CN105671492A - SERS substrate based on REBCO template and preparation method - Google Patents

Abstract

The invention discloses a SERS substrate based on a REBCO template and a preparation method thereof. The SERS substrate includes a REBCO template layer and a metal modification layer coated on the outer surface of the REBCO template layer; wherein, the REBCO template layer has a thickness of 10 ～2000nm is continuously adjustable, the structure is from amorphous to polycrystalline, a, b axis orientation and c axis orientation or mixed orientation can be adjusted arbitrarily; the metal modification layer is a metal thin film or metal particle layer; the thickness of the metal modification layer 5-200nm. Compared with the prior art, the substrate and its preparation method of the present invention have the advantages of: the SERS substrate prepared by the present invention has good uniformity, high sensitivity, and has the characteristics of metal flexibility, which can meet various application requirements; REBCO growth mechanism and growth The method has been studied extensively, and industrial production under precise control is easy to realize; meanwhile, the preparation method of the present invention is simple, and the experimental parameters in the growth process are easier to control than chemical methods, and the cost of industrial production can be lower than 0.5$/cm ² .

Description

A kind of SERS substrate and preparation method based on REBCO template

technical field

The invention relates to a SERS substrate based on a REBCO template and a preparation method thereof, that is, a SERS substrate prepared using a rare earth oxide coated conductor as a template and a preparation method thereof, in particular to a pulsed laser deposition technology (hereinafter referred to as PLD) and chemical methods to prepare rare earth oxide (referred to as REBCO, RE=rare earth element) coatings with certain orientation and defects, and then use this as a template to prepare uniform, obvious enhancement effect, low cost and repeatability on flexible substrates. A method for a strong SERS substrate.

Background technique

Surface-enhanced Raman spectroscopy (SERS) is a very powerful and highly sensitive analytical technique that can detect and analyze various molecules adsorbed on the surface of a substance. For some systems, its sensitivity even reaches the single-molecule level. After decades of development, there are still some urgent problems to be solved in the field of SERS, which generally include the following three aspects: first, expanding the range of SERS reinforcing materials; second, exploring the process of preparing appropriately rough SERS substrates ; Third, realize the theory and technology of SERS quantitative analysis. Obtaining a substrate with high sensitivity, high stability, and repeatability, and making the substrate have good selectivity, is a key issue in the design and manufacture of Raman detection substrates. However, in addition to meeting the appeal requirements, the real application of SERS substrates also depends to a large extent on the industrialization capabilities, production processes and production costs of SERS substrates. At present, there are two commonly used methods for preparing SERS substrates: bottom-up (Bottom-Up) and top-down (Top-Down). Generally speaking, the bottom-up method is based on the chemical synthesis of nanoparticles such as gold and silver. Although this method is simple and easy to synthesize, it has great disadvantages, including: 1. Nanoparticles synthesized by solution method In the prepared SERS substrate, in fact, only a small part of the particles have SERS activity, and other nanoparticles cover the surface of the substrate to inhibit the SERS detection effect. 2. It is difficult to control the agglomeration effect of the nanoparticles prepared from the solution, which will inevitably affect the stability and repeatability of the SERS detection effect. 3. It is particularly important that the method for controlling the synthesis of stable nano-SERS active hotspots is still immature, that is to say, there is a certain degree of randomness in controlling the synthesis of nanostructures with specific morphologies. The top-down method is generally based on some conventional physical techniques, mainly including focused ion beam method, stencil printing, CVD method, photolithography, etc., which can be used to construct novel and macroscopic SERS active substrates. The main disadvantages of this type of substrate are: 1. It is difficult to completely control the substrate with such a large surface area technically, which may lead to inconsistent surface morphology between different batches of substrates. 2. Generally, this kind of substrate has poor mechanical properties, especially poor flexibility and is easy to break. In addition, there are methods such as the use of biological templates to prepare three-dimensional active substrates, surface functional modification, and laser ablation. Although some of these methods have been able to achieve periodic structures in a small area and obtain high gains, SERS substrates that meet all the requirements for industrial applications have not yet appeared.

