CN109650325B - Surface-enhanced Raman scattering substrate, preparation method, and 3D enrichment and detection method - Google Patents

Abstract

A surface-enhanced Raman scattering substrate, a preparation method, and a 3D enrichment and detection method, the surface-enhanced Raman substrate comprises a substrate; a hydrophobic organic repolymerization nanochain layer is formed on the substrate; and metal nanoparticles The layer is formed on the surface of the hydrophobic organic repolymerization nanochain layer; wherein, the part where the hydrophobic organic repolymerization nanochain layer and the metal nanoparticle layer are in contact form metal-hydrophobic organic composite nanoparticles or chains. By rolling the sample droplets on the substrate, the metal-hydrophobic organic composite nanoparticles or chains on the surface of the substrate are adsorbed, and fully mixed with the analyte molecules in the sample droplets, and then the sample droplets are left to stand for evaporation. The sufficient mixing and 3D enrichment of analyte molecules and metal-hydrophobic organic composite nanoparticles or chains can further enhance the SERS detection signal intensity and improve the detection sensitivity.

Description

Surface-enhanced Raman scattering substrate, preparation method, and 3D enrichment and detection method

technical field

The invention relates to the technical field of surface-enhanced Raman scattering detection, in particular to a surface-enhanced Raman scattering substrate, a preparation method, and a 3D (ie, three-dimensional) enrichment and detection method.

Background technique

Raman scattering spectroscopic detection technology is a material structure analysis method that does not require labeling of the sample to be detected, and has the characteristics of non-destructive and non-contact. With the development of laser technology and weak signal detection and reception technology, as a means to realize the molecular level detection of material structure, Raman scattering spectroscopy detection technology is expected to be used in biological detection, disease diagnosis, food safety detection, environmental monitoring, chemical analysis, etc. field to obtain practical and extensive application.

Surface-enhanced Raman scattering (SERS) refers to the use of noble metal nanostructures to enhance the local electromagnetic field intensity under the action of a laser, so that the Raman scattering spectral signal intensity of the molecules attached to the surface of the noble metal nanostructures is amplified, so as to realize the detection of trace amounts. A technique for the detection of molecules.

At present, SERS substrates based on nano-rough surfaces or nano-structures are mostly used to enhance the intensity of Raman scattering signals. The reported preparation methods of SERS substrates mainly include sol particle method, electrochemical wet etching technology of metal electrodes, metal nanosphere etching technology, autocatalytic VLS chemical synthesis growth technology, electron beam lithography, focused ion beam etching and Other physical and chemical etching methods, etc., these technologies have more or less problems in terms of process complexity or process controllability, and it is difficult to achieve large-scale commercial production.

In addition, when the above-mentioned SERS substrate is used for molecular detection, the conventional SERS substrate is basically a hydrophilic structure, and the analyte droplets are dropped on the SERS substrate, and the droplet and the substrate have a small contact angle and a large contact angle. Due to the coffee ring effect, the analyte molecules are unevenly distributed at the edge position after evaporation, which reduces the concentration of the analyte molecules to a certain extent, resulting in weak detection signal intensity and low detection sensitivity. Based on the SERS substrates with superhydrophobic properties proposed in several previous studies, which are beneficial for the enrichment of detection molecules, superhydrophobic surfaces are defined as stable contact angles greater than 150° and rolling contact angles less than 10°. However, the existing SERS substrates with superhydrophobic properties have high preparation costs and complex preparation methods, which are not conducive to large-scale production. At the same time, the metal nanostructures on the traditional superhydrophobic SERS substrate are fixed on the surface of the substrate. The trace enrichment method based on this type of superhydrophobic SERS substrate only realizes the two-dimensional aggregation of molecules in a small area. If the molecules are aggregated into a dense layer , the incident laser light may be blocked, so the surface plasmon resonance cannot be excited.

SUMMARY OF THE INVENTION

In view of this, the main purpose of the present invention is to provide a surface-enhanced Raman scattering substrate, a preparation method, and a 3D enrichment and detection method, so as to at least partially solve at least one of the above-mentioned technical problems.

