Chiral gold nanomaterial with helical needle-like structure, preparation method and application thereof

Abstract

The application discloses a kind of chiral gold nanomaterials with spiral needle structure and preparation method and application.The chiral gold nanomaterials with spiral needle structure have a plurality of nanosticks extending outward, the nanostick is spiral needle structure, and spiral needle structure is mirror image symmetry.The preparation method includes that gold triangle seed solution, growth liquid and chiral inducer are mixed uniformly, and chiral gold nanomaterials with spiral needle structure are obtained by water bath reaction.The application can effectively improve the physical antibacterial activity and action efficiency of chiral gold nanomaterials with spiral needle structure by reasonably controlling the spiral direction of needle in spiral needle-shaped nanomaterial, and the physical antibacterial performance is excellent, and the matching effect of chiral configuration has important role in enhancing the antibacterial activity of physical antibacterial material, and can be widely applied in physical antibacterial or physical sterilization field.

Description

Technical Field

[0001] This invention belongs to the interdisciplinary field of materials and life sciences, specifically relating to a chiral gold nanomaterial with a helical needle-like structure, its preparation method, and its application. Background Technology

[0002] With the overuse of antibiotics, bacterial resistance poses a persistent threat to human health. Physical antibacterial agents, through the physical structure of nanomaterials (such as sharp edges and rough surfaces), directly disrupt the integrity of bacterial cell membranes, fundamentally avoiding the resistance risks caused by traditional chemical drugs. Their unique bactericidal mechanism has attracted widespread research and attention. However, physical antibacterial agents still face key bottlenecks in practical applications: indiscriminate killing due to passive contact with bacteria and limited antibacterial efficiency. Specifically, existing materials mostly rely on random contact or gravitational pressure during bacterial deposition on surfaces, lacking active recognition and efficient coupling with bacterial membranes. This "blind" physical impact often results in limited antibacterial efficiency, making it difficult to cope with complex biofilms or high-concentration bacterial communities. Therefore, there is an urgent need to develop novel physical antibacterial materials to address the shortcomings and deficiencies of traditional physical antibacterial materials.

[0003] Chirality is ubiquitous in nature, with numerous chiral components present in bacterial cell membranes, such as peptidoglycan in Escherichia coli and Staphylococcus aureus, and glycan portions in lipopolysaccharides. These provide natural fitting sites for physical antibacterial materials. When physical antibacterial nanomaterials possess a chiral structure that matches the bacterial surface, the interaction between them transforms from random physical contact into a directional, efficient "lock-and-key" binding. This results in stronger interactions, increases the "effective adhesion time" and "adhesion strength" of the nanomaterials on the bacterial surface, and not only enables precise capture of specific pathogens but also enhances the material's physical destructive effect on bacteria.

[0004] Currently, patent CN 114309636 A discloses a sea cucumber-like chiral gold nanoparticle antibacterial material. It also reports on the successful construction of nanotriangular sheets with novel chiral structural features using a chiral molecule-induced selective site growth regulation strategy. By controlling the competition between chiral molecules and kinetic and thermodynamic reaction growth conditions, precise control of the chiral growth path of anisotropic nanotriangular sheets is achieved. Other research has also been published... D Chiral antibacterial materials with spiked / horn-like structures exert their antibacterial effect through physical puncture. These inventions demonstrate the important role of chirality in enhancing the physical antibacterial properties of nanomaterials. However, the disclosed chiral materials are limited by their morphology, making it difficult to achieve highly efficient physical antibacterial effects at low material concentrations.

[0005] To address this problem, this invention innovatively designs and prepares a chiral nanomaterial with a helical needle-like structure. This material exhibits superior physical antibacterial properties through its unique hedgehog-like morphology, effectively disrupting bacterial structures. Simultaneously, its helical needle-like structure can specifically recognize and match the chiral microenvironment on the bacterial surface. This material demonstrates broad-spectrum and highly effective bactericidal effects against a variety of bacteria, significantly overcoming the limitations of traditional chiral nanomaterials in terms of physical antibacterial performance. Summary of the Invention

[0006] The main objective of this invention is to provide a chiral gold nanomaterial with a helical needle-like structure, its preparation method, and its application, so as to overcome the shortcomings of the prior art.

