Thermally controlled pre-concentrated SERS detection chip based on micro-heating technology and preparation method

Abstract

The present invention proposes a thermally controlled pre-concentrated SERS detection chip based on micro-heating technology and a preparation method, which is mainly composed of a SERS substrate composed of a plasmonic metal nanostructure with a strong "hot spot" effect, a detection / non-detection surface with different wetting properties, a heating module with local variable temperature heating, and an external amplification circuit. Droplets containing different surface properties and different molecules are dropped into the detection area, and a program-controlled temperature increase method is adopted to control the shrinkage morphology of the droplets by using the temperature difference and accelerate the evaporation speed of the droplets, so that the detection molecules are highly concentrated at the detection site. Under specific light excitation conditions, with the help of the strong "hot spot" effect of the detection site, a portable Raman spectrometer is used to detect its Raman signal and compare it. This method can realize trace molecule detection, has a broad-spectrum detection feature, and does not require large-scale Raman microscopic detection equipment. Its chip-based detection properties are conducive to the popularization and promotion of the new generation of SERS detection technology.

Description

Technical Field

[0001] The invention relates to the fields of nano materials, photocatalysis and thin film devices, and in particular to a thermally controlled pre-concentrated SERS detection chip based on micro-heating technology and a preparation method thereof. Background Art

[0002] Pesticide residues affect food safety and human health. Establishing efficient and rapid methods for detecting pesticide residues is crucial to ensuring food safety. Traditional detection methods (such as chromatography, mass spectrometry, chromatograph-mass spectrometry, and capillary electrophoresis) often have disadvantages such as complex steps, high cost, and the need for professional operation, and cannot meet the needs of rapid, large-scale, and on-site detection. Surface Enhanced Raman Spectroscopy (SERS) technology has attracted much attention due to its advantages such as high sensitivity, fast speed, and simple sample processing. It has great application potential in the field of pesticide residue detection. However, the current SRES technology has limitations. First, in terms of the preparation of highly sensitive detection substrates, the currently practical substrates often use coating or simple spherical structure self-assembly methods, and their SERS enhancement factors are often around 10. 7 , which cannot be further improved, limiting its upper limit of detection concentration. Second, in conventional SERS detection, due to the hydrophilicity of the substrate surface, the molecules to be detected will be evenly distributed on the substrate surface driven by flowing water, resulting in the detector being unable to effectively detect in a certain area due to the scarcity or even absence of molecules to be detected during the detection process, especially in trace detection applications, which limits its sensitivity to further improvement. At the same time, there is also a waste of molecules to be detected and substrates in the non-detection area, and the cost cannot be further reduced.

[0003] The local field enhancement characteristics of surface plasmon nanostructures related to their own morphology, size and environmental media provide opportunities for the development of highly sensitive SERS substrates. Surface plasmons are the phenomenon of collective oscillation of free electrons in conductors. Plasmon nanostructures made of metal have efficient absorption and scattering characteristics for photons in the optical frequency band. Especially under excitation conditions, the electromagnetic density near the metal surface will reach the maximum, thus significantly enhancing the information of molecules or structures near the nanostructure. In particular, for nanostructures with pointed surfaces or dense arrangements, light waves incident between metal nanoparticles will form a significant local enhancement of the light field, which is an optical "hotspot". When chemical molecules happen to be adsorbed near the "hotspot", their Raman signals will be enhanced by several orders of magnitude. How to construct a surface plasmon SERS substrate with a dense "hotspot" structure is a key link in achieving ultra-high sensitivity detection.

[0004] In addition to constructing the "hotspot" structure, the molecules to be tested also need to be highly concentrated. Substrates based on different wetting surface properties have also been proposed to achieve research on the fluid mechanics of the substrate surface. Under different surface wetting properties, the molecules to be tested can achieve directional movement and aggregation under the action of surface tension, combined with their own hydrophilic and lipophilic characteristics, and then form a high concentration in a specific area (such as the "hotspot" position mentioned above), breaking the limit of detection sensitivity. In conventional pre-concentration technology, the waiting time for droplet evaporation is long. If heating is used to promote the concentration and volatilization of droplets, auxiliary heating devices such as heating tables are required, which increases the cost and volume of SERS detection. Moreover, the actual required heating points are only localized in a very small area of ​​the detection substrate. This non-local variable temperature heating hot plate can only detect one substance at the same time, and cannot meet the needs of multiple or multiple pesticides or molecular detection. How to combine the surface wetting properties of the substrate with a flexible and fast heating method is an important factor in achieving low-cost, portable and high-speed detection.