For achieving the above object, technical scheme of the present invention is as follows:

As an aspect of the present invention, a surface-enhanced Raman scattering substrate is provided, comprising: a substrate; a hydrophobic organic repolymerized nanochain layer formed on the substrate; and a metal nanoparticle layer formed on the The surface of the hydrophobic organic repolymerized nanochain layer; wherein, the contact part of the hydrophobic organic repolymerized nanochain layer and the metal nanoparticle layer forms metal-hydrophobic organic composite nanoparticles or chains.

As another aspect of the present invention, a method for preparing a surface-enhanced Raman scattering substrate is provided, comprising the steps of: providing a substrate; forming a hydrophobic organic repolymerization nanochain layer on the substrate; The surface of the repolymerized nano-chain layer of the hydrophobic organic compound forms a metal nano-particle layer; wherein, the contact part of the re-polymerized nano-chain layer of the hydrophobic organic compound and the metal nano-particle layer forms a metal-hydrophobic organic compound nano-particle or chain.

As a further aspect of the present invention, there is provided a method for 3D enrichment of a sample using the above surface-enhanced Raman scattering substrate, comprising the steps of: providing a surface-enhanced Raman scattering substrate; A sample droplet is dropped on the scattering substrate, and the sample droplet is rolled on the surface-enhanced Raman scattering substrate to adsorb the metal-hydrophobic organic compound nanoparticles or chains in contact with the sample droplet.

As a further aspect of the present invention, there is provided a method for sample detection using the above-mentioned surface-enhanced Raman scattering substrate, comprising the steps of: providing a surface-enhanced Raman scattering substrate; The sample droplets are dropped onto the surface, and the sample droplets are rolled on the surface-enhanced Raman scattering substrate to adsorb the metal-hydrophobic organic composite nanoparticles or chains in contact with the sample droplets; The sample droplets of the metal-hydrophobic organic composite nanoparticles or chains are completely evaporated and enriched to obtain surface-enhanced Raman scattering active particles; the Raman test is carried out using the surface-enhanced Raman scattering active particles, and the test The laser focus is placed inside the surface-enhanced Raman scattering active particles.

Based on the above-mentioned technical scheme, the beneficial effects of the present invention are:

(1) In the surface-enhanced Raman scattering substrate provided by the present invention, the hydrophobic organic repolymerized nano-chain layer has super-hydrophobic properties, which is beneficial for the sample droplets to roll on it, and the metal-hydrophobic organic composite nanoparticles or chains on it. It can be adsorbed by rolling sample droplets and fully three-dimensional (3D) mixing with trace molecules of the analyte to achieve 3D enrichment of trace molecules and metal-hydrophobic organic composite nanoparticles or chains, which can be improved by standing evaporation. The concentration of trace molecules is used to complete the sample enrichment, and the trace molecules fall into the local space where the 3D hot spot is located to improve the detection signal intensity.

(2) The preparation method of the surface-enhanced Raman scattering substrate of the present invention is simple and flexible in many aspects. The evaporation and enrichment of molecules can further extend the detection limit of SERS technology, improve the detection sensitivity, and expand the measurable concentration range of trace substances.

(3) The collection dose of sample droplets can be controlled by the use of droplet injection groove, rolling groove flow channel structure, and detection groove. The rolling distance and rolling direction of sample droplets can be controlled by the design of the rolling groove flow channel structure, thereby controlling the metal - The degree of mixing and enrichment of hydrophobic organic composite nanoparticles or chains. In the case of effective enrichment, the detection tank fixes the trace enrichment area of the sample, which simplifies the positioning process of the sample during the test process and improves the test efficiency. , but also provides help for batch ultra-trace SERS detection.

Description of drawings

1 is a schematic diagram of a preparation device for preparing a hydrophobic organic repolymerized nanochain layer on a substrate according to the present invention;

Fig. 2 is the structural representation of the injection groove, the rolling groove flow channel and the detection groove of the SERS substrate of the present invention;

Fig. 3 is the structure schematic diagram of the hydrophobic organic repolymerization nano chain layer prepared by the present invention;

4 is a schematic structural diagram of a metal nanoparticle layer prepared on a hydrophobic organic repolymerized nanochain layer according to the present invention;

5 is a schematic side view of the present invention dropping a sample droplet on a SERS substrate;

Fig. 6 is the side schematic diagram of the sample droplet rolling on the SERS substrate of the present invention;

7 is a schematic diagram of the formation of SERS active particles after the sample droplets of the present invention are rolled and evaporated and enriched in the detection tank;

8 is a SEM image of PDMS repolymerized nanoparticles or chains in Example 1 of the present invention;

9 is a SEM image of the metal-PDMS composite nanoparticles or chains in Example 1 of the present invention;

FIG. 10 is a comparison diagram of the detection spectrum of SERS active particles in Example 1 of the present invention and the detection spectrum of common SERS substrates.

