Enhanced Raman detection platform, preparation method and detection method

Abstract

According to the enhanced Raman detection platform, the preparation method and the detection method provided by the invention, the enhanced Raman detection platform comprises an SERS substrate, a patterned micro-nano structure with a hydrophilic region is formed on the surface of the SERS substrate through a femtosecond laser etching technology, and a to-be-detected analyte molecular solution can form nearly spherical liquid drops in the patterned micro-nano structure region and is enriched in the hydrophilic region; the hydrophilic area is covered with the microsphere array film; according to the method, the patterned micro-nano structure substrate with the surface super-hydrophobic / hydrophilic function is designed and prepared by applying a femtosecond laser etching technology, so that the'coffee ring effect 'that analyte molecules are dispersed towards the edge in a sample dripping or soaking sample preparation process is effectively solved; the purposes of reducing the sample gathering area and enriching analytes are achieved; mesoscale dielectric microspheres with sub-diffraction limit scale light field focusing capability are introduced and coupled with hot spots on an SERS substrate, so that SERS signals are further enhanced, and ultra-sensitive detection of ultra-trace substance molecules is realized.

Description

Technical Field

[0001] The present application relates to the field of biosensor detection technology, and in particular to an enhanced Raman detection platform, a preparation method, and a detection method. Background Art

[0002] In areas such as early cancer diagnosis, forensic analysis, and food safety, the molecules to be tested that can be collected or obtained are usually very rare, which places high demands on the sensitivity of the detection technology. Raman scattering is the phenomenon in which the energy of photons changes after the interaction between light and molecules. It is a fingerprint spectrum that can reflect the molecular information of a substance. Surface-enhanced Raman scattering (SERS) can significantly enhance the Raman scattering signal on rough metal surfaces or nanostructures covered with heavy metal particles through electromagnetic and chemical enhancement mechanisms. It has many advantages such as label-free, non-invasive, high specificity, strong sensitivity, simple sample processing, high detection timeliness, and little influence from the aqueous solution spectrum. It is an ideal method for detecting and analyzing trace molecules of substances. Fabricating micro-nanoscale surface structures on substrates to help construct high-density enhanced "hotspots" that can support localized surface plasmon resonance is an important research direction in the field of SERS.

[0003] The signal intensity of conventional SERS substrates mainly depends on the electromagnetic enhancement of the nanostructured metal on the substrate, the charge transfer between the molecules and the substrate, and the number of target molecules in the "hot spot". The enhancement factor ranges from 10 5 -10 10 For ultra-trace molecules in small volume (such as a few microliters) of solution, it is difficult to effectively detect the analyte molecules using conventional SERS substrates. Summary of the Invention

[0004] In view of this, it is necessary to provide an enhanced Raman detection platform, preparation method and detection method that can achieve ultra-sensitive detection of ultra-trace substance molecules to address the defects of the existing technology.

[0005] To solve the above problems, this application adopts the following technical solutions:

[0006] One of the purposes of this application is to provide an enhanced Raman detection platform, comprising:

[0007] A SERS substrate, wherein a patterned micro-nanostructure having a hydrophilic region is formed on the surface of the SERS substrate by femtosecond laser etching technology, and a solution of analyte molecules to be tested can form nearly spherical droplets in the patterned micro-nanostructure region and be enriched in the hydrophilic region;

[0008] a microsphere array film, the microsphere array film covering the hydrophilic area; and

[0009] A Raman spectrometer is used to perform Raman detection on the hydrophilic area.

[0010] The second object of this application is to provide a method for preparing the enhanced Raman detection platform, comprising the following steps:

[0011] A SERS substrate is prepared, wherein a patterned micro-nanostructure with a hydrophilic region is formed on the surface of the SERS substrate by femtosecond laser etching technology, and a solution of analyte molecules to be tested can form nearly spherical droplets in the patterned micro-nanostructure region and be enriched in the hydrophilic region;

[0012] preparing a microsphere array film, wherein the microsphere array film is covered on the hydrophilic area;

[0013] A Raman spectrometer is provided, and the Raman spectrometer is used to perform Raman detection on the hydrophilic area.