[0007] To achieve the aforementioned objectives, the technical solution adopted by this invention includes: The first aspect of the present invention provides a chiral gold nanomaterial with a helical needle-like structure having a plurality of outwardly extending nano-spiks, wherein the nano-spiks are a chiral helical needle-like structure and the helical direction of the helical needle-like structure is mirror-symmetrical.

[0008] A second aspect of the present invention provides a method for preparing the chiral gold nanomaterial having a helical needle-like structure, comprising: The seed solution, growth solution and chiral inducer of the gold triangle were mixed evenly and reacted in a water bath to obtain chiral gold nanomaterials with a spiral needle-like structure. The growth solution includes a growth agent and a reducing agent. The growth agent comprises a combination of chloroauric acid and hexadecyltrimethylammonium bromide, the reducing agent comprises ascorbic acid, and the chiral inducing agent comprises... L -cysteine ​​or D - Cysteine, the Golden Triangle seed solution includes a growth agent, an etching agent and a pH adjuster, the etching agent including potassium iodide and the pH adjuster including sodium hydroxide.

[0009] A third aspect of the present invention provides the application of the chiral gold nanomaterial with the spiral needle-like structure in the field of physical antibacterial or physical sterilization.

[0010] A fourth aspect of the present invention provides a method for specific physical antibacterial treatment, comprising: Provided the chiral gold nanomaterial with the aforementioned helical needle-like structure; The chiral spiral structure of the chiral gold nanomaterial with the spiral needle structure is matched with the polysaccharides on the bacterial surface, thereby achieving specific physical antibacterial activity against bacteria.

[0011] Compared with the prior art, the present invention has at least the following beneficial effects: (1) This invention demonstrates for the first time that at the nanoscale, the helical chiral direction of the needle can significantly affect the physical puncture efficiency by topological matching with the chiral microenvironment of bacteria.

[0012] (2) This invention selects the spiral needle-like nanostructure with excellent physical antibacterial properties as the starting point for research. Through optimization and improvement of the material construction method, chiral gold nanomaterials with spiral needle-like structures are constructed, including those covered with spiral needles. L -Au NH and D -Au NH imparts a specific chiral helical direction to the spikes on the material surface, enabling them to recognize and match the chiral environment of the bacterial membrane like a "key." This enhances the affinity and mechanical interaction between the nanomaterial and the bacterial membrane, thereby significantly improving the material's physical destruction efficiency against the bacterial membrane. Its excellent physical antibacterial properties further demonstrate the important role of the chiral configuration matching effect in enhancing the antibacterial activity of physical antibacterial materials, providing a new approach to solving the problems of low antibacterial efficiency and indiscriminate killing in traditional physical antibacterial materials.

[0013] (3) The invention constructs D- Compared to traditional non-chiral needle-like structures, the needle-like spiral structure of Au NH can better recognize and match chiral substances on the bacterial surface, resulting in superior physical antibacterial properties. L -Au NH. D -Au NH can effectively avoid the drug resistance problem that is easily generated by chemical antibacterial methods, and is expected to provide a transformative solution for fields such as anti-infection coatings for implantable devices, wound dressings, and anti-biofilm catheters.