In the above drawings, the meanings of the reference numerals are explained as follows:

1-substrate, 2-hydrophobic organic repolymerization nanochain layer, 3-metal target, 4-metal nanoparticle, 5-metal nanoparticle layer, 6-sample droplet, 7-droplet injection tank, 8- Rolling groove flow channel structure, 9-detection groove, 10-SERS active particles, 11-high temperature furnace.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

The hot spot has a strong spatial localization of the electromagnetic field, which plays a very important role in SERS detection. The SERS signal of a small number of analyte molecules falling into the local space where the hot spot is located occupies a high proportion of the entire SERS signal. However, analyte molecules do not easily fall into the local space where the hot spot is located. Therefore, the "hot spot" problem is an important research direction to improve the sensitivity of SERS detection. The invention discloses a surface-enhanced Raman scattering substrate (referred to as a SERS substrate for short), a preparation method and a 3D enrichment and detection method, which enables sample droplets to roll on the SERS substrate and can adsorb metal-hydrophobic organic compound nanoparticles or Chain, which can realize 3D enrichment of analyte trace samples and metal-hydrophobic organic composite nanoparticles or chains. The surface of the substrate constructed by the hydrophobic organic nanostructure has super-hydrophobic properties. , which can greatly improve the distribution density of the sample molecules to be tested, and the analyte molecules can fall into the local space where the 3D hot spot is located, thereby improving the detection signal strength. In addition, the preparation cost of the SERS substrate is low, the preparation method is simple, and it can be used for large-scale production, avoiding the strict requirements for the substrate in the molecular detection of the existing SERS substrate, and expanding the measurable concentration range of trace substances.

In an exemplary embodiment of the present invention, a SERS substrate is provided, comprising a substrate 1, a hydrophobic organic repolymerized nanochain layer 2 and a metal nanoparticle layer 5, and the hydrophobic organic repolymerized nanochain layer 2 is formed on On the substrate 1, the metal nanoparticle layer 5 is formed on the surface of the hydrophobic organic repolymerization nanochain layer 2; wherein the part where the hydrophobic organic repolymerization nanochain layer 2 contacts the metal nanoparticle layer 5 forms a metal-hydrophobic organic substance Composite nanoparticles or chains.

As shown in FIG. 2 , the substrate 1 can be, for example, a silicon wafer, a glass wafer, a glass slide, a quartz wafer, a sapphire wafer, a metal wafer, a polymer film, a glass fiber substrate, a carbon fiber substrate or other high temperature resistant substrates. Further, a droplet injection groove 7; a detection groove 9; and a rolling groove flow channel structure 8 can be provided thereon, the two ends of which are respectively communicated with the droplet injection groove 7 and the detection groove 9; The diameter of the groove 7 and the detection groove 9 are both 2-5 mm, and the depth is 2-100 μm. The length of the rolling groove flow channel structure is 3-6 mm and the depth is 2-100 μm.

The hydrophobic organic repolymerized nanochain layer 2 can be prepared by chemical vapor deposition, and has nanochains formed by the accumulation of hydrophobic organic repolymerized nanoparticles, as shown in Figure 3, in order to clearly demonstrate the hydrophobic organic repolymerized nanochains Layer structure, magnified drawing of hydrophobic organic repolymerized nanoparticles. Preferably, the length of the nano-chains is 0.5-5 μm. If the length of the nano-chains is too short or too long, the device performance will be affected.