As a high-temperature superconducting material with the most application potential, REBCO coated conductors are considered likely to replace the first-generation high-temperature superconducting strips represented by bismuth systems due to their unique advantages, and are used in many superconducting strong materials. electric technology. Since its birth, it has been highly concerned at home and abroad, and countries all over the world have invested a lot of research funds in the research of its industrial preparation technology, and a series of theoretical and experimental results have been obtained. The REBCO coated conductor is essentially a granular ceramic oxide with poor flexibility and strong anisotropy. Therefore, the common process of the second-generation high-temperature superconducting strip is to use various coating methods in a very Thin (40-100 microns) traditional metal substrates (nickel-based alloys or stainless steel alloys) are coated with a layer of REBCO film with a thickness of about 1 to several microns and should have a biaxial texture at the same time, which is very demanding on the process ( Its typical structure is shown in Figure 1 of the description.

The REBCO superconducting film deposited directly on the metal substrate will have a large number of defects, and the superconducting performance is very poor. Therefore, a buffer layer must be added on the metal substrate for the preparation of superconducting applications. On the one hand, the role of the buffer layer is to induce the orientation growth of the REBCO superconducting film, and on the other hand, it can also be used as an isolation layer to prevent the reaction between REBCO and the metal substrate and element diffusion. Depending on the technical route of the coated conductor, the material selection of the buffer layer will also be different. Obviously, the selection, thickness, doping and growth conditions of the buffer layer material will greatly affect the growth condition of REBCO, and then affect its surface morphology. For example, CeO ₂ has a small lattice mismatch with superconducting layers and metal substrates, and has been used as a buffer layer material for high-temperature superconductors. However, when preparing a high-temperature superconducting coated conductor, when the thickness of the CeO ₂ buffer layer on the metal substrate exceeds a certain value (about 50nm), microcracks will appear. The appearance of microcracks in turn affects the epitaxial growth of the superconducting layer on the buffer layer. In addition, REBCO itself is extremely sensitive to growth conditions due to its complex structure. The key to preparing high-performance superconducting strips is to produce specific defects through the regulation of these factors. However, as far as the surface morphology is concerned, the regulation of these factors can also produce a series of changes in the surface morphology of REBCO (see the appendix figure 2). In terms of stability, REBCO superconducting coatings can be prepared at one time at a kilometer level of 300A/cm, which means that the uniformity and stability of the prepared REBCO coatings can be guaranteed during the production process. At the same time, with the improvement of process stability, the production cost of REBCO is decreasing year by year. At present, the average cost of REBCO coating produced by PLD preparation method is lower than 3￥/cm ² . This makes it possible to use REBCO-coated conductors as templates to modify coin-family metal thin films and nanoparticles to prepare SERS flexible substrates with uniform signal, high SERS activity, stable process, fast preparation speed and low manufacturing cost.

Contents of the invention

In response to this problem, the designer of the present applicant actively researched based on the experimental experience of REBCO thin film growth, and proposed a method of using REBCO coating as a template to prepare a SERS substrate, that is, a SERS substrate and its preparation method based on a REBCO template.

One of the objectives of the present invention is to provide a flexible SERS substrate with excellent properties using REBCO as a template.

Another object of the present invention is to provide a method for preparing a flexible SERS substrate with excellent properties using REBCO as a template.

The purpose of the present invention is achieved through the following technical solutions:

In order to achieve the first object of the present invention, the present invention provides a SERS substrate based on a REBCO stencil, the SERS substrate includes a REBCO (R=Y) stencil layer and a metal modification layer coated on the surface of the REBCO stencil layer.