[0014] In some embodiments, the steps of preparing the SERS substrate specifically include the following steps:

[0015] A femtosecond laser is used to etch a hydrophilic area with a grid structure on the surface of a metal substrate;

[0016] Chemically modifying the surface of the hydrophilic region to form a hydrophobic surface;

[0017] Etching the center of the hydrophobic surface to form a patterned micro-nanostructure with a hydrophilic area;

[0018] A noble metal thin film layer is deposited on the patterned micro-nano structure.

[0019] In some embodiments, in the step of etching a hydrophilic region having a grid structure on the surface of a metal substrate using a femtosecond laser, the energy density of the femtosecond laser is 7 to 9 J / cm 2 The etching interval of the grid is 20 to 60 μm.

[0020] In some embodiments, the step of modifying the surface of the hydrophilic region to form a hydrophobic surface specifically includes the following steps:

[0021] The modifying chemical reagent is dripped onto the surface of the hydrophilic area until the entire hydrophilic area is covered with the modifying chemical reagent, and the surface of the hydrophilic area is formed into a hydrophobic surface after the modifying chemical reagent evaporates.

[0022] In some embodiments, the modifying chemical reagent includes a stearic acid alcohol solution or a biocompatible fluorinated surfactant Flou-ST1 or Fluo-ST2.

[0023] In some embodiments, the step of etching the center of the hydrophobic surface to form a patterned micro-nanostructure having a hydrophilic region specifically includes the following steps: etching the center of the hydrophobic surface to remove the central hydrophobic surface to form a patterned micro-nanostructure having a hydrophilic region, wherein the laser energy density used in the etching is 7 to 9 J / cm 2 , the etching interval is 5 to 10 μm, and the number of etching times is 1 to 3 times.

[0024] In some embodiments, the step of depositing a noble metal thin film layer on the patterned micro-nanostructure specifically includes the following steps:

[0025] A noble metal film layer is deposited on the patterned micro-nano structure by magnetron sputtering or vacuum coating. The thickness of the noble metal film layer is 40-50 nm, and the material of the noble metal film layer includes gold or silver.

[0026] In some embodiments, the steps of preparing the microsphere array film specifically include the following steps:

[0027] Dropping the microsphere solution onto a tilted glass slide, and after the water molecules evaporate, the microspheres self-assemble to form a microsphere array structure;

[0028] Adding a curing agent to the glass sheet and performing spin coating, and then placing the curing agent at a temperature of 80 to 100° C. and allowing the curing agent to stand for 20 minutes to 1 hour to solidify the microsphere array structure on the glass sheet;

[0029] The glass sheet is placed in anhydrous ethanol to allow the microsphere array structure to fall off the glass sheet, thereby obtaining the microsphere array film.

[0030] In some embodiments, in the step of dropping a microsphere solution onto a tilted glass slide and allowing the microspheres to self-assemble into a microsphere array structure after evaporation of water molecules, the microsphere solution comprises silicon dioxide, soda-lime glass, barium titanate glass, or titanium dioxide.

[0031] In some embodiments, in the step of adding a curing agent to the glass sheet and performing spin coating, and then standing at 80-100° C. for 20 min to 1 h to cure the microsphere array structure on the glass sheet, the curing agent includes PDMS or PMMA or UV glue.

[0032] The third purpose of this application is to provide a detection method for the enhanced Raman detection platform, wherein a solution of analyte molecules to be detected is dripped into the patterned micro-nanostructure area to form nearly spherical droplets and is enriched in the hydrophilic area, the microsphere array film is covered on the hydrophilic area, and the Raman spectrometer is used to perform Raman detection on the hydrophilic area.

