KR102628030B1 - Triple or quadruple nanoring structure and method of manufacturing the same - Google Patents

Abstract

The triple nanoring structure according to an embodiment of the present invention includes an internal frame; a first outer frame having a closed loop structure surrounding the inner frame; a second outer frame having a closed loop structure surrounding the first outer frame; and a gold thin film layer covering the surfaces of the inner frame, the first outer frame, and the second outer frame. The inner frame and the first outer frame and the first outer frame and the second outer frame may be connected by at least one gold bridge.

Description

Triple or quadruple nanoring structure and manufacturing method thereof {TRIPLE OR QUADRUPLE NANORING STRUCTURE AND METHOD OF MANUFACTURING THE SAME}

The present invention relates to nanostructures, and more specifically, to nanostructures composed of triple or quadruple nanorings and a method of manufacturing the same.

Recently, interest in the synthesis of nanoparticles with a frame structure is increasing. Nanoparticles with a frame structure have the characteristic of having a larger exposed surface area relative to their volume than solid nanoparticles, so much research is being conducted, especially in bio and catalyst applications.

In order to increase the characteristics of the frame structure, research is actively being conducted to control the shape, size, and components of the frame, and representative frame synthesis methods include galvanic substitution reaction, selective growth, and etching methods.

However, the nanoframe structures synthesized through the above methods have only been studied on the shape, size, and component control within a single frame structure, and there is no way to precisely control nanoparticles with a complex frame structure or to achieve high uniformity. Research on possible synthesis methods is still lacking.

In addition, it is very difficult to precisely align the complex frame structure as multiple nanostructures within one particle in an aqueous solution. Conventionally, a simple chemical reaction involving a galvanic exchange reaction and a selective growth reaction using surface energy has been used to Only a single nanoring or single frame structure was feasible.

At this time, in order to solve the above problem, it was possible to realize a multi-ring structure in a substrate using lithography, but since the lithography method can only be manufactured on a substrate, its applicability is low and it is difficult to utilize it for applied research.

Republic of Korea Patent Publication No. 1844979

In order to solve the problems of the prior art as described above, the technical problem to be achieved by the present invention is to provide a new triple or quadruple nanoring structure in which multiple nanoparticles are integrated in one space through an elaborate chemical reaction in an aqueous solution and a method of manufacturing the same. will be.

In addition, since the internal spacing and shape of the triple or quadruple nanoring structure are precisely controlled, interaction with light is maximized to provide a surface-enhanced Raman scattering substrate that can be used in applied research such as bio and chemical detection. will be.

The technical problem to be achieved by the present invention is not limited to the technical problem mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description below. There will be.

In order to achieve the above technical problem, an embodiment of the present invention provides a triple nanoring structure.

The triple nanoring structure according to an embodiment of the present invention includes an inner frame of a closed loop structure; a first outer frame having a closed loop structure surrounding the inner frame; It may include a second outer frame having a closed loop structure surrounding the first outer frame; and a gold thin film layer covering surfaces of the inner frame, the first outer frame, and the second outer frame.

Additionally, the internal frame and the first external frame may be connected by at least one gold bridge, and the first external frame and the second external frame may be connected by at least one gold bridge.

Additionally, the inner frame, first outer frame, and second outer frame may be made of platinum.

In addition, there is a nano gap between the inner frame and the first outer frame and between the first outer frame and the second outer frame, and the degree of concentric growth of the gold thin film layer located on the frame is adjusted to control the nano gap. The distance of the gap can be adjusted.

Additionally, the electromagnetic field strength and distribution of the triple nanoring structure can be controlled by the distance of the nanogap.

Additionally, the triple nanoring structure has a symmetrical geometry, and through the symmetrical geometry, Raman scattering may be possible for light of near-infrared wavelengths in all directions.

In order to achieve the above technical problem, another embodiment of the present invention provides a substrate for surface-enhanced Raman scattering.

A substrate for surface-enhanced Raman scattering according to an embodiment of the present invention may include the triple nanoring structure described above.

In order to achieve the above technical problem, another embodiment of the present invention provides a quadruple nano ring structure.

The quadruple nano ring structure according to an embodiment of the present invention includes an inner frame of a closed loop structure; a first outer frame having a closed loop structure surrounding the inner frame; a second outer frame having a closed loop structure surrounding the first outer frame; A third outer frame having a closed loop structure surrounding the second outer frame; and a gold thin film layer covering the surfaces of the inner frame, the first outer frame, the second outer frame, and the third outer frame. .

Additionally, the inner frame and the first outer frame are connected by at least one gold bridge, the first outer frame and the second outer frame are connected by at least one gold bridge, and the second outer frame and the second outer frame are connected by at least one gold bridge. 3The outer frames may be connected by at least one gold bridge.

Additionally, the inner frame, the first outer frame, the second outer frame, and the third outer frame may be made of platinum.

In order to achieve the above technical problem, another embodiment of the present invention provides a method for manufacturing a triple nanoring structure.

The method for manufacturing the triple nanoring structure according to another embodiment of the present invention includes preparing a two-dimensional gold nanostructure; Forming a first platinum layer with a closed loop structure at an edge area of the two-dimensional gold nanostructure; forming a platinum single frame structure by removing gold inside the two-dimensional gold nanostructure on which the first platinum layer is formed; Forming a plate-shaped gold nanoring by faceted growing gold nanoparticles in an inner direction of the inner boundary surface and an outer direction of the outer boundary surface of the platinum single frame structure; forming a second platinum layer with a closed-loop structure on the inner edge region of the plate-shaped gold nanoring and a third platinum layer with a closed-loop structure on the outer edge region; The gold inside the plate-shaped gold nanoring on which the second platinum layer and the third platinum layer are formed is removed, and a gold bridge is located inside, and an inner frame, a first outer frame surrounding the inner frame, and the first outer frame are formed. It may include forming a platinum triple frame structure having a second surrounding external frame; and forming a gold thin film layer to cover the surface of the platinum triple frame structure to form a triple nanoring structure.

In addition, preparing the two-dimensional gold nanostructure includes preparing a two-dimensional triangular nanoprism made of gold; producing a two-dimensional circular nanodisk by performing a selective etching process on the triangular-shaped planar nanoprism; and performing an overgrowth process on the two-dimensional circular nanodisk to produce a circular or hexagonal two-dimensional nano gold structure. May include steps.

In addition, in the steps of forming the first platinum layer, the second platinum layer, and the third platinum layer, a silver thin film is formed on the two-dimensional gold nanostructure or the plate-shaped gold nanoring through a galvanic substitution reaction with platinum ions. It can be formed by

Additionally, in the step of forming the plate-shaped gold nanoring, a circular hollow may be formed inside the plate-shaped gold nanoring while maintaining the shape of the platinum single frame structure.

Additionally, in the step of forming the triple nanoring structure, the triple nanoring structure may be formed by performing concentric growth on the surface of the platinum triple frame structure.

In order to achieve the above technical problem, another embodiment of the present invention provides a method for manufacturing a triple nanoring structure.