Preferably, the thickness of the REBCO template layer is continuously adjustable from 10 to 2000 nm, the structure is from amorphous to polycrystalline, and the a, b axis orientation and c axis orientation or mixed orientation can be adjusted arbitrarily.

Preferably, the metal modification layer is a metal thin film or a metal particle layer; the thickness of the metal modification layer is 5-200 nm.

Further preferably, the metal modification layer is a single metal layer or a stack of different metal layers.

Further preferably, the metal of the metal modification layer includes Au, Ag, Cu or Al.

In order to achieve another object of the present invention, the present invention provides a method for preparing the SERS substrate based on the REBCO template, comprising the following steps:

Step 1: Heating the REBCO target material to the growth temperature, adjusting the laser energy and frequency, introducing oxygen, and the conveying device of the coating system drives the metal base tape through the coating area to form a REBCO template layer on the surface of the metal base band buffer layer;

In step 2, the REBCO target is replaced with a modified metal target in situ, and a metal modification layer is coated on the surface of the REBCO template layer by pulse deposition, magnetron sputtering or thermal evaporation to obtain a flexible SERS substrate.

Preferably, in step 1, the metal base tape needs to be cleaned with an organic solvent before use, in order to clean the buffer layer with a certain orientation on the metal base tape to remove surface impurities.

Preferably, in step 1, the REBCO is prepared by high-temperature sintering; the organic solvent refers to a non-polar organic solvent such as acetone.

Preferably, in step 1, the growth temperature is 650-850°C.

Preferably, in Step 1, the laser energy and frequency are specifically: E=50-300mJ, f=1-200Hz.

Preferably, in step 1, the oxygen specifically refers to pure oxygen with a purity of 99.99%.

Further, the coating area is in a vacuum state before the oxygen is introduced, and the air pressure in the coating area is 5-200 mTorr after the oxygen is introduced; further, the specific air pressure in the vacuum state is 1×10 ^-4 to 1×10 ^-7 Torr.

Preferably, in Step 1, the passage is to pass through the coating area once at a speed of 5-10 m/h, or pass through the multi-channel coating area at a speed of 30-50 m/h.

Preferably, in step 1, the distance from the REBCO target to the coating area is 5-25 cm;

Preferably, in step 1, the REBCO template layer is 10-2000 nm.

Preferably, in step 2, the in-situ replacement is specifically carried out under the conditions that the temperature of the heater used to heat the REBCO target is reduced to 50° C. and the vacuum degree of the coating area is lower than 1×10 ⁻⁷ Torr.

Preferably, in step 2, the metal modification layer coated on the surface of the REBCO template layer by the pulsed laser deposition method specifically includes: adjusting the laser energy and frequency, and the metal substrate coated with the REBCO template layer passes through the coating area, and the REBCO The surface of the template layer is plated with a metal decoration layer.

Further preferably, the laser energy and frequency specifically refer to: E=50-300mJ, f=1-200Hz.

Further preferably, the passing means that the metal substrate coated with the REBCO stencil layer passes through the coating area once at a speed of 30m/h, or passes through the multi-channel coating area at a speed of 150m/h.

Preferably, in step 2, said plating a metal modification layer on the surface of the REBCO stencil layer by magnetron sputtering specifically includes: winding the metal base tape coated with the REBCO stencil layer in a magnetron sputtering coating system, through Enter argon gas, control the sputtering power, and the metal substrate coated with the REBCO template layer passes through the multi-channel coating area, and the metal modification layer can be coated on the surface of the REBCO template layer.

Further preferably, the gas pressure in the coating area should reach glowing conditions after the argon gas is introduced.

Further preferably, the sputtering power is specifically 10-1000W.

Further preferably, the passing specifically refers to passing the metal substrate coated with the REBCO template layer through the coating area at a speed of 1-50 m/h once, or passing through the multi-channel coating area at a speed of 7-200 m/h.