As shown in FIG. 3 and FIG. 4 , the metal nanoparticle layer 5 can be obtained by depositing metal nanoparticles 4 on the surface of the hydrophobic organic repolymerization nanochain layer by sputtering, evaporation or spraying using a metal target 3, and the materials are selected from gold, silver, Copper, aluminum or platinum, preferably, the thickness of the metal nanoparticle layer 5 is 10 to 50 nm, and if it is too thick or too thin, the device performance will also be affected.

The size of the formed metal-hydrophobic organic compound nanoparticle is 500 nm to 1 μm; the length of the formed metal-hydrophobic organic compound nano chain is 0.5 to 5 μm.

In another exemplary embodiment of the present invention, a method for preparing a SERS substrate is also provided, comprising the following steps:

Step 1. Provide substrate 1;

Specifically, the substrate 1 includes a silicon wafer, a glass wafer, a glass slide, a quartz wafer, a sapphire wafer, a metal wafer, a polymer film, a glass fiber substrate, a carbon fiber substrate or other high temperature resistant substrates, more specifically, a substrate The size of the bottom 1 is 1cm×1cm to 3cm×3cm.

Preferably, the droplet injection groove 7, the rolling groove flow channel structure 8 and the detection groove 9 are prepared on the substrate 1 by a conventional photolithography or etching process. As shown in FIG. 2, two parts of the rolling groove flow channel structure 8 are prepared. The ends communicate with the droplet injection tank 7 and the detection tank 9, respectively. Specifically, the diameter of the droplet injection groove 7 and the detection groove 9 are both 2-5 mm and 2-100 μm in depth, and the length of the rolling groove flow channel structure 8 is 3-6 mm and the depth is 2-100 μm.

Step 2. Prepare a hydrophobic organic repolymerization nanochain layer 2 with super-hydrophobic properties on the above-mentioned substrate 1; The rolling contact angle is less than 10°.

For example, it can be prepared by chemical vapor deposition method. In one embodiment, the preparation of the hydrophobic organic repolymerized nanochain layer 2 is by placing the substrate 1 in a high-temperature furnace 11 in an oxygen atmosphere and decomposing it at a temperature of 400-700° C. The cured hydrophobic organics are redeposited on the substrate 1 as shown in FIG. 1 . As shown in FIG. 3 , the structure of the hydrophobic organic repolymerized nanochain layer is nanochains formed by the accumulation of hydrophobic organic repolymerized nanoparticles, and the length is 0.5-5 μm.

Step 3, preparing a metal nanoparticle layer 5 on the above-mentioned hydrophobic organic repolymerized nanochain layer 2 .

The organic particles on the hydrophobic organic repolymerization nanochain layer 2 in contact with the metal nanoparticle layer 5 cooperate with the metal nanoparticles in the metal nanoparticle layer 5 to form metal-hydrophobic organic composite nanoparticles or chains with SERS activity. The size of the metal-hydrophobic organic compound nanoparticle is 500 nm to 1 μm, and the length of the metal-hydrophobic organic compound nano chain is 0.5 to 5 μm.

Further, the metal nanoparticle layer 5 can be deposited by sputtering, evaporation or spraying, the thickness of the metal nanoparticle layer 5 is 10-50 nm, and the size of the metal nano-particles is 2-10 nm.

According to the above-mentioned SERS substrate based on the hydrophobic organic repolymerization nanochain layer and metal nanoparticle layer and its preparation method, further, the present invention provides a method for 3D enrichment of a sample, comprising the following steps:

Step a, providing the SERS substrate prepared above;

Preferably, it includes a substrate 1, a hydrophobic organic repolymerized nanochain layer 2 and a metal nanoparticle layer 5; the droplet injection groove 7, the rolling groove flow channel structure 8, the detection groove 9 and the hydrophobicity on the substrate 1 are prepared. For the specific process of repolymerizing the nanochain layer 2 and the metal nanoparticle layer 5 by sexual organic matter, reference may be made to the above description, which will not be repeated here.

Step b, drop the sample droplet 6 containing the analyte on the SERS substrate prepared above based on the hydrophobic organic repolymerized nanochain layer and the metal nanoparticle layer.

Specifically, the sample droplets 6 include pesticides, additives, pigments, food components, fruit and vegetable components or biomedical samples dissolved in a solvent, and the volume of the sample droplets 6 is 0.1-10 μL, preferably 2-4 μL.

