Surface-enhanced raman scattering detection substrate, method for preparing same, and raman scattering detection method

Abstract

The application relates to a surface-enhanced Raman scattering detection substrate and a preparation method and a Raman scattering detection method thereof. The surface-enhanced Raman scattering detection substrate comprises a substrate, a grating structure layer, a nanoparticle layer and a coating layer. The grating structure layer is arranged on the surface of the substrate, and the grating structure layer has a grating structure on the surface away from the substrate. The nanoparticle layer comprises metal nanoparticles, and the metal nanoparticles are arranged on the surface of the grating structure. The coating layer comprises a metal organic framework material, and at least part of the metal organic framework material is coated on the surface of the metal nanoparticles. The surface-enhanced Raman scattering detection substrate can realize better adsorption of the molecules to be detected, and thus realizes higher detection sensitivity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of Raman scattering detection, in particular to a surface-enhanced Raman scattering detection substrate, a preparation method thereof and a Raman scattering detection method. BACKGROUND

[0002] The surface-enhanced Raman scattering substrate has been widely applied in various analysis and detection scenes, such as disease diagnosis, environmental monitoring, food safety and biomedical fields, due to its excellent detection accuracy, unique fingerprint characteristics and non-destructive characteristics. The enhancement mechanism of surface-enhanced Raman scattering is mainly due to the local surface plasmon resonance of metal nanostructures, which will produce a strong local electromagnetic field enhancement acting on the molecules, i.e. "hot spots". In the surface-enhanced Raman scattering detection, the enhancement factor of the "hot spot" position can reach 10 8 , and the detection of organic molecules can reach the single molecule level.

[0003] However, in the traditional surface-enhanced Raman scattering substrate, although the metal nanostructures have more "hot spots", the surface-enhanced Raman scattering substrate is difficult to control the adsorption of analyte molecules on the metal surface, resulting in low sensitivity. SUMMARY

[0004] Therefore, it is necessary to provide a surface-enhanced Raman scattering detection substrate, a preparation method thereof and a Raman scattering detection method. The surface-enhanced Raman scattering detection substrate of the present application can realize better adsorption of the to-be-detected molecules, and thus realize higher detection sensitivity.

[0005] In a first aspect, the present application provides a surface-enhanced Raman scattering detection substrate, comprising a substrate, a grating structure layer, a nanoparticle layer and a coating layer.

[0006] The grating structure layer is arranged on the surface of the substrate, and the grating structure layer has a grating structure on the surface away from the substrate.

[0007] The nanoparticle layer comprises metal nanoparticles, and the metal nanoparticles are arranged on the surface of the grating structure.

[0008] The coating layer comprises a metal-organic framework material, and at least part of the metal-organic framework material is coated on the surface of the metal nanoparticles.

[0009] In some embodiments, the thickness of the coating layer is 50nm-2000nm.

[0010] In some embodiments, the particle size of the metal-organic framework material is 30nm-500nm.

[0011] In some embodiments, the metal organic framework material has a pore size of 0.34 nm to 50 nm.

[0012] In some embodiments, the metal organic framework material comprises at least one of ZIF-8, ZIF-7, and ZIF-90.

[0013] In some embodiments, the metal nanoparticles comprise metal nanorods.

[0014] In some embodiments, the metal nanorods comprise at least one of gold and silver.

[0015] In some embodiments, the metal nanorods have a length of 80 nm to 250 nm.

[0016] In some embodiments, the metal nanorods have a diameter of 25 nm to 60 nm.

[0017] In some embodiments, the material of the grating structure layer comprises at least one of polydimethylsiloxane and polystyrene.

[0018] In some embodiments, the substrate comprises at least one of a silicon substrate, a glass substrate, a quartz substrate, and a sapphire substrate.

