A controllable patterning method of tannic acid based on DNA origami templates

Abstract

The present invention discloses a controllable patterning method of tannic acid (TA) based on DNA origami template. Compared with dsDNA, ssDNA is more flexible and has more exposed hydrogen bond active sites, which is conducive to interaction with TA through hydrogen bonds. Therefore, we use DNA origami as a template and preset a specific pattern of clustered ssDNA (pcDNA) on its surface as an index for selective deposition of TA. TA monomers are preferentially adsorbed on pcDNA and bind to it through π-π stacking and Mg 2+ The mediated coordination interaction with the free TA monomers in the solution polymerizes and grows, thus forming a pre-designed TA nanopattern. Next, by changing the pH value and taking advantage of the degradation property of TA polymers in acidic environments, the TA nanopattern can be "erased" and "rewritten".

Description

Technical Field

[0001] The invention belongs to the technical field of nanomaterials, and particularly relates to a method for controllable patterning of tannic acid in a DNA origami template. Background Art

[0002] Tannic acid (TA) is a natural polyphenol that is widely found in fruits, seeds and vegetables. It undergoes hydrophobic interactions with other materials containing aromatic rings through π-π stacking, and its abundant phenolic hydroxyl groups facilitate binding to proteins, nucleic acids and various other biomacromolecules through hydrogen bonds. In recent years, tannic acid-based bioengineering materials have been widely studied for applications in multifunctional coatings, drug delivery, diagnosis, cell biomembranes, etc. Precise control of TA patterns can expand their potential applications. For example, the site-specific capture ability of proteins, metals and cells provided by TA micropatterned surfaces can be utilized in advanced biosensors and biochips. Current TA patterning methods mainly include photolithography and microcontact printing, but these methods usually require complex operations and expensive instruments, which limits the application and development of TA patterning.

[0003] With the advantages of programmability and addressability, DNA origami structures have been widely used as templates to customize various nanomaterials with pre-designed patterns, including proteins, metal nanoparticles, quantum dots, carbon nanotubes, polymers, etc. TA can interact with DNA through hydrogen bonds and has been reported to form DNA / TA hydrogels with adhesion, ductility, and biodegradability, as well as TA-DNA nanocomplexes with controllable assembly / disassembly behavior to achieve drug release.

[0004] Therefore, the use of DNA origami for precise TA nanopatterning has advantages but remains largely unexplored. Tannic acid, which has the potential to polymerize under appropriate conditions, can be patterned via bottom-up assembly. However, its rapid polymerization kinetics and strong adhesion often lead to its uncontrolled adsorption on most surfaces and objects, making the controllable processing of tannic acid patterning difficult to effectively address. Summary of the Invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the object of the present invention is to provide a method for controllable patterning of tannic acid using DNA origami templates to solve the problem of uncontrolled adsorption of tannic acid due to rapid polymerization kinetics and strong adhesion during the prior art processing.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention discloses a method for controllable patterning of tannic acid using a DNA origami template, comprising: using DNA origami as a template, presetting a specific pattern of protruding clustered ssDNA (i.e., pcDNA) on the template surface, utilizing the high flexibility and exposed aromatic bases of single-stranded DNA to provide active sites for TA-DNA interaction, so that tannic acid monomers are selectively adsorbed on the protruding clustered ssDNA (i.e., pcDNA) and grow through a polymerization reaction, thereby forming a tannic acid nanopattern according to the preset specific pattern.

[0008] Preferably, the method for controllable patterning of tannic acid in a DNA origami template comprises the following steps:

[0009] 1) Mixing the scaffold DNA, short-strand DNA, and protruding strand DNA in a buffer solution and annealing the mixture to produce a DNA origami solution with specific designed sites (specific designed sites capable of forming a specific pattern);

[0010] 2) preparing tannic acid solutions with different concentrations;

[0011] 3) The purified DNA origami solution is deposited on a support and adsorbed for several minutes. The freshly prepared tannic acid solution from step 2) is then added to the support surface and incubated at room temperature to allow the tannic acid to polymerize with the DNA origami (the tannic acid first hydrogen bonds with the ssDNA extending from the DNA origami and then self-polymerizes and grows to form a pattern), forming a tannic acid nanopattern with a specific pattern. The tannic acid nanopattern is then "erased" by adjusting the pH value and "reappeared" by adding tannic acid solution (tannic acid will first self-polymerize in the solution at a pH greater than 7. The design principle is to allow tannic acid to hydrogen bond with the ssDNA extending from the DNA origami and then self-polymerize and grow to form a pattern. Therefore, the pH of the buffer solution for the pattern reaction is 7. Tannic acid degrades at a pH below 7, so the pattern disappears by lowering the pH value).