Preferably, in step 2, said plating a metal modification layer on the surface of the REBCO stencil layer by means of thermal evaporation specifically includes: cutting and fixing the metal substrate coated with the REBCO stencil layer, adjusting the vacuum degree, melting and modifying For the metal target, turn on the MASK and vapor-deposit to the modified metal layer.

Further preferably, the vacuum degree specifically means that the vacuum degree is lower than 3×10 ^-6 Torr.

The technical solution above provides a method for preparing a flexible noble metal thin film with optical application potential using REBCO as a template. The REBCO template layer is prepared on a conventional metal substrate by a laser pulse deposition (PLD) system, and the metal modification layer on it can be realized by physical vapor deposition (such as magnetron sputtering, thermal evaporation). The diversity of surface morphology of RBCO can be effectively controlled by changing the deposition conditions such as growth temperature and film thickness. Thanks to the superconducting film growth control technology, the film has high morphology stability and repeatability during the process. At the same time, the metal modification layer of RBCO can also be regulated by changing the deposition time and other methods, in order to obtain the best SERS gain effect. The optimized sample still has an obvious detection signal (close to the single molecule level) for R6G at 10 ^-11 M, and the gain effect is evenly distributed on the sample surface. In terms of production speed and cost performance, the preparation process of the present invention is simpler than that of the superconducting wire, so it has faster production speed and lower cost. Moreover, thanks to the growth of the functional thin film on the flexible metal substrate, the SERS substrate of the present invention can also be processed into a desired shape according to the needs in actual use.

Advantage and positive effect of the present invention:

1. The SERS substrate prepared by the present invention has good uniformity, and the surface morphology, particle size and density are continuously adjustable;

2. The SERS substrate prepared by the present invention has high sensitivity, and the detection limit of the optimized sample is close to the single-molecule level;

3. The invention has the characteristics of metal flexibility, which can meet various application requirements, and can mechanically cut samples into required sizes, reducing the cost of use;

4. The growth mechanism and industrialized growth method of REBCO have been extensively studied, and the industrialized production under precise control is easy to realize;

5. At the same time, the preparation method of the present invention is simple, the experimental parameters in the growth process are easier to control than chemical methods, and the industrial production cost can be lower than 0.5$/cm ² .

Description of drawings

Other characteristics, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

Figure 1 The cross-sectional view of the REBCO template prepared based on IBAD technology;

Figure 2 AFM images of the surface morphology of REBCO under different temperature conditions (10μm*10μm);

Fig.3 AFM images of surface morphology of REBCO with different thicknesses (20μm20μm);

The XRD diffraction pattern of Fig. 4REBCO;

The enhancement effect of the same sample in Fig. 5 to different concentrations of R6G solutions;

The enhancing effect of Fig. 6 different substrates to the same concentration R6G solution;

The enhancement effect of the same concentration R6G solution on different thickness substrates of Fig. 7;

Figure 8 RAMmapping results of 200nm thick stencil;

Figure 9 Actual sample.

detailed description

The present invention will be described in detail below in conjunction with specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

As shown in Figure 1 of the description, it is a cross-sectional view of a REBCO coated conductor prepared by IBAD technology during the implementation of the present invention. It is characterized in that REBCO is grown on a substrate with a certain texture. In the following, this embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation and specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

Example 1

This embodiment provides a PLD preparation method for preparing a REBCO template layer and a metal modification layer on a metal substrate, comprising the following steps:

Step 1, sample preparation;

Step 1.1, taking out the metal base tape with the oriented buffer layer of the desired length and cleaning it with an organic solvent;

Step 1.2, the cerium oxide substrate base tape with biaxial texture is wound multiple times and placed in a multi-channel laser coating system;

Step 2, experiment preparation;

Step 2.1, turn on the equipment, and install the REBCO target and the precious metal target prepared by high-temperature sintering on the target holder in the cavity;

Step 2.2, adjust the distance from the target to the baseband coating area to be 25cm;