[0033] This application adopts the above technical solution, and its beneficial effects are as follows:

[0034] The enhanced Raman detection platform, preparation method and detection method provided by the present application include a SERS substrate, the surface of which is formed with a patterned micro-nanostructure having a hydrophilic area by femtosecond laser etching technology, and the analyte molecule solution to be detected can form nearly spherical droplets in the patterned micro-nanostructure area and be enriched in the hydrophilic area; a microsphere array film, the microsphere array film is covered on the hydrophilic area; and a Raman spectrometer, the Raman spectrometer is used to perform Raman detection on the hydrophilic area. The present invention uses femtosecond laser etching technology to design and prepare a patterned micro-nanostructure substrate with surface super-hydrophobic / hydrophilic functions, effectively solving the "coffee ring effect" in which analyte molecules are dispersed to the edge during the sample dripping or immersion sample preparation process, thereby achieving the purpose of reducing the sample aggregation area and enriching the analyte; by introducing mesoscopic-scale dielectric microspheres with sub-diffraction limit scale light field focusing capability, coupling with the "hot spots" on the SERS substrate, the SERS signal is further enhanced, and ultra-sensitive detection of ultra-trace substance molecules is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0036] Figure 1 This is a flow chart of the steps of the method for preparing the enhanced Raman detection platform provided in Example 2 of the present application.

[0037] Figure 2 This is a process flow chart for forming a patterned micro-nanostructure with a hydrophilic area using femtosecond laser etching technology provided in Example 2 of the present application.

[0038] Figure 3 This is a physical picture of the SERS substrate provided in Example 2 of this application.

[0039] Figure 4 This is a microstructure image of the SERS substrate provided in Example 2 of the present application.

[0040] Figure 5 This is a diagram showing the super-hydrophobic effect of the SERS substrate provided in Example 2 of the present application.

[0041] Figure 6 Schematic diagram of the process flow for preparing a microsphere array film provided in Example 2 of the present application.

[0042] Figure 7 This is a physical picture of the prepared microsphere array film provided in Example 2 of the present application.

[0043] Figure 8 This is a microscopic image of the structure of the microsphere array film prepared in Example 2 of the present application.

[0044] Figure 9 Schematic diagram of the testing process of the detection method of the enhanced Raman detection platform provided in Example 3 of the present application. DETAILED DESCRIPTION

[0045] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0046] In the description of this application, it should be understood that the terms "upper", "lower", "horizontal", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application.

[0047] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0048] In order to make the purpose, technical solutions and advantages of this application more clear, this application is further described in detail below with reference to the accompanying drawings and embodiments.

[0049] Example 1

[0050] The enhanced Raman detection platform provided in the embodiment of the present application includes: a SERS substrate, a microsphere array film, and a Raman spectrometer. The specific implementation of each component is described in detail below.

[0051] The surface of the SERS substrate is formed with a patterned micro-nanostructure having a hydrophilic area by femtosecond laser etching technology. The analyte molecule solution to be tested can form nearly spherical droplets in the patterned micro-nanostructure area and be enriched in the hydrophilic area.

[0052] It can be understood that compared with SERS substrates produced using technologies such as nanoimprinting, femtosecond laser-etched substrates have obvious advantages in production costs and significantly improved detection sensitivity. In addition, this embodiment uses femtosecond laser etching technology to design and prepare patterned micro-nanostructure substrates with surface super-hydrophobic / hydrophilic functions, effectively solving the "coffee ring effect" in which analyte molecules are dispersed to the edges during the sample dripping or immersion process, thereby achieving the purpose of reducing the sample aggregation area and enriching the analyte.

[0053] The microsphere array film is coated on the hydrophilic region. The microsphere array film provided in this embodiment, by introducing mesoscopic-scale dielectric microspheres with sub-diffraction-limited light field focusing capabilities, couples with "hot spots" on the SERS substrate, further enhancing the SERS signal and enabling ultrasensitive detection of trace molecules.

[0054] The Raman spectrometer is used to perform Raman detection on the hydrophilic region.

[0055] The enhanced Raman detection platform provided in the embodiments of the present application utilizes femtosecond laser micro-nano processing technology and chemical modification means to design and manufacture a substrate with super-hydrophobic / hydrophilic surface properties on the substrate surface for enriching analyte samples, and combines a mesoscopic-scale dielectric microsphere array film to synergistically enhance and improve the SERS substrate Raman scattering signal, thereby achieving ultra-sensitive detection of ultra-trace substance molecules.

[0056] Example 2

[0057] See also Figure 1 The method for preparing the enhanced Raman detection platform provided in Example 2 of the present application includes the following steps S10 to S30. The implementation method of each step is described in detail below.