[0012] Further preferably, in step 1), the scaffold DNA, short-chain DNA and protruding chain DNA are mixed in a buffer at a molar ratio of 1:10:10; after annealing, the final concentrations of the scaffold DNA, short-chain DNA and protruding chain DNA in the mixed system are 5 nM, 50 nM and 50 nM, respectively.

[0013] More preferably, the scaffold DNA adopts the M13mp18 scaffold.

[0014] More preferably, the buffer is 1×TAE / Mg 2+ Buffer (5 mM Tris, 1 mM EDTA, and 12.5 mM magnesium acetate, pH 8.0).

[0015] More preferably, the annealing treatment is to place the mixed sample in a PCR thermal cycler, heat it to 95°C for 5 minutes, and then cool it to 25°C at a rate of 0.1°C per 10 seconds.

[0016] Further preferably, since TA monomers are unstable in an aerobic alkaline reaction system and will rapidly polymerize into high molecular weight polymers through π-π stacking and intermolecular hydrogen bonds, tannic acid solutions of different concentrations are prepared in a reaction system with a neutral pH value.

[0017] More preferably, the buffer used to prepare tannic acid solutions of different concentrations is 1×HEPES / Mg 2+ Buffer containing 10 mM HEPES, 4 mM Mg 2+ , pH value is 7.0.

[0018] Further preferably, in step 3), the DNA origami with the specifically designed sites is purified by centrifugation and washing before use.

[0019] More preferably, the centrifugal washing is to filter the DNA origami solution in an Amicon Ultra-0.5 mL centrifugal filter with 1×HEPES / MgCl2 2+ The buffer was washed five times by centrifugation at 3000 g.

[0020] Further preferably, in step 3), the concentration of the tannic acid solution used in the polymerization reaction is 0.1-2 mM, and the polymerization reaction time is 1 to 30 min.

[0021] More preferably, in step 3), the concentration of the tannic acid solution used in the polymerization reaction is 0.7 mM, and the polymerization reaction time is 10 min.

[0022] Further preferably, the carrier is mica.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention discloses a controllable patterning method of tannic acid based on DNA origami templates. DNA origami is used as a template, and a clustered ssDNA (pcDNA) with a specific pattern is preset on its surface. The high flexibility and exposed aromatic bases of single-stranded DNA provide active sites for TA-DNA interaction, which is conducive to the interaction between ssDNA and TA through hydrogen bonds. Therefore, TA monomers are preferentially adsorbed on pcDNA rather than on the double-stranded DNA origami substrate (osDNA). Then, the TA monomers adsorbed on pcDNA can be synthesized through π-π stacking and Mg 2+The mediated coordination interaction with free TA monomers in solution polymerizes to form specific TA nanopatterns. This invention takes advantage of the programmability and addressability of DNA origami to provide a simple method for controllable nanopatterning of TA, thereby enabling the use of its unique properties to customize surface patterns for materials science and biomedicine. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The TA nanopatterns formed in this invention were observed and evaluated using atomic force microscopy (AFM). Figure a shows an "S" pattern composed of pcDNA on a DNA origami template before TA deposition and the corresponding AFM image; b shows an "S" pattern composed of pcDNA on a DNA origami template after TA deposition and the corresponding AFM image; c shows a cross-sectional analysis of the TA nanopattern on the DNA origami.

[0026] Figure 2 Figure 1 shows the effect of TA concentration on the "S" pattern on DNA origami. a is an AFM image of the "S" pattern on DNA origami at different TA concentrations; b is the corresponding average height and coverage area, where the gray bar represents the theoretical area ratio.