In a specific implementation, the sample droplets 6 can be obtained through a pipette, a dropper or other micro-containers, and the sample droplets 6 are dropped onto the surface of the SERS substrate prepared above, as shown in FIG. 5 .

Further, due to the superhydrophobic properties of the repolymerized nanochain layer 2 of the hydrophobic organics, the droplets have a larger contact angle and a smaller rolling angle on the substrate surface, and the contact surface between the droplet and the substrate surface is small. Furthermore, the sample droplets 6 can be dropped onto the droplet injection grooves 7 on the SERS substrate.

Step c, rolling the sample droplet 6 on the SERS substrate;

As shown in Fig. 6, the SERS substrate is inclined at a certain angle (about 3°), due to the superhydrophobic property of the repolymerized nanochain layer 2 of the hydrophobic organics, the sample droplet 6 can roll on the SERS substrate, and the sample droplet can roll on the SERS substrate after rolling. It contains both analyte molecules and metal-hydrophobic organic composite nanoparticles or chains with SERS activity, and the two are fully mixed to form a 3D uniform distribution.

Preferably, the sample droplet 6 rolls in the rolling groove flow channel structure 8 of the SERS substrate. The rolling groove flow channel structure 8 has a specific shape and size, and the rolling direction and distance can be controlled to control the metal- The number of hydrophobic organic composite nanoparticles or chains.

Further, the present invention also provides a method for sample detection using the above-mentioned SERS substrate, after the above-mentioned step c, further comprising:

In step d, the rolled sample droplets 6 are left standing until the sample droplets 6 are completely evaporated to achieve enrichment of sample molecules, thereby obtaining SERS active particles.

Step e: The Raman test is performed using the SERS active particles 10, and the laser focus is placed inside the SERS active particles during the test to improve the test signal intensity.

Specifically, the evaporation rate can be accelerated by placing the SERS substrate with the sample droplets 6 on a hot plate, an oven or a fume hood, or it can be placed in a normal room for more than 30 minutes until the surface water molecules evaporate completely. , the SERS active particles 10 are obtained, as shown in FIG. 7 , which is suitable for the enrichment of trace analyte molecules. At this time, the analyte molecules fall into the local space where the 3D hot spot is located, and the SERS substrate is transferred to the Raman test bench for testing.

In the following, polydimethylsiloxane (PDMS) is used as the hydrophobic organic substance to further illustrate the technical solution of the present invention, but it should be understood that other hydrophobic organic substances, such as other polysiloxane polymers other than PDMS, are used and implemented. A similar operation in Example 1 should also achieve the same effect:

Example 1

Prepare the SERS substrate:

Specifically include the following steps:

Step 1. Provide substrate 1;

In this embodiment, the substrate 1 is an ordinary single crystal silicon wafer, and the size of the substrate 1 is 2cm×2cm. Further, the diameter of the droplet injection groove 7 and the detection groove 9 prepared on the substrate 1 by the photolithography process are both 3 mm and 50 μm in depth; the length of the rolling groove flow channel structure 8 is 5 mm and the depth is 50 μm.

Step 2, preparing a PDMS repolymerized nanochain layer with super-hydrophobic properties on the above-mentioned substrate 1;

In this embodiment, the substrate 1 is placed in a high-temperature furnace in an oxygen atmosphere, and the cured PDMS is pyrolyzed at 410° C. and redeposited on the substrate 1. The obtained PDMS repolymerizes the nano-chain length of the nano-chain layer. is 0.5 to 5 μm, as shown in FIG. 8 .

Step 3, preparing a metal nanoparticle layer 5 on the PDMS repolymerized nanochain layer to obtain a SERS substrate;

In this embodiment, the metal nanoparticles obtained by sputtering are mainly distributed on the upper surface of the PDMS repolymerized nanochain layer. As shown in FIG. 9 , the size of the metal-PDMS composite nanoparticles formed by coordination is 500 nm to 1 μm. The length of the -PDMS composite nanochains is between 0.5 and 5 μm.