[0019] In a second aspect, the present application provides a preparation method of a surface enhanced Raman scattering detection substrate, comprising the following steps:

[0020] providing a substrate;

[0021] forming a grating structure layer on a surface of the substrate, the grating structure layer having a grating structure on a surface away from the substrate;

[0022] forming a nanoparticle layer on a surface of the grating structure layer, the nanoparticle layer comprising metal nanoparticles, the metal nanoparticles being arranged on the surface of the grating structure;

[0023] forming a coating layer on a surface of the nanoparticle layer, the coating layer comprising a metal organic framework material, the metal organic framework material being coated on a surface of the metal nanoparticles.

[0024] In some embodiments, forming a coating layer on a surface of the nanoparticle layer comprises the following steps:

[0025] immersing the substrate having the grating structure layer and the nanoparticle layer in a precursor solution for soaking treatment, the solute of the precursor solution comprising a soluble metal salt and an organic ligand, the organic ligand comprising 2-methylimidazole, benzimidazole, and 2-formylimidazole.

[0026] In some embodiments, the soaking treatment comprises the following steps:

[0027] The substrate with the grating structure layer and the nanoparticle layer is placed in a precursor solution for multiple sub-soaking treatments;

[0028] After each sub-soaking treatment, the substrate with the grating structure layer and the nanoparticle layer is taken out and dried.

[0029] In a third aspect, the present application provides a Raman scattering detection method, comprising the following steps:

[0030] A sample to be detected is carried on the surface-enhanced Raman scattering detection substrate prepared using the surface-enhanced Raman scattering detection substrate or the preparation method of the surface-enhanced Raman scattering detection substrate according to any one of the above.

[0031] The sample to be detected is subjected to Raman scattering detection.

[0032] In the surface-enhanced Raman scattering detection substrate, the metal nanoparticles are arranged on the surface of the grating structure, and the metal-organic framework material is coated on the surface of the metal nanoparticles. The metal-organic framework material is a crystal porous material with a periodic network structure formed by self-assembly of transition metal ions and organic ligands, and has the characteristics of high porosity and large specific surface area. In the surface-enhanced Raman scattering detection substrate, the metal-organic framework material can be well coated on the surface of the metal nanoparticles, and the pores of the metal-organic framework material can capture and enrich the molecules to be detected, so that the molecules to be detected have good adsorption effect on the surface of the metal nanoparticles, increase the Raman scattering cross section of the molecules to be detected, and enhance the Raman signal to improve the detection sensitivity. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 A preparation flowchart of the surface-enhanced Raman scattering detection substrate provided by an embodiment of the present application is shown in the figure;

[0034] Figure 2 The SEM image of the surface-enhanced Raman scattering detection substrate provided by Embodiment 1 of the present application is shown in the figure, wherein, Figure 2 The SEM images of the surface-enhanced Raman scattering detection substrate from different angles are shown in the figures a and b;

[0035] Figure 3 The Raman spectrum of p-aminophenylthiophenol in Embodiment 1 of the present application is shown in the figure.

[0036] REFERENCE NUMERALS

[0037] 10, substrate; 20, grating structure layer; 30, nanoparticle layer; 40, coating layer. DETAILED DESCRIPTION

[0038] In order to make the above objectives, features and advantages of the present application more clear and easily understood, the detailed description of the specific embodiments of the present application is made below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of different ways from those described herein without departing from the scope of the present application, and it is understood that similar improvements to those described herein will occur to those skilled in the art to which the present application pertains. Therefore, the present application is not intended to be limited to the specific embodiments disclosed below, but includes all variations falling within the scope of the present application.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0040] In the description of the present application, it needs to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0041] Referring to Figure 1 As shown in the drawings, an embodiment of the present application provides a surface-enhanced Raman scattering detection substrate, which comprises a substrate 10, a grating structure layer 20, a nanoparticle layer 30 and a coating layer 40. The grating structure layer 20 is arranged on the surface of the substrate 10, and the grating structure layer 20 has a grating structure on the surface away from the substrate 10. The nanoparticle layer 30 comprises metal nanoparticles, and the metal nanoparticles are arranged on the surface of the grating structure. The coating layer 40 comprises metal organic framework material, and at least part of the metal organic framework material is coated on the surface of the metal nanoparticles.

