Surface enhanced raman scattering structure comprising metal powder and manufacturing method thereof

Abstract

The present invention provides a surface enhanced raman scattering structure comprising: a main substrate; a first metal layer formed of a plurality of oxidation-resistant plasmonic first metal nanopatterns transferred onto a first surface of the main substrate; and a plasmonic nanoparticle layer formed of a plurality of plasmonic nanoparticles attached to the top of the first metal layer, wherein the plasmonic nanoparticles comprise a plasmonic second metal core that causes surface plasmon resonance and a first metal shell comprising the first metal and formed on the surface of the second metal core.

Description

Surface-enhanced Raman scattering structure containing metal powder and method for manufacturing the same

[0001] The present invention relates to a surface-enhanced Raman scattering structure, and more particularly, to a surface-enhanced Raman scattering structure including a metal powder having an oxidation-resistant metal shell structure that suppresses surface oxidation of an oxidizable surface-enhanced Raman scattering metal, and a method for manufacturing the same.

[0002] Raman spectroscopy is an analytical technique applied to research for the vibrational structure of molecules or qualitative / quantitative analysis of substances. When light is reflected from an analyte, the intensity of the reflected light is analyzed through a spectrum according to frequency, allowing analysis of the composition and structural information of the substance.

[0003] Raman spectroscopy is emerging as a next-generation analysis technology because it is fast, accurate, and non-destructive. However, existing Raman spectroscopy has the problem that it is difficult to analyze small amounts of the substance to be analyzed due to the low Raman scattering probability of molecules and the possibility of strong fluorescence.

[0004] Accordingly, a method using the Surface-Enhanced Raman Scattering (SERS) effect was proposed to solve the low signal intensity problem.

[0005] Surface-enhanced Raman scattering can significantly enhance the intensity of the Raman spectrum by absorbing energy at the surface, and the enhancement factor (EF), which is used as a measure of the magnitude of surface-enhanced Raman scattering, is usually 10. 4 10 inland 8 Since this is determined by the material and nano-structure pattern of the substrate surface, manufacturing a highly sensitive active substrate is emerging as a key task of surface-enhanced Raman scattering analysis technology. In other words, research is ongoing to optimize the material and nano-structure pattern of the substrate surface to improve the analysis performance of surface-enhanced Raman scattering substrates.

[0006] Recently, surface-enhanced Raman scattering (SAR) substrates have been developed to improve sensitivity for detecting trace amounts of substances. These substrates incorporate structures containing dispersed nanoparticles. However, the lack of uniform dispersion of the nanoparticles poses a challenge, affecting the uniformity of the analysis.

[0007] In addition, it has been proposed to fabricate a surface-enhanced Raman scattering substrate by forming nanostructures such as nanowires or nanoparticles, but this also has the disadvantage of being a complex process.

[0008] In addition, products with improved sensitivity are required for the detection of ultra-trace amounts of substances, and accordingly, silver (Ag)-based surface-enhanced Raman scattering substrates with higher sensitivity improvement characteristics are preferred over gold (Au)-based surface-enhanced Raman scattering substrates.

[0009] However, the existing silver (Ag)-based surface-enhanced Raman scattering substrate has a problem in that an oxidation reaction occurs on the silver (Ag) surface, which weakens the surface-enhanced Raman scattering performance and forms a background peak, i.e., a noise component, making accurate analysis difficult.

[0010] The background peak becomes sharper as the oxidation of silver (Ag) progresses, and the background peak of the chip becomes higher over time compared to the initial manufacturing stage.

[0011] The present invention aims to provide a high-performance surface-enhanced Raman scattering structure having a high signal enhancement effect and excellent signal uniformity and reproducibility, and a method for manufacturing the same.

[0012] The present invention aims to provide a surface-enhanced Raman scattering structure and a method for manufacturing the same, which can minimize the formation of a background peak by preventing oxidation of an oxidizable metal material that generates surface plasmon resonance by applying an oxidation-inhibiting layer.

[0013] The present invention aims to provide a surface-enhanced Raman scattering structure and a method for manufacturing the same, which can minimize the formation of a background peak by preventing oxidation of an oxidizable metal material that generates surface plasmon resonance by applying a protective layer.

[0014] One embodiment of the present invention provides a surface-enhanced Raman scattering structure comprising: a substrate; a first metal layer formed of a plurality of oxidation-resistant plasmonic first metal nanopatterns transferred onto a first surface of the substrate; and a plasmonic nanoparticle layer formed of a plurality of plasmonic nanoparticles attached to an upper portion of the first metal layer, wherein the plasmonic nanoparticles include a plasmonic second metal core that causes surface plasmon resonance and a first metal shell formed of the first metal on a surface of the second metal core.

