Construction method of three-dimensional laminated chiral nano composite structure based on DNA origami template
By designing symmetrically distributed DNA origami templates and modifying them with gold nanoparticles, the precise positioning and vertical stacking of gold nanodiscs and gold nanospheres in three-dimensional space were achieved. This solved the problem of insufficient positioning and capture of DNA templates in the construction of three-dimensional stacked chiral nanocomposite structures in the existing technology, and constructed a chiral nanocomposite structure with a three-dimensional stacking effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DONGHUA UNIV
- Filing Date
- 2026-02-03
- Publication Date
- 2026-05-05
AI Technical Summary
Existing technologies struggle to achieve precise positioning and ordered stacking of gold nanodisks and gold nanospheres in three-dimensional space, especially when constructing three-dimensional stacked chiral nanocomposite structures with vertical heterostructures, where the DNA template capture ability and stability are insufficient.
Using DNA origami templates, we designed and synthesized trapping sites with multiple symmetrical distributions. We modified gold nanodiscs and gold nanospheres with DNA, treated a silicon substrate with a plasma cleaner, spread the DNA origami templates, and performed hybridization assembly to form a three-dimensional stacked structure. We then cleaned up unbound nanoparticles to achieve a three-dimensional stacked combination of gold nanodiscs and gold nanospheres.
Precise positioning and ordered vertical stacking of gold nanodisks and gold nanospheres in three-dimensional space were achieved, constructing a chiral nanocomposite structure with a three-dimensional stacking effect, which enhanced the DNA template capture ability and structural stability.
Smart Images
Figure CN121978782A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of nanomaterials and nanophotonics, and specifically relates to a method for constructing a three-dimensional layered chiral nanocomposite structure based on a DNA origami template. Background Technology
[0002] The development of DNA nanotechnology clearly demonstrates the evolution of this field from conceptual emergence to structural precision. In 1982, Professor Seeman proposed the vision of constructing ordered nanostructures using branched DNA molecules with complementary ends, laying the foundation for rational assembly using DNA base pairing. Subsequently, researchers developed more robust modules such as double-cross (DX) structural units, successfully achieving the self-assembly of periodic two-dimensional lattices and verifying the feasibility of DNA as a nanostructure framework. A major technological breakthrough occurred in 2006 when Professor Rothemund's "DNA origami" completely transformed the field. This method utilizes the site-specific hybridization of a long-chain DNA with hundreds of short chains to efficiently and programmably fold complex two-dimensional nanostructures such as rectangles, triangles, and even stars. With its excellent positioning accuracy (~5nm) and rich shape library, DNA origami provides a universal rigid template platform for subsequent functional integration. Building on this foundation, research focus shifted to using DNA origami templates to guide the precise alignment of inorganic nanoparticles. Early work focused on assembling single-type nanoparticles (such as gold nanospheres) in a two-dimensional plane to construct periodic arrays. Subsequently, to introduce optical chirality, we began to explore simultaneously positioning isotropic nanospheres and anisotropic nanorods (such as gold nanorods) on origami templates. By carefully designing their relative positions and orientations within the plane, we successfully constructed two-dimensional chiral superlattices with significant circular dichroism responses. These in-plane arrangements fully demonstrate the powerful ability of DNA self-assembly to regulate the spatial arrangement of nanoparticles to generate novel collective optical properties.
[0003] However, as research deepens, the limitations of two-dimensional planar chiral structures have gradually become apparent: their optical chiral signal intensity and modulation degrees of freedom are often constrained by planar geometry. Recently, cutting-edge research has begun to point to a third dimension: constructing three-dimensional stacked nanosystems with vertically stacked configurations. These structures are expected to generate chiral optical responses far exceeding those of planar structures through strong electromagnetic field interactions and spatial coupling produced by vertical stacking. However, achieving this goal faces significant challenges: it requires DNA templates not only to be precisely localized in a plane but also to possess the ability to capture different nanoparticles stepwise and specifically in the vertical direction; simultaneously, how to stably construct vertical heterogeneous structures based on anisotropic nanosheets (such as gold nanodisks) remains an unresolved problem. Summary of the Invention
[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for constructing a three-dimensional stacked chiral nanocomposite structure based on a DNA origami template.
