阅读说明：本技术 一种包覆有氧化石墨烯的纳米金管复合薄膜及其制备方法 (Graphene oxide-coated nano-gold tube composite film and preparation method thereof ) 是由 林永兴 汪良 何辉 丁泽玄 田兴友 于 2019-11-13 设计创作，主要内容包括：本发明提供了一种包覆有氧化石墨烯的纳米金管复合薄膜及其制备方法,涉及纳米复合材料领域,所述纳米金管复合薄膜由中空管状纳米金膜层和氧化石墨烯层组成；所述中空管状纳米金膜层的厚度为60-150nm；所述氧化石墨烯层的厚度为0.6-12nm,本发明中金纳米颗粒相比较其他金属颗粒而言,具有更高的检测灵敏度,因而获得的拉曼增强效果更好,氧化石墨烯作为保护层可以防止金纳米颗粒的氧化,提高基底的稳定性,解决了其单独作为拉曼增强基底的不足。(The invention provides a nanogold tube composite film coated with graphene oxide and a preparation method thereof, and relates to the field of nanocomposite materials, wherein the nanogold tube composite film consists of a hollow tubular nanogold film layer and a graphene oxide layer; the thickness of the hollow tubular nano gold film layer is 60-150 nm; the thickness of the graphene oxide layer is 0.6-12nm, and compared with other metal particles, the gold nanoparticles have higher detection sensitivity, so that the obtained Raman enhancement effect is better, the graphene oxide serving as a protective layer can prevent the gold nanoparticles from being oxidized, the stability of the substrate is improved, and the defect that the graphene oxide layer is independently used as the Raman enhancement substrate is overcome.)

1. The graphene oxide-coated nano gold tube composite film is characterized by consisting of a hollow tubular nano gold film layer and a graphene oxide layer;

the thickness of the hollow tubular nano gold film layer is 60-150 nm;

the thickness of the graphene oxide layer is 0.6-12 nm.

2. The nanogold tube composite film according to claim 1, wherein the nanogold tube composite film is composed of a hollow tubular nanogold film layer and a graphene oxide layer;

the thickness of the hollow tubular nano gold film layer is 70 nm;

the thickness of the graphene oxide layer is 10 nm.

3. The preparation method of the nano-gold tube composite film as claimed in claim 1 or 2, which comprises the following steps:

(1) dissolving a polymer by using a solvent, and stirring for 10-15h to obtain a spinning solution;

(2) controlling the temperature at 18-25 ℃, the humidity at 50-60%, the positive voltage of electrospinning at 18-25KV, the negative voltage at 0KV, the spinning distance at 20cm, the spinning speed at 0.2-0.6mm/min, and directly spinning the spinning solution on a receiving plate to form a nanofiber film;

(3) taking down the nanofiber membrane, and evaporating a layer of gold nanoparticles on the surface of the nanofiber membrane by using a vacuum evaporation method to obtain a gold-plated nanofiber membrane;

(4) placing the gold-plated nano-fiber film in formic acid, standing for 5-10h, dissolving to remove nano-fibers, filtering, and drying at room temperature to obtain a hollow tubular nano-gold film;

(5) adding graphene oxide into deionized water, and performing ultrasonic dispersion to form a graphene oxide solution;

(6) and coating the graphene oxide solution on the surface of the hollow tubular nano gold film by adopting a conventional liquid drop coating method, and airing at room temperature to obtain the graphene oxide coated nano gold tube composite film.

4. The method for preparing a composite film of a nano-gold tube according to claim 3, wherein in the step (1), the polymer is any one of PA6, PA66, PAN and PVA, and the solvent is any one of formic acid, N-dimethylformamide and water.

5. The method for preparing a nano-gold tube composite film according to claim 3, wherein the solid-to-liquid ratio of the polymer to the solvent in the step (1) is 1: 6-35.

6. The method for preparing a nano-gold tube composite film according to claim 3, wherein the thickness of the nano-fiber film in the step (2) is not less than 6 μm.

7. The method for preparing a composite film of a nano-gold tube as claimed in claim 3, wherein the current is 30-50mA for 6-15min during vacuum evaporation in step (3).

8. The method of claim 3, wherein the concentration of the solution in the step (5) is 0.001-0.1 mg/ml.

9. A three-dimensional flexible raman-enhanced substrate, wherein the three-dimensional flexible raman-enhanced substrate is prepared from the nanogold tube composite film according to claim 1 or 2.