[0015] Another embodiment of the present invention provides a method for manufacturing a surface-enhanced Raman scattering structure, comprising: etching a first surface of a mother substrate to form a mother substrate nanostructure; forming a replica polymer pattern using the mother substrate on which the mother substrate nanostructure is formed; separating the replica polymer pattern from the mother substrate and then depositing an oxidation-resistant plasmonic first metal material on top of the replica polymer pattern to form a first metal layer including a first metal nanopattern; transferring the first metal layer from the replica polymer pattern to a mother substrate; and attaching plasmonic nanoparticles to the first metal layer transferred to the mother substrate to form a plasmonic nanoparticle layer, wherein the plasmonic nanoparticles include a plasmonic second metal core that causes surface plasmon resonance and a first metal shell formed of the first metal on a surface of the second metal core.

[0016] The first metal material may include at least one of gold (Au), palladium (Pd), platinum (Pt), titanium (Ti), chromium (Cr), nickel (Ni), and alloys thereof.

[0017] The second metal material may include silver (Ag).

[0018] The above plasmonic nanoparticles can be attached to only 1 to 10% of the surface area of ​​the first metal layer.

[0019] The above first metal nano-pattern may have a width and spacing of 30 nm to 100 nm.

[0020] The above plasmonic nanoparticles may have a diameter of 10 nm or more and less than 55 nm.

[0021] According to one embodiment, the present invention can provide a high-performance surface-enhanced Raman scattering structure having a high signal enhancement effect and excellent signal uniformity and reproducibility.

[0022] According to one embodiment, the present invention can minimize the formation of background peaks by applying an oxidation-resistant first metal shell to the surface of a second metal that generates surface plasmon resonance to prevent oxidation of the second metal material.

[0023] According to one embodiment, the present invention can minimize the formation of background peaks by applying a protective layer to prevent oxidation of a second metal that generates surface plasmon resonance.

[0024] Fig. 1 is a drawing showing a surface-enhanced Raman scattering structure (1) of an embodiment of the present invention.

[0025] Fig. 2 is a cross-sectional view of the surface-enhanced Raman scattering structure (1) of Fig. 1.

[0026] FIG. 3 is a cross-sectional view of an Ag core Au shell plasmonic nanoparticle (31) as an example of a second metal core first metal shell plasmonic nanoparticle of one embodiment of the present invention of FIG. 1.

[0027] Figure 4 is a flowchart showing a method for manufacturing a surface-enhanced Raman scattering structure according to one embodiment of the present invention.

[0028] Figure 5 is a process diagram showing a method for manufacturing a surface-enhanced Raman scattering structure according to one embodiment of the present invention.

[0029] Figure 6 is a graph showing the characteristics of a surface-enhanced Raman scattering structure having a plasmonic layer of only Ag or Au in the prior art.

[0030] Figure 7 is a graph comparing the surface plasmon resonance performance of the surface-enhanced Raman scattering structure of the prior art and the present invention.

[0031] Figure 8 is a graph comparing the occurrence of background peaks over time of the surface-enhanced Raman scattering structure of the prior art and the present invention.

[0032] Specific structural or functional descriptions of embodiments according to the concept of the present invention disclosed in this specification are merely illustrative for the purpose of explaining embodiments according to the concept of the present invention, and embodiments according to the concept of the present invention may be implemented in various forms and are not limited to the embodiments described in this specification.

[0033] Embodiments according to the concept of the present invention may have various modifications and take various forms, and thus, embodiments are illustrated in the drawings and described in detail in this specification. However, this is not intended to limit embodiments according to the concept of the present invention to specific disclosed forms, but rather includes modifications, equivalents, or alternatives that fall within the spirit and technical scope of the present invention.

[0034] While terms such as "first" or "second" may be used to describe various components, the components should not be limited by the terms. Terms are used solely to distinguish one component from another. For example, a first component may be referred to as a "second component," and similarly, a second component may also be referred to as a "first component," without departing from the scope of the invention.

[0035] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components in between. Conversely, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. Expressions that describe relationships between components, such as "between," "immediately between," or "directly adjacent to," should be interpreted similarly.

[0036] The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the present invention. The singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, it should be understood that the terms "comprises" or "has" are intended to specify the presence of a described feature, number, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0037] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0038] Hereinafter, embodiments will be described in detail with reference to the attached drawings. However, the scope of the patent application is not limited or restricted by these embodiments. The same reference numerals in each drawing represent the same components.