[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: A method for constructing a three-dimensional stacked chiral nanocomposite structure based on a DNA origami template includes the following steps: hydrophilic treatment of a silicon substrate using a plasma cleaner; designing and synthesizing a DNA origami template with multiple symmetrically distributed capture sites; modifying gold nanodiscs and gold nanospheres with DNA, respectively; spreading the DNA origami template on the treated substrate surface; first hybridizing the DNA-modified gold nanodiscs with the template and fixing them at the center; then hybridizing the DNA-modified gold nanospheres with the capture strands above the template to form a three-dimensional stacked structure; and cleaning unbound nanoparticles to obtain a chiral nanocomposite structure with a three-dimensional stacking effect.
[0006] By adopting the above technical solution, the beneficial effects of the present invention are as follows: This invention provides a method for constructing a three-dimensional stacked chiral nanocomposite structure based on a DNA origami template, comprising the following steps: hydrophilic treatment of a silicon substrate using a plasma cleaner; designing and synthesizing a DNA origami template with multiple symmetrically distributed capture sites; modifying gold nanodiscs and gold nanospheres with DNA, respectively; spreading the DNA origami template on the treated substrate surface; first hybridizing the DNA-modified gold nanodiscs with the template and fixing them at the center; then hybridizing the DNA-modified gold nanospheres with the capture strands above the template to form a three-dimensional stacked structure; and cleaning unbound nanoparticles to obtain a chiral nanocomposite structure with a three-dimensional stacking effect. This invention achieves precise positioning and ordered vertical stacking of gold nanodiscs and gold nanospheres in three-dimensional space using a DNA origami template, constructing a chiral nanocomposite structure with a three-dimensional stacking effect. Attached Figure Description
[0007] Figure 1 This is a scanning electron microscope image of a single-layer chiral nanocomposite structure based on a DNA origami template on a silica substrate surface, obtained by the method provided in Embodiment 1 of the present invention, at a resolution of 1 micrometer.
[0008] Figure 2 This is a scanning electron microscope image of a single-layer chiral nanocomposite structure based on a DNA origami template on a silica substrate surface, obtained by the method provided in Embodiment 1 of the present invention, at a resolution of 500 nm.
[0009] Figure 3This is a scanning electron microscope image of a three-dimensional stacked chiral nanocomposite structure based on a DNA origami template on a silica substrate surface, obtained by the method provided in Embodiment 2 of the present invention, at a resolution of 1 micrometer.
[0010] Figure 4 This is a scanning electron microscope image of a three-dimensional stacked chiral nanocomposite structure based on a DNA origami template on a silica substrate surface, obtained by the method provided in Embodiment 2 of the present invention, at a resolution of 500 nm. Detailed Implementation
[0011] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0012] A method for constructing a three-dimensional stacked chiral nanocomposite structure based on a DNA origami template is disclosed. The method utilizes DNA self-assembly technology to first prepare a DNA origami template, and simultaneously functionalize the DNA surface of nanodiscs, nanorods, and nanospheres. Subsequently, the modified nanomaterials are assembled onto preset sites of the DNA origami template through sequence-specific hybridization, ultimately constructing a three-dimensional stacked nanocomposite structure with chiral characteristics.
[0013] Furthermore, the basic structural unit of the above-mentioned DNA origami template is a triangular DNA tile, which is connected in an orderly manner by means of DNA edge strands. The geometric dimensions of the triangular DNA tile are a side length of 80 nm and a thickness of 2 nm.