[0014] (4) This invention is based on the "chiral preference" of bacteria, and achieves physical destruction through specific structures. Its high selectivity does not apply chemical screening pressure, and bacteria are extremely difficult to develop drug resistance. In contrast, the existing photothermal mechanism uses photothermal agents to convert light energy into heat energy under the irradiation of specific light sources (such as near-infrared light), and kills bacteria through local high temperature (>50°C). It lacks selectivity and can only kill bacteria and cells indiscriminately. The chemical mechanism uses chemical substances such as antibiotics and disinfectants to bind to specific targets of bacteria (such as cell membrane, enzymes, DNA), interfere with metabolism or destroy structure, and easily form "superbugs". Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1AThis is in Embodiment 1 of the present invention L - Scanning electron microscope (SEM) image of Au NH; Figure 1B This is in Embodiment 1 of the present invention L Schematic diagram of the structure of -AuNH; Figure 1C This is in Embodiment 1 of the present invention L High-resolution SEM image of Au NH; Figure 1D This is in Embodiment 1 of the present invention D - Scanning electron microscope (SEM) image of Au NH; Figure 1E This is in Embodiment 1 of the present invention D Schematic diagram of the structure of -AuNH; Figure 1F This is in Embodiment 1 of the present invention D High-resolution SEM image of Au NH; Figure 2 This is in Embodiment 1 of the present invention L -Au NH and D Circular dichroism spectrum of -Au NH; Figure 3A Different concentrations L -Au NH and D -Au NH treatment E. Coli (Gram-negative bacteria) colony plate image; Figure 3B Different concentrations L -Au NH and D -Au NH treatment E. Coli A statistical chart of post-bacterial survival rates; Figure 4A Different concentrations L -Au NH and D -Au NH treatment S. aureus (Colony plate image of Gram-positive bacteria); Figure 4B They are different concentrations L -Au NH and D -Au NH treatment S. aureus A statistical chart of post-bacterial survival rates; Figure 5A yes L -Au NH treatment E. Coli The following is a scanning electron microscope image; Figure 5B yes D -Au NH treatment E. Coli The following is a scanning electron microscope image; Figure 6 Different concentrations L -Au NH and D -Au NH pairs E. Coli Statistical chart of biofilm damage; Figure 7 Different concentrations L -Au NH and D -Au NH pairs S. aureus Statistical chart of biofilm damage. Detailed Implementation

[0017] In view of the problems existing in the above-mentioned prior art, after in-depth research, a chiral gold nanomaterial with a helical needle-like structure, its preparation method and application are provided.

[0018] The following will provide a further explanation of the technical solution, its implementation process, and its principles.

[0019] The first aspect of the present invention provides a chiral gold nanomaterial with a helical needle-like structure having a plurality of outwardly extending nano-spiks, wherein the nano-spiks are helical needle-like structures and the helical direction of the helical needle-like structure is mirror-symmetrical.

[0020] In some embodiments, the chiral gold nanomaterial with a helical needle-like structure includes L- Type II gold nanospirals ( L -Au NH) or D- Type II gold nanospirals ( D -Au NH).

[0021] In some embodiments, the chiral gold nanomaterial with a helical needle-like structure exhibits excellent physical antibacterial function, and the physical antibacterial effect shows a significant chiral configuration dependence. In some embodiments, the nanospikes have a spike helix of 20° to 40° and a length of 250 nm to 300 nm for a single nanospike.

[0022] The second aspect of the present invention provides a method for preparing the chiral gold nanomaterial with a helical needle-like structure, comprising: The seed solution, growth solution and chiral inducer of the gold triangle were mixed evenly and reacted in a water bath to obtain chiral gold nanomaterials with a spiral needle-like structure. The growth solution includes a growth agent and a reducing agent. The growth agent comprises a combination of chloroauric acid and hexadecyltrimethylammonium bromide, the reducing agent comprises ascorbic acid, and the chiral inducing agent comprises... L -cysteine ​​or D- Cysteine, the Golden Triangle seed solution includes a growth agent, an etching agent and a pH adjuster, the etching agent including potassium iodide and the pH adjuster including sodium hydroxide.

[0023] In some embodiments, the preparation method specifically includes: The hexadecyltrimethylammonium bromide solution, chloroauric acid solution, potassium iodide solution, and sodium hydroxide solution are mixed evenly to obtain the golden triangle seed solution; The growth solution is obtained by mixing hexadecyltrimethylammonium bromide solution, chloroauric acid solution and ascorbic acid solution evenly. Provide a chiral inducing agent solution, the chiral inducing agent solution comprising L -Cysteine ​​solution or D -Cysteine ​​solution; The growth solution and chiral inducer solution were added to the golden triangle seed solution, and the water-soluble reaction was carried out at 25~35℃ for 20~40 min to obtain the chiral gold nanomaterial with a spiral needle structure.

