Surface-enhanced Raman scattering detection substrate, preparation method thereof and Raman scattering detection method

Abstract

The invention relates to a surface-enhanced Raman scattering detection substrate, a preparation method thereof and a Raman scattering detection method. The surface enhanced Raman scattering detection substrate comprises a base, a grating structure layer, a nanoparticle layer and a coating layer. The grating structure layer is arranged on the surface of the substrate, and a grating structure is arranged on the surface, away from the substrate, of the grating structure layer. The nano-particle layer comprises metal nano-particles, and the metal nano-particles 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 coats the surfaces of the metal nanoparticles. The surface-enhanced Raman scattering detection substrate provided by the invention can realize a relatively good adsorption effect on molecules to be detected, so that relatively high detection sensitivity is realized.

Description

Technical Field

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

[0002] Surface-enhanced Raman scattering substrates have been widely used in various analytical detection scenarios due to their excellent detection accuracy, unique fingerprint characteristics and non-destructive properties, such as disease diagnosis, environmental monitoring, food safety and biomedicine. 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, namely "hot spots". In surface-enhanced Raman scattering detection, the enhancement factor at the "hot spot" position can reach 10 8 , and the detection of organic molecules can reach the single molecule level.

[0003] However, in traditional SERS substrates, although metal nanostructures have more "hot spots", it is difficult to control the adsorption of analyte molecules on the metal surface, resulting in low sensitivity. Summary of the invention

[0004] Based on this, it is necessary to provide a surface enhanced Raman scattering detection substrate and a preparation method thereof, and a Raman scattering detection method. The surface enhanced Raman scattering detection substrate of the present application can achieve a good adsorption effect on the molecules to be detected, thereby achieving a higher detection sensitivity.

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

[0006] 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;

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

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

[0009] In some embodiments, the coating layer has a thickness of 50 nm to 2000 nm.

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

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

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

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

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

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

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

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

[0018] In some embodiments, the substrate includes 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 method for preparing a surface enhanced Raman scattering detection substrate, comprising the following steps:

[0020] providing a substrate;

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

[0022] forming a nanoparticle layer on the surface of the grating structure layer, wherein the nanoparticle layer comprises metal nanoparticles, and the metal nanoparticles are disposed on the surface of the grating structure;

[0023] A coating layer is formed on the surface of the nanoparticle layer, wherein the coating layer comprises a metal organic framework material, and the metal organic framework material is coated on the surface of the metal nanoparticles.

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

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

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

[0027] placing the substrate having the grating structure layer and the nanoparticle layer in a precursor solution for multiple sub-immersion treatments;

[0028] After each sub-immersion treatment, the substrate having 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 surface-enhanced Raman scattering detection substrate prepared by using any of the surface-enhanced Raman scattering detection substrates described above or any of the surface-enhanced Raman scattering detection substrate preparation methods described above carries a sample to be tested;

[0031] Performing Raman scattering detection on the sample to be tested.

[0032] In the above-mentioned surface enhanced Raman scattering detection substrate, 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 crystalline 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 molecules to be tested can be captured and enriched through the pores of the metal organic framework material, so that the molecules to be tested have a better adsorption effect on the surface of the metal nanoparticles, increasing the Raman scattering cross section of the molecules to be tested, so as to enhance the Raman signal and improve the sensitivity of detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG1 is a schematic diagram of a preparation process of a surface enhanced Raman scattering detection substrate provided in an embodiment of the present application;

[0034] FIG. 2 is a SEM image of a surface enhanced Raman scattering detection substrate provided in Example 1 of the present application, wherein a and b in FIG. 2 are SEM images of the surface enhanced Raman scattering detection substrate at different viewing angles, respectively;

[0035] FIG3 is a Raman spectrum of p-aminothiophenol in Example 1 of the present application.