[0014] Furthermore, the aforementioned triangular DNA tiles are composed of a long single-stranded DNA of 7259 bases derived from the m13mp18 virus, a set of auxiliary DNA strands, and a capture DNA strand. The auxiliary DNA strands and the capture DNA strands pair with the long single-stranded DNA strands and fold to form the tile structure. The auxiliary DNA strands and the capture DNA strands total 168 strands, and the number of bases in each auxiliary strand is allowed to be different. The capture DNA strands contain two short sequences: the S1 sequence participates in the pairing of the long DNA strands, and the S2 sequence serves as a sticky end for binding nanodiscs or nanorods. There are also 24 DNA edge strands for connecting the triangular DNA tiles to form a DNA origami template.
[0015] Furthermore, by designing and adjusting the spatial distribution of the capture strands on triangular DNA tiles, a superlattice structure with a preset geometric arrangement can be constructed.
[0016] Furthermore, in the superlattice structure, each nanorod requires 16 trapping chains, each gold nanodisc is fixed by at least 2 trapping chains, and each gold nanosphere achieves vertical stacking assembly by hybridizing with the trapping chains above the gold nanodisc.
[0017] Furthermore, after spreading the DNA origami template onto the silica substrate surface, allow it to stand for 20 minutes to allow the origami template to stably bind to the substrate, followed by the use of buffer (1×TAE-Mg). 2+ Rinse to remove unbound DNA strands.
[0018] Furthermore, the DNA used to modify nanodiscs, nanorods, and nanospheres is a DNA sequence with thiol (-SH) modification.
[0019] Furthermore, the nanodiscs are gold nanodiscs, the nanorods are gold nanorods, and the nanospheres are gold nanospheres.
[0020] Furthermore, after completing the DNA modification of nanodiscs, nanorods, and nanospheres, the process also includes a step of removing excess DNA.
[0021] Furthermore, it also includes a step to remove excess DNA; this step is achieved by 2% agarose gel electrophoresis to purify the modified nanomaterials.
[0022] Furthermore, when hybridizing the DNA-modified nanodiscs and nanorods with the DNA origami template, the hybridization temperature should be controlled below the denaturation temperature of the DNA origami template.
[0023] The method for constructing a three-dimensional stacked chiral nanocomposite structure provided by this invention achieves precise positioning and ordered stacking of gold nanodiscs and gold nanospheres in three-dimensional space and vertical direction through DNA origami template, thereby constructing a chiral nanocomposite structure with a three-dimensional stacking effect.
[0024] The following detailed description, in conjunction with specific embodiments and accompanying drawings, illustrates the method for constructing the three-dimensional stacked chiral nanocomposite structure provided in the above embodiments of the present invention.
[0025] Example 1: A method for constructing a three-dimensional stacked chiral nanocomposite structure based on a DNA origami template, comprising the following steps: 1. DNA origami templates prepared using DNA self-assembly technology. A set of 100 µM auxiliary strands was mixed with long single-stranded DNA derived from the m13mp18 virus at a molar ratio of 10:1. Short-stranded DNA (referred to as the capture strand) for capturing nanorods was then added. This capture strand contains two functional sequences: a sticky end sequence S2 that complementarily pairs with the single-stranded DNA modified on the nanorod surface, and a sequence S1 that participates in specific hybridization with the m13mp18 long-stranded DNA, thus becoming a component of the basic triangular DNA tiles. Next, edge strands were added to connect the triangular DNA tiles, with a molar ratio of edge strands to m13mp18 long-stranded DNA of 20:1, to guide the self-assembly of the DNA origami template. Finally, 50×TAE-Mg... 2+ The buffer solution was used to adjust the system concentration to 1×TAE-Mg. 2+ Finally, the mixed solution was placed in a PCR instrument for annealing. The reaction conditions were 80°C starting and a slow cooling process of 101 hours until room temperature was reached, thus obtaining the required DNA origami template.
[0026] In this embodiment, the basic structural unit of the DNA origami template is preferably a triangular DNA tile, which is connected in an orderly manner by means of DNA edge strands. The geometric dimensions of the triangular DNA tile are a side length of 80 nm and a thickness of 2 nm. In addition, the structural unit can also use DNA tiles of other geometric shapes, such as squares, hexagons, etc.
