Biological pollution resistant nano bionic coating as well as preparation method and application thereof

Abstract

The invention relates to the technical field of sensor bionic coatings, in particular to an anti-biological-pollution nano bionic coating and a preparation method and application thereof.The preparation method comprises the steps that a stainless steel substrate is sequentially polished, cleaned and subjected to plasma treatment, and the activated substrate is obtained; preparing a substrate with a bionic micro-nano composite structure; preparing a substrate with nanoparticles; preparing a substrate with an amino silane transition layer; preparing a substrate with a dynamic Schiff base structure; and soaking the substrate in a sodium cyanoborohydride solution for 1-2 hours, taking out the substrate, performing heat treatment, cleaning the substrate again, and blow-drying the substrate with nitrogen to obtain the substrate with the nano bionic coating. By adopting the steps, the spirulina polysaccharide, the polyethylene glycol and the rare earth doped nanoparticles in the bionic coating have good biocompatibility, no toxic and harmful substances are released, the detection object of the biosensor cannot be interfered, and secondary pollution cannot be generated.

Description

Technical Field

[0001] This invention relates to the field of biomimetic coating technology for sensors, and in particular to an anti-biocontamination nano-biomimetic coating, its preparation method, and its application. Background Technology

[0002] In the field of biosensors, stainless steel is widely used as a substrate material due to its excellent mechanical strength, corrosion resistance, and biocompatibility. However, its smooth surface and strong biological inertness make it susceptible to the adhesion and proliferation of microorganisms such as bacteria and fungi in complex biological environments, leading to the formation of biofilms. Biofilm formation not only damages the surface integrity of biosensors but also interferes with their detection accuracy, stability, and response speed, shortening their lifespan and severely limiting the widespread application of stainless steel-based biosensors in fields such as medical diagnostics and environmental monitoring.

[0003] Currently, the core approach to solving biocontamination on stainless steel substrates is to prepare anti-biocontamination coatings on their surfaces. Existing coating preparation technologies are mainly divided into two categories: chemical antibacterial coatings and physical antifouling coatings. Among them, chemical antibacterial coatings mostly rely on antibacterial components such as antibiotics and heavy metal ions. Long-term use can easily lead to the development of antimicrobial resistance in microorganisms, and heavy metal ions are prone to detachment, causing secondary pollution, resulting in poor biocompatibility. Physical antifouling coatings mostly reduce microbial adhesion by creating a smooth surface, but the coating has weak adhesion to the substrate, is prone to wear and detachment, and has insufficient antifouling durability.

[0004] Meanwhile, existing coating preparation processes often suffer from cumbersome steps, difficulty in parameter control, and limited coating functionality, making it difficult to simultaneously achieve anti-biofouling performance, biocompatibility, coating stability, and adhesion strength to the substrate. Therefore, developing a process-controllable, high-performance, and adaptable method for preparing anti-biofouling nano-biomimetic coatings has become a pressing technical challenge in this field. Summary of the Invention

[0005] The purpose of this invention is to provide an anti-biocontamination nano-biomimetic coating, its preparation method and application. The spirulina polysaccharide, polyethylene glycol and rare earth doped nanoparticles in the biomimetic coating all have good biocompatibility, release no toxic or harmful substances, and will not interfere with the detection objects (such as biomolecules and cells) of the biosensor.

[0006] To achieve the above objectives, the present invention provides a method for preparing an anti-biocontamination nano-biomimetic coating, comprising the following steps: S1. The stainless steel substrate is polished, cleaned and plasma treated in sequence to obtain the activated substrate; S2. Use a laser to etch the substrate surface activated in S1 to obtain a substrate with a biomimetic micro-nano composite structure. S3. Spin-coat the nanoparticle sol doped with rare earth elements onto the surface of the biomimetic micro-nano composite structure in S2, dry and calcine to obtain a substrate with nanoparticles. S4. Immerse the substrate with nanoparticles in S3 in an aminosilane solution at 40-60℃ for 2-4 hours, rinse, dry and solidify to obtain a substrate with an aminosilane transition layer. S5. Dissolve aldehyde-modified spirulina polysaccharide in PBS buffer solution, then add aldehyde-modified polyethylene glycol, stir until homogeneous to obtain a mixed solution, immerse the substrate with aminosilane transition layer in S4 in the mixed solution to carry out Schiff base reaction, remove, wash and dry with nitrogen to obtain a substrate with dynamic Schiff base structure. S6. Immerse the substrate with the dynamic Schiff base structure in S5 in a sodium cyanoborohydride solution for 1-2 hours, remove it, heat treat it, clean it again, and dry it with nitrogen to obtain a substrate with a nano-biomimetic coating.

