Preparation method of SERS (Surface Enhanced Raman Scattering) substrate based on degradable material

Abstract

The invention belongs to the technical field of surface enhanced Raman scattering, and particularly relates to a preparation method of an SERS (Surface Enhanced Raman Scattering) substrate based on a degradable material, which comprises the following steps: S1, mixing cellulose acetate powder with an acetic acid solution under magnetic stirring to obtain a cellulose acetate solution; s2, carrying out electrostatic spinning on the cellulose acetate solution by utilizing an electrostatic spinning technology to obtain an electrospun fiber; and S3, heating the electrospinning fiber at a high temperature, and plating a metal material on the surface of the heated electrospinning fiber to obtain the SERS substrate. The cellulose acetate used in the method is wide in source and low in cost, has good biodegradability and biocompatibility, can remarkably reduce negative effects on the environment and is suitable for large-scale production.

Description

Technical Field

[0001] The present application belongs to the technical field of surface enhanced Raman scattering, and in particular relates to a method for preparing a SERS substrate based on a degradable material. Background Art

[0002] Surface enhanced Raman spectroscopy has been widely used in many fields such as biomedicine, environmental monitoring and food safety due to its high sensitivity detection of various Raman-sensitive analytes. With the rapid development and diversification of surface enhanced Raman scattering (SERS) substrates, the material selection of SERS substrates has attracted much attention. At present, most SERS substrates rely on non-degradable or potentially toxic materials, which not only causes the discarded SERS substrates to take decades or even longer to completely degrade in the natural environment, but also poses a long-term and invisible threat to the environment. From the perspective of sustainable development, exploring and developing environmentally friendly, biodegradable "green" SERS substrates has become a current research trend. Summary of the invention

[0003] In view of this, the purpose of the present application is to provide a method for preparing a SERS substrate based on a degradable material. The cellulose acetate used is not only widely available and low in cost, but also has good biodegradability and biocompatibility, can significantly reduce the negative impact on the environment and is suitable for large-scale production.

[0004] The present application provides a method for preparing a SERS substrate based on a degradable material, comprising: S1, mixing cellulose acetate powder and acetic acid solution under magnetic stirring to obtain cellulose acetate solution; S2, electrospinning the cellulose acetate solution using an electrospinning technique to obtain electrospun fibers; S3, heating the electrospun fiber at a high temperature, and coating a metal material on the surface of the heated electrospun fiber to obtain a SERS substrate.

[0005] Furthermore, the magnetic stirring time in step S1 is 12-18 hours, and the reaction condition is room temperature.

[0006] Furthermore, the concentration of the cellulose acetate solution in step S1 is 13-17% w / v.

[0007] Furthermore, the parameters of the electrospinning technology in step S2 are set as follows: The temperature is 20-30°C, the relative humidity is 30-50%, the voltage is 18-22 kV, and the flow rate of the cellulose acetate solution is 8-12 µL min -1 .

[0008] Furthermore, the inner diameter of the steel needle used in the electrospinning technology in step S2 is 0.51 mm.

[0009] Furthermore, the collector used in the electrospinning technology in step S2 is a drum collector with a rotation speed of 80-120 rpm.

[0010] Furthermore, the distance between the steel needle used in the electrospinning technology in step S2 and the drum collector is 10-20 cm.

[0011] Furthermore, the heating temperature in step S3 is 110-140° C. and the heating time is 5-15 min.

[0012] Furthermore, in step S3, the thickness of the metal material is 20-100 nm.

[0013] Furthermore, the metal material in step S3 includes: gold, silver, and copper.

[0014] Furthermore, after obtaining the SERS substrate, the method further comprises: The SERS substrate is subjected to SERS testing by the following steps: Step S4a, dropping 3 μL of rhodamine 6G solution onto the surface of the SERS substrate and drying under laboratory conditions; Step S4b: Use 633 nm laser as the excitation source, set the laser power to 4.75 mW, the exposure time to 10 s, the slit aperture to 50 µm, and collect 400-1800 cm under a 50x objective lens. -1 Spectra of the SERS substrate after drying in the range.

[0015] Furthermore, the concentration of the Rhodamine 6G solution in step S4a is 10 -4 -10 -8 M.

[0016] The present application provides a method for preparing a SERS substrate based on a degradable material. The cellulose acetate used is not only widely available and low in cost, but also has good biodegradability and biocompatibility, can significantly reduce the negative impact on the environment, and is suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A scanning electron microscope image of a SERS substrate provided in an embodiment of the present application is shown; Figure 2 An energy dispersion X-ray spectrum diagram of a SERS substrate provided in an embodiment of the present application is shown; Figure 3 The SERS substrate provided in the embodiment of the present application is shown in FIG. -4 -10-8 M's Rhodamine 6G is the Raman spectrum of the detection molecule. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the technical solution more clear, the technical solution is further described in detail below in conjunction with specific implementation methods. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the technical solution.

[0019] Cellulose acetate is a highly safe, biodegradable, non-toxic cellulose derivative with good thermal stability, high mechanical strength, strong hydrophobicity, etc. It is widely used in the fields of biopharmaceuticals, food packaging, etc. However, there are few studies on cellulose acetate in the field of SERS. Therefore, this application prepares a "green" SERS substrate based on cellulose acetate, which can promote scientific and technological progress while respecting and protecting the natural environment.

[0020] Embodiment 1

[0021] The present invention provides a method for preparing a SERS substrate based on a degradable material, comprising: Step 1: Mix cellulose acetate powder and acetic acid solution under magnetic stirring at room temperature for 12-18 hours to obtain a cellulose acetate solution with a concentration of 13-17% w / v.

