Agnwsmof composite sers substrate, preparation method and application thereof

Abstract

This invention discloses an AgNWs@MOF composite SERS substrate, its preparation method, and its applications, relating to the field of laser Raman detection technology. The preparation method includes the following steps: synthesizing silver nanowires using a solvothermal method; loading metal-organic frameworks (MOFs) onto the silver nanowires using a room-temperature static method or a solvothermal method to form a composite material; forming a tandem structure by combining the silver nanowires and MOFs; and centrifuging, washing, and drying the composite material to obtain the silver nanowire-loaded MOF SERS substrate. The silver nanowire-loaded MOF powder material in the SERS substrate prepared by this method exhibits a tandem morphology. The MOF structure in the silver nanowire-loaded MOF enhances the adsorption capacity for target pollutants, effectively capturing low-concentration analytes and achieving sensitive detection.

Description

Technical Field

[0001] This invention relates to the field of laser Raman detection technology, specifically to a surface-enhanced Raman scattering (SERS) substrate, and particularly to a composite SERS substrate of silver nanowires loaded with metal-organic frameworks (AgNWs@MOF), its preparation method, and its application in the detection of small molecule pollutants and dye pollutants. Background Technology

[0002] Surface-enhanced Raman scattering (SERS) is a highly sensitive fingerprint spectroscopy technique that can provide rich vibrational information about molecules adsorbed on the surface of reinforcing materials. It has broad application prospects in fields such as food safety, energy and environment, biomedicine and public safety.

[0003] Traditional SERS substrates are mainly composed of noble metal nanoparticles or nanostructures such as gold and silver. Although they perform well in terms of enhancement factors, noble metal nanoparticles are easily oxidized in air, leading to SERS signal decay over time and poor substrate stability. Furthermore, for analytes with low concentrations or low Raman scattering cross sections, single noble metal substrates are difficult to effectively enrich and capture, limiting detection sensitivity. To overcome these shortcomings, researchers have recently begun to combine metal-organic frameworks (MOFs) with noble metal nanostructures to construct MOF-noble metal composite SERS substrates. MOFs possess high specific surface area, tunable pore structure, and excellent adsorption and enrichment capabilities, enabling them to effectively capture target molecules and enrich them in "hot spot" regions on the noble metal surface. At the same time, the MOF shell can prevent the oxidation of noble metal nanoparticles, improving substrate stability. There are some existing reports on MOF-noble metal composite SERS substrates, such as loading noble metal nanoparticles onto the MOF surface using electrostatic adsorption, forming a core-shell structure by coating a MOF shell onto a noble metal surface using in-situ growth, or preparing MOF-derived semiconductor heterojunction SERS substrates using high-temperature calcination.

[0004] However, existing MOF-noble metal composite SERS substrates still face the following technical challenges: Firstly, most studies employ silver nanoparticles (AgNPs) as plasmon cores, but the localized surface plasmon resonance (LSPR) wavelength tuning range of AgNPs is narrow, limiting their adaptability to different excitation wavelengths. Secondly, precise control over MOF assembly is insufficient, making it difficult to achieve synergistic optimization between the MOF structure and AgNWs. Therefore, developing a novel AgNWs@MOF composite SERS substrate that combines high sensitivity, high selectivity, excellent stability, and a simple preparation process has significant scientific research value and broad application prospects. Summary of the Invention

[0005] Given the current problems of low reliability and low efficiency in the detection of small molecule pollutants and dye pollutants, the purpose of this invention is to provide an AgNWs@MOF composite SERS substrate, its preparation method, and its application for rapid and sensitive detection of small molecule pollutants and dye pollutants, thereby providing effective data support for water quality status assessment.

[0006] This invention is achieved through the following technical solution:

[0007] In a first aspect, this application provides a method for preparing an AgNWs@MOF composite SERS substrate, comprising the following steps:

[0008] Silver nanowires were synthesized using a solvothermal method.