10. Use of the three-dimensional flexible raman-enhanced substrate of claim 9 to obtain raman-enhanced spectra.

Technical Field

The invention relates to the field of nano composite materials, in particular to a graphene oxide coated nano gold tube composite film and a preparation method thereof.

Background

In recent years, with the rapid development of nanotechnology, metal nanostructures have been widely used in fields such as biomarkers and imaging, catalysis, electronic and information engineering, sensors, and surface enhanced raman spectroscopy. The nonlinear optical research of the nano gold particle film also draws high attention internationally because the incident light can generate strong near-field surface plasmon resonance enhancement effect among the metal particles and has 10²-10⁶And the local area enhancement effect is multiplied.

Graphene belongs to sp²The two-dimensional lamellar structure formed by the hybrid carbon contains a large amount of conjugated electrons and specific surface area, is easy to adsorb molecules and realize charge transfer, enhances Raman signals, is a typical material for realizing Raman enhancement effect by a chemical enhancement mechanism, and greatly enriches the selectivity of a Raman enhancement substrate. But the graphene enhancement factor alone is not high enough based on a chemical enhancement mechanism, and cannot be applied to analysis and detection alone. The advantages of a large number of functional groups on the surface of the graphene oxide, large specific surface area and the like are utilized, and pollutants can be adsorbed and enriched. On the other hand, the secondary excitation or amplification of certain wavelengths can be realized by utilizing the synergistic hybridization effect of the carbon plane six-membered ring and metal conduction band electrons on Raman optical signals. Therefore, when the graphene oxide is compounded with certain metals (such as gold, silver, copper and the like), the original surface enhanced Raman activity and catalytic activity of the metal nanoparticles are remarkably enhanced due to the synergistic effect between the graphene oxide and the metals.

The Chinese patent with patent number 201711098588.9, applied to Shandong university of teachers, discloses a graphene oxide/silver nanoparticle/pyramid PMMA three-dimensional flexible Raman enhanced substrate and a preparation method and application thereof, the pyramid-shaped silicon substrate is prepared by a wet etching process, a silver film is plated on the surface of the silicon substrate by a thermal evaporation method, silver nanoparticles are obtained by annealing in a tube furnace, PMMA is coated on the pyramid silicon with the silver nanoparticles, the pyramid-shaped PMMA/silver nanoparticle/pyramid-shaped silicon substrate is put in a sodium hydroxide solution to corrode a silicon wafer, then the residual sodium hydroxide solution is washed away, the silicon substrate is inverted and transferred to a glass sheet to obtain the silver nanoparticles/pyramid-shaped PMMA, and then the graphene oxide solution is coated on the surface of the silver nanoparticles/pyramid-shaped PMMA and dried to obtain the graphene oxide/silver nanoparticle/pyramid-shaped PMMA. The three-dimensional flexible Raman enhancement substrate disclosed by the invention combines the graphene oxide, the silver nanoparticles and the pyramid-shaped PMMA, so that the advantages of the graphene oxide, the silver nanoparticles and the pyramid-shaped PMMA can be fully exerted, and a Raman enhancement signal with high sensitivity, good stability and high uniformity can be obtained;

the biggest difference between the invention and the invention is that the invention adopts a hollow tubular nano gold film and graphene oxide to compound, and the patent adopts graphene oxide/silver nano particles/pyramid PMMA to compound, the applicant thinks that firstly, the surface of nano gold particles can strengthen Raman spectrum more than the surface of nano silver particles, and the surface resonance band of nano gold particles is more sensitive than nano silver particles, so the nano gold particles are better choice than nano silver particles, and in the patent, after PMMA is coated on the pyramid silicon with silver nano particles, the pyramid silicon substrate is put in sodium hydroxide solution to corrode the silicon wafer, and at the moment, the sodium hydroxide solution can generate adverse effect on the surface appearance of PMMA, thereby influencing the stability of Raman enhanced signals.

Disclosure of Invention

Aiming at the defects of the prior art, the technical problem to be solved by the invention is to provide the nanogold composite film coated with the graphene oxide and the preparation method thereof, the prepared nanogold composite film has the advantages of metal nanoparticles and the graphene oxide material as a Raman enhancement substrate, the preparation method is simple and low in cost, the batch preparation of the composite film can be realized, and the obtained Raman enhancement signal has high sensitivity, good stability, high uniformity and good application prospect.