[0039] FIG. 1 is a drawing showing a surface-enhanced Raman scattering structure (1) of an embodiment of the present invention, FIG. 2 is a cross-sectional view of the surface-enhanced Raman scattering structure (1) of FIG. 1, and FIG. 3 is a cross-sectional view of Ag core Au shell plasmonic nanoparticles (31) as an example of a second metal core first metal shell plasmonic nanoparticle of an embodiment of the present invention of FIG. 1.

[0040] As shown in FIGS. 1 and 2, the surface-enhanced Raman scattering structure (1) may include a substrate (10), a plasmonic first metal layer (20) formed on a first surface of the substrate (10), and a plasmonic nanoparticle layer (30) formed on the surface of the first metal layer (20).

[0041] The above-mentioned main substrate (10) may be a substrate onto which a plasmonic first metal layer (20) manufactured through a mother substrate (100) (see FIG. 6) to be described below is transferred. The main substrate (10) may be selectively made of a material such as a silicon wafer, a flexible polymer substrate, or a non-woven fabric, depending on the detection purpose.

[0042] The first metal layer (20) may be formed of a plurality of first metal nano-patterns (21). The width and height of the first metal nano-patterns (21) may be 30 nm to 100 nm. The first metal nano-patterns (21) may be arranged spaced apart from each other at intervals corresponding to the width. Although the first metal nano-pattern (21) is illustrated as having a band shape in the drawing of the embodiment, the first metal nano-pattern (21) may be formed in various structures depending on the mask pattern applied to the etching process, such as a grid shape. In addition, the first metal layer (20) may be formed to have a plurality of layers in which the first metal nano-patterns (21) intersect each other. The first metal layer (20) may be formed by a transfer printing process, as described below with reference to FIG. 6.

[0043] The above plasmonic nanoparticle layer (30) can be formed by dispersing and attaching plasmonic nanoparticles (31) that cause surface plasmon resonance to the surface of the first metal layer (20). As shown in Fig. 3, the plasmonic nanoparticles (31) can be formed by a plasmonic second metal core (35) and a first metal shell (33) formed of the first metal on the surface of the second metal core (35).

[0044] The thickness of the first metal shell (33) may be 1 to 10 nm.

[0045] The plasmonic first metal material forming the first metal nano-pattern (21) may be a material that generates surface plasmon resonance and has oxidation resistance. The first metal material may include at least one material selected from the group consisting of gold (Au), palladium (Pd), platinum (Pt), titanium (Ti), chromium (Cr), nickel (Ni), and alloys thereof.

[0046] The second metal material forming the second metal core (35) may include silver (Ag), which causes surface plasmon resonance more efficiently than the first metal material.

[0047] The diameter of the above plasmonic nanoparticles (31) may be 10 nm or more and less than the width of the first metal nanopattern (21). That is, the diameter of the above plasmonic nanoparticles (31) may be 10 nm or more and less than 55 nm.

[0048] The above plasmonic nanoparticles (31) can be attached to only 1 to 10% of the surface area of ​​the first metal layer. As a result, a space is formed between the plasmonic nanoparticles (31). The substance to be detected can be injected into the space between the plasmonic nanoparticles (31) to cause surface-enhanced Raman scattering due to surface plasmon resonance.

[0049] FIG. 4 is a flowchart showing a method for manufacturing a surface-enhanced Raman scattering structure according to one embodiment of the present invention, and FIG. 5 is a process diagram showing a method for manufacturing a surface-enhanced Raman scattering structure according to one embodiment of the present invention.

[0050] Referring to FIGS. 4 and 5, a method for manufacturing a surface-enhanced Raman scattering structure of one embodiment of the present invention may include a step of forming a mother substrate nanostructure (S10), a step of forming a replica polymer pattern (S20), a step of forming a first metal layer (S30), a step of transferring the first metal layer (S40), and a step of forming a plasmonic nanoparticle layer (S50).

[0051] The step (S10) of forming the above-described mother substrate nanostructure may be a step of forming the first surface mother substrate nanostructure (110) of the mother substrate (100) through etching using a mask (not shown) having a pattern corresponding to the mother substrate nanostructure (110) applied to the mother substrate (100), as shown in (a) and (b) of FIG. 5. The mother substrate (100) may be a silicon (Si) wafer.

[0052] The above-described substrate nanostructure (110) may have a structure in which a plurality of first protrusions (113) are formed spaced apart from each other with a first indentation (115) therebetween. The width of the first protrusions (113) and the first indentation (115) and the height of the first protrusions (113) may be 30 nm to 100 nm. In the drawing of the embodiment, the first protrusions (113) and the first indentation (115) are illustrated as having a band shape, but the first protrusions (113) and the first indentation (115) may be formed in various structures depending on the mask pattern applied to the visual process, such as a lattice pattern.