[0009] A metal-organic framework was loaded onto the silver nanowires by a room-temperature static loading method to form a composite material; the silver nanowires and the metal-organic framework were combined to form a tandem structure.

[0010] The composite material was centrifuged, washed, and dried to obtain a silver nanowire-supported metal-organic framework SERS substrate.

[0011] In one specific embodiment, the metal source of the metal-organic framework includes a cobalt source;

[0012] And / or the ligands of the metal-organic framework include 2-methylimidazole.

[0013] In one specific embodiment, the cobalt source includes cobalt nitrate hexahydrate.

[0014] In one specific embodiment, the method for synthesizing the silver nanowires includes the following steps:

[0015] Sodium chloride is dissolved in ethylene glycol to prepare solution A;

[0016] Dissolve silver nitrate in ethylene glycol to prepare solution B. After it is completely dissolved, add solution A and stir until homogeneous.

[0017] Polyvinylpyrrolidone was dissolved in ethylene glycol to prepare solution C;

[0018] Add solution C to the mixture of solution A and solution B, then transfer it to a high-pressure reactor and place it in an oven to react;

[0019] After the reaction was completed, the supernatant was removed by washing and centrifugation, and the resulting precipitate was silver nanowires.

[0020] In one specific embodiment, using a cobalt source as the metal source, the method for loading the silver nanowires onto the metal-organic framework includes the following steps:

[0021] Silver nanowires were dispersed in methanol to obtain a silver nanowire-methanol solution;

[0022] Polyvinylpyrrolidone was dissolved in methanol to obtain solution G;

[0023] Cobalt nitrate hexahydrate was dissolved in methanol to obtain solution H;

[0024] 2-Methylimidazole was dissolved in methanol to obtain solution I;

[0025] Disperse the silver nanowire-methanol solution in methanol, then add solution G, solution H and solution I in sequence, mix well and let stand;

[0026] After settling, the supernatant was removed by centrifugation, and the mixture was then washed with methanol and ethanol in sequence, followed by drying to obtain a material with a metal-organic framework supported by silver nanowires.

[0027] Secondly, this application provides an AgNWs@MOF composite SERS substrate, which is prepared using any of the preparation methods described above.

[0028] Thirdly, this application provides an application of the above-mentioned AgNWs@MOF composite SERS substrate, including its use for the detection of small molecule contaminants and dye contaminants, comprising the following steps:

[0029] The AgNWs@MOF composite SERS substrate described above is mixed with the target analyte or a standard solution containing the analyte to undergo an adsorption reaction; wherein the adsorption reaction time is 10 minutes; and / or the detection method described above has a detection limit of 10 for p-aminothiophenol. -8 mol / L.

[0030] The resulting mixture was subjected to surface-enhanced Raman spectroscopy to obtain the SERS signal.

[0031] Qualitative and quantitative analysis of the target analyte is performed based on the characteristic peak intensities in the SERS signal.

[0032] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0033] (1) The powder material of silver nanowire loaded metal-organic framework in SERS substrate prepared by the method of the present invention has a tandem morphology. The metal-organic framework (MOF) structure in the silver nanowire loaded metal-organic framework can enhance the adsorption capacity of target pollutants (such as p-aminothiophenol), effectively capture low concentration analytes, and achieve sensitive detection.

[0034] (2) The silver nanowires in the SERS substrate prepared by the method of the present invention provide abundant local surface plasmon resonance "hot spots", which significantly enhance the SERS signal.

[0035] (3) The SERS substrate organically bound silver nanowires prepared by the method of the present invention exhibit superior SERS performance due to the hot spot enhancement effect and the high adsorption performance of the metal-organic framework.