[0024] This invention utilizes a water bath reaction to strictly control the system at a constant temperature of 25-35°C, simultaneously optimizing the reduction rate, the template confinement ability of CTAB micelles, the selective adsorption strength of chiral molecules on the gold surface, and the surface mobility of gold atoms. These four factors achieve a precise balance within the temperature window, guiding gold atoms to accumulate layer by layer at the active sites along a helical trajectory determined by the chiral molecules, ultimately forming chiral gold nanomaterials with a helical needle-like structure.

[0025] Furthermore, the golden triangle seed solution is supplemented with cetyltrimethylammonium bromide solution, chloroauric acid solution, potassium iodide solution, and sodium hydroxide solution at an initial concentration of 7-10 mg / mL.

[0026] Furthermore, the volume ratio of hexadecyltrimethylammonium bromide solution, chloroauric acid solution, potassium iodide solution and sodium hydroxide solution in the Golden Triangle seed solution is 300~500:58~62:35~40:30~50:8~12.

[0027] Furthermore, the growth solution is supplemented with cetyltrimethylammonium bromide solution, chloroauric acid solution, and ascorbic acid solution at an initial concentration of 7-10 mg / mL.

[0028] Furthermore, the volume ratio of hexadecyltrimethylammonium bromide solution, chloroauric acid solution and ascorbic acid solution in the growth solution is 300~500:40~60:200~300.

[0029] Further, the chiral inducing agent solution comprises 0.0002~0.04 mg / mL L - Cysteine ​​solution or 0.0002~0.04 mg / mL D -Cysteine ​​solution.

[0030] Furthermore, the volume ratio of the golden triangle seed solution, growth solution and chiral inducer solution is 5~15:600~800:40~60.

[0031] Furthermore, the pH value of the Golden Triangle seed solution is 8-10.

[0032] The third aspect of the present invention provides the application of the chiral gold nanomaterial with a spiral needle-like structure in the field of physical antibacterial or physical sterilization.

[0033] In some embodiments, the application includes the use of chiral gold nanomaterials with a helical needle-like structure in the physical killing of Gram-positive and / or Gram-negative bacteria.

[0034] Preferably, the Gram-positive bacteria include E. Coli The Gram-negative bacteria include S. aureus .

[0035] A fourth aspect of the present invention provides a method for specific physical antibacterial treatment comprising: Provided the chiral gold nanomaterial with the aforementioned helical needle-like structure; The chiral spiral structure of the chiral gold nanomaterial with the spiral needle structure is matched with the polysaccharides on the bacterial surface, thereby achieving specific physical antibacterial activity against bacteria.

[0036] In the above-mentioned specific physical antibacterial methods, the physical matching mechanism between helical chirality and bacterial surface structure is specifically manifested as follows: the chiral spiral structure of chiral gold nanomaterials with helical needle-like structures originates from their stronger ability to recognize bacteria. They match the lipopolysaccharide (LPS) and peptidoglycan (PG) polysaccharides on the bacterial surface, resulting in stronger interfacial interactions, thereby achieving specific physical antibacterial action against bacteria.

[0037] The technical solution of the present invention will be further described below with reference to the embodiments. Where specific experimental steps or conditions are not specified in the embodiments, they can be performed according to the conventional experimental steps or conditions described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available. Other unmentioned raw materials and instruments are all conventionally selected and do not involve the core technical means of the present invention.

[0038] Example 1 This embodiment provides a chiral gold nanomaterial with a spiral needle-like structure.L -Au NH and D The preparation method of -AuNH is as follows: S1. Prepare 8 mg / mL CTAB solution, 7.88 mg / mL HAuCl4 solution, and 0.0024 mg / mL CTAB solution, respectively. L -Cys or D -Cys solution, 7 mg / mL AA solution, 1.6 mg / mL potassium iodide solution, 4 mg / mL sodium hydroxide solution.

[0039] S2. Mix 400 μL of CTAB solution with an initial concentration of 8 mg / mL, 61 μL of HAuCl4 solution with an initial concentration of 7.88 mg / mL, 37.5 μL of potassium iodide solution with an initial concentration of 1.6 mg / mL, and 40 μL of sodium hydroxide solution with an initial concentration of 4 mg / mL to obtain the Golden Triangle seed solution with a pH of 9.