[0027] Figure 3 The effect of different reaction times on the "S" pattern on DNA origami of the present invention. a is the AFM image of the "S" pattern on DNA origami at different reaction times; b is the corresponding average height and coverage area graph, where the gray bar represents the theoretical area ratio;

[0028] Figure 4 Figures 1 and 2 are AFM images of the "erasing" and "rewriting" of TA nanopatterns under pH regulation according to the present invention; Figure a is an AFM image of DNA origami with "S"-shaped pcDNA deposited on a mica surface before TA deposition; Figure b is an AFM image of the letter "S" formed by the successful polymerization of tannic acid by the pcDNA on the DNA origami surface after the addition of TA under neutral conditions; Figure c is an AFM image of the disappearance of the letter "S" after the addition of an acidic buffer solution to the nanopatterned mica surface and incubation; and Figure d is an AFM image of the reappearance of the letter "S" after the addition of TA and incubation under neutral conditions.

[0029] Figure 5 The area ratio of TA deposited at different pH values ​​was calculated based on AFM images, as well as the corresponding representative AFM images.

[0030] Figure 6 This is a schematic diagram of the principle of the present invention, showing the site-specific and controllable patterning of tannic acid on a DNA origami template. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0032] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0033] The present invention is described in further detail below with reference to the accompanying drawings:

[0034] See also Figure 6 The present invention discloses a controllable patterning method of tannic acid based on DNA origami templates. DNA origami is used as a template, and a clustered ssDNA (pcDNA) with a specific pattern of protrusions is preset on its surface. The high flexibility and exposed aromatic bases of single-stranded DNA provide active sites for TA-DNA interaction, which is conducive to the interaction between ssDNA and TA through hydrogen bonds. Therefore, TA monomers are preferentially adsorbed on pcDNA rather than on the double-stranded DNA origami substrate (osDNA). Then, the TA monomers adsorbed on pcDNA can be synthesized through π-π stacking and Mg 2+ The mediated coordination interaction polymerizes with free TA monomers in the solution to form a specific TA nanopattern. Next, by changing the pH value and taking advantage of the degradation property of TA polymers in acidic environments, the TA nanopattern can be "erased" and "rewritten".

[0035] The prominent clustered ssDNA is "pcDNA," an abbreviation of protruding clustered DNA. Compared to dsDNA, ssDNA is more flexible and has more exposed hydrogen bonding sites, which facilitates hydrogen bonding interactions with TA. Therefore, TA monomers preferentially adsorb to pcDNA rather than to double-stranded DNA origami substrates (osDNA). Consequently, by pre-setting specific patterns, pcDNA can form controllable TA nanopatterns.

[0036] Specifically, the method includes the following steps:

[0037] 1) Preparation of DNA origami templates: Scaffold DNA, short-strand DNA, and overhanging DNA are mixed in a buffer solution and annealed to produce DNA origami with specific designed sites.

[0038] 2) Preparation of TA solution: TA solutions with different concentrations were prepared by diluting with specific buffer;

[0039] 3) TA nanopatterns based on DNA origami templates: After the purified DNA origami solution was deposited onto mica and adsorbed for 3 minutes, freshly prepared TA solution was added to the mica surface and incubated at room temperature to react with the DNA origami, thereby forming specific TA nanopatterns that were characterized by AFM.

[0040] 4) Erasing and rewriting of TA nanopatterns: To erase the TA nanopatterns, an adjusted acidic buffer solution was added to the nanopatterned mica surface formed in step 3 and incubated. As the pH value decreased, the nanopattern disappeared. After adding TA solution and incubating again, the nanopattern reappeared.

[0041] Preferably, in step 1), the scaffold DNA adopts M13mp18 scaffold, and the scaffold DNA, short chain DNA and protruding chain DNA are mixed in a 1×TAE / MgCl2 solution at a molar ratio of 1:10:10. 2+ The mixed sample was placed in a PCR thermal cycler and heated to 95°C for 5 minutes, then cooled to 25°C at a rate of 0.1°C per 10 seconds.

[0042] More preferably, the final concentrations of the scaffold DNA, the short-strand DNA, and the protruding-strand DNA are 5 nM, 50 nM, and 50 nM, respectively.

[0043] Preferably, in step 2), since the TA monomer is unstable in the aerobic alkaline reaction system, it will rapidly polymerize into a high molecular weight polymer through π-π stacking and intermolecular hydrogen bonding, so it is necessary to keep the pH of the reaction system neutral. 2+Buffer (10 mM HEPES, 4 mM Mg 2+ TA solutions with different concentrations were prepared in 4% paraformaldehyde (pH 7.0).