[0036] (4) The SERS substrate prepared by the method of the present invention can achieve highly sensitive detection of small molecule pollutants (p-aminothiophenol), with a detection limit of 10. –8 The mol / L concentration provides a rapid, simple, and sensitive analytical method for monitoring small molecule pollutants and dye pollutants, effectively overcoming the difficulties of traditional methods such as high requirements for the detection environment and complex composition. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a scanning electron microscope image of the composite material prepared in Example 1 of the present invention;

[0039] Figure 2 XRD pattern of the composite material prepared in Example 1 of this invention;

[0040] Figure 3 SERS images (at the same concentration) of the composite material prepared in Example 1 of this invention were obtained by testing different probes.

[0041] Figure 4 The image shows the SERS signal gradient of ZIF-67 loaded on silver nanowires prepared in Example 1 of this invention against different concentrations of p-aminothiophenol.

[0042] Figure 5 The SERS of the PATP probe was tested for different placement times of the composite material prepared in Example 1 of this invention;

[0043] Figure 6 This is the SERS diagram of ZIF-67 of the present invention;

[0044] Figure 7 This is a scanning electron microscope image of Ag Nws from the present invention;

[0045] Figure 8 This is the SERS diagram of Ag Nws of the present invention. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments. The illustrative embodiments and descriptions of this invention are only used to explain this invention and are not intended to limit this invention.

[0047] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other embodiments, well-known materials or methods have not been specifically described in order to avoid obscuring the invention.

[0048] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "an embodiment," "an example," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described herein, as well as the features of those different embodiments or examples.

[0049] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60–120 and 80–110 are listed for a specific parameter, it is understood that ranges of 60–110 and 80–120 are also expected. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0050] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), indicating that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0051] Example 1

[0052] This embodiment provides a method for preparing an AgNWs@MOF composite SERS substrate, wherein the metal source of the metal-organic framework used in this embodiment is cobalt nitrate hexahydrate.

[0053] The specific steps are as follows:

[0054] Synthesis of S1 and silver nanowires

[0055] S1-1. Dissolve 0.8g of polyvinylpyrrolidone in 20ml of ethylene glycol until fully dissolved;

[0056] S1-2. Dissolve 7 mg of sodium chloride in 20 ml of ethylene glycol until fully dissolved;

[0057] S1-3. Dissolve 0.6794g of silver nitrate in 20ml of ethylene glycol. After it is completely dissolved, add 20ml of the solution obtained in step S1-2 and stir thoroughly. Then add the solution obtained in step S1-1 and mix well.

[0058] S1-4. Transfer the solution obtained in step S1-3 to a 50ml high-pressure reactor, place it in an oven, and react at 160℃ for 2.5 hours.

[0059] S1-5. After the reaction is complete, centrifuge the product at 5000 r / min for 5 min and remove the supernatant.

[0060] S1-6. The precipitate was washed repeatedly with methanol, water, methanol, and methanol in sequence. After each wash, it was centrifuged at 5000 r / min for 5 min. Finally, the precipitate was dispersed in 30 ml of methanol to obtain a silver nanowire-methanol solution.

[0061] S2, Synthesis of ZIF-67 Metal-Organic Framework Loaded on Silver Nanowires

[0062] S2-1. Weigh 450 mg of polyvinylpyrrolidone and dissolve it in 10 mL of methanol by sonication.

[0063] S2-2. Weigh 300 mg of cobalt nitrate hexahydrate and dissolve it in 10 mL of methanol, then sonicate to dissolve.

[0064] S2-3. Weigh 508.5 mg of 2-methylimidazole and dissolve it in 10 mL of methanol, then sonicate to dissolve.

[0065] S2-4. Take 10 mL of silver nanowire-methanol solution, add 40 mL of methanol, and then add the solutions obtained in steps S2-1, S2-2 and S2-3 in sequence. Mix well and let stand for 12 h.

[0066] S2-5. After standing, centrifuge at 5000 r / min for 5 min to remove the supernatant;

[0067] S2-6. After the reaction is complete, wash the precipitate with methanol and ethanol in sequence, then centrifuge the product at 8000 r / min for 10 min and remove the supernatant.

[0068] S2-7. The obtained solid was dried in a vacuum oven at 60 ℃ and then ground to obtain a powder material of ZIF-67 supported on silver nanowires.