Step 2.3, close the vacuum door of the coating system, and evacuate to 1×10 ^-7 Torr;

Step 3. Turn on the heater and turn the REBCO target at the same time to heat up to the required growth temperature of 850°C;

Step 4. Turn off the molecular pump, pass oxygen into the coating system, and control the total air pressure to the required air pressure value, such as 200mTorr;

Step 5, start the excimer laser, and increase the laser energy and frequency to the value required by the REBCO template layer coating process, E=300mJ, f=200Hz;

Step 6. After the air pressure, temperature, laser energy, and laser frequency are stable, turn on the laser light path switch to start the pre-evaporation process on the surface of the laser target. This process lasts for about 5 minutes;

Step 7. After the ellipsoidal plasma formed by laser evaporation is stable, start the transmission device of the coating system, so that the base tape pre-fixed in the coating system passes through the coating area at a speed of 10m/h, or passes through the coating area at a speed of 50m/h. Channel coating area;

Step 8. After the REBCO stencil layer coating is completed, turn off the laser light path switch, turn off the heater power switch, turn off the oxygen gas flow meter valve, turn on the vacuum system, gradually reduce the shutdown frequency and turn off the excimer laser;

Step 9. After the temperature of the heater drops below 50°C and the vacuum degree is lower than 1×10 ^-7 Torr, replace the REBCO target directly in the vacuum chamber with a noble metal target through in-situ target replacement;

Step 10, start the excimer laser, and raise the laser energy and frequency to the value required by the metal layer coating process, E=200mJ, f=50Hz;

Step 11. After the temperature, laser energy, and laser frequency are stable, turn on the laser optical path switch, and wait for the ellipsoidal plasma formed by laser evaporation to be stable, start the transmission device of the coating system, so that the baseband passes through the coating area at a speed of 30m/h. Or pass through the multi-channel coating area at a speed of 150m/h;

Step 12. After the metal layer coating is completed, turn off the laser light path switch to gradually reduce the shutdown frequency and turn off the excimer laser;

Step 13. Open the nitrogen inflation valve to inflate the vacuum chamber to 1 atmosphere, take out the sample and cut it into the required size, and test its SERS characteristics.

Example 2

This embodiment provides a method for preparing REBCO with PLD on a metal substrate and using magnetron sputtering to prepare a metal modification layer, including the following steps:

Step 1, sample preparation;

Step 1.1, taking out the metal base tape with the oriented buffer layer of the desired length and cleaning it with an organic solvent;

Step 1.2, the cerium oxide substrate base tape with biaxial texture is wound multiple times and placed in a multi-channel laser coating system;

Step 2, experiment preparation;

Step 2.1, turn on the equipment, and install the REBCO target and the precious metal target prepared by high-temperature sintering on the target holder in the cavity;

Step 2.2, adjust the distance from the target to the baseband coating area to be 5cm;

Step 2.3, close the vacuum door of the coating system, and evacuate to 1×10 ^-4 Torr;

Step 3. Turn on the heater and turn the REBCO target at the same time to heat up to the required growth temperature of 650°C;

Step 4. Turn off the molecular pump, pass oxygen into the coating system, and control the total air pressure to the required air pressure value, such as 5mTorr;

Step 5, start the excimer laser, and increase the laser energy and frequency to the value required by the REBCO template layer coating process, E=50mJ, f=1Hz;

Step 6. After the air pressure, temperature, laser energy, and laser frequency are stable, turn on the laser light path switch to start the pre-evaporation process on the surface of the laser target. This process lasts for about 5 minutes;

Step 7. After the ellipsoidal plasma formed by laser evaporation is stable, start the transmission device of the coating system, so that the base tape pre-fixed in the coating system passes through the coating area at a speed of 5m/h, or passes through the coating area at a speed of 30m/h. Channel coating area;