[0044] Preferably, in step 3), the DNA origami needs to be purified for subsequent reactions. The specific operation is as follows: the DNA origami solution is placed in an Amicon Ultra-0.5mL centrifugal filter (MWCO 100kD) and filtered with 1×HEPES / MgCl2. 2+ Buffer (10 mM HEPES, 4 mM Mg 2+ , pH 7.0) and washed five times by centrifugation at 3000 g.

[0045] Furthermore, in order to screen the optimal conditions for TA polymerization on DNA origami, the dependence of patterning on time and concentration was studied. First, the reaction time was kept at 10 minutes to observe the effect of TA concentration on patterning. 3 μL of the purified DNA origami solution was deposited on the freshly uncovered mica surface and adsorbed for 3 minutes. Subsequently, 30 μL of the solution was washed with 1×HEPES / MgCl2 solution and the mixture was stirred for 2 minutes. 2+ Buffer (10 mM HEPES, 4 mM Mg 2+ TA solutions of varying concentrations (0.1-2 mM) prepared in a 1% tantalum (pH 7.0) solution were deposited onto mica to react with the DNA origami. Finally, atomic force microscopy (AFM) was used to characterize and calculate the coverage of the TA pattern on the DNA origami surface, finding the optimal concentration to be 0.7 mM.

[0046] After finding the optimal reaction concentration, the reaction concentration was further optimized to 0.7 mM. The effect of reaction time on the TA deposition pattern was investigated, with reaction times ranging from 1 minute to 30 minutes. Similarly, AFM characterization and calculation of the TA pattern coverage on the DNA origami surface were performed, resulting in an optimal reaction time of 10 minutes. Therefore, a TA concentration of 0.7 mM and an incubation time of 10 minutes were selected as the optimal reaction conditions for TA patterning on DNA origami.

[0047] Preferably, in step 4), in order to achieve "erasing" of the TA nanopattern, 30 μL 1×HEPES / Mg 2+ Buffer (10 mM HEPES, 4 mM Mg 2+ , pH 5.5) was added to the nanopatterned mica surface formed in step 3) and incubated for 20 min.

[0048] Preferably, in step 4), in order to achieve "rewriting" of the TA nanopattern, 30 μL of 1×HEPES / Mg 2+ Buffer (10 mM HEPES, 4 mM Mg 2+TA solution (0.7 mM) was prepared with 1× HEPES / MgCl2 (pH 7.0) and incubated at room temperature for 10 minutes. 2+ The mica surface was rinsed with buffer to remove unreacted TA.

[0049] Atomic force microscopy (AFM) was used to image and analyze the TA nanopatterns on DNA origami. For AFM imaging, the sample solution was deposited onto freshly peeled mica, then deionized with water to remove excess salt and dried with nitrogen. The sample was then placed under an AFM in gas phase tapping mode for imaging.

[0050] The AFM imaging conditions were a temperature of 25° C. and a humidity below 40%. A “SCANASYST-AIR” probe (Bruker) with a spring constant of 0.4 N / m and a tip radius of 2 nm was selected for measurement.

[0051] Example 1

[0052] Step 1: Preparation of DNA origami template:

[0053] The scaffold DNA used was M13mp18 scaffold. The scaffold DNA, short-chain DNA, and protruding chain DNA were mixed in a 1×TAE / MgCl2 solution at a molar ratio of 1:10:10. 2+ The mixed samples were heated to 95°C in a PCR thermocycler for 5 minutes in a buffer (5 mM Tris, 1 mM EDTA, and 12.5 mM magnesium acetate, pH 8.0), then cooled to 25°C at a rate of 0.1°C per 10 seconds. The final concentrations of the M13mp18 scaffold, short DNA, and overhanging DNA were 5 nM, 50 nM, and 50 nM, respectively.

[0054] Step 2: Preparation of TA solution:

[0055] Since TA monomers are unstable in aerobic alkaline reaction systems and rapidly polymerize into high molecular weight polymers through π-π stacking and intermolecular hydrogen bonds, it is necessary to maintain the pH value of the reaction system at a neutral pH. 2+ Buffer (10 mM HEPES, 4 mM Mg 2+ TA solutions with different concentrations were prepared in 4% paraformaldehyde (pH 7.0).