[0007] Preferably, in S1, the polished substrate is sequentially immersed in acetone, anhydrous ethanol, and deionized water during cleaning, and ultrasonically cleaned for 10-15 minutes. The plasma treatment power is 100-300W, and the time is 5-10 minutes.

[0008] Preferably, in S2, the laser power for etching is 50-150mW, the scanning speed is 100-500μm / s, and the etching time is 10-30min.

[0009] Preferably, in S3, the nanoparticles in the nanoparticle sol doped with rare earth elements include silica nanoparticles or titanium dioxide nanoparticles with hydroxyl groups, and the rare earth elements include one or more of lanthanum, cerium, and neodymium.

[0010] Preferably, in S3, the spin coating speed is 2000-4000 r / min, the spin coating time is 30-60 s, the drying is at 80-100℃ for 10-20 min, and the calcination is at 300-400℃ for 1-2 h.

[0011] Preferably, in S4, the curing temperature is 100-120℃ and the curing time is 1-2h.

[0012] Preferably, in S5, the soaking is carried out in a constant temperature shaking incubator for the grafting reaction, with a rotation speed of 40-60 r / min, a soaking temperature of 30-40℃, and a soaking time of 12-24 h.

[0013] Preferably, in S5, the cleaning process involves sequentially using PBS and deionized water for ultrasonic cleaning for 3-8 minutes each.

[0014] Preferably, in S6, the heat treatment is performed at 60-80℃ for 1-2 hours.

[0015] The above-mentioned method for preparing an anti-biocontamination nano-biomimetic coating yields an anti-biocontamination nano-biomimetic coating.

[0016] The aforementioned anti-biocontamination nano-biomimetic coating is applied to the stainless steel surface of a biosensor.

[0017] Therefore, the present invention employs the above-mentioned anti-biocontamination nano-biomimetic coating, its preparation method, and its application, and its beneficial effects are as follows: 1. The preparation method provided by this invention uses a biomimetic micro-nano composite structure prepared by S2 to simulate the microscopic characteristics of the lotus leaf surface, reduce surface energy, and reduce the initial adhesion of microorganisms; the nanoparticle sol doped with rare earth elements in S3 works synergistically to achieve efficient antibacterial effect through mechanisms such as generating active oxygen species and destroying microbial cell membranes, and inhibiting biofilm formation; the dynamic Schiff base structure formed in S5 further enhances the coating's anti-bioadsorption capacity. The three work synergistically to significantly improve the coating's comprehensiveness and durability against biocontamination, effectively solving the problem of decreased detection accuracy caused by microbial adhesion on the surface of biosensors. 2. The spirulina polysaccharide, polyethylene glycol, and rare earth-doped nanoparticles in the biomimetic coating provided by this invention all have good biocompatibility, release no toxic or harmful substances, do not interfere with the detection objects of the biosensor (such as biomolecules and cells), and do not produce secondary pollution. 3. The nano-biomimetic coating provided by this invention is applied to the stainless steel surface of biosensors, precisely matching the application scenarios of biosensors, and can significantly improve the detection stability, service life and detection accuracy of stainless steel substrate biosensors.

[0018] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the surface of the substrate with nano-biomimetic coating in Embodiment 3 of the present invention after it has been operated in a high-density fermentation environment of Escherichia coli. Figure 2 This is a schematic diagram of the surface of the substrate with a nano-biomimetic coating in the comparative example of the present invention after it has been operated in a high-density fermentation environment of Escherichia coli. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments. Unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The features mentioned above or in the specific examples mentioned in this invention can be combined arbitrarily, and these specific embodiments are only used to illustrate the invention and are not intended to limit the scope of the invention.

[0021] This invention provides a method for preparing an anti-biocontamination nano-biomimetic coating, comprising the following steps: S1. The stainless steel substrate is polished, cleaned and plasma treated in sequence to obtain an activated substrate. Polishing is performed until the substrate surface is free of obvious scratches, has a uniform color and a mirror-like luster. Cleaning removes impurities from the substrate surface. Plasma treatment introduces active groups such as hydroxyl and carboxyl groups into the substrate surface.