The method for manufacturing the triple nanoring structure according to another embodiment of the present invention includes preparing a two-dimensional gold nanostructure; Forming a first platinum layer with a closed loop structure at an edge area of the two-dimensional gold nanostructure; forming a platinum single frame structure by removing gold (Au) inside the two-dimensional gold nanostructure on which the first platinum layer is formed; Forming a plate-shaped gold nanoring by faceted growing gold nanoparticles in an inner direction of the inner boundary surface and an outer direction of the outer boundary surface of the platinum single frame structure; forming a second platinum layer with a closed-loop structure on the inner edge region of the plate-shaped gold nanoring and a third platinum layer with a closed-loop structure on the outer edge region; forming a plate-shaped gold nanoplate by faceted growing gold nanoparticles in an inner direction of the inner boundary surface and an outer direction of the outer boundary surface of the plate-shaped gold nanoring on which the second platinum layer and the third platinum layer are formed; forming a fourth platinum layer having a closed loop structure at an edge region of the plate-shaped gold nanoplate; The gold inside the plate-shaped gold nanoring on which the fourth platinum layer is formed is removed, and a gold bridge is positioned inside, and an inner frame, a first outer frame surrounding the inner frame, and a second outer frame surrounding the first outer frame , forming a platinum quadruple frame structure having a third outer frame surrounding the second outer frame; and forming a gold thin film layer to cover the surface of the platinum quadruple frame structure to form a quadruple nanoring structure. It can be included.

In addition, preparing the two-dimensional gold nanostructure includes preparing a two-dimensional triangular nanoprism made of gold; manufacturing a two-dimensional circular nanodisk by performing a selective etching process on the triangular-shaped planar nanoprism; and manufacturing a circular or hexagonal two-dimensional nano gold structure by performing an overgrowth process on the two-dimensional circular nanodisk. May include steps.

According to one embodiment of the present invention, triple or quadruple platinum nanoring structures having different sizes can be manufactured in an aqueous solution by using a method for manufacturing a triple or quadruple nanoring structure.

In addition, more hot spot areas are formed within the single particle of the triple or quadruple platinum nanoring structure than in the existing single or double nanostructure, and the Raman signal of surface-enhanced Raman scattering is increased by 10 ⁹ times, resulting in surface-enhanced Raman scattering. This has the effect of dramatically improving the resolution of the signal.

In addition, the surface-enhanced Raman scattering signal detected from the triple or quadruple platinum nanoring structure has high reproducibility, and the Raman signal is uniform regardless of the direction of light and can exhibit high resolution.

The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

Figure 1 is a flowchart showing a method of manufacturing a triple nanoring structure according to an embodiment of the present invention.
Figure 2 is a schematic diagram showing a method of manufacturing a triple nanoring structure according to an embodiment of the present invention.
Figure 3 is a schematic diagram of the synthesis process of a triple nanoring structure according to an embodiment of the present invention and an electron microscope image of the synthesized nanoparticles.
Figure 4 is a schematic diagram and electron microscope image of a gold disk synthesis process in which gold growth is controlled on a platinum single nanoframe according to an embodiment of the present invention.
Figure 5 is a graph showing the electron microscope image, nano gap, and wavelength of the platinum triple frame structure and the triple nanoring structure with controlled gold growth according to an embodiment of the present invention.
Figure 6 shows the results of analyzing the surface-enhanced Raman scattering characteristics of a platinum triple frame structure according to an embodiment of the present invention.
Figure 7 is a schematic diagram and an electron microscope image of the synthesis process of a platinum quadruple frame structure according to an embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the attached drawings. However, the present invention may be implemented in various different forms and, therefore, is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts that are not related to the description are omitted, and similar parts are given similar reference numerals throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, combined)" with another part, this means not only "directly connected" but also "indirectly connected" with another member in between. "Includes cases where it is. In addition, when a part is said to “include” a certain component, this does not mean that other components are excluded, but that other components can be added, unless specifically stated to the contrary.

The terms used herein are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “comprise” or “have” are intended to indicate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, a triple nanoring structure according to an embodiment of the present invention will be described in detail with reference to the attached drawings.

With reference to FIG. 2, the triple nanoring structure will be described.

Figure 2 is a schematic diagram showing a method of manufacturing a triple nanoring structure according to an embodiment of the present invention.

The triple nanoring structure includes an internal frame 10 of a closed loop structure; a first outer frame (20) surrounding the inner frame; It may include a second outer frame 30 surrounding the first outer frame; and a gold thin film layer covering surfaces of the inner frame, the first outer frame, and the second outer frame.

At this time, the inner frame 10 and the first outer frame 20 and the first outer frame 20 and the second outer frame 30 may be connected by at least one gold bridge.

The gold bridge may connect the inner frame 10 and the first outer frame 20 and the first outer frame 20 and the second outer frame 30. If the respective frames are not connected, the inner frame And since the external frames cannot be formed within a single space, there may be a problem in which the triple nanoring structure cannot be formed.

At this time, the inner frame 10, the first outer frame 20, and the second outer frame 30 may be made of platinum.

At this time, the reason why the inner frame 10, the first outer frame 20, and the second outer frame 30 are made of platinum is because the structural stability of platinum is higher than that of other metal atoms such as gold or silver, so the inner support This is because it can be used as.

At this time, there is a nano gap between the inner frame 10 and the first outer frame 20 and between the first outer frame 20 and the second outer frame 30, and the gold thin film layer located on the frame The distance of the nano gap can be adjusted by controlling the degree of concentric growth.

If the potential applied during the concentric growth reduction reaction is higher than both the surface energy of the inner boundary (Einner-boundary) and the surface energy of the outer boundary (Eouter-boundary), the inner boundary (600) ) and the external boundary surface (500) so that the reduction reaction can proceed.

Therefore, since a reduction reaction can proceed at both the inner and outer boundaries of the platinum triple frame structure to form a gold thin film, the rate of the concentric growth reaction is adjusted to lower the reducing power of the metal atom, and the platinum triple frame structure is controlled to lower the reducing power of the metal atom. The distance of the nanogap can be adjusted when a silver atomic layer is formed on the entire surface to reduce the lattice mismatch constant between gold and platinum atoms to induce the growth of a gold thin film over the entire surface.

At this time, the electromagnetic field intensity and distribution of the plate-shaped triple nanoring structure can be adjusted by the distance of the nano gap.

When the distance of the nanogap is reduced by adjusting the distance of the nanogap, the incident electromagnetic field can be concentrated, so when the triple nanoring structure is applied to a surface-enhanced Raman scattering substrate, a high Raman enhancement value can be obtained.

At this time, the triple nanoring structure has a symmetrical geometry, and through the symmetrical geometry, Raman scattering may be possible for light of near-infrared wavelengths irradiated from all directions.

At this time, the diameter of the triple nanoring structure may be 140 nm to 150 nm.

At this time, among hollow nanostructures, the nanoring structure can be applied as a building block because it has a large surface-to-volume ratio, and the structure in which the inner hollow of the triple nanoring structure according to an embodiment of the present invention is formed is designed to improve the electric field. can do.

Additionally, the diameter of the internal frame of the triple nanoring structure may be 20 nm to 30 nm.

Additionally, the distance between the internal frame and the first external frame may be 9 nm to 13 nm.

An electric near field (electric field) is formed in the nanogap between the inner frame and the first outer frame.

near-fields) are strongly focused and can produce highly amplified Raman signals.

Additionally, the distance between the first external frame and the second external frame may be 6 nm to 10 nm.

At this time, since the nanogap can be reduced by the first outer frame located in the center of the triple nanoring structure according to an embodiment of the present invention, the first outer frame can act as a gap controller.