[0058] Step S10: preparing a SERS substrate, wherein a patterned micro-nanostructure with a hydrophilic region is formed on the surface of the SERS substrate by femtosecond laser etching technology, and the analyte molecule solution to be tested can form nearly spherical droplets in the patterned micro-nanostructure region and be enriched in the hydrophilic region.

[0059] See also Figure 2 , which is a process flow chart for forming a patterned micro-nanostructure with a hydrophilic area using the femtosecond laser etching technology provided in this embodiment, wherein: femtosecond laser 1, reflector 2, galvanometer 3, femtosecond laser 4, metal substrate 5, modified chemical reagent 6, modified hydrophobic layer 7, hydrophilic area 8, syringe filled with modified chemical reagent 9. The specific process steps are described in detail below.

[0060] In this embodiment, the steps of preparing the SERS substrate specifically include the following steps S101 to S104 , and the implementation of each step is described in detail below.

[0061] Step S101: using a femtosecond laser to etch a hydrophilic area having a grid structure on the surface of a metal substrate.

[0062] In this embodiment, in the step of etching a hydrophilic region having a grid structure on the surface of the metal substrate using a femtosecond laser, the energy density of the femtosecond laser is 7 to 9 J / cm 2 The etching interval of the grid is 20 to 60 μm.

[0063] In this embodiment, the metal substrate includes copper, aluminum, platinum, titanium or other metals.

[0064] Step S102: modifying the surface of the hydrophilic region to form a hydrophobic surface.

[0065] In this embodiment, the step of modifying the surface of the hydrophilic area to form a hydrophobic surface specifically includes the following steps: dripping a modifying chemical reagent onto the surface of the hydrophilic area until the entire hydrophilic area is covered with the modifying chemical reagent, and allowing the modifying chemical reagent to evaporate to form a hydrophobic surface on the surface of the hydrophilic area.

[0066] Specifically, the modification chemical reagent includes stearic acid alcohol solution or biocompatible fluorinated surfactant Flou-ST1 or Fluo-ST2.

[0067] For example, in this embodiment, a certain amount of 0.02 mol / L stearic acid alcohol solution is taken out with a syringe or other liquid dispenser, and the solution is added dropwise to the hydrophilic surface until the entire hydrophilic area is covered with the solution. The alcohol solution is then allowed to evaporate to form a layer of stearic acid film on the surface. That is, the hydrophilic surface is modified with the solution and the hydrophilic area is modified to form a hydrophobic surface.

[0068] Step S103: etching the center of the hydrophobic surface to form a patterned micro-nanostructure with a hydrophilic area.

[0069] In this embodiment, the step of etching the center of the hydrophobic surface to form a patterned micro-nanostructure having a hydrophilic region specifically includes the following steps: etching the center of the hydrophobic surface to remove the central hydrophobic surface to form a patterned micro-nanostructure having a hydrophilic region, wherein the laser energy density used in the etching is 7 to 9 J / cm 2 , the etching interval is 5 to 10 μm, and the number of etching times is 1 to 3 times.

[0070] It can be understood that when the modifying chemical reagent is a stearic acid alcohol solution, the center of the hydrophobic surface is etched to remove the central stearic acid film, and a hydrophilic area formed by a special pattern is etched in the central area to obtain a richer micro-nano structure.

[0071] Step S104: depositing a noble metal thin film layer on the patterned micro-nano structure.

[0072] In this embodiment, the step of depositing a precious metal thin film layer on the patterned micro-nano structure specifically includes the following steps: using a magnetron sputtering or vacuum coating method to deposit a precious metal thin film layer on the patterned micro-nano structure, the thickness of the precious metal thin film layer is 40-50nm, and the material of the precious metal thin film layer includes gold or silver.

[0073] Specifically, magnetron sputtering or vacuum coating is used to deposit a layer of precious metal film on the micro-nano structure obtained by laser processing. That is, the substrate is fixed on the sputtering disk, and then placed in a magnetron sputtering instrument to evacuate the vacuum before sputtering. The metal target can use pure gold or pure silver. The time is controlled between 90-100s, and a metal film of about 40-50nm can be formed.