[0005] In combination with the above features, the present invention proposes a thermally controlled pre-concentrated SERS detection chip and preparation method based on micro-heating technology. First, through surface modification technology, the hydrophilic and hydrophobic properties of the substrate surface are changed to form a "hotspot" intensive surface enhanced Raman scattering substrate with nano-scale hydrophilic wrinkles. At the same time, for detection molecules of different properties, such as hydrophobic and oleophobic, hydrophilic and oleophobic, etc., changing the hydrophilic and hydrophobic properties of the substrate can effectively concentrate the detection molecules and make them gather on dense "hot spots" to achieve high-sensitivity detection. In addition, the preparation of the flexible substrate and the design of the local heating unit are realized by combining electrospinning technology and 3D printing technology, respectively. The temperature control method is used to further control the morphology of the droplets to form a highly strict and controllable flow and aggregation behavior of the molecules to be tested, which can also shorten the detection time and greatly improve the detection efficiency. Summary of the invention

[0006] Technical problem: The purpose of the present invention is to solve the problems of low sensitivity of SERS detection substrate, long detection cycle, bulkiness and high cost, and proposes a thermally controlled pre-concentration SERS detection chip and preparation method based on micro-heating technology. This paper-based structure can realize the detection of various hydrophilic, lipophilic and hydrophobic molecules, and can also form a customized chip structure, which has broad practical value.

[0007] Technical solution: In order to solve the above technical problems, the present invention proposes a thermally controlled pre-concentration SERS detection chip based on micro-heating technology and a preparation method thereof, wherein the chip comprises: coated particles (1), a detection area (2), a nanofiber substrate (3), a supporting substrate (4), and a heating module (5); the coated particles (1) and the detection area (2) are both located on the upper surface of the nanofiber substrate (3), and the coated particles (1) are located in the detection area (2), the lower surface of the nanofiber substrate (3) is located on the upper surface of the supporting substrate (4), the heating module (5) is located on the lower surface of the supporting substrate (4), and the position of the heating module (5) corresponds one-to-one to the detection area (2).

[0008] The method comprises the following steps:

[0009] Step 1: dense self-assembly of metal nanoparticles on the surface of nanofibers;

[0010] 1-1) The prepared metal nanoparticles of different morphologies are centrifugally washed with water for more than two times to remove the surface ligands originally covered on the surface, the bottom precipitate is redissolved in deionized water, 10-100 mg of a surfactant is added, and it is stirred sufficiently to be uniformly adsorbed on the surface of the metal nanoparticles. The metal nanoparticles are centrifugally washed with water for more than two times to remove the excess and unadsorbed surfactant, and the precipitate is redispersed in deionized water to obtain a metal nanoparticle solution a.

[0011] 1-2) The nanofiber substrate (3) loaded on the surface of the supporting substrate (4) is cut into several pieces, and vertically inserted into the metal nanoparticle solution a. After standing at room temperature for 2-6 hours, the substrate is taken out and repeatedly rinsed with deionized water to remove the metal nanoparticles that are not firmly bound on the surface. In order to achieve dense self-assembly, the above process can be repeated 2-8 times until the color of the nanofiber surface no longer changes significantly, thereby obtaining nanofibers b loaded with metal nanoparticles.

[0012] Step 2: Preparation of SERS substrates with different wettability properties;

[0013] 1-1) The nanofiber b loaded with metal nanoparticles is immersed in an organic polymer solution (concentration of 0.1mM-50mM), and after standing in a dark place at room temperature for 6-18h, the sample is taken out and repeatedly rinsed with a mixed solution of anhydrous ethanol / n-hexane with a volume ratio of 1:1 to remove the organic polymer that is not firmly bound to the surface and in excess, thereby obtaining a nanofiber c containing a bound modified molecule.