Additionally, the first outer frame and the second outer frame can absorb light, enhance near-field focus, and cause very large Raman scattering of the analyte absorbed by the triple nanoring structure.

According to another embodiment of the present invention. A substrate for surface-enhanced Raman scattering is provided, comprising the triple nanoring structure.

The method of manufacturing a substrate for surface-enhanced Raman scattering, characterized in that it includes the triple nanoring structure, may include preparing a substrate; and forming a triple nanoring structure on the substrate.

The substrate for surface-enhanced Raman scattering containing the triple nanoring structure can be enhanced by more than 10 times compared to the substrate for surface-enhanced Raman scattering containing the double nanoring structure.

According to another embodiment of the present invention, a quadruple nanoring structure will be described.

The quadruple nanoring structure includes an inner frame of a closed loop structure; a first outer frame surrounding the inner frame; a second outer frame surrounding the first outer frame; A third outer frame surrounding the second outer frame; and a gold thin film layer covering surfaces of the inner frame, the first outer frame, the second outer frame, and the third outer frame.

At this time, the internal frame and the first external frame, the first external frame and the second external frame, and the second external frame and the third external frame may be connected by at least one gold bridge.

The inner frame, first outer frame, second outer frame, and third outer frame may be made of platinum.

At this time, the diameter of the quadruple nanoring structure may be 190 nm to 200 nm.

Additionally, the diameter of the internal frame of the triple nanoring structure may be 20 nm to 30 nm.

Additionally, the distance between the internal frame and the first external frame may be 9 nm to 13 nm.

Additionally, the distance between the first external frame and the second external frame may be 6 nm to 10 nm.

Additionally, the distance between the second external frame and the third external frame may be 10 nm to 15 nm.

In this way, the triple or quadruple nanoring structure forms two circular hot spots that can maximize the near-field electromagnetic field, allowing it to display a high-resolution surface-enhanced Raman signal regardless of the direction of light.

As the distance between the inner frame and the outer frame is reduced, the surface-enhanced Raman efficiency of this Raman signal can be increased by more than 10 times compared to the existing double nanoring structure.

Referring to Figures 1 and 2, a method for manufacturing a triple nanoring structure will be described.

The triple nanoring structure according to an embodiment of the present invention can be synthesized in an aqueous solution and can exhibit high yield and uniformity of more than 90% by a controllable method.

Figure 1 is a flowchart showing a method for manufacturing a triple nanoring structure according to an embodiment of the present invention.

Figure 2 is a schematic diagram showing a method for manufacturing a triple nanoring structure according to an embodiment of the present invention.

A method for manufacturing a triple nanoring structure according to an embodiment of the present invention will be described.

Figure 1 is a flowchart showing a method for manufacturing a triple nanoring structure according to an embodiment of the present invention.

The triple nanoring structure manufacturing method includes preparing a two-dimensional gold nanostructure (S100); Forming a first platinum layer with a closed loop structure at an edge area of the two-dimensional gold nanostructure (S200); Forming a platinum single frame structure by removing gold inside the two-dimensional gold nanostructure on which the first platinum layer is formed (S300); Forming a plate-shaped gold nanoring by faceted growth of gold nanoparticles in an inner direction of the inner boundary surface and an outer direction of the outer boundary surface of the platinum single frame structure (S400); Forming a second platinum layer with a closed-loop structure on the inner edge region of the plate-shaped gold nanoring and a third platinum layer with a closed-loop structure on the outer edge region (S500); The gold inside the plate-shaped gold nanoring on which the second platinum layer and the third platinum layer are formed is removed, and a gold bridge is located inside, and an inner frame, a first outer frame surrounding the inner frame, and the first outer frame are formed. Forming a platinum triple frame structure having a second surrounding outer frame (S600); And forming a gold thin film layer to cover the surface of the platinum triple frame structure to form a triple nanoring structure (S700). can do.

At this time, the triple nanoring structure can be manufactured by performing five chemical reactions, and each chemical reaction will be described later.

The five chemical reactions are over growth, rim on deposition, selective etching, faceted growth, and concentric growth.

The first step may include preparing a two-dimensional gold nanostructure. (S100)

Preparing the two-dimensional gold nanostructure includes preparing a two-dimensional triangular nanoprism made of gold; manufacturing a two-dimensional circular nanodisk by performing a selective etching process on the triangular-shaped planar nanoprism; and performing an overgrowth process on the two-dimensional circular nanodisk to form a circular or hexagonal two-dimensional nano gold structure in a wide planar shape. It may include the step of manufacturing.

At this time, in the step of preparing the two-dimensional triangular nanoprism made of gold, the two-dimensional triangular nanoprism made of gold may have a size of 140 nm to 150 nm.

At this time, in the step of manufacturing a two-dimensional circular nanodisk by performing a selective etching process on the triangular-shaped planar nanoprism, the two-dimensional triangular nanoprism includes forming gold trivalent ions into gold monovalent ions; And a step of oxidizing gold atoms by the gold monovalent ion can be performed to etch into a two-dimensional circular nanodisk.

In addition, in the step of manufacturing a circular or hexagonal two-dimensional nano gold structure in a wide planar shape by performing an overgrowth process on the two-dimensional circular nanodisk, the two-dimensional circular nanodisk is transformed into a circular shape by performing an overgrowth process. Alternatively, a hexagonal two-dimensional nano gold structure can be manufactured.

At this time, the overgrowth process may be performed through the steps of adding ascorbic acid to the reaction solution; and adding gold ions to the reaction solution to which ascorbic acid has been added.

At this time, a symmetrical two-dimensional nano gold structure can be manufactured in an aqueous solution through the overgrowth process.

In the second step, it may include forming a first platinum layer with a closed loop structure in the edge area of the two-dimensional gold nanostructure (S200).

In the step of forming the first platinum layer, a silver thin film may be formed on the two-dimensional gold nanostructure through a galvanic substitution reaction with platinum ions.

For example, a reducing agent and a silver precursor (e.g., silver nitrate) are added to a reaction solution containing a two-dimensional gold nanostructure to form a silver thin film, and a platinum salt (e.g., H ₂ PtCl ₄ ) is added. By adding and performing a galvanic substitution reaction under acidic conditions, a first platinum layer with a closed loop structure can be formed at the edge area of the two-dimensional gold nanoparticles.

Here, the reason why platinum selectively grows on the edge area of the gold nanoparticle is because the edge area of the gold nanoparticle has higher surface energy than the terrace area.

Due to this difference in surface energy, a galvanic substitution reaction occurs selectively between the silver thin film and platinum ions in the edge region, forming a first platinum layer.

In the third step, it may include forming a platinum single frame structure by removing gold inside the two-dimensional gold nanostructure on which the first platinum layer is formed. (S300)

Specifically, by etching the gold nanoparticles using a solution that provides trivalent gold ions, the exposed middle region of the gold nanoparticle from the first platinum layer can be removed, thereby forming a single frame with an empty middle region. A structure can be formed.

At this time, the solution providing the trivalent gold ions is preferably HAuCl ₄ ·nH ₂ O or HAuCl ₄ solution, but is not limited thereto.

In the fourth step, it may include forming a plate-shaped gold nanoring by faceted growth of gold nanoparticles in the inner direction of the inner boundary surface and the outer direction of the outer boundary surface of the platinum single frame structure (S400).