[0069] like Figure 1 The image shown is a scanning electron microscope (SEM) image of the silver nanowire-loaded ZIF-67 powder material prepared in this embodiment. As can be seen from the image, ZIF-67 is loaded on Ag nanowires to form a string structure, indicating the successful synthesis of the material.

[0070] like Figure 2 The image shows the X-ray diffraction pattern of the silver nanowire-loaded ZIF-67 powder material prepared in this embodiment. By comparing with the standard comparison card, it can be seen that the Ag nanowires have peaks at 38.1°, 44°, 64°, 77°, and 81°. Through the spectrum of ZIF-67, peaks can be seen at 7.27° and 12.7°, which proves the successful preparation of Ag@ZIF-67.

[0071] Example 2

[0072] This embodiment provides a method for detecting pollutants such as p-aminothiophenol, p-mercaptobenzoic acid, crystal violet, and methylene blue, using the silver nanowire-supported ZIF-6 material prepared in Example 1. A concentration of 10... -4 The specific steps for preparing a mol / L solution of p-aminothiophenol, p-mercaptobenzoic acid, crystal violet, and methylene blue are as follows:

[0073] Step 1: Weigh 0.1251 g of p-aminothiophenol (PATP) and 0.1542 g of p-mercaptobenzoic acid (MBA) and dissolve them in 10 mL of ethanol. Dissolve 0.4080 g of crystal violet (CV) and 0.3739 g of methylene blue (MB) in 10 mL of water. Mix thoroughly by sonication to prepare a solution of 10... -1 mol / L stock solution;

[0074] Step 2: Take 100 μL of each stock solution and add 9.9 mL of deionized water to obtain 10 -3 mol / L solution;

[0075] Step 3: Dilute with water step by step to obtain 10 -4 Up to 10 -8 mol / L series concentration solutions;

[0076] Step 4: Disperse 1 mg of the material obtained in Example 2 in 1 mL of water, sonicate, and mix 40 μL with an equal volume of different pollutant solutions of the same concentration for 10 min.

[0077] Step 5: Drop the mixture into the crucible, place it on the confocal Raman stage, and excite it with a 532 nm laser (30 mW power, integration time 10 s, integration once) to acquire the SERS signal.

[0078] like Figure 3 As shown, based on the changes in characteristic peaks at 1437 cm⁻¹ (+PATP), 1621 cm⁻¹ (+CV), 1502 cm⁻¹ (+MBA), and 1623 cm⁻¹ (+MB), this SERS substrate can achieve a range of 10... -4 A significant signal was detected at a concentration of mol / L, indicating that it has excellent SERS enhancement performance and is suitable for the detection of small molecule pollutants and dye pollutants.

[0079] Example 3

[0080] This embodiment provides a method for detecting p-aminothiophenol solution using the silver nanowire-supported ZIF-6 material prepared in Example 1. A concentration of 10... -3 Up to 10 -8 The specific steps are as follows: A mol / L solution of p-aminothiophenol was used as the target analyte.

[0081] Step 1: Weigh 0.1251 g of p-aminothiophenol and dissolve it in 10 mL of ethanol. Mix thoroughly by sonication to prepare a solution of 10 mL of ethanol. -1 mol / L stock solution;

[0082] Step 2: Take 100 μL of stock solution and add 9.9 mL of deionized water to obtain 10 -3mol / L solution;

[0083] Step 3: Dilute stepwise to obtain 10 -4 Up to 10 -8 mol / L series concentration solutions;

[0084] Step 4: Disperse 1 mg of the material obtained in Example 2 in 1 mL of water, sonicate, and mix 40 μL with an equal volume of probe solutions of different concentrations in the dark for 10 min.

[0085] Step 5: Drop the mixture into the crucible, place it on the confocal Raman stage, and excite it with a 532 nm laser (30 mW power, integration time 10 s, integration once) to acquire the SERS signal.