[0022] Step 2: electrospinning the cellulose acetate solution using electrospinning technology to obtain electrospun fibers.

[0023] Among them, the parameters of the electrospinning technology are set as follows: The temperature is 20-30°C, the relative humidity is 30-50%, the voltage is 18-22 kV, and the flow rate of the cellulose acetate solution is 8-12 µL min -1 ; The inner diameter of the steel needle used is 0.51mm; the collector used is a roller collector with a rotation speed of 80-120rpm; and the distance between the steel needle and the roller collector is 10-20cm.

[0024] Step 3: heating the electrospun fiber at 110-140° C. for 5-15 min, and coating the surface of the heated electrospun fiber with a metal material having a thickness of 20-100 nm to obtain a SERS substrate.

[0025] Among them, metal materials include: gold, silver and copper.

[0026] Embodiment 2

[0027] Another method for preparing a SERS substrate based on a degradable material provided in an embodiment of the present application comprises: Step 1: Mix cellulose acetate powder and acetic acid solution under magnetic stirring at room temperature for 15 hours to obtain a cellulose acetate solution with a concentration of 13% w / v.

[0028] Step 2: electrospinning the cellulose acetate solution using electrospinning technology to obtain electrospun fibers.

[0029] Among them, the parameters of the electrospinning technology are set as follows: The temperature was 25°C, the relative humidity was 40%, the voltage was 18 kV, and the flow rate of the cellulose acetate solution was 10 µL min -1 ; The inner diameter of the steel needle used is 0.51 mm; the collector used is a roller collector with a rotation speed of 100 rpm; and the distance between the steel needle and the roller collector is 15 cm.

[0030] Step 3: heating the electrospun fiber at 140° C. for 10 min, and plating silver with a thickness of 80 nm on the surface of the heated electrospun fiber to obtain a SERS substrate.

[0031] After obtaining the SERS substrate, firstly, the morphology of the SERS substrate was characterized by scanning electron microscopy, and the following Figure 1 Scanning electron microscopy image of the SERS substrate shown. Figure 1 It is shown that the SERS substrate is composed of a continuous fiber structure.

[0032] Secondly, the structure of the SERS substrate was characterized by X-ray diffractometer, and the following Figure 2 Energy dispersive X-ray spectra of the SERS substrate shown. Figure 2 The figure shows the presence of silver on the surface of the SERS substrate, indicating that silver has been successfully modified on the surface of the electrospun fiber.

[0033] Finally, the SERS substrate is subjected to a SERS test by the following steps: Step 4a, adding 3 μL of rhodamine 6G solution to the surface of the SERS substrate and drying it under laboratory conditions; wherein the concentration of the rhodamine 6G solution is 10 -4 -10 -8 M.

[0034] Step 4b: Use 633 nm laser as the excitation source, set the laser power to 4.75 mW, the exposure time to 10 s, the slit aperture to 50 µm, and collect 400-1800 cm under a 50x objective lens. -1 Spectra of the SERS substrate after drying in the range.

[0035] Here, please see Figure 3 The SERS substrate shown is 10 -4 -10 -8M's Rhodamine 6G is the Raman spectrum of the detection molecule. Figure 3 It can be seen that at 610 cm -1 、772 cm -1 , 1182 cm -1 、1310 cm -1 、1361 cm -1 、1504 cm -1 、1573 cm -1 and 1648 cm -1 There is an obvious characteristic peak of Rhodamine 6G Raman vibration at the SERS substrate, indicating that the SERS substrate has high sensitivity. Moreover, the corresponding peak intensity decreases with the decrease of Rhodamine 6G concentration, indicating that the Raman intensity is directly related to the Rhodamine 6G concentration.

[0036] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, many changes can be made in the specific implementation methods and application scopes based on the ideas of the technical content. As long as these changes do not deviate from the concept of the present invention, they all fall within the scope of protection of this patent.

Claims

1. A method for preparing a SERS substrate based on a degradable material, characterized in that: The method comprises: S1, mixing cellulose acetate powder and acetic acid solution under magnetic stirring to obtain cellulose acetate solution; S2, electrospinning the cellulose acetate solution using an electrospinning technique to obtain electrospun fibers; S3, heating the electrospun fiber at a high temperature, and coating a metal material on the surface of the heated electrospun fiber to obtain a SERS substrate.

2. The method according to claim 1, characterized in that The magnetic stirring time in step S1 is 12-18 hours, and the reaction condition is room temperature.

3. The method according to claim 1, characterized in that The concentration of the cellulose acetate solution in step S1 is 13-17% w / v.

4. The method according to claim 1, characterized in that The parameters of the electrospinning technology in step S2 are set as follows: The temperature is 20-30°C, the relative humidity is 30-50%, the voltage is 18-22 kV, and the flow rate of the cellulose acetate solution is 8-12 µL min -1 .

5. The method according to claim 1, characterized in that The inner diameter of the steel needle used in the electrospinning technology in step S2 is 0.51 mm.

6. The method according to claim 1, characterized in that The collector used in the electrospinning technology in step S2 is a drum collector with a rotation speed of 80-120 rpm.

7. The method according to claim 5 or 6, characterized in that The distance between the steel needle used in the electrospinning technology in step S2 and the drum collector is 10-20 cm.

8. The method according to claim 1, characterized in that The heating temperature in step S3 is 110-140° C. and the heating time is 5-15 min.

9. The method according to claim 1, characterized in that The thickness of the metal material in step S3 is 20-100 nm.

10. The method according to claim 1, characterized in that The metal materials in step S3 include: gold, silver, and copper.

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