[0027] In this embodiment, the triangular DNA tiles are composed of a long single-stranded DNA of 7259 bases derived from the m13mp18 virus, a set of auxiliary DNA strands, and a capture DNA strand. The auxiliary DNA strands and the capture DNA strands pair with the long single-stranded DNA strands and fold to form the tile structure. There are a total of 168 auxiliary DNA strands and capture DNA strands, and the number of bases in each auxiliary strand can be different. The capture DNA strand contains two short sequences: the S1 sequence participates in the pairing of the long DNA strand, and the S2 sequence serves as a sticky end for binding nanodiscs or nanorods. There are also 24 DNA edge strands for connecting the triangular DNA tiles to form a DNA origami template.
[0028] In this embodiment, a superlattice structure with a preset geometric arrangement can be constructed by designing and adjusting the spatial distribution of the capture strands on the triangular DNA tiles.
[0029] In this embodiment, in the superlattice structure, each nanorod requires 16 trapping strands, and each gold nanodisc is fixed by at least 2 trapping strands. In the specific implementation of this invention, the m13mp18 viral long single-stranded DNA used has a sequence length of 7259 bases and is obtained by isolating and purifying from the m13mp18 virus.
[0030] 2. DNA surface modification of nanorods and nanodiscs Nanorods coated with hexadecyltrimethylammonium bromide (CTAB) were first purified by centrifugation: centrifuged at 9000 rpm for 10 minutes, the supernatant was discarded, and the nanorods were redispersed with ultrapure water. This centrifugation process was repeated once, and after discarding the supernatant again, an appropriate amount of DNA solution was added to the precipitate, and the mixture was frozen at -18°C for 3 hours. After thawing, the frozen sample was resuspended in 0.5×TBE buffer containing 1% SDS. Subsequently, 5 mol / L NaCl solution was gradually added with slow stirring, and the mixture was incubated for 24 hours until the final NaCl concentration reached 500 mM. After modification, unbound free DNA was separated and removed by 2% agarose gel electrophoresis. The target band was excised and concentrated, and its concentration was finally determined using UV-Vis spectroscopy to ensure that excess DNA was completely removed to avoid interference with subsequent hybridization and localization processes.
[0031] An aqueous solution of citrate-coated gold nanoparticles was mixed with a thiolized DNA solution at a specific molar ratio, and TCEP (200 mM) was added to assist subsequent binding. n-Butanol was then added to the mixture to adjust the volume ratio of n-butanol to water to 9:1, allowing the aqueous phase to be rapidly extracted and removed by n-butanol. 0.5 × TBE was added to the dehydrated solid-phase mixture to redissolve and disperse the mixture in the aqueous phase.
[0032] In this embodiment, the DNA used to modify the nanorods and nanodiscs is preferably a thiol-modified sequence. The thiol group (-SH) at the end of the DNA forms a stable covalent connection with the surface of the nanorods through a gold-sulfur bond (Au-S bond), thereby achieving the firm fixation of DNA on the nanorods.
[0033] In the embodiments provided by the present invention, the nanorods are preferably gold nanorods, and the nanodiscs are preferably gold nanodiscs.
[0034] 3. Fix the DNA origami template onto the surface of the plasma-treated silicon substrate. First, the silicon wafers were ultrasonically cleaned in anhydrous ethanol to remove surface contaminants. Then, a plasma cleaner was used to treat the silicon wafers for 15 minutes to enhance their surface hydrophilicity. Next, a pre-prepared DNA origami solution was dropped onto the treated silicon wafer surface and allowed to stand for 20 minutes to promote full adsorption of the origami onto the substrate. The silicon wafers were then gently rinsed with 1×TAE-Mg²⁺ buffer to remove any unstable, excess DNA strands. After the silicon wafer surface had air-dried, it was ready for subsequent hybridization assembly with the previously purified and modified gold nanorods and gold nanodiscs.
[0035] 4. The DNA-modified nanorods were hybridized and assembled with DNA origami templates to form a single-layer two-dimensional chiral nanocomposite structure as a reference.