[0053] The step (S20) of forming the replica polymer pattern may be a step of coating the replica polymer (120) on the mother substrate nanostructure (110) and curing it ((c) of FIG. 5), and then separating the cured replica polymer (120) from the mother substrate (100) using a release film (130) ((d) and (e) of FIG. 5).

[0054] The above replica polymer (120) may be PMMA (Poly(methyl methacrylate)), PDMS (Polydimethylsiloxane), PS (Polystyrene), etc.

[0055] The replica polymer (120) can be coated on the mother substrate nanostructure (110) by spin coating or the like. At this time, a replica polymer pattern (121) is formed on the surface of the replica polymer (120) that is in contact with the mother substrate (100). The replica polymer (120) on which the replica polymer pattern (121) is formed can be separated from the mother substrate (100) by a release film (130). The release film (130) can be a PI (Poly Imid) tape or the like.

[0056] The step (S30) of forming the first metal layer may be a step ((f) of FIG. 5) of forming a first metal layer (20) composed of first metal nano-patterns (21) by depositing a first metal material on a replica polymer pattern (121) of the replica polymer (120) separated from the main substrate (10). The deposition of the first metal material may be performed by PVD (Physical Vapor Deposition), CVD (Chemical Vapor Deposition), or the like. After the first metal material is deposited on the replica polymer pattern (121), heat treatment may be performed.

[0057] The step (S40) of transferring the first metal layer may be a step ((g) of FIG. 5) of transferring the heat-treated first metal layer (20) from the replica polymer (120) to the main substrate (10). The step (S40) of transferring the first metal layer may be a step of attaching the surface of the replica polymer (120) on which the first metal layer (20) is formed to the main substrate (10) and then removing the release film (130) and the replica polymer (120) ((g), (h) and (i) of FIG. 5).

[0058] The step (S50) of forming the plasmonic nano particle layer may be a step of forming a plasmonic nano particle layer (30) on the surface of the substrate (10) on which the first metal layer (20) is formed by applying or immersing the substrate (10) on which the first metal layer (20) is transferred, with a solution in which plasmonic nano particles are dispersed, and then performing a heat treatment (Fig. 5 (j)).

[0059] The step (S40) of transferring the first metal layer may be performed on the substrate (10) on which the first metal layer (20) and the plasmonic nanoparticle layer (30) are formed. Thereafter, the step (S50) of forming the plasmonic nanoparticle layer may be performed. In this case, the first metal layer (20) may be transferred onto the first metal layer (20) and the plasmonic nanoparticle layer (30) such that the first metal nanopattern of the lower first metal layer (20) and the first metal nanopattern of the upper first metal layer (20) intersect with each other. As a result, a surface-enhanced Raman scattering structure in which the first metal layer (20) and the plasmonic nanoparticle layer (30) are laminated in multiple layers may be manufactured.

[0060] Figure 6 is a graph showing the characteristics of a surface-enhanced Raman scattering structure having a plasmonic layer of only Ag or Au in the prior art.

[0061] As shown in Fig. 6, more background peaks were generated in the Ag SERS chip than in the Au SERS chip. In contrast, the Raman shift was significantly improved in the Ag SERS chip than in the Au SERS chip.

[0062] Figure 7 is a graph comparing the surface plasmon resonance performance of the surface-enhanced Raman scattering structure of the prior art and the present invention.

[0063] Fig. 7 (a) shows the surface plasmon resonance performance of a surface-enhanced Raman scattering structure without a plasmonic nanoparticle layer (30) of the prior art. Fig. 7 (b) shows the surface plasmon resonance performance of a surface-enhanced Raman scattering structure (1) having a plasmonic nanoparticle layer (30) according to an embodiment of the present invention.

[0064] As shown in FIG. 7, in the case of the surface-enhanced Raman scattering structure (1) having a plasmonic nanoparticle layer (30) according to an embodiment of the present invention, it was found that the surface plasmon resonance performance was improved by more than 7 times compared to the surface-enhanced Raman scattering structure not having a plasmonic nanoparticle layer (30) of the prior art.

[0065] Figure 8 is a graph comparing the occurrence of background peaks over time of the surface-enhanced Raman scattering structure of the prior art and the present invention.

[0066] Figures 8 (a), (b), and (c) respectively show the background peak changes immediately after (a), after 30 days (b), and after 60 days of fabrication of a surface-enhanced Raman scattering structure without a plasmonic nanoparticle layer (30) of the prior art.