In one embodiment, a reducing agent, a silver precursor (e.g., silver nitrate), and a gold precursor (e.g., HAuCl ₄ ) are added to the reaction solution containing the single frame structure to form a first gold thin film on the single frame structure. It can grow.

At this time, the reducing agent may be ascorbic acid, known as vitamin C, but is not limited to the reducing agent.

At this time, although some of the gold nanoparticles remain inside the single frame structure used, the silver thin film is uniformly formed on the single frame structure to induce high lattice constant matching between the gold atoms to be grown and the surface atoms of the silver thin film, By inducing a high growth rate of gold atoms, the gold nanoparticles cover the platinum single frame structure and tend to grow in a plane at an equal rate on the inner or outer boundary of the single frame structure.

At this time, the planar growth can form a plate-shaped gold nanoring while maintaining a thickness of 42 nm to 53 nm.

Therefore, the plate-shaped gold nanorings are grown on a single frame structure in a faceted growth mode, and by controlling the degree of faceted growth, the internal gap distance of the triple frame structure, which will be described later, can be precisely adjusted. You can.

At this time, the diameter of the plate-shaped gold nanoring structure may be 155 nm to 167 nm, and the diameter of the internal cavity of the plate-shaped gold nanoring structure may be 51 nm to 63 nm.

At this time, the plate-shaped gold nanoring may maintain the shape of the platinum single frame structure while forming a circular hollow inside.

In the fifth step, it may include forming a second platinum layer with a closed loop structure on the inner edge region of the plate-shaped gold nanoring and forming a third platinum layer with a closed loop structure on the outer edge region (S500).

The step of forming the second platinum layer and the third platinum layer may be performed in the same manner as the step of forming the first platinum layer described above, and after forming the silver thin film on the two-dimensional plate-shaped gold nanoring, It can be formed by subjecting a silver thin film to a galvanic substitution reaction with platinum ions.

For example, a reducing agent and a silver precursor (e.g., silver nitrate) are added to a reaction solution containing a two-dimensional gold nanostructure to form a silver thin film, and a platinum salt (e.g., H ₂ PtCl ₄ ) is added. By adding and performing a galvanic substitution reaction under acidic conditions, a first platinum layer with a closed loop structure can be formed at the edge area of the two-dimensional gold nanoparticles.

Here, the reason why platinum selectively grows on the edge area of the gold nanoparticle is because the edge area of the gold nanoparticle has higher surface energy than the terrace area.

Due to this difference in surface energy, a galvanic substitution reaction occurs selectively between the silver thin film and platinum ions in the edge region, forming a second platinum layer and a third platinum layer.

Referring to FIG. 3D, it can be confirmed that the second platinum layer and the third platinum layer were selectively deposited as there are bright lines at the inner edge region and the outer edge region of the plate-shaped gold nanoring structure.

As such, the platinum layer can be deposited by non-epitaxial platinum growth, which has a large lattice mismatch difference between gold and platinum of about 4.8%, making corners and vertices more reactive than dots and flat terraces. The platinum layer may be formed due to the high point.

At this time, when the second platinum layer and the third platinum layer are deposited, the diameter may be 203 nm to 187 nm.

In the sixth step, the gold inside the plate-shaped gold nanoring on which the second platinum layer and the third platinum layer are formed is removed, and a gold bridge is placed inside, an inner frame, a first outer frame surrounding the inner frame, and the second outer frame are formed. Forming a platinum triple frame structure having a second outer frame surrounding the first outer frame. (S600)

At this time, the gold inside the plate-shaped gold nanoring on which the second platinum layer and the third platinum layer are formed can be selectively etched to form the platinum triple frame structure. Specifically, a solution providing gold monovalent ions may be used. By etching the gold nanoparticles, the middle region of the gold nanoparticles excluding the first, second, and third platinum layers can be removed, thereby forming a triple frame structure with an empty interior. You can.

At this time, the gold nanoparticles can be etched by performing a reaction to balance the monovalent gold ions, and the reaction formula is as follows [Chemical Formula 1].

[Formula 1]

AuCl ₄ ^- + 2Au + 2Cl ^- →3AuCl ₂ ^-

At this time, the solution containing the monovalent gold ion is preferably a distilled water solution containing a surfactant, but is not limited thereto.

At this time, the gold bridge may be formed by removing less gold particles after the reaction in the aqueous solution for etching the gold nanoparticles proceeds.

At this time, a gold bridge may be located inside the platinum triple nanoframe, and the internal frame and the first external frame and the first external frame and the second external frame may be connected by at least one gold bridge.

At this time, the connection of the gold bridge may result in high structural stability of the complex structure.

In the seventh step, it may include forming a triple nanoring structure by forming a gold thin film layer to cover the surface of the platinum triple frame structure. (S700)

Alternatively, the gold thin film layer may be formed on the surfaces of each of the inner frame, the first outer frame, and the second outer frame.

The triple nanoring structure may be formed by performing concentric growth on the surface of the platinum triple frame structure.

At this time, the concentric growth occurs when the potential applied during the reduction reaction is higher than both the surface energy of the inner boundary (Einner-boundary) and the surface energy of the outer boundary (Eouter-boundary). A reduction reaction may proceed at both (600) and the outer boundary surface (500) to form a gold thin film.

At this time, since some of the gold nanoparticles of the plate-shaped gold nanoring remain inside the platinum triple frame structure used, there is a lattice mismatch constant between the gold nanoparticles and the first, second, and third platinum layers. The growth rate of the gold thin film may vary due to differences in constant).

At this time, in order to prevent selective growth and grow the gold thin film evenly throughout the surface of the platinum triple frame structure, after forming a silver thin film on the platinum triple frame structure, a reducing agent and a gold precursor (e.g., By adding HAuCl ₄ ), a gold thin film can be formed on the surface of the platinum triple frame structure by concentric growth.

As described above, when a silver thin film is formed on the platinum triple frame structure, the difference in lattice mismatch constant is reduced, allowing the gold thin film to grow evenly throughout the surface of the double frame structure. (Gold: 0.4065nm, Platinum: 0.3912nm)

At this time, the thickness of the gold thin film on the surface of the platinum triple frame structure can be adjusted through control of the gold concentric growth, and the size of the nano gap of the triple nanoring structure can be adjusted by adjusting the thickness of the gold thin film.

A method for manufacturing a quadruple nanoring structure according to an embodiment of the present invention will be described.

The method for manufacturing the quadruple nanoring structure will be described with reference to FIG. 7.

The method for manufacturing the quadruple nanoring structure may include manufacturing a platinum quadruple frame structure; and forming a gold thin film layer to cover the platinum quadruple frame structure.

At this time, manufacturing the platinum quadruple frame structure includes preparing a two-dimensional gold nanostructure; Forming a first platinum layer with a closed loop structure at an edge area of the two-dimensional gold nanostructure; forming a platinum single frame structure by removing gold (Au) inside the two-dimensional gold nanostructure on which the first platinum layer is formed; Forming a plate-shaped gold nanoring by faceted growing gold nanoparticles in an inner direction of the inner boundary surface and an outer direction of the outer boundary surface of the platinum single frame structure; forming a second platinum layer with a closed-loop structure on the inner edge region of the plate-shaped gold nanoring and a third platinum layer with a closed-loop structure on the outer edge region; forming a plate-shaped gold nanoplate by faceted growing gold nanoparticles in an inner direction of the inner boundary surface and an outer direction of the outer boundary surface of the plate-shaped gold nanoring on which the second platinum layer and the third platinum layer are formed; and forming a fourth platinum layer having a closed loop structure at an edge region of the plate-shaped gold nanoplate. The gold inside the plate-shaped gold nanoring on which the fourth platinum layer is formed is removed, and a gold bridge is positioned inside, and an inner frame, a first outer frame surrounding the inner frame, and a second outer frame surrounding the first outer frame , forming a platinum quadruple frame structure having a third outer frame surrounding the second outer frame; and forming a gold thin film layer to cover the surface of the platinum quadruple frame structure to form a quadruple nanoring structure. Includes.