[0036] Purified gold nanorods and gold nanodiscs were dropwise added to the surface of a silicon wafer immobilized with a DNA origami template, and then incubated at 28°C for 2 to 3 hours, keeping the solution layer moist to prevent evaporation and drying. After incubation, the wafers were gently rinsed with 0.5×TBE buffer to remove unassembled free gold nanorods and nanodiscs. It is essential to ensure that the hybridization reaction temperature is below the melting temperature of the DNA origami template to maintain structural stability. The spatial localization of the gold nanorods and nanodiscs is achieved through the specific recognition and pairing of the pre-defined trapping strand terminal sequences on the DNA origami template with complementary DNA sequences modified on the surfaces of the nanorods and nanodiscs.
[0037] Please see Figure 1 and Figure 2 , Figure 1 and Figure 2 The image shows a scanning electron microscope (SEM) image of a monolayer superlattice structure on a silica substrate obtained by the method provided in Embodiment 1 of the present invention. As can be seen from the image, the method for constructing a monolayer two-dimensional chiral nanocomposite structure based on a DNA origami template provided in this embodiment of the present invention can achieve precise positioning and ordered arrangement of gold nanodiscs and gold nanorods in a two-dimensional array, and achieve their controllable assembly in two-dimensional space.
[0038] The method for constructing a single-layer two-dimensional chiral nanocomposite structure based on a DNA origami template, as provided in the above embodiments, involves rationally designing the spatial layout of the capture strands in the DNA array, enabling them to specifically bind to nanorods and nanodiscs with complementary sequences on their surfaces, thereby forming a structurally regular single-layer two-dimensional chiral nanocomposite structure.
[0039] The method for constructing a single-layer two-dimensional chiral nanocomposite structure based on a DNA origami template, as provided in the above embodiments, relies on DNA self-assembly technology to construct a two-dimensional template and uses DNA modification to achieve the functionalization of nanomaterials. Finally, through a sequence-guided hybridization process, the modified nanorods are precisely assembled to preset positions to form a structurally regular single-layer two-dimensional chiral nanocomposite structure. The method for constructing a single-layer two-dimensional chiral nanocomposite structure provided in the above embodiments of the present invention rationally designs the spatial layout of the capture strands in the DNA array, enabling them to specifically bind to nanorods and nanodiscs with complementary sequences modified on their surfaces, thereby forming a structurally regular single-layer two-dimensional chiral nanocomposite structure.
[0040] Example 2: A method for constructing a three-dimensional stacked chiral nanocomposite structure based on a DNA origami template, comprising the following steps: 1. DNA origami templates prepared using DNA self-assembly technology. A set of 100 µM auxiliary strands was mixed with long single-stranded DNA derived from the m13mp18 virus at a molar ratio of 10:1. Short-stranded DNA (referred to as the capture strand) for capturing nanorods was then added. This capture strand contains two functional sequences: a sticky end sequence S2 that complementarily pairs with the single-stranded DNA modified on the nanorod surface, and a sequence S1 that participates in specific hybridization with the m13mp18 long-stranded DNA, thus becoming a component of the basic triangular DNA tiles. Next, edge strands were added to connect the triangular DNA tiles, with a molar ratio of edge strands to m13mp18 long-stranded DNA of 20:1, to guide the self-assembly of the DNA origami template. Finally, 50×TAE-Mg... 2+ The buffer solution was used to adjust the system concentration to 1×TAE-Mg. 2+ Finally, the mixed solution was placed in a PCR instrument for annealing. The reaction conditions were 80°C starting and a slow cooling process of 101 hours until room temperature was reached, thus obtaining the required DNA origami template.
[0041] In this embodiment, the basic structural unit of the DNA origami template is preferably a triangular DNA tile, which is connected in an orderly manner by means of DNA edge strands. The geometric dimensions of the triangular DNA tile are a side length of 80 nm and a thickness of 2 nm. In addition, the structural unit can also use DNA tiles of other geometric shapes, such as squares, hexagons, etc.