[0056] Step 3: TA nanopatterning based on DNA origami templates:

[0057] First, the DNA origami needs to be purified for subsequent reactions. The specific operation is as follows: the DNA origami solution is placed in an Amicon Ultra-0.5mL centrifugal filter (MWCO 100kD) and filtered with 1× HEPES / MgCl2.2+ Buffer (10 mM HEPES, 4 mM Mg 2+ , pH 7.0) and washed five times by centrifugation at 3000 g. Then 3 μL of the purified DNA origami solution was deposited on the newly uncovered mica and adsorbed for 3 minutes. Subsequently, 30 μL of the solution was washed with 1× HEPES / MgCl2. 2+ Freshly prepared TA solution (0.7 mM) in buffer was added to the mica surface and incubated at room temperature for 10 min to react with the DNA origami.

[0058] See also Figure 1 To observe and evaluate the formed TA nanopatterns using AFM. pcDNA on the DNA origami surface ( Figure 1 Middle a) Successfully guided tannic acid polymerization to form the letter "S" pattern, as shown by the bright area on the origami ( Figure 1 Cross-sectional analysis shows that the average height of the TA pattern on the origami template after polymerization reaches ∼2.5 nm, with good spatial selectivity ( Figure 1 (c)

[0059] We then investigated the time and concentration dependence of patterning to identify optimal reaction conditions. First, we maintained a 10-minute reaction time to observe the effect of TA concentration on patterning. TA solutions of varying concentrations (0.1-2 mM) were deposited on mica to react with the DNA origami.

[0060] See also Figure 2 To investigate the effects of varying TA concentrations on the "S" pattern on DNA origami. (a) AFM images of the "S" pattern on DNA origami at varying TA concentrations; (b) corresponding average height and coverage area plots, with the gray bar representing the theoretical area ratio. With increasing TA concentration, both the coverage area and height increased. At a concentration of 1 mM, TA coverage reached ~35% of the DNA origami surface, with a height of ~6 nm. Theoretically, the designed pcDNA moiety should occupy 23.1-29.5% of the origami surface area. At a concentration of 0.7 mM, TA coverage reached ~28%, which was selected as the optimal reaction concentration.

[0061] Next, the reaction concentration was set to 0.7 mM to explore the effect of reaction time on the TA deposition pattern. Figure 3 (a) AFM images of "S" patterns on DNA origami at different reaction times; (b) corresponding average height and coverage area plots, with the gray bar representing the theoretical area ratio. As the incubation time increased to 30 minutes, the area ratio increased from ~10% to ~43%, and the height increased from ~3 nm to ~11 nm. The optimal reaction conditions were a TA concentration of 0.7 mM and an incubation time of 10 minutes.

[0062] Step 4: “Erasing” and “Rewriting” of TA nanopatterns:

[0063] By changing the pH value and taking advantage of the degradation characteristics of TA polymer in acidic environment, the TA nanopattern can be “erased” and “rewritten”. Specific process: In order to “erase” the TA nanopattern, 30μL 1×HEPES / Mg 2+ Buffer (10 mM HEPES, 4 mM Mg 2+ , pH 5.5) was added to the nanopatterned mica surface formed in step 3 and incubated for 20 minutes. In order to achieve the "rewriting" of the TA nanopattern, 30 μL of 1× HEPES / MgCl2 was added again. 2+ Buffer (10 mM HEPES, 4 mM Mg 2+ TA solution (0.7 mM) prepared with 1×HEPES / MgCl2 (pH 7.0) was added and incubated at room temperature for 10 minutes. 2+ The mica surface was rinsed with buffer to remove unreacted TA.

[0064] See also Figure 4 Figure 3: AFM images of "erasing" and "rewriting" TA nanopatterns under pH regulation; (a) is an AFM image of DNA origami with "S"-shaped pcDNA deposited on the mica surface before TA deposition; (b) is an AFM image of the letter "S" formed by the successful polymerization of tannic acid guided by pcDNA on the DNA origami surface after the addition of TA under neutral conditions; (c) is an AFM image of the disappearance of the letter "S" after the addition of acidic buffer to the above-mentioned nanopatterned mica surface and incubation; (d) is an AFM image of the reappearance of the letter "S" after the addition of TA and incubation under neutral conditions.

