepared by the method of claim 1 in the preparation of antibacterial materials.

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