[0042] In this embodiment, the triangular DNA tiles are composed of a long single-stranded DNA of 7259 bases derived from the m13mp18 virus, a set of auxiliary DNA strands, and a capture DNA strand. The auxiliary DNA strands and the capture DNA strands pair with the long single-stranded DNA strands and fold to form the tile structure. There are a total of 168 auxiliary DNA strands and capture DNA strands, and the number of bases in each auxiliary strand can be different. The capture DNA strand contains two short sequences: the S1 sequence participates in the pairing of the long DNA strand, and the S2 sequence serves as a sticky end for binding nanodiscs or nanorods. There are also 24 DNA edge strands for connecting the triangular DNA tiles to form a DNA origami template.
[0043] In this embodiment, a superlattice structure with a preset geometric arrangement can be constructed by designing and adjusting the spatial distribution of the capture strands on the triangular DNA tiles.
[0044] In this embodiment, in the superlattice structure, each nanorod requires 16 trapping chains, each gold nanodisc is fixed by at least 2 trapping chains, and each gold nanosphere achieves vertical stacking assembly by hybridizing with the trapping chains above the gold nanodisc. In the specific implementation of this invention, the m13mp18 viral long single-stranded DNA used has a sequence length of 7259 bases and is obtained by isolating and purifying from the m13mp18 virus.
[0045] 2. DNA surface modification of nanorods and nanodiscs Nanorods coated with hexadecyltrimethylammonium bromide (CTAB) were first purified by centrifugation: centrifuged at 9000 rpm for 10 minutes, the supernatant was discarded, and the nanorods were redispersed with ultrapure water. This centrifugation process was repeated once, and after discarding the supernatant again, an appropriate amount of DNA solution was added to the precipitate, and the mixture was frozen at -18°C for 3 hours. After thawing, the frozen sample was resuspended in 0.5×TBE buffer containing 1% SDS. Subsequently, 5 mol / L NaCl solution was gradually added with slow stirring, and the mixture was incubated for 24 hours until the final NaCl concentration reached 500 mM. After modification, unbound free DNA was separated and removed by 2% agarose gel electrophoresis. The target band was excised and concentrated, and its concentration was finally determined using UV-Vis spectroscopy to ensure that excess DNA was completely removed to avoid interference with subsequent hybridization and localization processes.
[0046] An aqueous solution of citrate-coated gold nanoparticles was mixed with a thiolized DNA solution at a specific molar ratio, and TCEP (200 mM) was added to assist subsequent binding. n-Butanol was then added to the mixture to adjust the volume ratio of n-butanol to water to 9:1, allowing the aqueous phase to be rapidly extracted and removed by n-butanol. 0.5 × TBE was added to the dehydrated solid-phase mixture to redissolve and disperse the mixture in the aqueous phase.
[0047] In this embodiment, the DNA used to modify the nanorods and nanodiscs is preferably a thiol-modified sequence. The thiol group (-SH) at the end of the DNA forms a stable covalent connection with the surface of the nanorods through a gold-sulfur bond (Au-S bond), thereby achieving the firm fixation of DNA on the nanorods.
[0048] In the embodiments provided by the present invention, the nanorods are preferably gold nanorods, and the nanodiscs are preferably gold nanodiscs.
[0049] 3. DNA surface modification of nanoparticles Gold nanoparticles with a diameter of approximately 40 nm, prepared by sodium citrate reduction, were mixed with DNA at a molar ratio of 1:300, and pH 3 was used to promote binding. After reacting for 10 minutes, 10×TBE buffer was added, followed by centrifugation at 6500 rpm for 5 minutes. The supernatant was discarded, and 1×TBE buffer was added again to transfer the system from the aqueous phase to the TBE phase. DNA was added continuously to increase the molar ratio of gold nanoparticles to DNA to 1:3000, and the system was frozen at -18°C for 3 hours. After thawing, NaCl solution was added in batches until the final concentration reached 500 mM, and the mixture was continuously shaken for more than 12 hours to complete binding. Subsequently, the modified nanoparticles were purified by 1% agarose gel electrophoresis, the target band was removed and concentrated, and the concentration was determined by UV-Vis spectroscopy to ensure that unbound DNA was completely removed to avoid interfering with the precise positioning of the nanoparticles during subsequent hybridization.