[0067] (d), (e) and (f) of FIG. 8 respectively show the background peak changes immediately after (a), after 30 days (b) and after 60 days of fabrication of the surface-enhanced Raman scattering structure (1) having the plasmonic nanoparticle layer (30) of the embodiment of the present invention.

[0068] As shown in Fig. 8, it can be seen that the surface-enhanced Raman scattering structure (1) according to the embodiment of the present invention prevents oxidation of the first metal core (35) by the oxidation resistance of the first metal shell (33), thereby suppressing the occurrence of a background peak even over time.

[0069] Ultimately, by using the present invention, a high-performance surface-enhanced Raman scattering structure having excellent signal uniformity and reproducibility can be provided.

[0070] In addition, by using the present invention, the formation of a background peak can be minimized by preventing oxidation of the second metal material by attaching plasmonic nanoparticles having a structure in which a plasmonic core formed of a second metal is wrapped with a first metal shell that suppresses oxidation of the second metal to a first metal layer.

[0071] Although the embodiments described above have been described with limited drawings, those skilled in the art will recognize that various modifications and variations are possible based on the above description. For example, appropriate results can still be achieved even if the described techniques are performed in a different order than described, and / or components of the described devices, structures, apparatuses, circuits, etc. are combined or combined in a different manner than described, or are replaced or substituted with other components or equivalents.

[0072] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims described below.

[0073] The present invention can be applied to non-destructive testing devices, etc.

Claims

1. Circuit board; A first metal layer formed of a plurality of oxidation-resistant plasmonic first metal nanopatterns transferred onto a first surface of the above-described substrate; and A plasmonic nanoparticle layer formed of a plurality of plasmonic nanoparticles attached to the upper portion of the first metal layer, The above plasmonic nanoparticles are, A plasmonic second metal core that causes the surface plasmon resonance and a first metal shell formed of the first metal on the surface of the second metal core, Surface-enhanced Raman scattering structure.

2. In paragraph 1, The above first metal material is, Characterized in that it comprises at least one material selected from the group consisting of gold (Au), palladium (Pd), platinum (Pt), titanium (Ti), chromium (Cr), nickel (Ni) and alloys thereof. Surface-enhanced Raman scattering structure.

3. In paragraph 1, The above second metal material is, characterized by containing silver (Ag) Surface-enhanced Raman scattering structure.

4. In paragraph 1, The above plasmonic nanoparticles are, Attached to only 1 to 10% of the surface area of ​​the first metal layer, Surface-enhanced Raman scattering structure.

5. In paragraph 1, The above first metal nano pattern is, Having a width and spacing of 30 nm to 100 nm, Surface-enhanced Raman scattering structure.

6. In paragraph 5, The above plasmonic nanoparticles are, having a diameter of 10 nm or more and less than 55 nm, Surface-enhanced Raman scattering structure.

7. A step of forming a mother substrate nano structure by etching the first surface of the mother substrate; A step of forming a replica polymer pattern using the mother substrate on which the mother substrate nanostructure is formed; A step of forming a first metal layer including a first metal nano-pattern by depositing an oxidation-resistant plasmonic first metal material on top of the replica polymer pattern after separating the replica polymer pattern with the mother substrate; a step of transferring the first metal layer from the replica polymer pattern to the main substrate; and A step of forming a plasmonic nanoparticle layer by attaching plasmonic nanoparticles to the first metal layer transferred to the above circuit board, The above plasmonic nanoparticles are, A plasmonic second metal core that causes surface plasmon resonance and a first metal shell formed of the first metal on the surface of the second metal core, Method for manufacturing a surface-enhanced Raman scattering structure.

8. In paragraph 7, The above first metal material is, Containing at least one material selected from the group consisting of gold (Au), palladium (Pd), platinum (Pt), titanium (Ti), chromium (Cr), nickel (Ni) and alloys thereof; The above second metal material is, characterized by containing silver (Ag) Method for manufacturing a surface-enhanced Raman scattering structure.

9. In paragraph 7, The above first metal nano pattern is, having a width and spacing of 30 nm to 100 nm, The above plasmonic nanoparticles are, having a diameter of 10 nm or more and less than 55 nm, Method for manufacturing a surface-enhanced Raman scattering structure.

10. In paragraph 8, The step of forming a plasmonic nanoparticle layer is: The plasmonic nanoparticles are attached to only 1 to 10% of the surface area of ​​the first metal layer. Method for manufacturing a surface-enhanced Raman scattering structure.

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