[0022] S2. Using a laser to etch the substrate surface activated in S1, a substrate with a biomimetic micro-nano composite structure is obtained; the biomimetic micro-nano composite structure has interwoven nanoscale protrusions and micrometer-scale grooves, simulating the microstructure of the lotus leaf surface.

[0023] S3. Spin-coating the nanoparticle sol doped with rare earth elements onto the surface of the biomimetic micro-nano composite structure in S2, and then drying and calcining to obtain a substrate with nanoparticles; further control the surface roughness, and utilize the antibacterial and stability properties of rare earth elements to enhance the corrosion resistance and long-term anti-fouling properties of the biomimetic coating.

[0024] S4. Immerse the substrate with nanoparticles from S3 in an aminosilane solution at 40-60℃ for 2-4 hours. After rinsing, dry and cure to obtain a substrate with an aminosilane transition layer. The siloxy groups in the aminosilane molecules hydrolyze and undergo condensation reactions with the hydroxyl groups on the substrate and nanoparticle surfaces to form Si-O-Si covalent bonds. Simultaneously, the amino groups at the ends of the aminosilane molecules are exposed on the surface, serving as active sites for subsequent Schiff base reactions, thus achieving the connection between the substrate and subsequent materials. Drying and curing further promotes the cross-linking polymerization of aminosilane molecules, forming a dense transition layer and enhancing the water resistance of the coating.

[0025] S5. Aldehyde-modified spirulina polysaccharide is dissolved in PBS buffer solution, and then aldehyde-modified polyethylene glycol is added. The mixture is stirred until homogeneous to obtain a mixed solution. The substrate with the aminosilane transition layer in S4 is immersed in the mixed solution to perform a Schiff base reaction. After removal, it is washed and dried with nitrogen to obtain a substrate with a dynamic Schiff base structure. The grafting of aldehyde-modified spirulina polysaccharide and polyethylene glycol on the substrate surface is achieved through the Schiff base reaction to form a dynamic Schiff base structure. The hydrophilicity of spirulina polysaccharide and the steric hindrance effect of polyethylene glycol can reduce microbial adsorption. At the same time, the dynamic Schiff base structure has a certain self-healing ability, which improves the stability of the coating.

[0026] S6. Immerse the substrate with the dynamic Schiff base structure from S5 in a sodium cyanoborohydride solution for 1-2 hours. After removal, heat treat, clean again, and dry with nitrogen to obtain a substrate with a nano-biomimetic coating. Sodium cyanoborohydride, as a reducing agent, can reduce the C=N double bond in the Schiff base structure to a CN single bond, enhancing the stability of the Schiff base structure and preventing its hydrolysis in complex biological environments. Subsequent heat treatment further promotes cross-linking between biomimetic coating molecules, improving the density and wear resistance of the biomimetic coating. Cleaning and nitrogen drying again remove residual impurities from the surface, obtaining a stable nano-biomimetic coating.

[0027] In some embodiments of the present invention, in step S1, the polished substrate is sequentially immersed in acetone, anhydrous ethanol, and deionized water for ultrasonic cleaning for 10-15 minutes. Acetone has strong solubility for oil and organic impurities, anhydrous ethanol can remove residual acetone and lipophilic impurities, and deionized water removes inorganic salts. Cleaning with these three solutions ensures thorough removal of impurities. The plasma treatment power is 100-300W, and the time is 5-10 minutes. This ensures sufficient activation of the substrate surface while avoiding excessively long treatment times that could lead to abnormal surface roughness, affecting subsequent etching and coating load.

[0028] In some embodiments of the present invention, in step S2, the laser power for etching is 50-150mW, the scanning speed is 100-500μm / s, and the etching time is 10-30min. This enables precise etching, forming uniform micron-level trenches and nano-level protrusions. The diameter of the nanopillars / holes is 50-500nm, the height / depth is 100-1000nm, and the uniform spacing is set to 50-500nm.