That is, the method for manufacturing a quadruple nanoring structure according to an embodiment of the present invention is the same as the method for manufacturing a triple nanoring structure up to the step of forming the second platinum layer and the third platinum layer.

The method for manufacturing the quadruple nanoring structure is different from the next step. After performing faceted growth of gold nanoparticles on the plate-shaped gold nanoring structure formed with the second and third platinum layers, a platinum layer is added to the edge. After forming a tetra nanoring by removing the gold nanoparticles located inside, a platinum quadruple frame structure can be manufactured, and a gold thin film layer can be formed to cover the surface of the platinum quadruple frame structure.

Preparing the two-dimensional gold nanostructure includes preparing a two-dimensional triangular nanoprism made of gold; manufacturing a two-dimensional circular nanodisk by performing a selective etching process on the triangular-shaped planar nanoprism; and manufacturing a circular or hexagonal two-dimensional nano gold structure by performing an overgrowth process on the two-dimensional circular nanodisk. May include steps.

At this time, forming the first platinum layer of the platinum quadruple frame manufacturing method, forming the platinum single frame structure, forming a plate-shaped gold nanoring, and forming a second platinum layer and a third platinum layer. , the specific method of forming a plate-shaped gold nanoplate, forming a fourth platinum layer of a closed loop structure, forming a platinum quadruple frame structure, and forming a quadruple nanoring structure is the platinum triple frame manufacturing method. Same as

Therefore, the triple or quadruple nanoring structure manufacturing method has excellent structural control ability (controlling the nano gap between internal ring structures, controlling the shape of the nanoring structure), so the uniformity of the size and shape of the structure is high at more than 90%. .

In addition, triple or quadruple platinum nanoring structures having different sizes can be manufactured in an aqueous solution by using a method for manufacturing triple or quadruple nanoring structures.

In addition, more hot spot areas are formed within the single particle of the triple or quadruple platinum nanoring structure than in the existing single or double nanostructure, and the Raman signal of surface-enhanced Raman scattering is increased by 10 ⁹ times, resulting in surface-enhanced Raman scattering. This has the effect of dramatically improving the resolution of the signal.

In addition, the surface-enhanced Raman scattering signal detected from the triple or quadruple platinum nanoring structure has high reproducibility, and the Raman signal is uniform regardless of the direction of light and can exhibit high resolution.

Manufacturing example 1

First, a two-dimensional triangular nanoprism made of gold with a diameter of 140 nm was prepared.

Next, the trivalent gold ion was formed into a gold monovalent ion in the triangular-shaped planar nanoprism, and the gold monovalent ion oxidized the gold atom and selectively etched the two-dimensional circular nanodisk.

Next, the two-dimensional circular nanodisk was subjected to an overgrowth process by adding ascorbic acid to the reaction solution and adding gold ions to prepare a hexagonal two-dimensional nano gold structure.

Next, in the presence of iodide ions (50mM), 5mL of dispersed gold nanoparticles, 20mL of 50mM cetyltrimethylammonium bromide (CTAB), 340mL of 0.1M sodium hydroxide, and 2mM silver nitrate solution were added to the vial, and 426mL of 10mM ascorbic acid was added. , the solution was maintained at 70°C for 1 hour to form a silver thin film.

Next, 540 mL of 2mM H ₂ PtCl ₆ aqueous solution was added to the mixed solution, and the mixture was subjected to a galvanic substitution reaction at 70°C for about 3 hours to form a first platinum layer with a closed loop structure at the edge area of the gold nanoparticles.

Next, gold nanoparticles with the first platinum layer formed were dispersed in 5 ml of distilled water, etched in 2 ml of 0.05 M cetyltrimethylammonium bromide (CTAB) aqueous solution as a metal nanoparticle stabilizer, and 100 ㎕ of 2 mM HAuCl4 aqueous solution as a gold precursor. After adding 300㎕, etching was performed at a temperature of 50°C for 30 minutes to form a single frame structure.

Next, 4.5 ㎕ of 10mM ascorbic acid in 2ml of 0.05M cetyltrimethylammonium chloride (CTAC) aqueous solution as a metal nanoparticle stabilizer, 45 ㎕ of 2mM AgNO ₃ as a precursor, and 45 ㎕ of 2mM HAuCl ₄ aqueous solution as a gold precursor were mixed at 60°C at a temperature of 50°C. A plate-like gold nanoring structure was formed by planar growth for a few minutes.

Next, a second platinum layer was formed in the inner edge region and a third platinum layer was formed in the outer edge region in the same manner as the first platinum layer.

Next, a platinum triple frame structure was formed by etching using the same method as the single frame structure formation method.

Next, a silver nitrate solution was added to the solution containing the triple frame structure to form a silver thin film, and then 100 μl of a 2 mM HAuCl ₄ aqueous solution and 250 μl of 5.3 mM ascorbic acid were added to grow a second gold thin film. , triple frame nanoparticles were prepared.

Manufacturing example 2

First, a two-dimensional triangular nanoprism made of gold with a diameter of 140 nm was prepared.

Next, the trivalent gold ion was formed into a gold monovalent ion in the trivalent planar nanoprism, and the gold monovalent ion oxidized the gold atom and selectively etched the two-dimensional circular nanodisk.

Next, the two-dimensional circular nanodisk was subjected to an overgrowth process by adding ascorbic acid to the reaction solution and adding gold ions to prepare a hexagonal two-dimensional nano gold structure.

Next, in the presence of iodide ions (50mM), 5mL of dispersed gold nanoparticles, 20mL of 50mM cetyltrimethylammonium bromide (CTAB), 340mL of 0.1M sodium hydroxide, and 2mM silver nitrate solution were added to the vial, and 426mL of 10mM ascorbic acid was added. , the solution was maintained at 70°C for 1 hour to form a silver thin film.

Next, 540 mL of 2mM H ₂ PtCl ₆ aqueous solution was added to the mixed solution, and the mixture was subjected to a galvanic substitution reaction at 70°C for about 3 hours to form a first platinum layer with a closed loop structure at the edge area of the gold nanoparticles.

Next, gold nanoparticles with the first platinum layer formed dispersed in 5 ml of distilled water in an aqueous solution in which 2 ml of 0.05 M cetyltrimethylammonium bromide (CTAB) aqueous solution as a metal nanoparticle stabilizer was etched and 100 ㎕ of 2 mM HAuCl4 aqueous solution as a gold precursor was added. After adding 300㎕, etching was performed at a temperature of 50°C for 30 minutes to form a single frame structure.

Next, 4.5 ㎕ of 10mM ascorbic acid in 2 ml of 0.05M cetyltrimethylammonium chloride (CTAC) aqueous solution as a metal nanoparticle stabilizer, 45 ㎕ of 2mM AgNO ₃ as a precursor, and 45 ㎕ of 2mM HAuCl ₄ aqueous solution as a gold precursor were mixed at 60°C at a temperature of 50°C. A plate-like gold nanoring structure was formed by planar growth for a few minutes.