[0036] Description of Reference Numerals

[0037] 10. Substrate; 20. Grating structure layer; 30. Nanoparticle layer; 40. Coating layer. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0040] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0041] As shown in FIG1 , an embodiment of the present application provides a surface enhanced Raman scattering detection substrate, comprising a substrate 10, a grating structure layer 20, a nanoparticle layer 30 and a coating layer 40. The grating structure layer 20 is disposed on the surface of the substrate 10, and the surface of the grating structure layer 20 away from the substrate 10 has a grating structure. The nanoparticle layer 30 includes metal nanoparticles, and the metal nanoparticles are disposed on the surface of the grating structure. The coating layer 40 includes a metal organic framework material, and at least a portion of the metal organic framework material is coated on the surface of the metal nanoparticles.

[0042] In the above-mentioned surface enhanced Raman scattering detection substrate, 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 crystalline 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 molecules to be tested can be captured and enriched through the pores of the metal organic framework material, so that the molecules to be tested have a better adsorption effect on the surface of the metal nanoparticles, increasing the Raman scattering cross section of the molecules to be tested, so as to enhance the Raman signal and improve the sensitivity of detection.

[0043] It should be noted that the high sensitivity of the detection means that the molecules to be tested at a lower concentration in the sample to be tested can be effectively captured. It should be noted that at least part of the metal organic framework material is coated on the surface of the metal nanoparticles, which means that the metal organic framework material molecules located in the upper layer may not directly contact the metal nanoparticles, but are connected to the metal nanoparticles by connecting to the metal organic framework material molecules in the lower layer.

[0044] Referring to Figure 2, Figure 2 is a SEM image of the surface enhanced Raman scattering detection substrate of the present application. It can be seen that the metal organic framework material has a good coating effect on the surface of the metal nanoparticles. It can be understood that the spherical particles in the uppermost layer in the SEM image are the metal organic framework material. Since the coating of the metal organic framework material is relatively dense, it has a shielding effect on the metal nanoparticles in the lower layer, so the metal nanoparticles are not clearly shown in the SEM image. That is, after the metal organic framework material is coated on the surface of the metal nanoparticles, the metal organic framework material and the metal nanoparticles jointly cover the surface of the grating structure. The surface enhanced Raman scattering detection substrate of the present application can be used to capture the molecules to be detected and perform Raman detection on them. Exemplarily, the molecules to be detected can be organic molecules.

[0045] It is understood that the grating structure includes raised portions and recessed portions that are periodically spaced. The metal nanoparticles are arranged on the surface of the grating structure, which means that the raised portions and recessed portions of the grating structure are both provided with metal nanoparticles. The metal organic framework material and the metal nanoparticles jointly cover the surface of the grating structure, which means that the metal organic framework material and the metal nanoparticles jointly cover the surface of the raised portions and recessed portions of the grating structure.

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

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

[0048] In some embodiments, the coating layer 40 has a thickness of 50 nm to 2000 nm.

[0049] It is understandable that the thickness of the coating layer 40 refers to the maximum thickness of the coating layer 40 along the normal direction of the plane where the substrate 10 is located. In this direction, there will be a number of metal organic framework material particles accumulated in the coating layer 40, thereby forming a coating layer 40 with a certain thickness. The thickness of the coating layer 40 is different, and the detection sensitivity of the surface enhanced Raman scattering detection substrate is different. When the thickness of the coating layer 40 is too small, the number of molecules to be detected captured and enriched by the metal organic framework material is small, and the Raman signal is weak. When the thickness of the coating layer 40 is too large, it is difficult for the molecules to be detected to effectively diffuse to the vicinity of the metal nanorods, and the Raman signal is weak. Within the above-mentioned thickness range of the coating layer 40, the surface enhanced Raman scattering detection substrate can achieve a better effect of capturing and enriching the molecules to be detected, and the detection sensitivity is high. Optionally, the thickness of the coating layer 40 is 50nm~300nm. Further optionally, the thickness of coating layer 40 is 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, 200nm, 210nm, 220nm, 230nm, 240nm, 250nm, 260nm, 270nm, 280nm, 290nm or 300nm. Alternatively, the thickness of coating layer 40 can also be in the range between any two of the above thicknesses.