Sample enrichment and analysis:

Specifically include the following steps:

Step a, providing the above-mentioned SERS substrate;

Step b, dropping 3 μL of the sample droplet 6 containing the analyte rhodamine 6G (R6G) with a concentration of 10ppb into the droplet injection tank 7;

Step c, rolling the sample droplet 6 to the detection groove 9 through the rolling groove flow channel structure 8 of the SERS substrate;

In step d, the rolled sample droplets 6 are kept and placed on a hot plate at 80° C. for 10 minutes, until the sample droplets 6 are completely evaporated to obtain SERS active particles;

Step e: The SERS substrate loaded with the SERS active particles is transferred to a Raman test bench for testing. During the test, the laser focus is placed on the inside of the SERS active particles to improve the test signal intensity.

Figure 10 shows the detection spectrum of the signal intensity obtained inside the tested SERS active particles; and the detection spectrum of the signal intensity of the same concentration of R6G on a common Raman substrate. The characteristic peak at 610 cm ^-1 of the R6G analyte was selected as the analysis point, and the obtained spectral signal was more than 30 times higher than that of the common SERS substrate. It can be seen that the obtained SERS active particles have excellent improvement performance.

To sum up, the present invention uses a SERS substrate with superhydrophobic properties to adsorb the metal-hydrophobic organic compound nanoparticles or chains on the surface of the substrate through the rolling of sample droplets on the SERS substrate, and make them interact with the analyte molecules at the surface. Fully mixing in the sample droplet, followed by the rolling of the sample droplet 6 and the standing evaporation can realize the full mixing and 3D enrichment of the analyte molecules and the metal-hydrophobic organic compound nanoparticles or chains, which can further improve the SERS detection signal intensity. Improve detection sensitivity. The preparation method of the SERS substrate of the present invention is simple and flexible in various aspects, and when the 3D enrichment is performed by the rolling-standing-evaporation method, the detection limit of the SERS technology can be further extended.

In addition, the introduction of droplet injection grooves and detection grooves on the SERS substrate can control the movement and position of the sample droplets, and the rolling distance and rolling direction of the sample droplets can be controlled by the design of the flow channel structure of the rolling groove, which can further control the tested droplets. The mixed 3D enrichment degree of sample molecules and metal-hydrophobic organic composite nanoparticles or chains will not affect SERS detection due to excessive metal-hydrophobic organic composite nanoparticles in the case of effective ultra-trace enrichment; The detection tank fixes the enriched area of the sample, which improves the test efficiency and is expected to help batch SERS detection.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above-mentioned specific embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention. Within the spirit and principle of the present invention, any modifications, equivalent replacements, improvements, etc. made should be included within the protection scope of the present invention.

Claims (19)