Next, a second platinum layer was formed on the inner edge region of the plate-shaped gold nanoring structure and a third platinum layer was formed on the outer edge region in the same manner as the first platinum layer.

Next, 4.5 ㎕ of 10mM ascorbic acid in 2ml of 0.05M cetyltrimethylammonium chloride (CTAC) aqueous solution as a metal nanoparticle stabilizer, 45㎕ of 2mM AgNO3 as a precursor, and 45㎕ of 2mM HAuCl4 aqueous solution as a gold precursor were placed on a flat surface at 50°C for 60 minutes. It grew to form a plate-like gold nanoring structure.

Next, a fourth platinum layer was formed in the outer edge region in the same manner as the first platinum layer.

Next, a quadruple frame structure was formed by etching using the same method as the single frame structure formation method.

Next, a silver nitrate solution was added to the solution containing the quadruple frame structure to form a silver thin film, and then 100 ㎕ of a 2 mM HAuCl ₄ aqueous solution and 250 ㎕ of 5.3 mM ascorbic acid were added to grow a second gold thin film. , quadruple frame nanoparticles were prepared.

Experiment example

Referring to FIGS. 3 to 7, an experimental example of the triple nanoring structure manufactured according to the above manufacturing example will be described.

Figure 3 is a schematic diagram of the synthesis process of a triple nanoring structure according to an embodiment of the present invention and an electron microscope image of the synthesized nanoparticles.

Figure 3A is a schematic diagram of the synthesis process of the triple nanoring structure, Figures 3B to 3I are electron microscope images of the synthesized triple nanoring structure, and Figure 3J is a schematic diagram of the synthesis process of each triple nanoring structure. This is a graph that allows you to check the localized surface plasmon resonance (LSPR) of the structures.

Figures 3B to 3G show a single frame (Figure 3B), a plate-shaped nanoring structure (Figure 3C, Figure 3D), and a triple nanoring structure (Figure 3E, Figure 3F, Figure 3G) formed during the manufacturing process of the triple nanoring structure. It can be seen that there is high uniformity in shape and size.

Additionally, Figure 3H shows that the triple nanoring structure has a thickness of 50 nm to 59 nm.

In addition, Figures 3G to 3H are transmission scanning electron microscope images (TEM), which can show that the triple nanoring structure is interconnected by a metal bridge, has the two circular nanogap regions, and has three frames. You can check that.

In addition, by checking the image mapping data of Figure 3I, it can be seen that the platinum of the core is uniformly coated with gold nanoparticles, and at this time, the atomic fractions of Ag, Au, and Pt are 6%, 61%, and 33%, respectively. It may be %.

In addition, the change in shape of the nanostructure of Figure 3J was monitored through ultraviolet (UV)-visible (vis)-near infrared (NIR) spectroscopy.

At this time, referring to FIG. 3J, it can be seen that the platinum and gold alloy nanoring has no LSPR band due to the plasmon inactivity of platinum in the UV-vis-NIR spectrum region.

In addition, three LSPR modes were observed at 531, 603, and 858 nm in the plate-like gold nanoring structure in which gold nanoparticles were grown in a planar manner on the platinum single frame, originating from out-of-plane dipole, in-plane quadrupole, and in-plane dipole modes, respectively.

In addition, when platinum was deposited along the edge of the plate-like nanoring structure, the in-plane dipole mode and the out-of-plane dipole mode were red-shifted from 858 nm to 1077 nm and 531 nm to 565 nm, respectively, and it was confirmed that the in-plane quadrupole mode disappeared. You can.

This is due to the loss of gold crystals when gold is converted into a plate-like nanoring structure with a platinum layer formed.

Additionally, after etching the gold inside the plate-shaped nanoring structure with the platinum layer formed, the small amount of gold remaining does not cause an LSPR band.

At this time, the amount of gold residue in the triple nanoframe is not sufficient to generate collective vibration of surface free electrons on the platinum surface.

Additionally, when a gold thin film layer is formed in the triple nanoframe, a broadband LSPR band appears over a wide spectral window range of 500 to 1200 nm.

Figure 4 is a schematic diagram and electron microscope image of a gold disk synthesis process in which gold growth is controlled on a platinum single nanoframe according to an embodiment of the present invention.

Figure 4A is a schematic diagram of the gold disk synthesis process in which gold growth is controlled on a platinum single nanoframe, and Figures 4B, 4G, 4H, I, J, and K are electron microscope images.

In addition, Figures 4C and D show experimental result data of the center-grown gold nanoring, Figures 4E and F show experimental result data of the plate-like gold nanoring structure, and Figure 4L shows the data obtained during the synthesis of each triple nanoring structure. This is a graph that allows you to check the localized surface plasmon resonance (LSPR) of the structures.

Referring to FIG. 4A, gold growth in the platinum single frame structure can be performed in two different ways: concentric growth or planar growth.

To analyze the gold growth pattern in detail, SEM, AFM (Atomic Force Spectroscopy), and XRD (X-ray diffraction) analysis were performed.

Referring to Figures 4B and 4G, it can be confirmed through SEM images of gold formed on the platinum single structure that the nanoring was manufactured by a different growth method.

Specifically, in Figure 4B, it can be seen that gold nanoparticles were uniformly deposited on the surface in the form of nanorings on a platinum single frame with a concentric growth pattern with an uneven surface, and in contrast, Figure 4G It can be seen that in the faceted growth pattern, a nanoring was manufactured on the platinum single frame in which the gold atoms maintain a hexagonal external shape with a flat top and a flat bottom.

In addition, the AFM data of FIGS. 4C and 4E indicate that the plate-like gold nanoring structure in the planar growth mode has a flatter surface and preferential gold growth in the lateral direction with a lower height than in other cases (concentric growth). .

In addition, Figure 4F shows XRD data. The plate-shaped gold nanoring structure showed two unique diffraction peaks ({111} and {222}) and the nanoring with a concentric growth pattern (Figure 4F) showed an additional peak ({111} , {200}, {220} and {222}).

At this time, in order to investigate in detail the growth pattern mechanism of the plate-shaped gold nanoring structure according to an embodiment of the present invention, the pH was changed and the reduction rate was controlled by using a halide ion as a planar growth blocker.

At this time, in the presence of the I- or Br- ions, the plate-shaped gold nanoring structure may prefer a concentric growth pattern regardless of pH.

However, in the presence of Cl-, the reaction can proceed in a planar growth pattern at pH 3 to 7.

Additionally, an epitaxial silver (Ag) UPD (underpotential deposition) layer is formed on the entire surface of the plate-like gold nanoring structure, so that specific planes (eg, {100} and {111}) can be maintained.

At this time, in order to further prove the influence of the silver layer on the gold growth pattern, the ratio of Au ³⁺ and Ag ⁺ ions was controlled while fixing the amount of trivalent gold ions (Au ³⁺ ).

As the ratio of gold (Au) and silver (Ag) decreases from 20 to 1 (i.e., Ag+ increases), the surface shape of the plate-like gold nanoring structure can change from a rough surface to a flat surface.

At this time, as the amount of silver (Ag ⁺ ) ions in the reaction solution increases, the Ag UPD layer with epitaxial growth completely covers the entire surface, allowing gold (Au) to grow uniformly.