[0050] In some embodiments, the metal organic framework material and the metal nanoparticles are connected via weak coordination interactions.

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

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

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

[0054] Within the range of the pore diameter of the pores of the above-mentioned metal organic framework material, the pore diameter of the pores of the metal organic framework material is adjusted to detect molecules of different sizes to be tested. Different pore sizes can be achieved by replacing the coordinated metal ions and organic ligands in the metal organic framework material. Optionally, the pore diameter of the pores of the metal organic framework material is 0.34nm~5nm. Further optionally, the pore diameter of the pores of the metal organic framework material is 0.34nm~1nm. Further optionally, the pore diameter of the pores of the metal organic framework material is 0.34nm, 0.35nm, 0.36nm, 0.4nm, 0.45nm, 0.5nm, 0.6nm, 0.7nm, 0.8nm, 0.9nm or 1nm. Alternatively, the pore diameter of the pores of the metal organic framework material can also be within the range between any two of the above pore diameters.

[0055] It is understandable that, depending on the type, synthesis time, and preparation process of the metal organic framework material, the metal organic framework material may exhibit different morphologies. For example, the metal organic framework material may be spherical, spherical-like, or a 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] Among them, 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 length of the metal nanorods is 80 nm to 250 nm.

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

[0062] In some embodiments, the diameter of the metal nanorods is 25 nm to 60 nm.

[0063] Optionally, the diameter of the metal nanorod is 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm or 60 nm. Alternatively, the diameter of the metal nanorod may also be within the range between any two of the above 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] Another embodiment of the present application provides a method for preparing a surface enhanced Raman scattering detection substrate, comprising the following steps:

[0067] Providing a substrate 10;

[0068] A grating structure layer 20 is formed on the surface of the substrate 10, wherein the surface of the grating structure layer 20 away from the substrate 10 has a grating structure;

[0069] Forming a nanoparticle layer 30 on the surface of the grating structure layer 20, wherein the nanoparticle layer 30 includes metal nanoparticles, and the metal nanoparticles are disposed on the surface of the grating structure;

[0070] A coating layer 40 is formed on the surface of the nanoparticle layer 30 . The coating layer 40 includes a metal organic framework material. The metal organic framework material is coated on the surface of the metal nanoparticles.

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

[0072] The substrate 10 having 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 includes a soluble metal salt and an organic ligand. The organic ligand includes 2-methylimidazole, benzimidazole and 2-formylimidazole.

[0073] It is understandable that the immersion treatment can be achieved by a single immersion for a longer time, or by multiple immersions for a shorter time. By adjusting the immersion treatment time, the distribution density of the metal organic framework material can be adjusted.

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

[0075] Optionally, the temperature of the immersion treatment is 25° C., 28° C., 30° C., 32° C., 35° C., 38° C., 40° C., 42° C., 45° C., 48° C., 50° C., 52° C., 55° C., 58° C. or 60° C. Alternatively, the temperature of the immersion treatment may 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] The immersion treatment time is adjusted so that the metal organic framework material has different distribution densities in different detection areas.

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

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

[0080] In some embodiments, the soaking treatment comprises the following steps:

[0081] The substrate 10 having 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 having the grating structure layer 20 and the nanoparticle layer 30 is taken out and dried.

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

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

[0085] Providing a substrate, and etching a grating structure template on the surface of the substrate;

[0086] Covering the grating structure template with a polymer and curing it to form a grating structure layer pre-finished product;

[0087] The grating structure layer pre-finished product and the grating structure template are separated and the grating structure layer pre-finished 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 includes the following steps:

[0089] The nanoparticle layer 30 is formed on the surface of the grating structure layer 20 by evaporation using a metal source.