[0029] In some embodiments of the present invention, in step S3, the nanoparticles in the rare earth element-doped nanoparticle sol include hydroxyl-containing silica nanoparticles or titanium oxide nanoparticles, and the rare earth elements include one or more of lanthanum, cerium, and neodymium. The hydroxyl-containing silica nanoparticles or titanium oxide nanoparticles have an average particle size of 20 nm-100 nm. Silica nanoparticles have good biocompatibility, chemical stability, and dispersibility, which can improve the density and wear resistance of the coating; titanium oxide nanoparticles have photocatalytic antibacterial properties and can generate reactive oxygen species under light irradiation, destroying the cell membrane of microorganisms and achieving an antibacterial effect. Both are nanoscale in size and can be uniformly loaded on the surface of biomimetic micro / nano structures without destroying the structural integrity. At the same time, they work synergistically with rare earth elements to enhance the antibacterial effect. Rare earth elements possess unique electronic structures and redox properties. When doped into nanoparticles, they can modulate the photocatalytic performance and antibacterial activity of nanoparticles, improve the generation efficiency of reactive oxygen species, and inhibit nanoparticle aggregation, thereby enhancing their dispersibility. In addition, rare earth elements can improve the corrosion resistance and stability of coatings, extend their service life, and have excellent biocompatibility, without interfering with the detection of biosensors.

[0030] In some embodiments of the present invention, in step S3, the spin coating speed is 2000-4000 r / min, the spin coating time is 30-60 s, the drying is carried out at 80-100℃ for 10-20 min, and the calcination is carried out at 300-400℃ for 1-2 h. Calcination removes dispersants and residual organic matter from the coating, while simultaneously promoting chemical bonding between the nanoparticles and the substrate surface, thus enhancing the bonding strength. It also increases the crystallinity of the nanoparticles, enhancing their antibacterial properties, while avoiding oxidative damage to the substrate or nanoparticles due to excessively high calcination temperatures.

[0031] In some embodiments of the present invention, in step S4, the curing temperature is 100-120°C and the curing time is 1-2 hours. This promotes the cross-linking reaction between aminosilane molecules, forming a dense Si-O-Si cross-linked network, enhancing the density and water resistance of the transition layer, and enabling the transition layer to form a strong bond with the substrate and nanoparticles, thus preventing the transition layer from falling off in subsequent steps.

[0032] In some embodiments of the present invention, in step S5, the immersion is carried out in a constant temperature shaking incubator for the grafting reaction, with a rotation speed of 40-60 r / min, an immersion temperature of 30-40℃, and an immersion time of 12-24 h. Shaking allows the mixed solution to fully contact the aminosilane transition layer, avoiding uneven grafting caused by uneven solution concentration, ensuring the Schiff base reaction proceeds fully, and achieving uniform and firm grafting of the aldehyde-based composite layer onto the substrate surface.

[0033] In some embodiments of the present invention, in step S5, the cleaning process involves sequentially using PBS and deionized water for ultrasonic cleaning for 3-8 minutes each.

[0034] In some embodiments of the present invention, in step S6, the heat treatment is performed at 60-80°C for 1-2 hours. The heat treatment promotes further cross-linking between coating molecules, improving the density and wear resistance of the coating, while also removing residual trace amounts of moisture and solvent from the coating.

[0035] In some embodiments of the present invention, the biomimetic nano-biomimetic coating prepared by the above-described method is described. The prepared biomimetic coating structure comprises, from the inside out, a stainless steel substrate, a biomimetic micro / nano structure, a rare earth-doped nanoparticle layer, an aminosilane transition layer, and a Schiff base composite layer. The synergistic effect of each layer gives the coating excellent anti-biomimetic performance, stability, and biocompatibility.

[0036] In some embodiments of the present invention, the aforementioned anti-biocontamination nano-biomimetic coating is applied to the stainless steel surface of a biosensor. The stainless steel substrate of a biosensor is prone to biocontamination, leading to decreased detection accuracy and shortened lifespan. This coating effectively inhibits microbial adhesion and biofilm formation. Simultaneously, the nano-biomimetic coating bonds firmly to the stainless steel substrate and exhibits excellent biocompatibility, without interfering with the biosensor's detection process. This significantly improves the detection stability, accuracy, and lifespan of the biosensor, meeting the application needs of biosensors in medical, environmental, and other fields.

[0037] Example 1 S1. Polish the stainless steel substrate with sandpaper, then immerse the polished substrate sequentially in acetone, anhydrous ethanol, and deionized water, and ultrasonically clean for 12 minutes. Place it in a plasma cleaner for plasma treatment at room temperature. The plasma treatment power is 300W, and the time is 8 minutes to obtain the activated substrate.