Additionally, referring to Figures 4H to 4K, the shape evolution of the plate-like gold nanoring structure with a planar growth pattern can be monitored by adjusting the amount of gold ions (Au ³⁺ ) in the reaction solution.

At this time, Figure 4H shows that the diameter of the platinum single frame structure is 139 ± 6 nm, the internal cavity is 95 ± 5 nm, and the height is 20 ± 3 nm.

At this time, as the amount of gold containing the platinum increases, the outer diameter of the nanoring increases from 139 ± 6 to 171 ± 6 nm, the height increases from 20 ± 3 to 53 ± 4 nm, and the diameter of the inner cavity increases from 95 ± 6 nm. It can be seen that it has decreased from ±5 nm to 41 ±4 nm.

Additionally, while cracks grow laterally, resulting in well-defined edges, a concentric growth pattern leads to a bumpy surface.

Additionally, as shown in Figure 4L, the change in the shape of the nanoring and the corresponding in-plane dipole mode blue-shifted from 951 nm to 855 nm or 833 nm, while the out-of-plane dipole mode shifted from 520 nm to 529 nm or 547 nm. You can see that it has shifted to red.

Additionally, in-plane quadrupole modes began to appear at 600 nm and 591 nm as flat terraces developed.

Figure 5 is a graph showing the electron microscope image, nano gap, and wavelength of the platinum triple frame structure and the triple nanoring structure with controlled gold growth according to an embodiment of the present invention.

Figure 5A is an SEM image of a platinum single frame structure, and Figure 5D is data showing the hollow size and gap distance of the platinum single frame structure.

Figure 5B is an SEM image of a thin triple nanoring structure, and Figure 5E is data showing the hollow size and gap distance of the thin triple nanoring structure.

Figure 5C is an SEM image of a thick triple nanoring structure, and Figure 5F is data showing the hollow size and gap distance of the thick triple nanoring structure.

Figures 5G and H are graphs showing the localized surface plasmon resonance (LSPR) of the structures formed during the synthesis of each triple nanoring structure.

Figure 5I is data showing the three unique surface plasmon resonance modes of the internal nanorings of the triple nanoring structure through surface charge distribution calculation.

The thickness of the triple nanoring structure can be adjusted by precisely controlling the amount of Au ³⁺ in the reaction solution.

Figure 5A shows that the hollow size of the platinum single frame structure is 40 ± 7 nm, the distance between the inner frame and the first outer frame is 30 ± 5 nm, and the distance between the first outer frame and the second outer frame is 16 ± 4 nm. It can be confirmed that it has .

As the amount of gold coating around the platinum frame increases, the thickness of the gold thin film increases, the size of the hollow decreases to 25 ± 5 nm, and the distance between the first and second outer frames decreases to 11 ± 2 nm. decreased to .

Referring to Figure 5G, the triple nanoring structure has a high level of homogeneity in both size and shape, allowing the corresponding LSPR to be systematically investigated, centered at 1040 nm as the amount of gold surrounding the platinum ring increases. It can be seen that a single broadband band begins to appear and eventually changes to a band of 1277 nm.

At this time, measurements were made in D2O to extend the observation spectral window up to 1600 nm.

Additionally, electromagnetic simulations were performed using finite element method (FEM) to understand the broad LSPR functionality.

Three distinct features may arise from the complex coupling between the theoretically calculated UV-vis-NIR spectrum (Figure 5H) and the charge distribution map of the nanoring (Figure 5I).

The discrepancy between the experimental and calculated spectra is due to the polydispersity of the triple nanoring structure based on its physical dimensions compared to the single shape considered in the calculations.

Figure 6 shows the results of analyzing the surface-enhanced Raman scattering characteristics of a platinum triple frame structure according to an embodiment of the present invention.

Figures 6A, D, G, and J show a gold double nanoring structure prepared as a sample for comparison to systematically understand the near-field focusing function of the triple nanoring structure.

The gold double nanoring structure is similar in size and shape to the triple nanoring structure except for the number of nanorings.

At this time, one sample had two gold nanorings, the diameter was 30 nm, and the distance within the gap was fixed at 210 nm.

It can be confirmed that the LSPR test results of the double nanoring structure do not show spectral features in the investigated spectral window.

In Figure 6B, E, H, and K, the gold double nanoring structure was prepared as another sample for comparison to systematically understand the near-focusing function of the triple nanoring structure.

The sample had two gold nanorings, the diameter was 14 nm, and the distance within the gap was fixed at 150 nm.

The LSPR profile of the double nanoring structure showed a band at 832 nm.

At this time, the 2-napthalenethiol was used as the analyte and a laser with 785 nm excitation was used (179 μW), each nanoring with a different geometric structure was dispersed on a cover glass substrate, and surface-enhanced Raman scattering (SERS) of a single particle was used. ) were monitored using an optical microscope while measuring each nanoring.

Referring to Figures 6A and 6D, 6B and 6E, 6C and 6F, after the surface enhanced Raman scattering (SERS) measurement, the same sample was analyzed by SEM to confirm that the observed signal came from a single particle.

Referring to Figure 6G, a representative single particle surface-enhanced Raman scattering (SERS) signal of the triple nanoring structure was obtained and compared with the surface-enhanced Raman scattering (SERS) signal of the gold double nanoring structure of Figures 6H and 6I.

At this time, the triple nanoring structure exhibits a surface-enhanced Raman scattering (SERS) signal that is approximately 4 to 7 times higher than that of the gold double nanoring structure.

At this time, the simulated near-field focus maps of Figures 6J, 6K, and 6L show that near-field focusing was not observed without the middle nanoring, which indicates that the middle ring is "gap" to maximize LSPR coupling between the three nanorings. It can be confirmed that it acts as a “controller”.

At this time, comparing Figures 6J and 6K, the presence of the outer ring can play an important role in absorbing light and enhancing near focus.

In Figure 6M, it can be seen that the results of measuring 30 individual triple nanoring structures all show consistent and reproducible single particle surface-enhanced Raman scattering (SERS) signals, as shown in Figure 4M.

In Figure 6N, it can be seen that the measured average enhancement coefficient of the triple nanoring structure (about 1.3 × 10 ⁹ ) is larger than that of the double nanoring (1.1 × 108 and 1.8 × 10 ⁷ , respectively).

At this time, the triple nanoring structure with the two circular nanogap regions can effectively focus the incident electromagnetic field, and the electric near field can be greatly improved in the circular nanogap region, which is the inner frame.

Additionally, analytes absorbed between the outer, middle and core rings can cause tremendous Raman enhancement.

In addition, as can be seen from the XPS data, the surface of the triple nanoring structure is covered with gold, and due to the structural uniqueness of the triple nanoring structure, high Raman enhancement values can be obtained and an enlarged hotspot area can be derived. (ca .30% of total area).

Additionally, given that the surface exposure of silver (Ag) is very small, as can be seen from TEM-EDS mapping and XPS analysis, the contribution due to trace amounts of silver (Ag) can be almost ignored.

Figure 7 is a schematic diagram and an electron microscope image of the synthesis process of a platinum quadruple frame structure according to an embodiment of the present invention.

Figure 7 shows the possibility of expansion into a quadruple nanoring structure.

Compared to the synthesis of the triple nanoring structure, the quadruple nanoring structure can clearly show a synthetic route based on repetition of “in-plane growth of gold”.