Step 8. After the coating of the REBCO stencil layer is completed, turn off the laser light path switch, turn off the heater power switch, turn off the oxygen gas flow meter valve, gradually reduce the switching frequency and turn off the excimer laser;

Step 9. When the temperature drops below 50°C, open the nitrogen inflation valve to make the atmospheric pressure in the vacuum chamber reach one atmospheric pressure, take out the sample and wind the base tape with the REBCO template layer multiple times and set it on the multi-channel magnetron sputtering coating In the system, the control vacuum degree is lower than 1×10 ^-7 Torr;

Step 10, feed argon gas until the ignition condition is reached, start the current until the ignition, and control the sputtering power to 10W;

Step 11. After the sputtering is stable, start the transmission device of the coating system, so that the base tape passes through the coating area at a speed of 1m/h, or passes through the multi-channel coating area at a speed of 7m/h;

Step 13. Open the nitrogen inflation valve to inflate the vacuum chamber to 1 atmosphere, take out the sample and cut it into the required size, and test its SERS characteristics;

Example 3

This embodiment provides a method for preparing a REBCO template layer using PLD on a metal substrate and preparing a metal modification layer by vacuum evaporation, including the following steps:

Step 1, sample preparation;

Step 1.1, taking out the metal base tape with the oriented buffer layer of the desired length and cleaning it with an organic solvent;

Step 1.2, the cerium oxide substrate base tape with biaxial texture is wound multiple times and placed in a multi-channel laser coating system;

Step 2, experiment preparation;

Step 2.1, turn on the equipment, and install the REBCO target and the precious metal target prepared by high-temperature sintering on the target holder in the cavity;

Step 2.2, adjust the distance from the target to the baseband coating area to be 25mm;

Step 2.3, close the vacuum door of the coating system, and evacuate to 1×10 ^-6 Torr;

Step 3. Turn on the heater and turn the REBCO target at the same time to heat up to the required growth temperature of 700°C;

Step 4. Turn off the molecular pump, pass oxygen into the coating system, and control the total air pressure to the required air pressure value, such as 100mTorr;

Step 5, start the excimer laser, and raise the laser energy and frequency to the value required by the REBCO template layer coating process, E=200mJ, f=100Hz;

Step 6. After the air pressure, temperature, laser energy, and laser frequency are stable, turn on the laser light path switch to start the pre-evaporation process on the surface of the laser target. This process lasts for about 5 minutes;

Step 7. After the ellipsoidal plasma formed by laser evaporation is stable, start the transmission device of the coating system, so that the base tape pre-fixed in the coating system passes through the coating area at a speed of 10m/h, or passes through the coating area at a speed of 50m/h. Channel coating area;

Step 8. After the REBCO stencil layer coating is completed, turn off the laser light path switch, turn off the heater power switch, turn off the oxygen gas flow meter valve, turn on the vacuum system, gradually reduce the shutdown frequency and turn off the excimer laser;

Step 9. When the temperature drops below 50°C, open the nitrogen inflation valve to make the atmospheric pressure in the vacuum chamber reach one atmospheric pressure, take out the sample and cut it into the required size;

Step 10, fix the sample on the sample holder, and control the vacuum degree to be lower than 3×10 ^-6 Torr; Step 11, turn on the current to melt the pre-placed titanium, turn on the MASK and start vapor deposition to a thickness of about 10nm, then turn off the MASK;

Step 12, turn on the pre-placed financialization by passing current, turn on the mask and start evaporation to a thickness of about 30nm, then turn off the mask;

Step 13. Open the nitrogen inflation valve to inflate the vacuum chamber to 1 atmosphere, take out the sample and cut it into the required size, and test its SERS characteristics.