[0014] 1-2) The customized metal mask is tightly attached to the surface of the nanofiber c containing the bound modified molecules, and placed in a plasma cleaning machine for 1-5 minutes to remove the organic polymers on the exposed surface. Then, the sample is placed in a coating machine for surface wettability modification. According to subsequent needs, different target materials and protective gases are selected for magnetron sputtering coating to obtain surfaces with different wettability. The thickness of the coating particles (1) is set to 10-100nm to obtain a SERS substrate d with different wettability surfaces.

[0015] Step 3: Preparation of a program-controlled, highly sensitive heating module with controllable heating area.

[0016] The dispensing printing technology is used to print a heating patch with adjustable morphology and size on the back of the SERS substrate d. The heating patch corresponds to the detection area (2) one by one to meet the pixel heating requirements. According to the requirements of the heating temperature range, an external amplification circuit and a control circuit are connected to obtain a SERS substrate e with a heating module.

[0017] The method for preparing a thermally controlled pre-concentrated SERS detection chip based on micro-heating technology is characterized in that the surfactant is a surface ligand molecule with a positive charge on the surface after hydrolysis of hexadecyltrimethylamine, polyvinylpyrrolidone or 3-aminopropyltriethoxysilane, or a surface ligand molecule with a negative charge on the surface after hydrolysis of trisodium citrate, mercaptopropionic acid or poly(sodium 4-styrene sulfonate). The metal nanoparticle solution a is a metal material formed by gold, silver, copper or an alloy of the above elements, and the morphology is a nanorod, nanoplate or nanostar with a nanostructure with multiple tips, the aspect ratio is 0.01-10, and the temperature can be 0-500°C.

[0018] The method for preparing a thermally controlled pre-concentrated SERS detection chip based on micro-heating technology is characterized in that the polymer nanofiber is a macromolecular material with a positive surface charge after hydrolysis of polyethyleneimine or dimethylaminoethyl ester, or a macromolecular material with a negative surface charge after hydrolysis of polyacrylic acid, polyethylene terephthalate or hydrolyzed polyacrylamide. The aspect ratio is 0.1-10000, the porosity is 0.50-0.99, the thickness is 0.1-100000 μm, and the temperature that can be withstood is 0-300°C.

[0019] The method for preparing a thermally controlled pre-concentrated SERS detection chip based on micro-heating technology is characterized in that the organic polymer solution is a solution formed by perfluorodecanethiol, dodecanethiol or polydimethylsiloxane hydrophobic molecules.

[0020] The method for preparing a thermally controlled pre-concentrated SERS detection chip based on micro-heating technology is characterized in that the target material is gold, silver or aluminum metal material, and the protective gas is argon, nitrogen or helium inert gas, or hydrogen sulfide, oxygen or methane reaction gas.

[0021] The method for preparing a thermally controlled pre-concentrated SERS detection chip based on micro-heating technology is characterized in that the metal mask plate has a mask area with a circular, triangular or star-shaped morphology and a duty cycle of 0.00001-0.01.

[0022] The method for preparing a thermally controlled pre-concentrated SERS detection chip based on micro-heating technology is characterized in that the heating module is composed of an external circuit and a heating patch, the external circuit is composed of a DAC module and an amplifier circuit, the DAC module output resistance is 5-20kΩ, the output voltage is 0-3.3V, and the accuracy is 0.0001-0.001V / ℃; the amplifier circuit is composed of 1-10 triodes, and the current amplification factor is 100-1000 times. The morphology of the heating patch is grid-type, round-shaped or interdigital, the size is 0.1-100mm, and the temperature range is 0-1000℃.