[0050] In this embodiment, the DNA used to modify the nanoparticles is preferably a thiol-modified sequence. The thiol group (-SH) at the end of the DNA forms a stable covalent connection with the surface of the nanoparticles through a gold-sulfur bond (Au-S bond), thereby achieving the firm fixation of DNA on the nanoparticles.
[0051] In this embodiment, the nanoparticles are preferably gold nanoparticles.
[0052] 4. Fix the DNA origami template onto the surface of the plasma-treated silicon substrate. First, the silicon wafers were ultrasonically cleaned in anhydrous ethanol to remove surface contaminants. Then, a plasma cleaner was used to treat the silicon wafers for 15 minutes to enhance their surface hydrophilicity. Next, a pre-prepared DNA origami template solution was dropped onto the treated silicon wafer surface and allowed to stand for 20 minutes to promote full adsorption of the origami onto the substrate. Subsequently, the silicon wafers were gently rinsed with 1×TAE-Mg²⁺ buffer to remove any unstable, excess DNA strands. After the silicon wafer surface had air-dried, it was ready for subsequent hybridization assembly with the previously purified and modified gold nanorods and gold nanodiscs.
[0053] 5. DNA-modified nanorods, nanodiscs, and nanoparticles are hybridized and assembled with DNA origami templates to form a three-dimensional stacked chiral nanocomposite structure.
[0054] Purified gold nanorods and gold nanodiscs were dropwise added to the surface of a silicon wafer immobilized with a DNA origami template, and then incubated at 28°C for 2 to 3 hours, keeping the solution layer moist to prevent evaporation and drying. After incubation, the wafers were gently rinsed with 0.5×TBE buffer to remove unassembled free gold nanorods and nanodiscs. The hybridization temperature must be kept below the melting temperature of the DNA origami to maintain structural stability. Spatial localization of the gold nanorods and nanodiscs is achieved through the specific recognition and pairing of the pre-defined trap strand terminal sequences on the DNA origami template with complementary DNA sequences modified on the surfaces of the nanorods and nanodiscs. Each gold nanosphere achieves vertical stacking assembly by hybridizing with the trap strand above the gold nanodisc.
[0055] Please see Figure 3 and Figure 4 , Figure 3 and Figure 4 The images show scanning electron microscope (SEM) images of a three-dimensional stacked chiral nanocomposite structure on a silica substrate obtained by the method provided in Embodiment 2 of the present invention. As can be seen from the images, the method for constructing a three-dimensional stacked chiral nanocomposite structure based on a DNA origami template provided in this embodiment of the present invention can achieve precise positioning and orderly arrangement of gold nanodiscs, gold nanorods, and gold nanospheres in three-dimensional space, and achieve their controllable assembly in three-dimensional space.
[0056] The method for constructing a three-dimensional stacked chiral nanocomposite structure provided in the above embodiments allows for precise spatial positioning of nanoparticles, nanorods, and nanodisks by designing the position of the capture strands on the DNA array, thereby enabling spatial addressability and construction of a specially designed three-dimensional stacked chiral nanocomposite structure.
[0057] The method for constructing a three-dimensional stacked chiral nanocomposite structure provided in the above embodiments utilizes DNA self-assembly technology to construct a two-dimensional DNA array, modifies nanoparticles, nanorods, and nanodiscs with DNA, and hybridizes the DNA-modified nanoparticles, nanorods, and nanodiscs with the above two-dimensional DNA array to form a three-dimensional stacked chiral nanocomposite structure.