[0090] In some embodiments, a method for preparing a surface enhanced Raman scattering detection substrate comprises the following steps:

[0091] (1) Providing a substrate, etching a grating structure template on the surface of the substrate, covering the grating structure template with a polymer, and curing to form a grating structure layer pre-finished product.

[0092] (2) Providing a substrate 10 , separating the grating structure layer pre-finished product from the grating structure template, and fixing the grating structure layer pre-finished product on the surface of the substrate 10 .

[0093] (3) Using a metal source, a nanoparticle layer 30 is formed on the surface of the grating structure layer 20 by evaporation. The nanoparticle layer 30 includes metal nanoparticles. The metal nanoparticles are disposed on the surface of the grating structure.

[0094] (4) placing the substrate 10 having the grating structure layer 20 and the nanoparticle layer 30 in a precursor solution for multiple sub-immersion treatments, wherein the solute of the precursor solution includes a soluble metal salt and an organic ligand, wherein the organic ligand includes 2-methylimidazole, benzimidazole and 2-formylimidazole, taking out the substrate 10 and drying it, repeating the above sub-immersion treatment for a preset number of times, and forming a coating layer 40 on the surface of the nanoparticle layer 30, wherein the coating layer 40 includes a metal organic framework material, and the metal organic framework material is coated on the surface of the metal nanoparticles.

[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 of the above surface-enhanced Raman scattering detection substrates or any of the above surface-enhanced Raman scattering detection substrate preparation methods carries a sample to be tested;

[0097] The Raman scattering test is performed on the sample to be tested.

[0098] In some embodiments, performing Raman scattering detection on a sample to be tested comprises the following steps:

[0099] Placing a surface enhanced Raman scattering detection substrate in a solution containing molecules to be detected, and capturing the molecules to be detected by the surface enhanced Raman scattering detection substrate;

[0100] A Raman scattering detection device is used to perform Raman scattering detection on the surface enhanced Raman scattering detection substrate after the molecules to be detected are captured.

[0101] Example 1

[0102] Preparation method of surface enhanced Raman scattering detection substrate:

[0103] (1) A silicon wafer is used as a substrate, and anhydrous ethanol and deionized water are used to ultrasonically clean the silicon wafer in sequence. The silicon wafer is then blown dry with a nitrogen gun and heated to remove excess water. The cleaned silicon wafer surface is spin-coated with photoresist, and then exposed and developed on a dual-beam exposure system to obtain a silicon wafer with a photoresist mask having a periodic nanostructure. The silicon wafer is placed in a reactive ion beam etcher for etching, and the etched sample surface is cleaned and de-bonded with acetone to form 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 to cure. A layer of epoxy resin is coated on the surface of the cured polydimethylsiloxane, and the epoxy resin is covered with a glass sheet as a substrate 10. After the epoxy resin is cured under ultraviolet light, the polydimethylsiloxane is peeled off from the silicon wafer to complete the preparation of the grating structure layer 20.

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

[0105] (3) The substrate 10 having the grating structure layer 20 and the metal nanoparticle layer 30 is immersed in a mixed solution containing zinc nitrate hexahydrate and 2-methylimidazole at 25°C to 60°C, wherein the mixed solution includes 1.5 mL of 2-methylimidazole methanol solution with a concentration of 50 mM and 1 mL of zinc nitrate hexahydrate methanol solution with a concentration of 25 mM. After the substrate 10 is immersed for 3 minutes, the substrate 10 is taken out, rinsed with methanol, and then blown dry with nitrogen. The above immersion step is repeated for 1 to 7 cycles to adjust the thickness of the coating layer 40 within the range of 50 nm to 300 nm.