[0074] See also Figure 3 and Figure 4 The physical image and structural micrograph of the SERS substrate prepared in this embodiment are respectively: Figure 4 It is a microscopic characterization of super hydrophobic / hydrophilic patterned micro-nanostructure substrates. Figure 4 It can be seen that the outer grid structure array part is the super hydrophobic area, the annular grid array area adjacent to the grid array structure is the hydrophilic area, and the middle circular area is the central area where the hydrophobic layer is removed.

[0075] See also Figure 5 , which is a diagram showing the super-hydrophobic effect of the SERS substrate prepared in this embodiment, Figure 5 It can be seen from the figure that the contact angle of water droplets on the patterned micro-nanostructure substrate is greater than 150°, which means that the substrate has superhydrophobic properties.

[0076] It can be understood that compared with SERS substrates produced using technologies such as nanoimprinting, femtosecond laser-etched substrates have obvious advantages in production costs and significantly improved detection sensitivity. At the same time, the present invention uses femtosecond laser etching technology to design and prepare patterned micro-nanostructure substrates with surface super-hydrophobic / hydrophilic functions, effectively solving the "coffee ring effect" in which analyte molecules are dispersed to the edges during sample preparation by dripping or immersion, thereby achieving the purpose of reducing sample aggregation area and enriching analytes.

[0077] Step S20: preparing a microsphere array film, wherein the microsphere array film is covered on the hydrophilic area.

[0078] See also Figure 6, is a schematic diagram of the process flow for preparing a microsphere array film provided in this embodiment, wherein: a curing agent 10, a microsphere solution 11, a glass sheet 12, and a small culture dish 13. The specific process steps are described in detail below.

[0079] In this embodiment, the steps of preparing the microsphere array film specifically include the following steps S201 to S203 , and the implementation of each step is described in detail below.

[0080] Step S201: dropping a microsphere solution onto an inclined glass sheet, and after water molecules evaporate, the microspheres self-assemble to form a microsphere array structure.

[0081] In this embodiment, the microsphere solution includes silicon dioxide, soda-lime glass, barium titanate glass or titanium dioxide.

[0082] Step S202: adding a curing agent to the glass sheet and performing spin coating, and then placing the curing agent at a temperature of 80-100° C. for 20 minutes to 1 hour to solidify the microsphere array structure on the glass sheet.

[0083] In this embodiment, in the step of adding a curing agent to the glass sheet and performing spin coating, and then standing at 80-100° C. for 20 min-1 h to cure the microsphere array structure on the glass sheet, the curing agent includes PDMS or PMMA or UV glue.

[0084] Specifically, PDMS was added using a disposable measuring cup at a ratio of 10:1 between the main agent (PDMS) and the curing agent. A vacuum was used to remove the bubbles from the mixed reagents. The solution was set aside after it became clear and free of bubbles. A glass slide was placed on a spin coating apparatus, and an appropriate amount of PDMS was added and spin-coated at a speed of 900 rpm for 15 seconds. The glass slide was placed on a 90°C hot plate and allowed to stand for 20 minutes to 1 hour, waiting for the PDMS to solidify until it was hard enough to support manual peeling.

[0085] Step S203: placing the glass sheet in anhydrous ethanol to cause the microsphere array structure to fall off the glass sheet, thereby obtaining the microsphere array film.

[0086] Specifically, a glass slide was placed in anhydrous ethanol, and tweezers were used to gradually peel off the microsphere array film from the glass slide starting from the edge of the glass slide.

[0087] See also Figure 7 and Figure 8 The actual image and microscopic image of the microsphere array film prepared in the above embodiments of this embodiment are respectively Figure 8 This is a microscopic characterization of the self-assembled array microspheres during the coupling process. The microspheres have little overlap and are relatively evenly distributed.

[0088] It can be understood that this embodiment uses a self-assembly method to produce a mesoscopic-scale dielectric microsphere array embedded in a polymer film. By introducing mesoscopic-scale dielectric microspheres with sub-diffraction limit light field focusing capabilities and coupling them with the "hot spots" on the SERS substrate, the SERS signal is further enhanced, achieving ultra-sensitive detection of ultra-trace substance molecules.