[0065] See also Figure 5 To calculate the area ratio of TA deposited at different pH values ​​based on AFM images, and the corresponding representative AFM images, as the pH value decreased from 7.0 to 5.5, the coverage area ratio of TA decreased from the original ∼28% to ∼4%, and increased to ∼30% after adding TA again and incubating at pH 7.0 for 10 min, achieving the “erasing” and “rewriting” of the TA nanopattern.

[0066] In summary, the present invention demonstrates a controllable TA nanopatterning strategy based on DNA origami templates. Using DNA origami as a template, clustered ssDNA (pcDNA) with a specific pattern of protrusions is preset on its surface. The high flexibility and exposed aromatic bases of single-stranded DNA provide active sites for TA-DNA interaction, so TA monomers are preferentially adsorbed on pcDNA rather than on double-stranded DNA origami substrates (osDNA). Then, the TA monomers adsorbed on pcDNA can be transported to the substrate through π-π stacking and Mg 2+The mediated coordination interaction polymerizes with free TA monomers in solution to form specific TA nanopatterns. The present invention leverages the programmability and addressability of DNA origami to provide a simple method for controllable TA nanopatterning, resolving the complex operations and expensive instrumentation required by existing technologies and the uncontrolled adsorption caused by the rapid polymerization kinetics and strong adhesion of tannic acid. This allows the use of its unique properties to customize surface patterns for materials science and biomedicine.

[0067] The above content is only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for controllable patterning of tannic acid using a DNA origami template, characterized in that: include: Using DNA origami as a template, a pcDNA with a specific pattern is preset on the template surface, and tannic acid monomers are selectively adsorbed on the pcDNA and grown through polymerization reaction to form a tannic acid nanopattern according to the preset specific pattern. The specific steps include: 1) Mixing the scaffold DNA, short-strand DNA, and protruding strand DNA in a buffer solution and annealing them to produce a DNA origami solution with a specific pattern; 2) preparing tannic acid solutions with different concentrations; 3) The purified DNA origami solution is deposited on a support and allowed to adsorb for several minutes. The freshly prepared tannic acid solution from step 2) is then added to the support surface and incubated at room temperature to allow the tannic acid to polymerize with the DNA origami, forming a tannic acid nanopattern with a specific pattern. The tannic acid nanopattern can then be "erased" and "reappeared" by adjusting the pH value.

2. The method for controllable patterning of tannic acid using a DNA origami template according to claim 1, wherein: In step 1), the scaffold DNA, short-chain DNA, and protruding chain DNA are mixed in a buffer at a molar ratio of 1:10:10; after annealing, the final concentrations of the scaffold DNA, short-chain DNA, and protruding chain DNA in the mixed system are 5 nM, 50 nM, and 50 nM, respectively.

3. The method for controllable patterning of tannic acid in a DNA origami template according to claim 1, characterized in that: Tannic acid solutions of different concentrations were prepared in a reaction system with a neutral pH value.

4. The method for controllable patterning of tannic acid using a DNA origami template according to claim 3, wherein: The buffer used to prepare tannic acid solutions of different concentrations was 1×HEPES / Mg 2+ Buffer containing 10 mM HEPES, 4 mM Mg 2+ , pH value is 7.

0.

5. The method for controllable patterning of tannic acid in a DNA origami template according to claim 1, wherein: In step 3), the DNA origami solution is purified by centrifugation and washing before use.

6. The method for controllable patterning of tannic acid in a DNA origami template according to claim 5, wherein: The DNA origami solution was washed by centrifugation in an Amicon Ultra-0.5 mL centrifugal filter with 1× HEPES / MgCl2. 2+ The buffer was washed five times by centrifugation at 3000 g.

7. The method for controllable patterning of tannic acid using a DNA origami template according to claim 6, wherein: In step 3), the concentration of the tannic acid solution used in the polymerization reaction is 0.1-2 mM, and the polymerization reaction time is 1-30 min.

8. The method for controllable patterning of tannic acid using a DNA origami template according to claim 1, wherein: In step 3), the concentration of the tannic acid solution used in the polymerization reaction is 0.7 mM, and the polymerization reaction time is 10 min.

9. The method for controllable patterning of tannic acid in a DNA origami template according to any one of claims 1 to 8, wherein: The carrier is mica.

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