[0086] like Figure 4 As shown, based on the variation of the characteristic peak at 1437 cm⁻¹, this SERS substrate can achieve a range of 10... -8 A significant signal was still detected at a concentration of mol / L, indicating that it has excellent SERS enhancement performance and is suitable for the detection of the target pollutant p-aminothiophenol.

[0087] Example 4

[0088] This embodiment provides a method for evaluating the stability of SERS substrate materials, using the ZIF-6 material supported on silver nanowires prepared in Example 1 for testing. The concentration was 10... -4 The specific steps for using a mol / L p-aminothiophenol solution as the target analyte are as follows:

[0089] Step 1: Weigh 0.1251 g of p-aminothiophenol and dissolve it in 10 mL of ethanol. Mix thoroughly by sonication to prepare a solution of 10 mL of ethanol. -1 mol / L stock solution;

[0090] Step 2: Take 100 μL of stock solution and add 9.9 mL of deionized water to obtain 10 -3 mol / L solution;

[0091] Step 3: Dilute stepwise to obtain 10 -4 Concentration solution;

[0092] Step 4: Take 1 mg of each of the materials obtained in Example 2 but with different storage times (freshly prepared material, material left in air for 5 months, and material left in air for 10 months), disperse them in 1 mL of water, sonicate, and take 40 μL of each material with an equal volume concentration of 10. -4 Mix the mol / L p-aminothiophenol solution for 10 min;

[0093] Step 5: Drop the mixture into the crucible, place it on the confocal Raman stage, and excite it with a 532 nm laser (30 mW power, integration time 10 s, integration once) to acquire the SERS signal.

[0094] like Figure 5 As shown, based on the change in the characteristic peak at 1437 cm⁻¹, this SERS substrate can still maintain its properties after being stored in air for 10 months. -4 A significant signal was detected at a concentration of mol / L, indicating that it has excellent SERS enhancement performance as well as good stability, making it suitable for SERS detection.

[0095] Comparative Example 1

[0096] This comparative example provides a method for detecting small molecule pollutants and dye pollutants using ZIF-67 material, which is free of silver nanowires. A concentration of 10... -4 The specific steps for preparing a mol / L p-aminothiophenol solution are as follows:

[0097] Step 1: Weigh 0.1251 g of p-aminothiophenol and dissolve it in 10 mL of ethanol. Mix thoroughly by sonication to prepare a solution of 10 mL of ethanol. -1 mol / L stock solution;

[0098] Step 2: Take 100 μL of stock solution and add 9.9 mL of deionized water to obtain 10 -3 mol / L solution;

[0099] Step 3: Dilute stepwise to obtain 10 -4 Concentration solution;

[0100] Step 4: Disperse 1 mg of ZIF-67 material in 1 mL of water, sonicate, and take 40 μL. Mix with an equal volume of 10... - 4 Mix the mol / L p-aminothiophenol solution for 10 min;

[0101] Step 5: Drop the mixture into the crucible and acquire the SERS signal under the same Raman detection conditions as in Example 2.

[0102] like Figure 6 As shown, based on the changes in characteristic peaks, no obvious signal can be detected in this comparative material.

[0103] Comparative Example 2

[0104] This comparative example provides a method for detecting small molecule pollutants and dye pollutants using silver nanowire materials, specifically materials that do not support metal-organic frameworks. A concentration of 10... -4The specific steps for preparing a mol / L p-aminothiophenol solution are as follows:

[0105] Step 1: Weigh 0.1251 g of p-aminothiophenol and dissolve it in 10 mL of ethanol. Mix thoroughly by sonication to prepare a solution of 10 mL of ethanol. -1 mol / L stock solution;

[0106] Step 2: Take 100 μL of stock solution and add 9.9 mL of deionized water to obtain 10 -3 mol / L solution;

[0107] Step 3: Dilute stepwise to obtain 10 -4 Concentration solution;

[0108] Step 4: Take 1 mL of silver nanowire-methanol solution, sonicate it, and then take 40 μL of the solution. Mix it with an equal volume of 10... -4 Mix the mol / L p-aminothiophenol solution for 10 min;

[0109] Step 5: Drop the mixture into the crucible and acquire the SERS signal under the same Raman detection conditions as in Example 2.