[0089] Step S30: providing a Raman spectrometer, wherein the Raman spectrometer is used to perform Raman detection on the hydrophilic region.

[0090] Specifically, 5 μL of the analyte molecule solution to be tested is sucked up with a liquid dispenser and dropped into the mixed super-hydrophobic / hydrophilic patterned area of ​​the SERS substrate, forming a nearly spherical droplet in the area. After the water molecules evaporate naturally, the analyte molecules to be tested are enriched in the hydrophilic area. Tweezers are used to transfer the microsphere array film to the substrate, allowing the microspheres to cover the hydrophilic area. The substrate is then moved under the microscope objective of the Raman spectrometer, and Raman detection is performed on the hydrophilic area.

[0091] The preparation method of the enhanced Raman detection platform provided in the embodiment of the present application utilizes femtosecond laser micro-nano processing technology and chemical modification means to design and manufacture a substrate with super-hydrophobic / hydrophilic surface properties on the substrate surface for enriching analyte samples, and combines a mesoscopic-scale dielectric microsphere array film to synergistically enhance and improve the SERS substrate Raman scattering signal, thereby realizing ultra-sensitive detection of ultra-trace substance molecules.

[0092] Example 3

[0093] The present application also provides a detection method for the enhanced Raman detection platform, wherein a solution of analyte molecules to be detected is dripped into the patterned micro-nanostructure area to form nearly spherical droplets that are enriched in the hydrophilic area, the microsphere array film is covered on the hydrophilic area, and the Raman spectrometer is used to perform Raman detection on the hydrophilic area.

[0094] See also Figure 9 , which is a schematic diagram of the test process of the detection method of the enhanced Raman detection platform provided in this embodiment, wherein: a spectrometer 14, a Raman spectrometer 15, a microscope objective 16, an excitation light 17; a microsphere array film 18 and a SERS substrate 19 with a sample.

[0095] The detection method of the enhanced Raman detection platform provided in this embodiment has obvious advantages in production cost over SERS substrates produced using technologies such as nanoimprinting. The femtosecond laser-etched substrate has obvious advantages in production cost and has a significant improvement in detection sensitivity. This improvement in detection sensitivity is due to the combined effect of the hybrid superhydrophobic / hydrophilic patterned structure enriching analyte molecules and the mesoscopic-scale dielectric microlens further enhancing the traditional SERS substrate signal. It has extremely high detection sensitivity and can detect analyte molecules at sub-femtomolar concentrations.

[0096] The present invention has been experimentally verified to be feasible. The prepared hybrid super-hydrophobic / hydrophilic patterned SERS substrate can effectively enrich analyte molecules, and the synergistic enhancement effect of the cascade of the microsphere array and the SERS substrate can greatly enhance the Raman scattering signal of the molecules of the detected substance.

[0097] It can be understood that the various technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features in the above-mentioned 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.

[0098] The above are merely preferred embodiments of the present application and only specifically describe the technical principles of the present application. These descriptions are intended only to explain the principles of the present application and should not be construed in any way as limiting the scope of protection of the present application. Based on the explanations herein, any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present application, as well as other specific implementations of the present application that can be conceived by those skilled in the art without inventive effort, shall be included within the scope of protection of the present application.

Claims

1. An enhanced Raman detection platform, characterized in that: include: A SERS substrate, wherein a patterned micro-nanostructure having a hydrophilic region is formed on the surface of the SERS substrate by femtosecond laser etching technology, and a solution of analyte molecules to be tested can form nearly spherical droplets in the patterned micro-nanostructure region and be enriched in the hydrophilic region; a microsphere array film, wherein the microsphere array film is covered on the hydrophilic area; A Raman spectrometer is used to perform Raman detection on the hydrophilic area.

2. A method for preparing the enhanced Raman detection platform according to claim 1, characterized in that: The steps include: A SERS substrate is prepared, wherein a patterned micro-nanostructure with a hydrophilic region is formed on the surface of the SERS substrate by femtosecond laser etching technology, and a solution of analyte molecules to be tested can form nearly spherical droplets in the patterned micro-nanostructure region and be enriched in the hydrophilic region; preparing a microsphere array film, wherein the microsphere array film is covered on the hydrophilic area; A Raman spectrometer is provided, and the Raman spectrometer is used to perform Raman detection on the hydrophilic area.