[0040] S3. Mix 400 μL of CTAB solution with an initial concentration of 8 mg / mL, 50 μL of HAuCl4 solution with 7.88 mg / mL, and 250 μL of AA solution with 7 mg / mL until homogeneous to obtain the growth solution.

[0041] S4. Add 50 μL of 0.0024 mg / mL to 700 μL of growth medium. L -Cys or D -Cys solution was added to 10 μL of golden triangle seed solution and kept in a water bath at 30 ℃ for 30 min; the reaction was stopped after the reaction was completed.

[0042] S5. After the reaction is complete, centrifuge the reaction solution at 3000 rpm for 4 min, remove the supernatant, then redissolve the precipitate in pure water, and repeat the washing twice to remove excess unreacted reactants.

[0043] The above L -Cys Synthesis L -Au NH, D -Cys Synthesis D -Au NH.

[0044] Example 2 The difference between this embodiment and Embodiment 1 is that: Add cetyltrimethylammonium bromide solution, chloroauric acid solution, potassium iodide solution, and sodium hydroxide solution to the seed solution of the Golden Triangle at an initial concentration of 7 mg / mL; Add cetyltrimethylammonium bromide solution, chloroauric acid solution, and ascorbic acid solution with an initial concentration of 7 mg / mL to the growth medium; The chiral inducer solution is either a 0.0002 mg / mL L-cysteine ​​solution or a 0.0002 mg / mL D-cysteine ​​solution.

[0045] The remaining steps are the same as in Example 1.

[0046] Example 3 The difference between this embodiment and Embodiment 1 is that: Add cetyltrimethylammonium bromide solution, chloroauric acid solution, potassium iodide solution, and sodium hydroxide solution to the seed solution of the Golden Triangle at an initial concentration of 10 mg / mL; Add hexadecyltrimethylammonium bromide solution, chloroauric acid solution, and ascorbic acid solution to the growth medium at an initial concentration of 10 mg / mL; The chiral inducer solution is either a 0.04 mg / mL L-cysteine ​​solution or a 0.04 mg / mL D-cysteine ​​solution.

[0047] The remaining steps are the same as in Example 1.

[0048] Example 4 The difference between this embodiment and Embodiment 1 is that: The volumes of hexadecyltrimethylammonium bromide solution, chloroauric acid solution, potassium iodide solution, and sodium hydroxide solution in the Golden Triangle seed solution were 300 μL, 58 μL, 35 μL, 30 μL, and 8 μL, respectively.

[0049] The volumes of hexadecyltrimethylammonium bromide solution, chloroauric acid solution, and ascorbic acid solution in the growth medium were 300 μL, 40 μL, and 200 μL, respectively.

[0050] The volumes of the Golden Triangle seed solution, growth solution, and chiral inducer solution were 5 μL, 600 μL, and 40 μL, respectively.

[0051] The remaining steps are the same as in Example 1.

[0052] Example 5 The difference between this embodiment and Embodiment 1 is that: The volumes of hexadecyltrimethylammonium bromide solution, chloroauric acid solution, potassium iodide solution, and sodium hydroxide solution in the Golden Triangle seed solution were 500 μL, 62 μL, 40 μL, 50 μL, and 12 μL, respectively.

[0053] The volumes of hexadecyltrimethylammonium bromide solution, chloroauric acid solution, and ascorbic acid solution in the growth medium were 500 μL, 60 μL, and 300 μL, respectively.

[0054] The volumes of the Golden Triangle seed solution, growth solution, and chiral inducer solution were 15 μL, 800 μL, and 60 μL, respectively.

[0055] The remaining steps are the same as in Example 1.

[0056] Comparative Example 1 The difference between this comparative example and Example 1 is that no additives are used. L -Cys or D -Cys solution, the rest is the same as in Example 1.

[0057] In this comparative example, due to the lack of L -Cys or D -Cys leads to disordered growth of gold nanomaterials, making it impossible to form chiral gold nanomaterials with helical needle-like structures.

[0058] Comparative Example 2 The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 uses sea cucumber-like chiral gold nanomaterials, which are prepared according to the preparation method in patent CN114309636A.