[0042] In the aforementioned surface-enhanced Raman scattering (SERS) detection substrate, metal nanoparticles are disposed on the surface of a grating structure, and a metal-organic framework (MOF) material is coated onto the surface of the metal nanoparticles. MOF materials are porous crystalline materials with a periodic network structure formed by the self-assembly of transition metal ions and organic ligands, characterized by high porosity and large specific surface area. In the SERS detection substrate, the MOF material can effectively coat the surface of the metal nanoparticles. Through the pores of the MOF material, analyte molecules can be trapped and enriched, resulting in better adsorption of analyte molecules on the surface of the metal nanoparticles. This increases the Raman scattering cross-section of the analyte molecules, thereby enhancing the Raman signal and improving detection sensitivity.

[0043] It should be noted that high detection sensitivity refers to the ability to effectively capture analyte molecules at low concentrations in the sample. It should also be noted that "at least part of the metal-organic framework material is coated on the surface of the metal nanoparticles" means that the upper layer of metal-organic framework molecules may not be in direct contact with the metal nanoparticles, but rather connect to the metal nanoparticles by attaching to the lower layer of metal-organic framework molecules.

[0044] Reference Figure 2 As shown, Figure 2 This is a SEM image of the surface-enhanced Raman scattering (SERS) detection substrate of this application. It can be seen that the metal-organic framework (MOF) material has a good coating effect on the surface of the metal nanoparticles. It is understood that the uppermost spherical particles in the SEM image are the MOF material. Due to the dense coating of the MOF material, it has a masking effect on the lower metal nanoparticles, therefore the metal nanoparticles are not clearly visible in the SEM image. That is, after the MOF material coats the surface of the metal nanoparticles, the MOF material and the metal nanoparticles together cover the surface of the grating structure. The surface-enhanced Raman scattering (SERS) detection substrate of this application can be used to capture analytes and perform Raman detection on them. For example, the analyte molecule can be an organic molecule.

[0045] It is understood that the grating structure includes periodically spaced protrusions and recesses. "Metal nanoparticles disposed on the surface of the grating structure" means that metal nanoparticles are disposed on both the protrusions and recesses of the grating structure. "Metal-organic framework material and metal nanoparticles jointly cover the surface of the grating structure" means that metal-organic framework material and metal nanoparticles jointly cover the surfaces of the protrusions and recesses of the grating structure.

[0046] In some embodiments, the grating structure layer 20 includes different detection regions, and the grating structures located in each detection region have different periods.

[0047] The period of the grating structure refers to the interval between adjacent protrusions. The grating structures with different periods in each detection area can realize the surface-enhanced Raman scattering detection substrate suitable for different wavelength lasers for Raman scattering detection.

[0048] In some embodiments, the thickness of the cladding layer 40 is 50 nm to 2000 nm.

[0049] It can be understood that the thickness of the cladding layer 40 refers to the maximum thickness of the cladding layer 40 along the normal direction of the plane in which the substrate 10 is located. In this direction, there will be a number of metal-organic framework material particles accumulated in the cladding layer 40, thereby forming a cladding layer 40 with a certain thickness. The detection sensitivity of the surface-enhanced Raman scattering detection substrate is different when the thickness of the cladding layer 40 is different. When the thickness of the cladding layer 40 is too small, the number of metal-organic framework materials that capture and enrich the molecules to be tested is small, and the Raman signal is weak. When the thickness of the cladding layer 40 is too large, the molecules to be tested are difficult to diffuse effectively near the metal nanorod, and the Raman signal is weak. Within the above-mentioned thickness range of the cladding layer 40, the surface-enhanced Raman scattering detection substrate can achieve better capture and enrichment effect of the molecules to be tested, and has higher detection sensitivity. Optionally, the thickness of the cladding layer 40 is 50 nm to 300 nm. Further optionally, the thickness of the cladding layer 40 is 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm or 300 nm. Alternatively, the thickness of the cladding layer 40 can also be within the range between any two of the above thicknesses.

[0050] In some embodiments, the metal-organic framework material and the metal nanoparticles are connected through weak coordination interaction.

[0051] In some embodiments, the particle size of the metal-organic framework material is 30 nm to 500 nm.