[0038] S2. The substrate surface activated in S1 was etched using a laser. The etching operation was performed in a sterile and dry environment. The laser power was 100mW, the scanning speed was 200μm / s, and the etching time was 20min, resulting in a substrate with a biomimetic micro / nano composite structure. In the micro / nano composite structure, the diameter of the nanopillars / pores was 200nm, the height / depth was 500nm, and the uniform spacing was set to 100nm.

[0039] S3. A rare-earth element-doped nanoparticle sol (lanthanum-doped silica nanoparticles with an average particle size of 80 nm) was spin-coated onto the biomimetic micro / nano composite structure surface described in S2. The spin-coating speed was 3000 r / min, and the spin-coating time was 40 s. The substrate was dried at 90 °C for 15 min, followed by calcination at 400 °C for 1.5 h in air to obtain a substrate with nanoparticles.

[0040] S4. The substrate with nanoparticles in S3 is immersed in an aminosilane solution at 50°C for 3 hours. After rinsing, it is dried and cured at 100°C for 2 hours to obtain a substrate with an aminosilane transition layer.

[0041] S5. Aldehyde-modified spirulina polysaccharide was dissolved in PBS buffer solution, and then aldehyde-modified polyethylene glycol was added. The mixture was stirred until homogeneous to obtain a homogeneous solution. The substrate with the aminosilane transition layer in S4 was immersed in the homogeneous solution to carry out the Schiff base reaction. Immersion was carried out in a constant temperature shaking incubator at a rotation speed of 50 r / min, an immersion temperature of 37℃, and an immersion time of 18 h. After removal, the substrate was ultrasonically cleaned with PBS and deionized water for 5 min each, and then dried with nitrogen to obtain a substrate with a dynamic Schiff base structure.

[0042] S6. The substrate with the dynamic Schiff base structure in S5 is immersed in a 0.1 mol / L sodium cyanoborohydride solution for 1.5 h. After being taken out, it is heat-treated at 70 °C for 2 h, washed again with deionized water and dried with nitrogen to obtain a substrate with a nano-biomimetic coating thickness of 5 μm.

[0043] Example 2 S1. Polish the stainless steel substrate with sandpaper, then immerse the polished substrate sequentially in acetone, anhydrous ethanol, and deionized water, and ultrasonically clean for 12 minutes. Place it in a plasma cleaner for plasma treatment at room temperature. The plasma treatment power is 300W, and the time is 8 minutes to obtain the activated substrate.

[0044] S2. The substrate surface activated in S1 was etched using a laser. The etching operation was performed in a sterile and dry environment. The laser power was 100mW, the scanning speed was 200μm / s, and the etching time was 20min, resulting in a substrate with a biomimetic micro / nano composite structure. In the micro / nano composite structure, the diameter of the nanopillars / pores was 200nm, the height / depth was 500nm, and the uniform spacing was set to 100nm.

[0045] S3. A rare-earth element-doped nanoparticle sol (silica nanoparticles doped with cerium and neodymium, with an average particle size of 80 nm) was spin-coated onto the biomimetic micro / nano composite structure surface described in S2. The spin-coating speed was 3000 r / min, and the spin-coating time was 40 s. After drying at 90 °C for 15 min, the substrate was calcined at 400 °C for 1.5 h in air to obtain a substrate with nanoparticles.

[0046] S4. The substrate with nanoparticles in S3 is immersed in an aminosilane solution at 50°C for 3 hours. After rinsing, it is dried and cured at 100°C for 2 hours to obtain a substrate with an aminosilane transition layer.

[0047] S5. Aldehyde-modified spirulina polysaccharide was dissolved in PBS buffer solution, and then aldehyde-modified polyethylene glycol was added. The mixture was stirred until homogeneous to obtain a homogeneous solution. The substrate with the aminosilane transition layer in S4 was immersed in the homogeneous solution to carry out the Schiff base reaction. Immersion was carried out in a constant temperature shaking incubator at a rotation speed of 50 r / min, an immersion temperature of 37℃, and an immersion time of 18 h. After removal, the substrate was ultrasonically cleaned with PBS and deionized water for 5 min each, and then dried with nitrogen to obtain a substrate with a dynamic Schiff base structure.

[0048] S6. The substrate with the dynamic Schiff base structure in S5 is immersed in a 0.1 mol / L sodium cyanoborohydride solution for 1.5 h. After being taken out, it is heat-treated at 70 °C for 2 h, washed again with deionized water and dried with nitrogen to obtain a substrate with a nano-biomimetic coating thickness of 5 μm.