[0059] Because the sea cucumber-like chiral gold nanoparticles in Comparative Document 1 lack significant physical sharpness and chiral characteristics, while the surface of this invention is densely covered with sharp, slender, radial tips, it greatly increases its specific surface area, and the tips enhance its surface piercing effect. Furthermore, its large specific surface area significantly improves its bactericidal efficiency and provides abundant molecular binding sites, making it an ideal platform for constructing multifunctional physical antibacterial materials. Therefore, the antibacterial performance of the sea cucumber-like chiral gold nanoparticles is significantly weaker than that of the chiral gold nanomaterials with a spiral needle-like structure of this invention.

[0060] Comparative Example 3 The difference between this comparative example and Example 1 is that the antibacterial material is a chiral gold triangle / propeller-shaped particle.

[0061] The gold triangular / propeller-shaped particles have a less distinct physical morphology, resulting in fewer contact points with bacteria and thus a weaker physical antibacterial effect compared to the chiral gold nanomaterials with a spiral needle-like structure described in this application.

[0062] Comparative Example 4 The non-chiral helical needle-like structure was prepared according to the paper "Pham TMT, Jeong TH, Kim JH, et al. Tomography Study and Growth Control of Spiky Gold Nanoparticles[J]. SmallStructures, 2024, 5(4): 2300502."

[0063] Because the non-chiral helical needle-like structure has radially distributed spikes, the overall structure is highly symmetrical, has no specific rotation direction, and does not respond to light with polarization selectivity. The photothermal effect is mainly achieved through the plasmon resonance absorption of the gold nanomaterial itself, and it has no specific ability.

[0064] The present invention has helical or twisted spikes that disrupt rotational symmetry. The spikes themselves have a clear chiral orientation and selectively absorb chiral light (CPL) (circular dichroism CD). The photothermal temperature can be controlled thereby to achieve chiral-dependent targeting of bacteria.

[0065] Performance testing and characterization (1) L -Au NH and D Structural characterization and analysis of -Au NH.

[0066] Figure 1A for L SEM images of Au NH, Figure 1D for D SEM image of -Au NH. Figure 1A and 1D This indicates that nanomaterials with uniform size and spiral spikes on the surface have been successfully synthesized, with diameters ranging from approximately 250 to 300 nm. Figure 1C and Figure 1F The high-resolution SEM images further reveal a twisted spiral structure on the spike surface, with arrows indicating the spiral direction: L -Au NH has a right-hand thread, while D- Au NH has a left-hand thread, and the two are mirror-symmetrical. (Illustration) Figure 1B and Figure 1E It more intuitively explains its helical configuration and clarifies the origin of the material's chiral structure. L -Au NH and D The preparation method for Au NH samples was as follows: the washed product solution was dropped onto the surface of a silicon wafer, allowed to dry naturally, and then observed using SEM. Simultaneously, we used a circular dichroism (CD) spectrometer to analyze the washed product. L -Au NH and D -Au NH is used for testing chiral optical signals. Figure 2 for L -Au NH and D The CD spectrum of -Au NH. The results show that... L -Au NH and D -Au NH exhibits a strong mirror-symmetric chiral signal in the 400-900 nm range. These results confirm the presence of a highly chiral optically active and chiral structure. L -Au NH and D Controlled synthesis of -Au NH.

[0067] (2) L -Au NH and D Evaluation of the physical antibacterial properties of -Au NH.

[0068] Next, we will... L- Au NH and D -Au NH pairs E. Coli and S. aureus The physical antibacterial properties were tested using different concentrations of [agent name]. L -AuNH and D -AuNH was used to determine the effects of different incubation times on... E. Coli and S. aureus The material exhibits physical killing ability. The specific operating procedure involves diluting the purified material to a gradient concentration and reacting it with the bacterial suspension to ensure a uniform bacterial concentration. After shaking thoroughly for different times, quantitative amounts of the reaction solution are taken and incubated on bacterial culture plates for 12 hours, after which bacterial growth is observed. Figure 3 shows the material's effect on... E. Coli The killing effect. Figure 3A The results showed that with increasing material concentration and reaction time, the number of surviving colonies decreased significantly, and D -Au NH consistently exhibits superior antibacterial effects compared to other compounds. L -Au NH. Quantitative statistical results show ( Figure 3B ), D -Au NH at 0.5 hours E. Coli The antibacterial rate reaches 98.5%, and after 1 hour it can reach over 99.9%. Figure 4 shows the antibacterial effect against... S. aureus The test results. Similarly, Figure 4A The results show that as the material concentration and reaction time increase, S. aureus The number of surviving colonies was significantly reduced. It had a significant effect on [the body's response] after 0.5 hours. S. aureus The antibacterial rate is 90%, reaching 99.9% after 2 hours. Quantitative statistical results show ( Figure 4B The results showed that, under the same antibacterial conditions, D -Au NH has significantly better antibacterial activity than L -AuNH.