1. A surface-enhanced Raman scattering substrate, wherein the surface-enhanced Raman scattering substrate comprises: substrate; A hydrophobic organic repolymerized nanochain layer is formed on the substrate, and the hydrophobic organic repolymerized nanochain layer has nanochains formed by stacking hydrophobic organic repolymerized nanoparticles; and a metal nanoparticle layer formed on the surface of the hydrophobic organic repolymerized nanochain layer; Wherein, the contact part of the hydrophobic organic repolymerized nanochain layer and the metal nanoparticle layer forms metal-hydrophobic organic composite nanoparticles or chains. 2 . The surface-enhanced Raman scattering substrate according to claim 1 , wherein the nano-chains have a length of 0.5-5 μm. 3 . 3 . The surface-enhanced Raman scattering substrate according to claim 1 , wherein the hydrophobic organic repolymerized nanochain layer is prepared by chemical vapor deposition using cured hydrophobic organics. 4 . 4 . The surface-enhanced Raman scattering substrate according to claim 1 , wherein the hydrophobic organic repolymerized nanochain layer is a polydimethylsiloxane repolymerized nanochain layer, and the cured polydimethylsiloxane is used. 5 . Siloxanes are prepared by chemical vapor deposition. 5. The surface-enhanced Raman scattering substrate according to claim 1, wherein: The material of the metal nanoparticle layer is gold, silver, copper, aluminum or platinum, and the metal nanoparticle layer is deposited by sputtering, evaporation or spraying; The substrate is a silicon wafer, a glass wafer, a quartz wafer, a sapphire wafer, a glass slide, a metal wafer, a polymer film, a glass fiber substrate or a carbon fiber substrate. 6 . The surface-enhanced Raman scattering substrate according to claim 1 , wherein the thickness of the metal nanoparticle layer is 10-50 nm. 7 . 7. The surface-enhanced Raman scattering substrate according to claim 1, wherein the surface of the substrate is further provided with: droplet injection tank; detection slot; and The two ends of the rolling groove flow channel structure are respectively communicated with the droplet injection groove and the detection groove. 8 . The surface-enhanced Raman scattering substrate according to claim 7 , wherein the diameter of the droplet injection groove and the detection groove are both 2-5 mm, and the depth is 2-100 μm, and the rolling groove flow channel The length of the structure is 3 to 6 mm, and the depth is 2 to 100 μm. 9. A preparation method of a surface-enhanced Raman scattering substrate, wherein the preparation method comprises the following steps: provide a substrate; forming a hydrophobic organic repolymerization nanochain layer on the substrate; A metal nanoparticle layer is formed on the surface of the hydrophobic organic repolymerized nanochain layer; Wherein, the contact part of the hydrophobic organic repolymerized nanochain layer and the metal nanoparticle layer forms metal-hydrophobic organic composite nanoparticles or chains. 10 . The preparation method according to claim 9 , wherein the hydrophobic organic repolymerization nanochain layer is prepared by chemical vapor deposition using cured hydrophobic organics. 11 . 11 . The preparation method according to claim 9 , wherein the length of the nano-chains of the hydrophobic organic repolymerized nano-chain layer is 0.5-5 μm. 12 . 12. preparation method according to claim 9, is characterized in that, described hydrophobic organic repolymerization nano chain layer is specially prepared by following method: The cured hydrophobic organic matter is used as an evaporation source and the substrate is put into an oxygen atmosphere furnace at a temperature of 400-700° C. for evaporation and deposition. 13. preparation method according to claim 9, is characterized in that: The metal nanoparticle layer is deposited by sputtering, evaporation or spraying; The step of providing the substrate further includes the step of preparing a droplet injection groove, a detection groove and a rolling groove flow channel structure on the substrate, wherein the two ends of the rolling groove flow channel structure are respectively connected to the The droplet injection tank is communicated with the detection tank. 14 . The preparation method according to claim 9 , wherein the thickness of the metal nanoparticle layer is 10-50 nm. 15 . 15. A method for 3D enrichment of samples using the surface-enhanced Raman scattering substrate according to any one of claims 1 to 8, wherein the method comprises the following steps: Provide surface-enhanced Raman scattering substrate; A sample droplet is dropped on the surface-enhanced Raman scattering substrate, and the sample droplet is rolled on the surface-enhanced Raman scattering substrate, so as to adsorb the metal-hydrophobic organic composite nanometers in contact with the sample droplet Particles or chains. 16. The method of claim 15, wherein: The step of rolling the sample droplet on the surface-enhanced Raman scattering substrate specifically includes: After the droplet of the sample is dropped onto the droplet injection groove on the surface-enhanced Raman scattering substrate, it is rolled along the flow channel structure of the rolling groove to the detection groove and left to stand. 17. The method according to claim 16, wherein the sample droplets comprise pesticides, additives, pigments, food components, fruit and vegetable components or biomedical samples dissolved in a solvent, and the volume of the sample droplets is 0.1 to 10 μL. 18. A method for sample detection using the surface-enhanced Raman scattering substrate according to any one of claims 1 to 8, wherein the method comprises the steps of: Provide surface-enhanced Raman scattering substrate; A sample droplet is dropped on the surface-enhanced Raman scattering substrate, and the sample droplet is rolled on the surface-enhanced Raman scattering substrate, so as to adsorb the metal-hydrophobic organic composite nanometers in contact with the sample droplet particles or chains; Standing the sample droplets adsorbed with the metal-hydrophobic organic compound nanoparticles or chains, so that the sample droplets are completely evaporated and enriched to obtain surface-enhanced Raman scattering active particles; The Raman test is performed using the surface-enhanced Raman scattering active particles, and the laser focus is placed inside the surface-enhanced Raman scattering active particles during the test. 19. The method of claim 18, wherein the step of fully evaporating and enriching the sample droplets comprises using heat or ventilation to accelerate the evaporation of the sample droplets.

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