Surface enhanced raman scattering detection substrate, preparation method and application thereof

Abstract

A surface-enhanced Raman scattering (SERS) detection substrate comprises a polyvinylidene fluoride (PVDF) layer and a nanocomposite functional layer with a thickness of 10 nm to 100 nm. The nanocomposite functional layer is disposed on the PVDF layer and includes graphite-phase carbon nitride nanosheets and gold nanorods. The present invention also provides a method for preparing the SERS detection substrate, comprising performing a hydrophilic surface treatment on a PVDF film to obtain a PVDF layer; depositing graphite-phase carbon nitride nanosheets on the surface of the PVDF layer; and depositing gold nanorods on the graphite-phase carbon nitride nanosheets and the PVDF layer, thereby forming a nanocomposite functional layer with a thickness of 10 nm to 100 nm. The present invention also provides an application of the above-described SERS detection substrate in water pollution monitoring.

Claims

1. A surface-enhanced Raman scattering detection substrate, comprising: a polyvinylidene fluoride (PVDF) layer; and a nanocomposite functional layer disposed on the PVDF layer, comprising a plurality of graphitic carbon nitride nanosheets deposited on the surface of the PVDF layer, and a plurality of gold nanorods deposited on the graphitic carbon nitride nanosheets and the PVDF layer, wherein the thickness of the nanocomposite functional layer is in the range of 10 nm to 100 nm.

2. The surface-enhanced Raman scattering detection substrate as described in claim 1, wherein, The average long axis dimension of these gold nanorods ranges from 50 nm to 80 nm, and the average short axis dimension ranges from 10 nm to 20 nm.

3. The surface-enhanced Raman scattering detection substrate as described in claim 1, wherein, The surface plasma resonance absorption wavelength of the long axis of these gold nanorods is 530 nm, and the surface plasma resonance absorption wavelength of the short axis is 780 nm.

4. The surface-enhanced Raman scattering detection substrate as described in claim 1, wherein, The polyvinylidene fluoride layer includes multiple pores with a diameter of 0.22 μm.

5. The surface-enhanced Raman scattering detection substrate as described in claim 1, wherein, The polyvinylidene fluoride layer is a polyvinylidene fluoride layer with a hydrophilic surface treatment.

6. A method for preparing a surface-enhanced Raman scattering detection substrate, comprising the following steps: (a) performing a hydrophilic surface treatment on a polyvinylidene fluoride (PVDF) film with an aqueous solution of alkyl alcohol and sodium chloride to obtain a PVDF layer; (b) using the PVDF layer to vacuum filter a mixture comprising a plurality of graphitic carbon nitride nanosheets, so that the graphitic carbon nitride nanosheets are deposited on the surface of the PVDF layer to obtain a semi-finished product; and (c) using the semi-finished product to vacuum filter a colloidal solution comprising a plurality of gold nanorods, so that the gold nanorods are deposited on the graphitic carbon nitride nanosheets and the PVDF layer, thereby allowing the graphitic carbon nitride nanosheets and the gold nanorods to form a nanocomposite functional layer, wherein the thickness of the nanocomposite functional layer is in the range of 10 nm to 100 nm.

7. The method for fabricating a surface-enhanced Raman scattering detection substrate as described in claim 6, wherein, The graphite-phase carbon nitride nanosheets in the mixture are obtained by calcining a urea precursor at a temperature ranging from 500°C to 550°C.

8. The method for fabricating a surface-enhanced Raman scattering detection substrate as described in claim 6, wherein, The alkyl alcohol is selected from methanol or ethanol.

9. An application of a surface-enhanced Raman scattering (SERS) detection substrate as described in any one of claims 1 to 5 in water pollution monitoring, comprising: dropping a water sample containing pollutants onto a SERS detection substrate as described in any one of claims 1 to 5, so that the pollutants are adsorbed and concentrated by the polyvinylidene fluoride (PVDF) layer of the SERS detection substrate; performing SERS spectroscopy on the SERS detection substrate adsorbing the pollutants using a Raman spectrometer to obtain a fingerprint spectrum of the pollutants; and irradiating the SERS detection substrate adsorbing the pollutants with ultraviolet light or visible light, thereby photocatalytically degrading the pollutants by the nanocomposite functional layer of the SERS detection substrate to remove the pollutants.

10. The application as described in claim 9, wherein, The pollutant is selected from Rhodamine 6G, Malachite Green, Methylene Blue, or Paraquat.

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