[0110] like Figure 7 As shown in the scanning electron microscope image, segments of Ag nanowires with uniform thickness were synthesized, demonstrating the successful synthesis of the comparative material.

[0111] like Figure 8 As shown, based on the changes in the spectrum, it seems that obvious characteristic signals can be detected. However, since the material needs to be dispersed in methanol to maintain a stable and dispersed morphology, this dispersion condition will interfere with SERS detection. Therefore, this comparative material is not suitable for direct use in SERS detection.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for preparing an AgNWs@MOF composite SERS substrate, characterized in that, Includes the following steps: Silver nanowires were synthesized using a solvothermal method. A metal-organic framework is loaded onto the silver nanowires by a room temperature static method or a solvothermal method to form a composite material; the silver nanowires and the metal-organic framework are combined to form a tandem structure. The composite material was centrifuged, washed, and dried to obtain an AgNWs@MOF composite SERS substrate.

2. The method for preparing an AgNWs@MOF composite SERS substrate according to claim 1, characterized in that, The metal source of the metal-organic framework includes a cobalt source; And / or the ligands of the metal-organic framework include 2-methylimidazole.

3. The method for preparing an AgNWs@MOF composite SERS substrate according to claim 2, characterized in that, The cobalt source includes cobalt nitrate hexahydrate.

4. The method for preparing an AgNWs@MOF composite SERS substrate according to claim 1, characterized in that, The method for synthesizing the silver nanowires includes the following steps: Sodium chloride is dissolved in ethylene glycol to prepare solution A; Dissolve silver nitrate in ethylene glycol to prepare solution B. After it is completely dissolved, add solution A and stir until homogeneous. Polyvinylpyrrolidone was dissolved in ethylene glycol to prepare solution C; Add solution C to the mixture of solution A and solution B, then transfer it to a high-pressure reactor and place it in an oven to react; After the reaction was completed, the supernatant was removed by washing and centrifugation, and the resulting precipitate was silver nanowires.

5. The method for preparing an AgNWs@MOF composite SERS substrate according to claim 2, characterized in that, The method of loading silver nanowires onto the metal-organic framework using a cobalt source as the metal source includes the following steps: Silver nanowires were dispersed in methanol to obtain a silver nanowire-methanol solution; Polyvinylpyrrolidone was dissolved in methanol to obtain solution G; Cobalt nitrate hexahydrate was dissolved in methanol to obtain solution H; 2-Methylimidazole was dissolved in methanol to obtain solution I; Disperse the silver nanowire-methanol solution in methanol, then add solution G, solution H and solution I in sequence, mix well and let stand; After settling, the supernatant was removed by centrifugation, and the mixture was then washed with methanol and ethanol in sequence, followed by drying to obtain a material with a metal-organic framework supported by silver nanowires.

6. An AgNWs@MOF composite SERS substrate, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 5.

7. An application of the SERS substrate of silver nanowire-supported metal-organic framework as described in claim 6, characterized in that, Including detection for efficient and sensitive SERS.

8. A highly efficient and sensitive SERS detection method for probes, characterized in that, Includes the following steps: The AgNWs@MOF composite SERS substrate described in claim 6 was mixed with a standard solution containing small molecule pollutants and dye pollutants to carry out an adsorption reaction. The resulting mixture was subjected to surface-enhanced Raman spectroscopy to obtain the SERS signal.

9. The method for detecting small molecule pollutants and dye pollutants according to claim 8, characterized in that, The analytes include p-aminothiophenol.

10. The method for detecting small molecule pollutants and dye pollutants according to claim 8, characterized in that, The Raman detection uses a laser excitation wavelength of 532nm or 633nm.

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