[0052] In the particle size range of the metal organic framework material, the metal organic framework material can have a good combination effect with the metal nanoparticles, so as to achieve a good coating effect of the coating layer. Optionally, the particle size of the metal organic framework material is 30 nm to 100 nm. Optionally, the particle size of the metal organic framework material is 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm or 100 nm. Alternatively, the particle size of the metal organic framework material can also be in the range between any two of the above particle sizes.

[0053] In some embodiments, the pore size of the pores of the metal organic framework material is 0.34 nm to 50 nm.

[0054] In the pore size range of the pores of the metal organic framework material, adjusting the pore size of the pores of the metal organic framework material can achieve detection of different sizes of molecules to be detected. Different pore sizes can be achieved by replacing the coordination metal ions and organic ligands in the metal organic framework material. Optionally, the pore size of the pores of the metal organic framework material is 0.34 nm to 5 nm. Further optionally, the pore size of the pores of the metal organic framework material is 0.34 nm to 1 nm. Further optionally, the pore size of the pores of the metal organic framework material is 0.34 nm, 0.35 nm, 0.36 nm, 0.4 nm, 0.45 nm, 0.5 nm, 0.6 nm, 0.7 nm, 0.8 nm, 0.9 nm or 1 nm. Alternatively, the pore size of the pores of the metal organic framework material can also be in the range between any two of the above pore sizes.

[0055] It can be understood that the metal organic framework material can exhibit different morphologies according to the type of the metal organic framework material, the synthesis time and the preparation process. For example, the metal organic framework material can be spherical, spherical-like structure, or rhombic dodecahedron structure.

[0056] In some embodiments, the metal organic framework material includes at least one of ZIF-8, ZIF-7 and ZIF-90.

[0057] The CAS number of ZIF-8 is 59061-53-9, the CAS number of ZIF-7 is 909531-29-9, and the CAS number of ZIF-90 is 1062147-37-8.

[0058] In some embodiments, the metal nanoparticles include metal nanorods.

[0059] In some embodiments, the material of the metal nanorods includes at least one of gold and silver.

[0060] In some embodiments, the metal nanorod has a length of 80 nm to 250 nm.

[0061] Optionally, the metal nanorod has a length of 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, 105 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, or 250 nm. Alternatively, the metal nanorod can have a length within a range between any two of the aforementioned lengths.

[0062] In some embodiments, the metal nanorod has a diameter of 25 nm to 60 nm.

[0063] Optionally, the metal nanorod has a diameter of 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, or 60 nm. Alternatively, the metal nanorod can have a diameter within a range between any two of the aforementioned diameters.

[0064] In some embodiments, the material of the grating structure layer 20 includes at least one of polydimethylsiloxane and polystyrene.

[0065] In some embodiments, the substrate 10 includes at least one of a silicon substrate, a glass substrate, a quartz substrate, and a sapphire substrate.

[0066] Yet another embodiment of the present application provides a preparation method of a surface-enhanced Raman scattering detection substrate, including the following steps:

[0067] providing a substrate 10;

[0068] forming a grating structure layer 20 on a surface of the substrate 10, the grating structure layer 20 having a grating structure on a surface thereof away from the substrate 10;

[0069] forming a nanoparticle layer 30 on a surface of the grating structure layer 20, the nanoparticle layer 30 including metal nanoparticles, the metal nanoparticles being disposed on surfaces of the grating structure;

[0070] forming a coating layer 40 on a surface of the nanoparticle layer 30, the coating layer 40 including a metal-organic framework material, the metal-organic framework material being coated on surfaces of the metal nanoparticles.

[0071] In some embodiments, forming the coating layer 40 on the surface of the nanoparticle layer 30 includes the following steps:

[0072] The substrate 10 with the grating structure layer 20 and the nanoparticle layer 30 is placed in a precursor solution for immersion treatment, the solute of the precursor solution including a soluble metal salt and an organic ligand, the organic ligand including 2-methylimidazole, benzimidazole, and 2-formylimidazole.