[0049] Example 3 S1. Polish the stainless steel substrate with sandpaper, then immerse the polished substrate sequentially in acetone, anhydrous ethanol, and deionized water, and ultrasonically clean for 12 minutes. Place it in a plasma cleaner for plasma treatment at room temperature. The plasma treatment power is 300W, and the time is 8 minutes to obtain the activated substrate.

[0050] S2. The substrate surface activated in S1 was etched using a laser. The etching operation was performed in a sterile and dry environment. The laser power was 100mW, the scanning speed was 200μm / s, and the etching time was 20min, resulting in a substrate with a biomimetic micro / nano composite structure. In the micro / nano composite structure, the diameter of the nanopillars / pores was 200nm, the height / depth was 500nm, and the uniform spacing was set to 100nm.

[0051] S3. A rare-earth element-doped nanoparticle sol (titanium oxide nanoparticles doped with lanthanum and cerium, with an average particle size of 80 nm) was spin-coated onto the biomimetic micro / nano composite structure surface described in S2. The spin-coating speed was 3000 r / min, and the spin-coating time was 40 s. After drying at 90 °C for 15 min, the substrate was calcined at 400 °C for 1.5 h in air to obtain a substrate with nanoparticles.

[0052] S4. The substrate with nanoparticles in S3 is immersed in an aminosilane solution at 50°C for 3 hours. After rinsing, it is dried and cured at 100°C for 2 hours to obtain a substrate with an aminosilane transition layer.

[0053] S5. Aldehyde-modified spirulina polysaccharide was dissolved in PBS buffer solution, and then aldehyde-modified polyethylene glycol was added. The mixture was stirred until homogeneous to obtain a homogeneous solution. The substrate with the aminosilane transition layer in S4 was immersed in the homogeneous solution to carry out the Schiff base reaction. Immersion was carried out in a constant temperature shaking incubator at a rotation speed of 50 r / min, an immersion temperature of 37℃, and an immersion time of 18 h. After removal, the substrate was ultrasonically cleaned with PBS and deionized water for 5 min each, and then dried with nitrogen to obtain a substrate with a dynamic Schiff base structure.

[0054] S6. The substrate with the dynamic Schiff base structure in S5 is immersed in a 0.1 mol / L sodium cyanoborohydride solution for 1.5 h. After being taken out, it is heat-treated at 70 °C for 2 h, washed again with deionized water and dried with nitrogen to obtain a substrate with a nano-biomimetic coating thickness of 5 μm.

[0055] Comparative Example S1. Polish the stainless steel substrate with sandpaper, then immerse the polished substrate sequentially in acetone, anhydrous ethanol, and deionized water, and ultrasonically clean for 12 minutes. Place it in a plasma cleaner for plasma treatment at room temperature. The plasma treatment power is 300W, and the time is 8 minutes to obtain the activated substrate.

[0056] S2. The substrate surface activated in S1 was etched using a laser. The etching operation was performed in a sterile and dry environment. The laser power was 100mW, the scanning speed was 200μm / s, and the etching time was 20min, resulting in a substrate with a biomimetic micro / nano composite structure. In the micro / nano composite structure, the diameter of the nanopillars / pores was 200nm, the height / depth was 500nm, and the uniform spacing was set to 100nm.

[0057] S3. A rare-earth element-doped nanoparticle sol (neodymium-doped silica nanoparticles with an average particle size of 80 nm) was spin-coated onto the biomimetic micro / nano composite structure surface described in S2. The spin-coating speed was 3000 r / min, and the spin-coating time was 40 s. After drying at 90 °C for 15 min, the substrate was calcined at 400 °C for 1.5 h in air to obtain a substrate with a 5 μm thick nano-biomimetic coating.

[0058] Performance testing a. The substrates with nano-biomimetic coatings obtained in Example 3 and the comparative example were continuously operated in a high-density E. coli fermentation environment (e.g., OD600 > 100) for 6 cycles, each cycle lasting 14 days. Figure 1 As shown, the substrate surface with the nano-biomimetic coating in Example 3 is clean, as... Figure 2 As shown, in the comparative example, the substrate with the nano-biomimetic coating exhibits partial mycelial scaling.

[0059] b. The stability of the substrates with nano-biomimetic coatings obtained in Example 3 and the comparative example after sterilization at 121°C was tested. The substrates were sterilized with saturated steam at 121°C for 30 minutes per cycle, and the results are shown in Table 1.