3. The method for preparing the enhanced Raman detection platform according to claim 2, wherein: The steps of preparing the SERS substrate specifically include the following steps: A femtosecond laser is used to etch a hydrophilic area with a grid structure on the surface of a metal substrate; Chemically modifying the surface of the hydrophilic region to form a hydrophobic surface; Etching the center of the hydrophobic surface to form a patterned micro-nanostructure with a hydrophilic area; A noble metal thin film layer is deposited on the patterned micro-nano structure.

4. The method for preparing the enhanced Raman detection platform according to claim 3, wherein: In the step of etching a hydrophilic area with a grid structure on the surface of the metal substrate using a femtosecond laser, the energy density of the femtosecond laser is 7 to 9 J / cm 2 The etching interval of the grid is 20 to 60 μm.

5. The method for preparing the enhanced Raman detection platform according to claim 3, wherein: The step of chemically modifying the surface of the hydrophilic region to form a hydrophobic surface specifically includes the following steps: The modifying chemical reagent is dripped onto the surface of the hydrophilic area until the entire hydrophilic area is covered with the modifying chemical reagent, and the surface of the hydrophilic area is formed into a hydrophobic surface after the modifying chemical reagent evaporates.

6. The method for preparing the enhanced Raman detection platform according to claim 5, wherein: The modification chemical reagent includes stearic acid alcohol solution or biocompatible fluorinated surfactant Flou-ST1 or Fluo-ST2.

7. The method for preparing the enhanced Raman detection platform according to claim 5, wherein: The step of etching the center of the hydrophobic surface to form a patterned micro-nanostructure with a hydrophilic region specifically includes the following steps: etching the center of the hydrophobic surface to remove the hydrophobic layer in the center to form a patterned micro-nanostructure with a hydrophilic region, wherein the laser energy density used in the etching is 7 to 9 J / cm 2 , the etching interval is 5 to 10 μm, and the number of etching times is 1 to 3 times.

8. The method for preparing the enhanced Raman detection platform according to claim 3, wherein: The step of depositing a noble metal thin film layer on the patterned micro-nanostructure specifically includes the following steps: A noble metal film layer is deposited on the patterned micro-nano structure by magnetron sputtering or vacuum coating. The thickness of the noble metal film layer is 40-50 nm, and the material of the noble metal film layer includes gold or silver.

9. The method for preparing the enhanced Raman detection platform according to claim 2, wherein: The steps of preparing the microsphere array film specifically include the following steps: Dropping the microsphere solution onto a tilted glass slide, and after the water molecules evaporate, the microspheres self-assemble to form a microsphere array structure; Adding a curing agent to the glass sheet and performing spin coating, and then placing the glass sheet at a temperature of 80 to 100° C. and allowing the microsphere array structure on the glass sheet to stand for 20 minutes to 1 hour to solidify; The glass sheet is placed in anhydrous ethanol to allow the microsphere array structure to fall off the glass sheet, thereby obtaining the microsphere array film.

10. The method for preparing the enhanced Raman detection platform according to claim 9, wherein: In the step of dropping a microsphere solution onto a tilted glass sheet and allowing the microspheres to self-assemble to form a microsphere array structure after water molecules evaporate, the microsphere solution comprises silicon dioxide, soda-lime glass, barium titanate glass or titanium dioxide.

11. The method for preparing the enhanced Raman detection platform according to claim 9, wherein: In the step of adding a curing agent to the glass sheet and performing spin coating, and then standing at 80-100° C. for 20 minutes to 1 hour to solidify the microsphere array structure on the glass sheet, the curing agent includes PDMS, PMMA or UV glue.

12. A detection method for the enhanced Raman detection platform according to claim 1, characterized in that: The steps include: The analyte molecule solution to be tested is dripped into the patterned micro-nanostructure area to form nearly spherical droplets which are enriched in the hydrophilic area. The microsphere array film is covered on the hydrophilic area and the hydrophilic area is subjected to Raman detection using the Raman spectrometer microscope.

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