Degradable SERS substrate and preparation method thereof

Abstract

The invention belongs to the technical field of surface enhanced Raman scattering, and particularly discloses a degradable SERS (Surface Enhanced Raman Scattering) substrate and a preparation method thereof.The preparation method comprises the steps that a cellulose acetate solution with the concentration larger than 12% w / v is prepared into a fiber pad through an electrostatic spinning technology; dropwise adding a HAuCl4 or AgNO3 solution to the surface of the fiber pad; and irradiating the metal salt solution on the surface of the fiber pad by using an ultraviolet lamp to obtain the SERS substrate. Compared with the prior art, the preparation method has the advantages that renewable and degradable cellulose acetate is prepared into the fiber pad by utilizing an electrostatic spinning technology, the specific surface area is increased, the surface of cellulose acetate is modified with metal nanoparticles based on the synergistic reduction capability of ultraviolet light and cellulose acetate, and the detection sensitivity of SERS is improved. Therefore, the method provided by the invention has a wide prospect and potential in the field of SERS (Surface Enhanced Raman Scattering).

Description

Technical Field

[0001] The invention relates to the technical field of surface enhanced Raman scattering, in particular to a degradable SERS substrate and a preparation method thereof. Background Art

[0002] As a non-destructive, rapid and highly sensitive spectral analysis technology, surface enhanced Raman scattering (SERS) technology can identify the structural characteristics and material composition information of the molecules to be tested, and has shown wide application potential in many fields such as medical testing, food safety monitoring, and environmental pollutant detection. However, traditional SERS substrate materials often use potentially toxic or non-degradable materials, which to a certain extent limits the further promotion and application of SERS technology, especially in today's society that pursues environmental protection and sustainable development. At present, biodegradable materials have attracted widespread attention in the development of SERS substrates. Among them, cellulose acetate, as a new type of renewable and degradable material, has good biocompatibility and processability, and shows great application prospects in the preparation of SERS substrates. The application of cellulose acetate in the preparation of SERS substrates can not only significantly improve the environmental performance of SERS technology and effectively reduce its potential impact on the ecological environment, but also promote the practical application of SERS technology in the fields of environmental protection and sustainable development.

[0003] Therefore, it is urgent to develop a degradable SERS substrate based on cellulose acetate. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a degradable SERS substrate and a preparation method thereof.

[0005] To achieve the above object, the present invention is implemented according to the following technical solutions: One of the purposes of the present invention is to provide a method for preparing a degradable SERS substrate, comprising the following steps: S1, preparing a fiber mat from a cellulose acetate solution having a concentration greater than 12% w / v by electrospinning technology; S2, adding HAuCl4 or AgNO3 solution to the surface of the fiber mat; S3. Use ultraviolet light to irradiate the metal salt solution on the surface of the fiber mat to obtain a SERS substrate.

[0006] Furthermore, the amount of HAuCl4 or AgNO3 solution added to the fiber mat is 1-10 μL / cm 2 .

[0007] Furthermore, the concentration of the HAuCl4 or AgNO3 solution is 6-24 mM.

[0008] Furthermore, the power density of the ultraviolet lamp is 40-66 mW / cm 2 , the irradiation time is 5-25min.

[0009] The second objective of the present invention is to provide a degradable SERS substrate prepared by the above method.

[0010] Compared with the prior art, the present invention uses electrospinning technology to prepare renewable and degradable cellulose acetate into a fiber mat, thereby increasing the specific surface area, and based on the synergistic reduction ability of ultraviolet light and cellulose acetate, metal nanoparticles are modified on the surface of cellulose acetate, thereby improving the detection sensitivity of SERS. Therefore, the method proposed in this application has broad prospects and potential in the field of SERS. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A scanning electron microscope image of a SERS substrate provided in an embodiment of the present application is shown; Figure 2 The ultraviolet-visible absorption spectrum of the SERS substrate provided in the 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 M's Rhodamine 6G is the Raman spectrum of the detection molecule. DETAILED DESCRIPTION

[0012] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the invention.

[0013] Example 1

[0014] Step 1, using electrospinning technology to prepare a fiber mat from a 12% w / v cellulose acetate solution; Step 2: Cut the fiber mat into 1×1cm 2 A 12 mM HAuCl4 solution with a volume of 10 μL was added dropwise to the surface; Step 3: Use a power density of 53mW / cm 2 The HAuCl4 solution on the surface of the fiber mat was irradiated with an ultraviolet lamp for 10 minutes to obtain a SERS substrate sample 1.

[0015] Example 2

[0016] The difference from Example 1 is that a 10 μL AgNO 3 solution is dripped onto the surface of the fiber mat, and finally a SERS substrate sample 2 is prepared.

[0017] Taking SERS substrate sample 1 as an example, SERS test was performed: First, the morphology of the SERS substrate was characterized using a scanning electron microscope, and the following results were obtained: Figure 1 Scanning electron microscopy image of the SERS substrate shown. Figure 1 The SERS substrate is shown to be composed of fibers loaded with gold nanoparticles.

[0018] Secondly, the UV-visible absorption spectrum of SERS substrate sample 1 was characterized, and the following Figure 2 UV-visible absorption spectrum of the SERS substrate shown. Figure 2 The figure shows that there is an obvious peak at a wavelength of 530 nm, indicating that the gold nanoparticles are successfully modified on the surface of the cellulose acetate pad.

[0019] Finally, the SERS test was performed on the SERS substrate sample 1, and the following results were obtained: Figure 3 Raman spectrum of the SERS substrate shown. Figure 3 Displayed at 610, 772, 1182, 1310, 1361, 1504, 1573 and 1648 cm -1 There is a characteristic Raman vibration peak of Rhodamine 6G at the surface, indicating that the SERS substrate has high sensitivity.

[0020] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. All technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing a degradable SERS substrate, characterized in that: The following steps are involved: S1, preparing a fiber mat from a cellulose acetate solution having a concentration greater than 12% w / v by electrospinning technology; S2, adding HAuCl4 or AgNO3 solution to the surface of the fiber mat; S3. Use ultraviolet light to irradiate the metal salt solution on the surface of the fiber mat to obtain a SERS substrate.

2. The method for preparing a degradable SERS substrate according to claim 1, characterized in that: The amount of HAuCl4 or AgNO3 solution added to the fiber mat is 1-10 μL / cm 2 .

3. The method for preparing a degradable SERS substrate according to claim 1, characterized in that: The concentration of the HAuCl4 or AgNO3 solution is 6-24 mM.

4. The method for preparing a degradable SERS substrate according to claim 1, characterized in that: The power density of the UV lamp is 40-66 mW / cm 2 , the irradiation time is 5-25min.

5. A degradable SERS substrate prepared by the method according to any one of claims 1 to 4.

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