Example 4

This embodiment provides a method for preparing REBCO with PLD on a metal substrate and using magnetron sputtering to prepare a metal modification layer, including the following steps:

Step 1, sample preparation;

Step 1.1, taking out the metal base tape with the oriented buffer layer of the desired length and cleaning it with an organic solvent;

Step 1.2, the cerium oxide substrate base tape with biaxial texture is wound multiple times and placed in a multi-channel laser coating system;

Step 2, experiment preparation;

Step 2.1, turn on the equipment, and install the REBCO target and the precious metal target prepared by high-temperature sintering on the target holder in the cavity;

Step 2.2, adjust the distance from the target to the baseband coating area to be 5cm;

Step 2.3, close the vacuum door of the coating system, and evacuate to 1×10 ^-4 Torr;

Step 3. Turn on the heater and turn the REBCO target at the same time to heat up to the required growth temperature of 650°C;

Step 4. Turn off the molecular pump, pass oxygen into the coating system, and control the total air pressure to the required air pressure value, such as 5mTorr;

Step 5, start the excimer laser, and increase the laser energy and frequency to the value required by the REBCO template layer coating process, E=50mJ, f=1Hz;

Step 6. After the air pressure, temperature, laser energy, and laser frequency are stable, turn on the laser light path switch to start the pre-evaporation process on the surface of the laser target. This process lasts for about 5 minutes;

Step 7. After the ellipsoidal plasma formed by laser evaporation is stable, start the transmission device of the coating system, so that the base tape pre-fixed in the coating system passes through the coating area at a speed of 5m/h, or passes through the coating area at a speed of 30m/h. Channel coating area;

Step 8. After the coating of the REBCO stencil layer is completed, turn off the laser light path switch, turn off the heater power switch, turn off the oxygen gas flow meter valve, gradually reduce the switching frequency and turn off the excimer laser;

Step 9. When the temperature drops below 50°C, open the nitrogen inflation valve to make the atmospheric pressure in the vacuum chamber reach one atmospheric pressure, take out the sample and wind the base tape with the REBCO template layer multiple times and set it on the multi-channel magnetron sputtering coating In the system, the control vacuum degree is lower than 1×10 ^-7 Torr;

Step 10, feed argon gas to 5mTorr, start the current to glow, and control the sputtering power to 1000W;

Step 11. After the sputtering is stable, start the transmission device of the coating system, so that the base tape passes through the coating area at a speed of 50m/h, or passes through the multi-channel coating area at a speed of 200m/h;

Step 13. Open the nitrogen inflation valve to inflate the vacuum chamber to 1 atmosphere, take out the sample and cut it into the required size, and test its SERS characteristics.

Obtain a kind of SERS substrate based on REBCO stencil by above-mentioned preparation method, described SERS substrate comprises REBCO (R=Y) stencil layer and the metal modification layer that described REBCO stencil layer exterior is coated; The thickness of described REBCO stencil layer is in 10 -2000nm is continuously adjustable, the structure is from amorphous to polycrystalline, a, b-axis orientation and c-axis orientation or mixed orientation can be adjusted arbitrarily; the metal modification layer is a metal film or metal particle layer; the thickness of the metal modification layer 5-200nm. Accompanying drawing 2 is the AFM result of the surface characteristic change of REBCO under different growth temperatures during the preparation process; The XRD measurement result of accompanying drawing 4 shows that it has the characteristics of a, c-axis transitional growth state, and nano-clusters of columnar particles are formed on the surface; 3 is the morphology characteristics of the REBCO template layer at different thicknesses at the set temperature of 900°C. According to the XRD measurement results of Figure 4, as the thickness of the REBCO template layer increases, the surface particles gradually grow and the number gradually increases ; The RAM test samples in Figure 6 and Figure 7 were immersed in the corresponding concentration solution for about 10 minutes, and then dried naturally. The measurement results showed that the enhancement effect was closely related to the surface morphology of REBCO, and multiple experiments showed that it had excellent The preparation stability and enhanced uniformity (accompanying drawing 8); accompanying drawing 5 is that the experimental sample (see figure 9) still has obvious gain for the 10 ^-11 M R6G solution.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims (10)