[0073] It can be understood that the immersion treatment can be realized by a single long-time immersion or by multiple short-time immersions. By adjusting the time of the immersion treatment, the distribution density of the metal-organic framework material can be adjusted.

[0074] In some embodiments, the temperature of the immersion treatment is 25-60°C.

[0075] Alternatively, the temperature of the immersion treatment can also be within a range between any two of the above temperatures.

[0076] In some embodiments, forming the coating layer 40 on the surface of the nanoparticle layer 30 further includes the following steps:

[0077] By adjusting the time of the immersion treatment, the metal-organic framework material in different detection regions has different distribution densities.

[0078] It can be understood that the distribution density of the metal-organic framework material refers to the number of crystal grains of the metal-organic framework material per unit area in the horizontal direction. By adjusting the time of the immersion treatment, the metal-organic framework material in different detection regions has different distribution densities, so that different detection regions have different abilities to capture and enrich the molecules to be detected, thereby having different detection sensitivities.

[0079] In some embodiments, the soluble metal salt includes at least one of zinc nitrate and zinc nitrate hexahydrate.

[0080] In some embodiments, the immersion treatment includes the following steps:

[0081] The substrate 10 with the grating structure layer 20 and the nanoparticle layer 30 is placed in a precursor solution for multiple sub-immersion treatments;

[0082] After each sub-immersion treatment, the substrate 10 with the grating structure layer 20 and the nanoparticle layer 30 is taken out and dried.

[0083] It can be understood that the thickness of the coating layer 40 can be adjusted by adjusting the number of sub-soaking treatments. Exemplarily, the number of sub-soaking treatments can be 2-8 times. Alternatively, the preset number can be 2, 3, 4, 5, 6, 7 or 8 times. By coating the metal organic framework material on the surface of the metal nanoparticles through multiple sub-soaking treatments, the coating layer 40 in different detection areas can have different thicknesses, so that different detection areas have different abilities to capture and enrich the to-be-detected molecules, thereby having different detection sensitivities.

[0084] In some embodiments, forming the grating structure layer 20 on the surface of the substrate 10 comprises the following steps:

[0085] A substrate is provided, and a grating structure template is etched on the surface of the substrate;

[0086] The grating structure template is covered with a polymer, and a grating structure layer pre-product is formed by curing;

[0087] The grating structure layer pre-product and the grating structure template are separated, and the grating structure layer pre-product is fixed on the surface of the substrate 10.

[0088] In some embodiments, forming the nanoparticle layer 30 on the surface of the grating structure layer 20 comprises the following steps:

[0089] A metal source is used to form the nanoparticle layer 30 on the surface of the grating structure layer 20 by evaporation.

[0090] In some embodiments, the preparation method of the surface-enhanced Raman scattering detection substrate comprises the following steps:

[0091] (1) A substrate is provided, and a grating structure template is etched on the surface of the substrate, and a grating structure layer pre-product is formed by covering the grating structure template with a polymer and curing.

[0092] (2) A substrate 10 is provided, and the grating structure layer pre-product and the grating structure template are separated, and the grating structure layer pre-product is fixed on the surface of the substrate 10.

[0093] (3) A metal source is used to form the nanoparticle layer 30 on the surface of the grating structure layer 20 by evaporation, and the nanoparticle layer 30 comprises metal nanoparticles, and the metal nanoparticles are arranged on the surface of the grating structure.

[0094] (4) the substrate 10 with the grating structure layer 20 and the nanoparticle layer 30 is placed in a precursor solution for multiple sub-immersion treatments, the solute of the precursor solution includes a soluble metal salt and an organic ligand, the organic ligand includes 2-methyl imidazole, benzimidazole, and 2-formyl imidazole, the substrate 10 is taken out and dried, the above sub-immersion treatment is repeated a preset number of times, and a coating layer 40 is formed on the surface of the nanoparticle layer 30, the coating layer 40 includes a metal organic framework material, and the metal organic framework material is coated on the surface of the metal nanoparticle.