[0060] Table 1. Stability test data for Example 3 and the comparative example.

[0061] As can be seen from the results in Table 1, the substrate with the nano-biomimetic coating in Example 3 can withstand 121°C and multiple sterilization cycles over 30 minutes. Compared with the substrate with the nano-biomimetic coating in the comparative example, the nano-biomimetic coating in Example 3 exhibits superior performance.

[0062] Therefore, the present invention adopts the above-mentioned anti-biocontamination nano-biomimetic coating, its preparation method and application. The spirulina polysaccharide, polyethylene glycol and rare earth doped nanoparticles in the biomimetic coating all have good biocompatibility, release no toxic or harmful substances, and will not interfere with the detection objects (such as biomolecules and cells) of the biosensor.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing an anti-biocontamination nano-biomimetic coating, characterized in that: Includes the following steps: S1. The stainless steel substrate is polished, cleaned and plasma treated in sequence to obtain the activated substrate; S2. Use a laser to etch the substrate surface activated in S1 to obtain a substrate with a biomimetic micro-nano composite structure. S3. Spin-coat the nanoparticle sol doped with rare earth elements onto the surface of the biomimetic micro-nano composite structure in S2, dry and calcine to obtain a substrate with nanoparticles. S4. Immerse the substrate with nanoparticles in S3 in an aminosilane solution at 40-60℃ for 2-4 hours, rinse, dry and solidify to obtain a substrate with an aminosilane transition layer. S5. Aldehyde-modified spirulina polysaccharide was dissolved in PBS buffer solution, and then aldehyde-modified polyethylene glycol was added. The mixture was stirred until homogeneous to obtain a mixed solution. The substrate with the aminosilane transition layer in S4 was immersed in the mixed solution to carry out the Schiff base reaction. After removal, it was washed and dried with nitrogen to obtain a substrate with a dynamic Schiff base structure. S6. Immerse the substrate with the dynamic Schiff base structure in S5 in a sodium cyanoborohydride solution for 1-2 hours, remove it, heat treat it, clean it again, and dry it with nitrogen to obtain a substrate with a nano-biomimetic coating.

2. The method for preparing an anti-biocontamination nano-biomimetic coating according to claim 1, characterized in that: In S1, the polished substrate is sequentially immersed in acetone, anhydrous ethanol, and deionized water during cleaning, and ultrasonically cleaned for 10-15 minutes. The plasma treatment power is 100-300W, and the time is 5-10 minutes.

3. The method for preparing an anti-biocontamination nano-biomimetic coating according to claim 1, characterized in that: In S2, the laser power for etching is 50-150mW, the scanning speed is 100-500μm / s, and the etching time is 10-30min.

4. The method for preparing an anti-biocontamination nano-biomimetic coating according to claim 1, characterized in that: In S3, the nanoparticles in the nanoparticle sol doped with rare earth elements include silicon dioxide nanoparticles or titanium oxide nanoparticles, and the rare earth elements include one or more of lanthanum, cerium and neodymium.

5. The method for preparing an anti-biocontamination nano-biomimetic coating according to claim 1, characterized in that: In S3, the spin coating speed is 2000-4000 r / min, the spin coating time is 30-60 s, the drying is at 80-100℃ for 10-20 min, and the calcination is at 300-400℃ for 1-2 h.

6. The method for preparing an anti-biocontamination nano-biomimetic coating according to claim 1, characterized in that: In S4, the curing temperature is 100-120℃ and the curing time is 1-2 hours.

7. The method for preparing an anti-biocontamination nano-biomimetic coating according to claim 1, characterized in that: In S5, the grafting reaction was carried out in a constant temperature shaking incubator at a rotation speed of 40-60 r / min, a soaking temperature of 30-40℃, and a soaking time of 12-24 h.

8. The method for preparing an anti-biocontamination nano-biomimetic coating according to claim 1, characterized in that: In S6, the heat treatment is performed at 60-80℃ for 1-2 hours.

9. A biomimetic nano-coating for resisting biofouling, characterized in that: It was prepared using the method for preparing an anti-biofouling nano-biomimetic coating as described in any one of claims 1-8.

10. The application of a biomimetic nano-coating for resisting biofouling, characterized in that: The anti-biocontamination nano-biomimetic coating as described in claim 9 is applied to the stainless steel surface of a biosensor.

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