Referring to FIG. 7, after planar growth of gold using a single platinum frame with a small diameter (75 ± 7 nm) as a starting material, selective platinum growth was applied.

Then, planar growth of gold was performed again, selective growth of platinum was performed, and finally, it was confirmed that a platinum quadruple frame structure was manufactured by selectively etching the gold.

Referring to Figures 7B and 7D, as can be seen in the magnified and low-magnification SEM images, a nanoring in which four frames connected to a metal bridge are entangled can be confirmed.

At this time, the characteristic is that a nanoring with four frames entangled can form a thicker outermost ring than a nanoring with three frames entangled.

In addition, as can be seen in the schematic diagram of Figure 7A, the thickness of the nanoring continues to increase as growth progresses.

Additionally, it is universally applicable to nanorings of different shapes (e.g., triangular triple nanorings and tetrananorings).

The description of the present invention described above is for illustrative purposes, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. will be. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. For example, each component described as unitary may be implemented in a distributed manner, and similarly, components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the patent claims described below, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

10: Inner frame
20: first external frame
30: second outer frame

Claims (17)

Internal frame of closed loop structure;
a first outer frame having a closed loop structure surrounding the inner frame;
a second outer frame having a closed loop structure surrounding the first outer frame; and
A triple nanoring structure comprising a gold thin film layer covering surfaces of the inner frame, the first outer frame, and the second outer frame. According to paragraph 1,
A triple nanoring structure, wherein the internal frame and the first external frame are connected by at least one gold bridge, and the first external frame and the second external frame are connected by at least one gold bridge. According to paragraph 1,
A triple nanoring structure, wherein the inner frame, the first outer frame, and the second outer frame are made of platinum. According to paragraph 1,
There is a nano gap between the inner frame and the first outer frame and between the first outer frame and the second outer frame, and the degree of concentric growth of the gold thin film layer located on the frame is adjusted to adjust the degree of concentric growth of the nano gap. Triple nanoring structure characterized by adjustable distance. According to paragraph 4,
A triple nanoring structure, wherein the electromagnetic field intensity and distribution of the triple nanoring structure are controlled by the distance of the nano gap. According to paragraph 1,
The triple nanoring structure has a symmetrical geometry, and is capable of Raman scattering of light of near-infrared wavelengths in all directions through the symmetrical geometry. A substrate for surface-enhanced Raman scattering, comprising the triple nanoring structure of claim 1. Internal frame of closed loop structure;
a first outer frame having a closed loop structure surrounding the inner frame;
a second outer frame having a closed loop structure surrounding the first outer frame;
a third outer frame having a closed loop structure surrounding the second outer frame; and
A quadruple nano ring structure comprising a gold thin film layer covering surfaces of the inner frame, the first outer frame, the second outer frame, and the third outer frame. According to clause 8,
The inner frame and the first outer frame are connected by at least one gold bridge, the first outer frame and the second outer frame are connected by at least one gold bridge, and the second outer frame and the third outer frame are connected by at least one gold bridge. The frame is a quadruple nanoring structure characterized in that it is connected by at least one gold bridge. According to clause 8,
A quadruple nanoring structure, wherein the inner frame, the first outer frame, the second outer frame, and the third outer frame are made of platinum. Preparing a two-dimensional gold nanostructure;
Forming a first platinum layer with a closed loop structure at an edge area of the two-dimensional gold nanostructure;
forming a platinum single frame structure by removing gold inside the two-dimensional gold nanostructure on which the first platinum layer is formed;
Forming a plate-shaped gold nanoring by faceted growing gold nanoparticles in an inner direction of the inner boundary surface and an outer direction of the outer boundary surface of the platinum single frame structure;
forming a second platinum layer with a closed-loop structure on the inner edge region of the plate-shaped gold nanoring and a third platinum layer with a closed-loop structure on the outer edge region;
The gold inside the plate-shaped gold nanoring on which the second platinum layer and the third platinum layer are formed is removed, and a gold bridge is located inside, and an inner frame, a first outer frame surrounding the inner frame, and the first outer frame are formed. forming a platinum triple frame structure having a surrounding second outer frame; and
A method for manufacturing a triple nanoring structure, comprising forming a gold thin film layer to cover the surface of the platinum triple frame structure to form a triple nanoring structure. According to clause 11,
The step of preparing the two-dimensional gold nanostructure is,
Preparing a two-dimensional triangular nanoprism made of gold;
manufacturing a two-dimensional circular nanodisk by performing a selective etching process on the two-dimensional triangular nanoprism; and
A method for manufacturing a triple nanoring structure, comprising the step of performing an overgrowth process on the two-dimensional circular nanodisk to produce a circular or hexagonal two-dimensional nano gold structure. According to clause 11,
In the step of forming the first platinum layer and the step of forming the second platinum layer and the third platinum layer,
A method of manufacturing a triple nanoring structure, characterized in that it is formed by galvanic substitution reaction of a silver thin film with platinum ions on the two-dimensional gold nanostructure or the plate-shaped gold nanoring. According to clause 11,
In the step of forming the plate-shaped gold nanoring,
A method of manufacturing a triple nanoring structure, wherein the plate-shaped gold nanoring maintains the shape of the platinum single frame structure and has a circular hollow inside. According to clause 11,
In the step of forming the triple nanoring structure,
A method of manufacturing a triple nanoring structure, characterized in that the triple nanoring structure is formed by performing concentric growth on the surface of the platinum triple frame structure. Preparing a two-dimensional gold nanostructure;
Forming a first platinum layer with a closed loop structure at an edge area of the two-dimensional gold nanostructure;
forming a platinum single frame structure by removing gold (Au) inside the two-dimensional gold nanostructure on which the first platinum layer is formed;
Forming a plate-shaped gold nanoring by faceted growing gold nanoparticles in an inner direction of the inner boundary surface and an outer direction of the outer boundary surface of the platinum single frame structure;
forming a second platinum layer with a closed-loop structure on the inner edge region of the plate-shaped gold nanoring and a third platinum layer with a closed-loop structure on the outer edge region;
Forming a plate-shaped gold nanoplate by faceted growing gold nanoparticles in an inner direction of the inner boundary surface and an outer direction of the outer boundary surface of the plate-shaped gold nanoring on which the second platinum layer and the third platinum layer are formed;
forming a fourth platinum layer having a closed loop structure at an edge region of the plate-shaped gold nanoplate;
The gold inside the plate-shaped gold nanoring on which the fourth platinum layer is formed is removed, and a gold bridge is located inside, an inner frame, a first outer frame surrounding the inner frame, and a second outer frame surrounding the first outer frame. , forming a platinum quadruple frame structure having a third outer frame surrounding the second outer frame; and
A method for manufacturing a quadruple nanoring structure, comprising the step of forming a quadruple nanoring structure by forming a gold thin film layer to cover the surface of the platinum quadruple frame structure. According to clause 16,
The step of preparing the two-dimensional gold nanostructure is,
Preparing a two-dimensional triangular nanoprism made of gold;
manufacturing a two-dimensional circular nanodisk by performing a selective etching process on the two-dimensional triangular nanoprism; and
A method for manufacturing a quadruple nanoring structure, comprising the step of performing an overgrowth process on the two-dimensional circular nanodisk to produce a circular or hexagonal two-dimensional nano gold structure.