[0023] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0024] 1. A thermally controlled pre-concentrated SERS detection chip based on micro-heating technology is proposed. While maintaining the original SERS detection effect, it uses the surface wettability modification method to achieve high concentration of detection molecules, breaking through the upper limit of traditional SERS detection sensitivity. In addition, real-time and efficient detection of different detection molecules or the same detection molecule but at different concentrations can be achieved on the same substrate surface at the same time, making the traditional SERS substrate chip-based, the detection equipment portable and low-cost, which is conducive to the popularization and promotion of the new generation of SERS detection technology.

[0025] 2. A method of using temperature control to affect the morphology of droplets during volatilization is proposed. By controlling the dispensing process parameters to adjust them to match the heating of a specific area size, highly localized, rapid, and widely adjustable temperature range heating can be achieved. On the one hand, this heating method can accelerate the volatilization of droplets, which significantly reduces the detection cycle and improves the detection efficiency compared to the natural volatilization process. On the other hand, heating at different temperatures can affect the morphology of droplets and the fluid dynamics process during volatilization, making the concentration process of the probe molecules to be detected more controllable, and the distribution characteristics of the probe molecules are easier to adjust, avoiding the randomness of the concentration process, significantly improving the concentration efficiency, and thus enhancing the detection efficiency. In addition, compared with the traditional hot plate heating method, variable temperature heating can be performed according to the actual situation of each detection site, and the heating process can be "pixelated", which greatly reduces the detection cost.

[0026] 3. A method of constructing different wetting surface forms by using a template method is proposed, so that the surface characteristics of the detection area are compatible with the droplets containing the molecules to be detected, while the non-detection area has completely opposite wetting characteristics. This concentration method can achieve high enrichment of molecules. Compared with the disadvantage of highly dispersed molecules to be detected caused by traditional immersion methods, it can achieve trace molecule detection without causing large-scale waste of substrate. In terms of process, the time and cost of using a mask coating solution are much lower than processes such as electron beam lithography, and it does not affect the optical enhancement characteristics of the plasmon "hotspot". In addition, the test substrate formed by this process can be used for portable Raman spectroscopy testing, breaking away from the testing limitations of large confocal Raman spectrometers. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the structural diagram of the pre-concentrated SERS detection chip based on micro-heating technology. 1 is the coated particles, 2 is the detection area, 3 is the nanofiber substrate, 4 is the supporting substrate, and 5 is the heating module.

[0028] Figure 2 31 is a plasmon "hotspot" structure, 32 is a triangle "hotspot" structure, 33 is a rod-shaped "hotspot" structure, and 34 is a spherical "hotspot" structure.

[0029] Figure 3 21 is a spherical mask area, 22 is a triangular mask area, 23 is a flower-shaped mask area, and 24 is a mixed morphology mask area.

[0030] Figure 4 It is a heating patch design, 51 is a grid-type heating electrode, 52 is a circular heating electrode, and 53 is a cross-finger heating electrode.

[0031] Figure 5 It is the design of heating module and external control circuit. The external control circuit is composed of power supply, two NPN transistors and output voltage of digital-to-analog converter.

[0032] Figure 6 Concept diagram of thermal controlled pre-concentration. Figure (a) shows the pre-concentration of droplets under low-temperature heating conditions, Figure (b) shows the pre-concentration of droplets under high-temperature heating conditions, Figure (c) shows the distribution of detected molecules after droplets evaporate under low-temperature heating conditions, and Figure (d) shows the distribution of detected molecules after droplets evaporate under high-temperature heating conditions. DETAILED DESCRIPTION

[0033] The present invention is further described below by specific examples:

[0034] Embodiment 1:

[0035] Step 1: dense self-assembly of metal nanoparticles on the surface of nanofibers;

[0036] 1-1) The prepared gold nanostars were centrifugally washed with water for more than two times to remove the surface ligands originally covered on the surface, the bottom precipitate was redissolved in deionized water, 10 mg of hexadecyltrimethylammonium bromide was added, and it was stirred thoroughly so that it was uniformly adsorbed on the surface of the gold nanostars. The gold nanostars were centrifugally washed with water for more than two times to remove the excess and unadsorbed hexadecyltrimethylammonium bromide, and the precipitate was redispersed in deionized water to obtain a metal nanoparticle solution a.