[0095] Another embodiment of the present application provides a Raman scattering detection method, comprising the following steps:

[0096] A surface-enhanced Raman scattering detection substrate prepared by any one of the above preparation methods or a surface-enhanced Raman scattering detection substrate prepared by the preparation method of any one of the above is used to carry a sample to be detected.

[0097] The sample to be detected is subjected to Raman scattering detection.

[0098] In some embodiments, the Raman scattering detection of the sample to be detected comprises the following steps:

[0099] The surface-enhanced Raman scattering detection substrate is placed in a solution containing a molecule to be detected, and the molecule to be detected is captured by the surface-enhanced Raman scattering detection substrate.

[0100] The surface-enhanced Raman scattering detection substrate after capturing the molecule to be detected is subjected to Raman scattering detection by using a Raman scattering detection device.

[0101] Embodiment 1

[0102] A preparation method of a surface-enhanced Raman scattering detection substrate comprises the following steps:

[0103] (1) A silicon wafer is used as a substrate, and the silicon wafer is sequentially ultrasonically cleaned with anhydrous ethanol and deionized water, then the silicon wafer is blown dry with a nitrogen gun and heated to remove excess water. The surface of the cleaned silicon wafer is spin-coated with photoresist, and after exposure and development on a double-beam exposure system, a silicon wafer with a periodic nanostructure photoresist mask is obtained. The silicon wafer is placed in a reactive ion beam etching machine for etching, and the surface of the etched sample is cleaned with acetone to remove the photoresist, thereby forming a template with a periodic nano-grating structure. A layer of polydimethylsiloxane is spin-coated on the surface of the template with the periodic nano-grating structure, and then heated and cured. A layer of epoxy resin is coated on the surface of the cured polydimethylsiloxane, a glass sheet serving as a substrate 10 is used to cover the epoxy resin, and the epoxy resin is cured under ultraviolet light. After that, the polydimethylsiloxane is peeled off from the silicon wafer, and the preparation of the grating structure layer 20 is completed.

[0104] (2) Put the substrate 10 with the grating structure layer 20 into an electron beam evaporation machine, adjust the inclination angle of the substrate table to 70°~88°, select the plating material of the crucible to be gold or silver, and start the film plating. Set the film plating thickness of the electron beam evaporation machine to 100nm~200nm, evaporate metal nanorods on the surface of the grating structure to obtain the substrate 10 with the metal nanoparticle layer 30.

[0105] (3) Put the substrate 10 with the grating structure layer 20 and the metal nanoparticle layer 30 into a mixed solution containing zinc nitrate hexahydrate and 2-methylimidazole and soak at 25℃~60℃, wherein the mixed solution includes 1.5mL of 2-methylimidazole methanol solution with a concentration of 50mM and 1mL of zinc nitrate hexahydrate methanol solution with a concentration of 25mM. After soaking the substrate 10 for 3 minutes, take out the substrate 10, rinse with methanol and dry with nitrogen. Repeat the above soaking step 1~7 cycles to control the thickness of the coating layer 40 in the range of 50nm~300nm.

[0106] Raman scattering detection:

[0107] Use the prepared surface-enhanced Raman scattering detection substrate to perform Raman detection on p-aminophenylthiol molecules, place multiple surface-enhanced Raman scattering detection substrates in different concentrations of p-aminophenylthiol ethanol solution, capture the p-aminophenylthiol molecules through the metal-organic framework, and then naturally air dry the surface-enhanced Raman scattering detection substrate. Then detect the Raman signal of the surface-enhanced Raman scattering detection substrate through the Raman scattering detector. According to the different periods of the grating structure on the surface-enhanced Raman scattering detection substrate, there are different absorption peak positions, and the excitation wavelength of the Raman scattering detector is selected according to the absorption peak position.

[0108] Referring again to Figure 2 Fig. 1, the Raman scattering substrate 10 prepared in Embodiment 1 of the present application has good uniformity of the overall structure. Referring to Figure 3 Fig. 2, Figure 3 The Raman spectra of the surface-enhanced Raman scattering detection substrates after adsorbing different concentrations of p-aminophenylthiol ethanol solution on the surface-enhanced Raman scattering detection substrates can be seen. The concentration of the p-aminophenylthiol molecules that can be detected by the surface-enhanced Raman scattering detection substrate of the present application is as low as 10 -11 M. That is, the surface-enhanced Raman scattering detection substrate of the present application has good detection sensitivity.