[0069] We use E. Coli and S. aureus SEM tests were performed on the materials after interaction. L- Au NH and D The degree of damage that Au NH causes to bacterial membranes. For example... Figure 5A and Figure 5B As shown, the results indicate that D -Au NH has a higher ability to adhere to and disrupt bacterial films; the blue circle indicates this. E. Coli The holes formed in the bacterial membrane by the sharp objects are indicated by red circles, which show the material penetrating the membrane. E. Coli Internal state. This result provides a clearer explanation of... D -Au NH exhibits superior physical antibacterial properties.

[0070] In addition, we L- Au NH and D -Au NH destruction and removal E. Coli and S. aureus The performance of the biofilm was evaluated. Different concentrations of [specific reagents / methods] were used. L- Au NH and D -Au NH pairs E. Coli biofilms and S. aureus Biofilm is disrupted and removed. The specific procedure involves... E. Coli and S. aureus Incubate in 24-well plates for 3-4 days to form a mature biofilm. Then, incubate the biofilm with different concentrations of... L- Au NH or D -Au NH co-incubation for 2 hours. Finally, after methanol fixation and crystal violet staining, the biofilm residue was assessed. Figure 6 The results show that as the concentration of the material treatment increases, the crystal violet staining... E. Coli The biofilm lightened in color. This indicates that, under the influence of the material, E. Coli The biofilm was effectively disrupted. And under the same treatment conditions, D -Au NH treatment significantly improved the color of biofilm compared to L -Au NH treatment resulted in lighter-colored biofilms. 。 Statistical results show that 50 μg / mL D -Au NH treatment resulted in biofilms being damaged to a degree of up to 87.7%, which fully demonstrates D Au NH exhibits excellent physical antibacterial properties. Furthermore, statistical results show that at the same material treatment concentration... D -AuNH is more effective than L -AuNH.

[0071] Figure 7 yes L-Au NH and D -Au NH pairs S. aureus Test results related to biofilm disruption and removal. Similarly, with increasing material treatment concentration, the biofilm stained with crystal violet became lighter in color, indicating... S. aureus Biofilms can be effectively disrupted. 50 μg / mL D -Au NH treatment S. aureus Biofilms were damaged to a degree of up to 78.2%. These results not only further confirm that... L- Au NH and D The physical antibacterial properties of Au NH further clarify this. D The superiority of -Au NH in physical antibacterial applications demonstrates the importance of chiral structures in enhancing the antibacterial properties of physical antibacterial materials.

[0072] In addition, the present invention has also conducted experiments with other raw materials, process operations and process conditions described in this specification, with reference to the foregoing embodiments, and has obtained relatively ideal results in all cases.

[0073] Although the invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions, and / or additions can be made without departing from the spirit and scope of the invention, and that elements of the embodiments can be substituted with substantially equivalents. Furthermore, many modifications can be made without departing from the scope of the invention to adapt particular situations or materials to the teachings of the invention. Therefore, this invention is not intended to be limited to the specific embodiments disclosed for carrying out the invention, but rather is intended to encompass all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated otherwise, any use of the terms first, second, etc., does not indicate any order or importance, but is used to distinguish one element from another.

Claims

1. A chiral gold nanomaterial with a helical needle-like structure, characterized in that: The chiral gold nanomaterial with a helical needle-like structure has multiple outwardly extending nano-spiks, which are helical needle-like structures with mirror-symmetric helical directions.