[0037] 1-2) Cut the prepared polymer nanofibers into several pieces, insert them vertically into the metal nanoparticle solution a, let them stand at room temperature for 2 hours, take out the substrate and repeatedly rinse it with deionized water to remove the metal nanoparticles that are not firmly bound on the surface. To achieve dense self-assembly, the above process can be repeated twice until the surface color no longer changes significantly, and nanofibers b loaded with metal nanoparticles are obtained.

[0038] Step 2: Preparation of SERS substrates with different wettability properties;

[0039] 1-1) The nanofiber b loaded with metal nanoparticles is immersed in an ethanol solution of perfluorodecanethiol (concentration of 50 mM), and after standing in the dark at room temperature for 18 hours, the sample is taken out and repeatedly rinsed with a mixed solution of anhydrous ethanol / n-hexane with a volume ratio of 1:1 to remove the perfluorodecanethiol molecules that are not firmly bound to the surface and in excess, thereby obtaining a nanofiber c containing bound modified molecules.

[0040] 1-2) A metal mask with a circular mask area and a duty cycle of 0.001 was closely attached to the surface of the nanofiber c containing the bound modified molecules, and placed in a plasma cleaner for 2 minutes to remove the perfluorodecanethiol molecules on the exposed surface. Then, the sample was placed in a coating machine and a gold target was selected for coating. The coating thickness was set to 15 nm, and a SERS substrate d with different wetting surface properties was obtained.

[0041] Step 3: Preparation of program-controlled, high-sensitivity heating module.

[0042] The dispensing printing technology is used to print the interdigitated heating patch on the back of the SERS substrate d. The heating patch corresponds to the test site one by one to meet the pixelated heating requirements, and an external amplification circuit and a control circuit are connected to obtain a SERS substrate e with a heating module.

[0043] Embodiment 2:

[0044] Step 1: dense self-assembly of metal nanoparticles on the surface of nanofibers;

[0045] 1-1) The prepared silver nanoplates were centrifugally washed with water for more than two times to remove the surface ligands originally covered on the surface, the bottom precipitate was redissolved in deionized water, 20 mg of surfactant was added, and it was fully stirred so that it was uniformly adsorbed on the surface of the metal nanoparticles. The excess and unadsorbed surfactants were removed by centrifugation and washed with water for more than two times, and the precipitate was redispersed in deionized water to obtain a metal nanoparticle solution a.

[0046] 1-2) Cut the polymer nanofibers into several pieces, insert them vertically into the metal nanoparticle solution a, and after standing at room temperature for 3 hours, remove the substrate and repeatedly rinse it with deionized water to remove the silver nanoplates that are not firmly bound on the surface. To achieve dense self-assembly, the above process can be repeated 6 times until the surface color no longer changes significantly, and nanofibers b loaded with metal nanoparticles are obtained.

[0047] Step 2: Preparation of SERS substrates with different wettability properties;

[0048] 1-1) The nanofiber b loaded with metal nanoparticles is immersed in a dodecanethiol solution (concentration of 25 mM), and after standing in the dark at room temperature for 8 hours, the sample is taken out and repeatedly rinsed with a mixed solution of anhydrous ethanol / n-hexane with a volume ratio of 1:1 to remove the excess dodecanethiol that is not firmly bound to the surface, thereby obtaining a nanofiber c containing a bound modified molecule.

[0049] 1-2) The customized metal mask is tightly attached to the surface of the nanofiber c containing the bound modified molecules, and placed in a plasma cleaner for 2 minutes to remove the exposed surface dodecanethiol. Then, the sample is placed in a coating machine and a silver target is selected for coating. The coating thickness is set to 20nm, and a SERS substrate d with different wetting surface properties is obtained.

[0050] Step 3: Preparation of program-controlled, high-sensitivity heating module.

[0051] The dispensing printing technology is used to print a circular heating patch on the back of the SERS substrate d. The heating patch corresponds to the test site one by one to meet the pixelated heating requirements, and an external amplification circuit and a control circuit are connected to obtain a SERS substrate e with a heating module.