[0109] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not exist, they should be considered as the scope of the present disclosure.

[0110] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be pointed out that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims, and the description and drawings can be used to explain the content of the claims.

Claims

1. A surface-enhanced Raman scattering detection substrate, characterized in that, It includes a substrate, a grating structure layer, a nanoparticle layer, and a coating layer; The grating structure layer is disposed on the surface of the substrate, and the surface of the grating structure layer away from the substrate has a grating structure; The nanoparticle layer includes metal nanoparticles disposed on the surface of the grating structure; the metal nanoparticles include metal nanorods, and the material of the metal nanorods includes at least one of gold and silver; the length of the metal nanorods is 80 nm to 250 nm; the diameter of the metal nanorods is 25 nm to 60 nm. The coating layer comprises a metal-organic framework material, which includes at least one of ZIF-8, ZIF-7, and ZIF-90. At least a portion of the metal-organic framework material is coated on the surface of the metal nanoparticles. After the metal-organic framework material is coated on the surface of the metal nanoparticles, the metal-organic framework material and the metal nanoparticles together cover the surface of the grating structure. The metal-organic framework material and the metal nanoparticles are connected through weak coordination interactions. The thickness of the coating layer is 50 nm to 300 nm.

2. The surface-enhanced Raman scattering detection substrate according to claim 1, characterized in that, The particle size of the metal-organic framework material is 30nm~500nm.

3. The surface-enhanced Raman scattering detection substrate according to claim 1, characterized in that, The pore size of the metal-organic framework material is 0.34 nm to 50 nm.

4. The surface-enhanced Raman scattering detection substrate according to any one of claims 1 to 3, characterized in that, The material of the grating structure layer includes at least one of polydimethylsiloxane and polystyrene; and / or, The substrate includes at least one of silicon substrate, glass substrate, quartz substrate and sapphire substrate.

5. A method for preparing a surface-enhanced Raman scattering detection substrate, characterized in that, Includes the following steps: Provide a base; A grating structure layer is formed on the surface of the substrate, and the surface of the grating structure layer away from the substrate has a grating structure; A nanoparticle layer is formed on the surface of the grating structure layer. The nanoparticle layer includes metal nanoparticles, which are disposed on the surface of the grating structure. The metal nanoparticles include metal nanorods, and the material of the metal nanorods includes at least one of gold and silver. The length of the metal nanorods is 80 nm to 250 nm, and the diameter of the metal nanorods is 25 nm to 60 nm. A substrate having the grating structure layer and the nanoparticle layer is immersed in a precursor solution to form a coating layer on the surface of the nanoparticle layer. The coating layer includes a metal-organic framework material, which includes at least one of ZIF-8, ZIF-7, and ZIF-90. After the metal-organic framework material coats the surface of the metal nanoparticles, the metal-organic framework material and the metal nanoparticles together cover the surface of the grating structure. The thickness of the coating layer is 50 nm to 300 nm.

6. The method for preparing a surface-enhanced Raman scattering detection substrate according to claim 5, characterized in that, The solute in the precursor solution includes a soluble metal salt and an organic ligand, wherein the organic ligand includes 2-methylimidazole, benzimidazole, and 2-formylimidazole.

7. The method for preparing a surface-enhanced Raman scattering detection substrate according to claim 6, characterized in that, The soaking treatment includes the following steps: The substrate having the grating structure layer and the nanoparticle layer was placed in a precursor solution for multiple sub-immersion treatments. After each sub-immersion treatment, the substrate having the grating structure layer and the nanoparticle layer is removed and dried.

8. A Raman scattering detection method, characterized in that, Includes the following steps: The surface-enhanced Raman scattering detection substrate prepared by the preparation method of any one of claims 1 to 4 or any one of claims 5 to 7 carries the sample to be tested; Raman scattering detection was performed on the sample to be tested.

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