[0058] The method for constructing a three-dimensional stacked chiral nanocomposite structure provided in the above embodiments allows for precise spatial positioning of nanoparticles, nanorods, and nanodisks by designing the position of the capture strands on a two-dimensional DNA array, thereby enabling spatial addressability and construction of a specially designed three-dimensional stacked chiral nanocomposite structure.
[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been shown above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.
Claims
1. A method for constructing a three-dimensional stacked chiral nanocomposite structure based on a DNA origami template, characterized in that, Includes the following steps: The silicon substrate was hydrophilicized using a plasma cleaner; Design and synthesize DNA origami templates with multiple symmetrically distributed capture sites; Gold nanodiscs and gold nanospheres were modified with DNA, respectively. Spread the DNA origami template onto the treated substrate surface; First, the DNA-modified gold nanodiscs are hybridized with the template and fixed at the center. The DNA-modified gold nanospheres are then hybridized with the trapping strand above the template to form a three-dimensional stacked structure. By cleaning unbound nanoparticles, a chiral nanocomposite structure with a three-dimensional stacking effect is obtained.
2. The method for constructing a three-dimensional stacked chiral nanocomposite structure according to claim 1, characterized in that, The basic structural unit of the DNA origami template is a triangular DNA tile, which is connected in an orderly manner by means of DNA edge strands. The geometric dimensions of the triangular DNA tile are 80 nm in side length and 2 nm in thickness.
3. The method for constructing a three-dimensional stacked chiral nanocomposite structure according to claim 2, characterized in that, The triangular DNA tiles are composed of a long single-stranded DNA of 7259 bases derived from the m13mp18 virus, a set of auxiliary DNA strands, and a capture DNA strand. The auxiliary DNA strands and the capture DNA strands pair with the long single-stranded DNA strands and fold to form the tile structure. There are a total of 168 auxiliary DNA strands and capture DNA strands, and the number of bases in each auxiliary strand can be different. The capture DNA strand contains two short sequences: the S1 sequence participates in the pairing of the long DNA strand, and the S2 sequence serves as a sticky end for binding nanodiscs or nanorods. There are also 24 DNA edge strands for connecting the triangular DNA tiles to form a DNA origami template.
4. The method for constructing a three-dimensional stacked chiral nanocomposite structure according to claim 3, characterized in that, By designing and adjusting the spatial distribution of the capture strands on triangular DNA tiles, a superlattice structure with a preset geometric arrangement is constructed.
5. The method for constructing a three-dimensional stacked chiral nanocomposite structure according to claim 4, characterized in that, In the superlattice structure, each nanorod requires 16 trapping chains, each gold nanodisc is fixed by at least 2 trapping chains, and each gold nanosphere achieves vertical stacking assembly by hybridizing with the trapping chains above the gold nanodisc.
6. The method for constructing a three-dimensional stacked chiral nanocomposite structure according to claim 1, characterized in that, After spreading the DNA origami template onto the silica substrate, it was left to stand for 20 minutes to allow the template to bond stably with the substrate. Then, 1×TAE-Mg was used. 2+ Rinse with buffer solution to remove unbound DNA strands.
7. The method for constructing a three-dimensional stacked chiral nanocomposite structure according to claim 1, characterized in that, The DNA used to modify nanodiscs, nanorods, and nanospheres is a DNA sequence with thiol modification.
8. The method for constructing a three-dimensional stacked chiral nanocomposite structure according to claim 1 or 7, characterized in that, The nanodiscs are gold nanodiscs, the nanorods are gold nanorods, and the nanospheres are gold nanospheres.
9. The method for constructing a three-dimensional stacked chiral nanocomposite structure according to claim 1, characterized in that, After DNA modification of nanodiscs, nanorods, and nanospheres, a step is also included to remove excess DNA; this step is achieved by 2% agarose gel electrophoresis to purify the modified nanomaterials.
10. The method for constructing a three-dimensional stacked chiral nanocomposite structure according to claim 1, characterized in that, When hybridizing the DNA-modified nanodiscs and nanorods with the DNA origami template, the hybridization temperature should be controlled below the denaturation temperature of the DNA origami template.