[0052] Embodiment 3:

[0053] Step 1: dense self-assembly of metal nanoparticles on the surface of nanofibers;

[0054] 1-1) The prepared silver nanoplates are centrifugally washed with water for more than two times to remove the surface ligands originally covered on the surface, the bottom precipitate is redissolved in deionized water, 10-100 mg of polyvinyl pyrrolidone is added, and it is stirred sufficiently to be uniformly adsorbed on the surface of the metal nanoparticles. The silver nanoplates are centrifugally washed with water for more than two times to remove the excess and unadsorbed polyvinyl pyrrolidone, and the precipitate is redispersed in deionized water to obtain a metal nanoparticle solution a.

[0055] 1-2) Cut the polymer nanofibers into several pieces, insert them vertically into the metal nanoparticle solution a, and after standing at room temperature for 6 hours, remove the substrate and repeatedly rinse it with deionized water to remove the metal nanoparticles that are not firmly bound on the surface. To achieve dense self-assembly, the above process can be repeated 4 times until the surface color no longer changes significantly, and nanofibers b loaded with metal nanoparticles are obtained.

[0056] Step 2: Preparation of SERS substrates with different wettability properties;

[0057] 1-1) The nanofiber b loaded with metal nanoparticles is immersed in a dodecanethiol ethanol solution (concentration of 10 mM), and after standing in the dark at room temperature for 16 hours, the sample is taken out and repeatedly rinsed with a mixed solution of anhydrous ethanol / n-hexane with a volume ratio of 1:1 to remove the excessive dodecanethiol molecules that are not firmly bound to the surface, thereby obtaining a nanofiber c containing bound modified molecules.

[0058] 1-2) A metal mask with a triangular mask area and a duty cycle of 0.0001 was closely attached to the surface of the nanofiber c containing the bound modified molecules, and placed in a plasma cleaner for 1 min to remove the exposed surface dodecanethiol molecules. Next, the sample was placed in a coating machine and a silver target was selected for coating. The coating thickness was set to 25 nm to obtain a SERS substrate d with superwetting surface properties.

[0059] Step 3: Preparation of program-controlled, high-sensitivity heating module.

[0060] The dispensing printing technology is used to print a grid-type heating patch on the back of the SERS substrate d. The heating patch corresponds to the test site one by one to meet the pixelated heating requirements, and an external amplification circuit and a control circuit are connected to obtain a SERS substrate e with a heating module.

Claims

1. A thermally controlled pre-concentration SERS detection chip based on micro-heating technology, characterized in that: include: Coated particles (1), a detection area (2), a nanofiber substrate (3), a supporting substrate (4), and a heating module (5); the coated particles (1) and the detection area (2) are both located on the upper surface of the nanofiber substrate (3), and the coated particles (1) are located in the detection area (2), the lower surface of the nanofiber substrate (3) is located on the upper surface of the supporting substrate (4), the heating module (5) is located on the lower surface of the supporting substrate (4), and the position of the heating module (5) corresponds one-to-one to the detection area (2); The method for preparing the thermally controlled pre-concentrated SERS detection chip comprises the following steps: Step 1: dense self-assembly of metal nanoparticles on the surface of nanofibers; 1-1) The prepared metal nanoparticles of different morphologies are centrifuged and washed with water to remove the surface ligands originally covered on the surface, the bottom precipitate is redissolved in deionized water, 10-100 mg of surfactant is added, and it is fully stirred to make it evenly adsorbed on the surface of the metal nanoparticles, and the excess and unadsorbed surfactants are removed by centrifugation and washing, and the precipitate is redispersed in deionized water to obtain a metal nanoparticle solution a; 1-2) cutting the nanofiber substrate (3) loaded on the surface of the supporting substrate (4) into several pieces, inserting them into the metal nanoparticle solution a, leaving them to stand at room temperature for 2-6 hours, taking out the substrate and repeatedly rinsing it with deionized water to remove the metal nanoparticles that are not firmly bound to the surface; in order to achieve dense self-assembly, repeating steps 1-2) several times until the color of the nanofiber surface no longer changes significantly, thereby obtaining nanofibers b loaded with metal nanoparticles; Step 2: Prepare SERS substrates with different wettability surfaces; 2-1) Soak the nanofiber b loaded with metal nanoparticles in an organic polymer solution, let it stand in the dark at room temperature for 6-18 hours, take out the sample, rinse it repeatedly to remove the organic polymer that is not firmly bound on the surface and in excess, and obtain the nanofiber c containing the bound modified molecules; 2-2) The customized metal mask is tightly attached to the surface of the nanofiber c containing the bound modification molecules, and placed in a plasma cleaning machine to remove the organic polymers on the exposed surface; then, the sample is placed in a coating machine to modify the surface wettability, and according to subsequent needs, different target materials and protective gases are selected to perform magnetron sputtering coating to obtain surfaces with different wettability; the thickness of the coating particles (1) is set to 10-100 nm, and a SERS substrate d with different wettability surfaces is obtained; Step 3: Use dispensing printing technology to print a heating patch with adjustable morphology and size on the back of the SERS substrate d. The heating patch corresponds to the detection area (2) one by one to meet the pixelated heating requirements, and an external amplification circuit and a control circuit are connected according to the requirements of the heating temperature range to obtain a SERS substrate e with a heating module (5).