1. A SERS substrate based on a REBCO template, characterized in that, the SERS substrate comprises a REBCO template layer and a metal modification layer coated on the outer surface of the REBCO template layer; Wherein, the thickness of the REBCO template layer is continuously adjustable from 10 to 2000 nm, the structure is from amorphous to polycrystalline, and the a, b axis orientation and c axis orientation or mixed orientation can be adjusted arbitrarily; The metal modification layer is a metal thin film or a metal particle layer; the thickness of the metal modification layer is 5-200 nm. 2. a kind of preparation method based on the SERS substrate of REBCO template according to claim 1, is characterized in that, comprises the following steps: Step 1: Heating the REBCO target to the growth temperature, adjusting the laser energy and frequency, introducing oxygen, and the conveying device of the coating system drives the metal base tape through the coating area to form a REBCO template layer on the surface of the metal base band buffer layer; In step 2, the REBCO target is replaced with a modified metal target in situ, and a metal modification layer is coated on the surface of the REBCO template layer by pulse deposition, magnetron sputtering or evaporation to obtain a flexible SERS substrate. 3. The method for preparing a SERS substrate based on a REBCO template according to claim 2, wherein in step 1, the growth temperature is 650-850°C; The laser energy and frequency are specifically: E=50-300mJ, f=1-200°C; Before the oxygen is introduced, the coating area is in a vacuum state, and after the oxygen is introduced, the pressure in the coating area is 5-200mTorr. 4. The method for preparing a SERS substrate based on a REBCO template according to claim 2, wherein in step 1, the passage is to pass through the coating area once at a speed of 5 to 10 m/h, or to pass through the coating area at a speed of 30 to 50 m/h The speed of h passes through the multi-channel coating area. 5. the preparation method of the SERS substrate based on REBCO template according to claim 2, it is characterized in that, in step 2, described by pulse deposition method in described REBCO template layer surface plating metal modification layer specifically comprises: adjusting laser energy and frequency, the metal substrate coated with the REBCO template layer passes through the coating area, and the surface of the REBCO template layer can be coated with a metal modification layer. 6. The method for preparing a SERS substrate based on a REBCO template according to claim 5, wherein the laser energy and frequency specifically refer to: E=50-300mJ, f=1-200Hz; The passing means that the metal substrate coated with the REBCO stencil layer passes through the coating area once at a speed of 30m/h, or passes through the multi-channel coating area at a speed of 150m/h. 7. the preparation method of the SERS substrate based on REBCO template according to claim 2, is characterized in that, in step 2, described by magnetron sputtering method at described REBCO template layer surface plating metal modification layer specifically comprises: The metal base tape coated with the REBCO template layer is wound and set in the magnetron sputtering coating system, and argon gas is passed through to control the sputtering power. The metal base tape coated with the REBCO template layer passes through the multi-channel coating area, and the REBCO template layer The surface is coated with a metal finishing layer. 8. the preparation method of the SERS substrate based on REBCO template according to claim 7, is characterized in that, the air pressure in coating area after passing into argon gas should reach glowing condition; The sputtering power is specifically 10-1000W; The passing specifically refers to passing the metal substrate coated with the REBCO template layer through the coating area at a speed of 1-50 m/h once, or passing through the multi-channel coating area at a speed of 7-200 m/h. 9. the preparation method of the SERS base based on REBCO template according to claim 2, it is characterized in that, in step 2, described by vapor deposition method in described REBCO template layer surface plating metal decoration layer specifically comprises: to described Cut and fix the metal base tape coated with REBCO template layer, adjust the vacuum degree, melt and modify the metal target, open the MASK and evaporate to the modified metal layer, and that’s it. 10 . The method for preparing a REBCO template-based SERS substrate according to claim 9 , wherein the vacuum degree specifically refers to a vacuum degree lower than 3×10 ⁻⁶ Torr. 11 .