[0106] Raman scattering detection:

[0107] The prepared surface enhanced Raman scattering detection substrate is used to perform Raman detection on the p-aminothiophenol molecule, and multiple surface enhanced Raman scattering detection substrates are placed in ethanol solutions of p-aminothiophenol with different concentrations, and the p-aminothiophenol molecules are captured by the metal organic framework material, and the surface enhanced Raman scattering detection substrate is taken out and naturally air-dried. The Raman signal of the surface enhanced Raman scattering detection substrate is then detected by a Raman scattering detector, and different absorption peak positions are corresponding to different periods of the grating structure on the surface enhanced Raman scattering detection substrate, and the excitation wavelength of the Raman scattering detector is selected according to the absorption peak position.

[0108] Referring again to FIG. 2 , the Raman scattering substrate 10 prepared in Example 1 of the present application has good overall structural uniformity. Referring to FIG. 3 , FIG. 3 is a Raman spectrum of each surface enhanced Raman scattering detection substrate after the p-aminothiophenol ethanol solution with different concentrations is adsorbed on the surface enhanced Raman scattering detection substrate. It can be seen that the surface enhanced Raman scattering detection substrate of the present application can detect the concentration of p-aminothiophenol molecules 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 may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0110] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims, and the description and drawings may be used to interpret the contents 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, and the metal nanoparticles are arranged on the surface of the grating structure; The coating layer includes a metal organic framework material, and at least a portion of the metal organic framework material is coated on the surface of the metal nanoparticles.

2. The surface enhanced Raman scattering detection substrate according to claim 1, characterized in that: The thickness of the coating layer is 50nm~2000nm.

3. 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 to 500nm; and / or, The pores of the metal organic framework material have a pore size of 0.34 nm to 50 nm; and / or, The metal organic framework material includes at least one of ZIF-8, ZIF-7 and ZIF-90.

4. The surface enhanced Raman scattering detection substrate according to claim 1, characterized in that: The metal nanoparticles include metal nanorods.

5. The surface enhanced Raman scattering detection substrate according to claim 4, characterized in that: The material of the metal nanorods includes at least one of gold and silver; and / or, The length of the metal nanorods is 80 nm to 250 nm; and / or, The diameter of the metal nanorods is 25nm-60nm.

6. The surface enhanced Raman scattering detection substrate according to any one of claims 1 to 5, 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 a silicon substrate, a glass substrate, a quartz substrate and a sapphire substrate.

7. A method for preparing a surface enhanced Raman scattering detection substrate, characterized in that: The steps include: providing a substrate; forming a grating structure layer on the surface of the substrate, wherein the grating structure layer has a grating structure on a surface away from the substrate; forming a nanoparticle layer on the surface of the grating structure layer, wherein the nanoparticle layer comprises metal nanoparticles, and the metal nanoparticles are disposed on the surface of the grating structure; A coating layer is formed on the surface of the nanoparticle layer, wherein the coating layer comprises a metal organic framework material, and the metal organic framework material is coated on the surface of the metal nanoparticles.

8. The method for preparing a surface enhanced Raman scattering detection substrate according to claim 7, characterized in that: Forming a coating layer on the surface of the nanoparticle layer comprises the following steps: The substrate having the grating structure layer and the nanoparticle layer is placed in a precursor solution for immersion treatment. The solute of the precursor solution includes a soluble metal salt and an organic ligand. The organic ligand includes 2-methylimidazole, benzimidazole and 2-formylimidazole.

9. The method for preparing a surface enhanced Raman scattering detection substrate according to claim 8, characterized in that: The soaking process comprises the following steps: placing the substrate having the grating structure layer and the nanoparticle layer 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 taken out and dried.

10. A Raman scattering detection method, characterized in that: The steps include: The surface enhanced Raman scattering detection substrate prepared by the surface enhanced Raman scattering detection substrate according to any one of claims 1 to 6 or the surface enhanced Raman scattering detection substrate preparation method according to any one of claims 7 to 9 carries the sample to be tested; Performing Raman scattering detection on the sample to be tested.

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