2. A thermally controlled pre-concentration SERS detection chip based on micro-heating technology as claimed in claim 1, characterized in that: The surfactant is a surface ligand molecule with a positive charge on the surface after hydrolysis of hexadecyltrimethylamine, polyvinylpyrrolidone or 3-aminopropyltriethoxysilane, or a surface ligand molecule with a negative charge on the surface after hydrolysis of trisodium citrate, mercaptopropionic acid or poly (sodium 4-styrene sulfonate); the metal nanoparticle solution a is a metal material formed by gold, silver, copper or an alloy of gold, silver and copper elements, and has a morphology of nanorods, nanoplates or nanostars with multiple pointed nanostructures, an aspect ratio of 0.01-10, and can withstand a temperature of 0-500°C.

3. The thermally controlled pre-concentration SERS detection chip based on micro-heating technology according to claim 1, characterized in that: The nanofiber is a macromolecular material with a positive surface charge after hydrolysis of polyethyleneimine or dimethylaminoethyl ester, or a macromolecular material with a negative surface charge after hydrolysis of polyacrylic acid, polyethylene terephthalate or hydrolyzed polyacrylamide; the aspect ratio is 0.1-10000, the porosity is 0.50-0.99, the thickness is 0.1-100000 μm, and the temperature that can be withstood is 0-300°C.

4. The thermally controlled pre-concentration SERS detection chip based on micro-heating technology according to claim 1, characterized in that: The organic polymer solution is a solution formed by perfluorodecanethiol, dodecanethiol or polydimethylsiloxane hydrophobic molecules.

5. The thermally controlled pre-concentration SERS detection chip based on micro-heating technology according to claim 1, characterized in that: The target material is gold, silver or aluminum metal material; the protective gas is argon, nitrogen or helium inert gas, or hydrogen sulfide, oxygen or methane reaction gas.

6. A thermally controlled pre-concentration SERS detection chip based on micro-heating technology as claimed in claim 1, characterized in that The metal mask plate has a mask area with a circular, triangular or star-shaped shape, and a duty ratio of 0.00001-0.

01.

7. The thermally controlled pre-concentration SERS detection chip based on micro-heating technology according to claim 1, characterized in that: The heating module is composed of an external circuit and a heating patch. The external circuit is composed of a DAC module and an amplifier circuit. The output resistance of the DAC module is 5-20 kΩ, the output voltage is 0-3.3 V, and the accuracy is 0.0001-0.001 V / ℃; the amplifier circuit is composed of 1-10 triodes, and the current amplification factor is 100-1000 times; the morphology of the heating patch is grid-type, circular-type or interdigital-type, the size is 0.1-100 mm, and the temperature range is 0-1000℃.

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