2. The chiral gold nanomaterial with a helical needle-like structure according to claim 1, characterized in that: The chiral gold nanomaterial with a helical needle-like structure includes L- Gold nanospirals or D- Gold nanospirals; And / or, the chiral gold nanomaterial with a helical needle-like structure has physical antibacterial properties; And / or, the tip helix of the nanospikes is 20°~40°, and the length of a single nanospike is 250 nm~300 nm.

3. The method for preparing the chiral gold nanomaterial with a helical needle-like structure according to claim 1 or 2, characterized in that, include: The seed solution, growth solution and chiral inducer of the gold triangle were mixed evenly and reacted in a water bath to obtain chiral gold nanomaterials with a spiral needle-like structure. The growth solution includes a growth agent and a reducing agent. The growth agent comprises a combination of chloroauric acid and hexadecyltrimethylammonium bromide, the reducing agent comprises ascorbic acid, and the chiral inducing agent comprises... L -cysteine ​​or D - Cysteine, the Golden Triangle seed solution includes a growth agent, an etching agent and a pH adjuster, the etching agent including potassium iodide and the pH adjuster including sodium hydroxide.

4. The preparation method according to claim 3, characterized in that, Specifically, it includes: The hexadecyltrimethylammonium bromide solution, chloroauric acid solution, potassium iodide solution, and sodium hydroxide solution are mixed evenly to obtain the golden triangle seed solution; The growth solution is obtained by mixing hexadecyltrimethylammonium bromide solution, chloroauric acid solution and ascorbic acid solution evenly. Provide a chiral inducing agent solution, the chiral inducing agent solution comprising L -Cysteine ​​solution or D -Cysteine ​​solution; The growth solution and chiral inducer solution were added to the golden triangle seed solution, and the water-soluble reaction was carried out at 25-35℃ for 20-40 minutes to obtain the chiral gold nanomaterial with a spiral needle structure.

5. The preparation method according to claim 4, characterized in that: The golden triangle seed solution is supplemented with cetyltrimethylammonium bromide solution with an initial concentration of 7-10 mg / mL, chloroauric acid solution with an initial concentration of 7-10 mg / mL, potassium iodide solution with an initial concentration of 1-3 mg / mL, and sodium hydroxide solution with an initial concentration of 2-5 mg / mL. And / or, the volume ratio of hexadecyltrimethylammonium bromide solution, chloroauric acid solution, potassium iodide solution and sodium hydroxide solution in the Golden Triangle seed solution is 300~500:58~62:35~40:30~50:8~12.

6. The preparation method according to claim 4, characterized in that: The growth medium was supplemented with cetyltrimethylammonium bromide solution, chloroauric acid solution, and ascorbic acid solution at initial concentrations of 7-10 mg / mL; And / or, the volume ratio of hexadecyltrimethylammonium bromide solution, chloroauric acid solution and ascorbic acid solution in the growth solution is 300~500:40~60:200~300.

7. The preparation method according to claim 4, characterized in that: The chiral inducing agent solution comprises 0.0002~0.04 mg / mL L - Cysteine ​​solution or 0.0002~0.04 mg / mL D -Cysteine ​​solution; And / or, the volume ratio of the golden triangle seed solution, growth solution and chiral inducer solution is 5~15:600~800:40~60; And / or, the pH value of the Golden Triangle seed solution is 8~10.

8. The application of the chiral gold nanomaterial with a helical needle-like structure as described in claim 1 or 2 in the field of physical antibacterial or physical sterilization.

9. The application according to claim 8, characterized in that: The applications include the use of chiral gold nanomaterials with a helical needle-like structure in the physical killing of Gram-positive and / or Gram-negative bacteria; Preferably, the Gram-positive bacteria include E. Coli The Gram-negative bacteria include S. aureus .

10. A method for specific physical antibacterial activity, characterized in that, include: Provide a chiral gold nanomaterial with a helical needle-like structure as described in claim 1 or 2; The chiral spiral structure of the chiral gold nanomaterial with the spiral needle structure is matched with the polysaccharides on the bacterial surface, thereby achieving specific physical antibacterial activity against bacteria.

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