In order to achieve the purpose, the invention adopts the following technical scheme:

a nano-gold tube composite film coated with graphene oxide consists of a hollow tubular nano-gold film layer and a graphene oxide layer;

the thickness of the hollow tubular nano gold film layer is 60-150 nm;

the thickness of the graphene oxide layer is 0.6-12 nm.

Further, the nanogold tube composite film consists of a hollow tubular nanogold film layer and a graphene oxide layer;

the thickness of the hollow tubular nano gold film layer is 70 nm;

the thickness of the graphene oxide layer is 10 nm.

The preparation method of the nano gold tube composite film specifically comprises the following steps:

(1) dissolving a polymer by using a solvent, and stirring for 10-15h to obtain a spinning solution;

(2) controlling the temperature at 18-25 ℃, the humidity at 50-60%, the positive voltage of electrospinning at 18-25KV, the negative voltage at 0KV, the spinning distance at 20cm, the spinning speed at 0.2-0.6mm/min, and directly spinning the spinning solution on a receiving plate to form a nanofiber film;

(3) taking down the nanofiber membrane, and evaporating a layer of gold nanoparticles on the surface of the nanofiber membrane by using a vacuum evaporation method to obtain a gold-plated nanofiber membrane;

(4) placing the gold-plated nano-fiber film in formic acid, standing for 5-10h, dissolving to remove nano-fibers, filtering, and drying at room temperature to obtain a hollow tubular nano-gold film;

(5) adding graphene oxide into deionized water, and performing ultrasonic dispersion to form a graphene oxide solution;

(6) and coating the graphene oxide solution on the surface of the hollow tubular nano gold film by adopting a conventional liquid drop coating method, and airing at room temperature to obtain the graphene oxide coated nano gold tube composite film.

Further, in the step (1), the polymer is any one of PA6, PA66, PAN and PVA, and the solvent is any one of formic acid, N-dimethylformamide and water.

Further, the solid-to-liquid ratio of the polymer to the solvent in the step (1) is 1: 6-35.

Further, the thickness of the nanofiber membrane in the step (2) is more than or equal to 6 microns.

Further, when vacuum evaporation is carried out in the step (3), the current is 30-50mA, and the time is 6-15 min.

Further, the concentration of the solution in the step (5) is 0.001 to 0.1mg/ml, more preferably 0.01 to 0.1 mg/ml.

A three-dimensional flexible Raman enhancement substrate prepared by the nano-gold tube composite film.

The three-dimensional flexible Raman enhancement substrate is applied to obtaining Raman enhancement spectrum.

Compared with the prior art, the invention has the beneficial effects that:

the graphene oxide-coated nano gold tube composite film provided by the invention combines graphene oxide and gold nanoparticles, and can give full play to the advantages of the graphene oxide and the gold nanoparticles: compared with graphene, the graphene oxide serving as a derivative of graphene has better biocompatibility and chemical stability, so that the graphene oxide is very beneficial to adsorption of biomolecules, and due to functional groups on the surface of the graphene oxide, the graphene oxide is easier to realize specific modification on the surface of the graphene oxide, so that specific detection on the biomolecules can be realized; compared with other metal particles, the gold nanoparticles have higher detection sensitivity, so that the obtained Raman enhancement effect is better, the oxidized graphene serving as a protective layer can prevent the gold nanoparticles from being oxidized, the stability of the substrate is improved, the defect that the oxidized graphene serves as the Raman enhancement substrate alone is overcome, and the Raman enhancement signal with high sensitivity, good stability and high uniformity can be obtained. The preparation method is non-toxic and pollution-free, is simple to operate, and omits complicated steps.

Drawings

FIG. 1 is a scanning electron micrograph of the gold-plated nanofiber film prepared in example 1.

FIG. 2 is a scanning electron microscope image of the composite film of the nano-gold tube prepared in example 1.

FIG. 3 shows the detection concentration of 10 using the nano-gold tube composite thin film and the nano-gold tube thin film prepared in example 1 and comparative example as the surface enhanced Raman substrate^-8And (3) a Raman spectrogram of the mol/L rhodamine solution.

FIG. 4 is a sectional view of the composite film of the nano-gold tube prepared in example 1.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.