阅读说明：本技术 一种石墨烯/TiN-Ag复合材料及其制备方法 (graphene/TiN-Ag composite material and preparation method thereof ) 是由 高祥贵 于 2020-09-15 设计创作，主要内容包括：一种石墨烯/TiN-Ag复合材料,包括形成于硅片上利用聚乳酸微球排列形成的二维结构阵列模板,在该模板上交替沉积的TiN-Ag层和石墨烯层。制备石墨烯/TiN-Ag复合材料的步骤包括：一、利用聚乳酸微球通过自组装技术制备二维周期性结构阵列,得到聚乳酸微胶体球模板；二、旋涂TiN层和磁控溅射Ag层；三、电子回旋等离子体溅射沉积石墨烯层。本发明的一种石墨烯/TiN-Ag复合材料其中的石墨烯层和TiN-Ag层的复合作用,使得基底可以实现对于多种激发波长下的拉曼增强,一定程度上克服了基底对于激发光源的依赖性,拓宽了其拉曼分析应用范围。(A graphene/TiN-Ag composite material comprises a two-dimensional structure array template formed on a silicon chip by utilizing polylactic acid microspheres, and TiN-Ag layers and graphene layers alternately deposited on the template. The preparation method of the graphene/TiN-Ag composite material comprises the following steps: firstly, preparing a two-dimensional periodic structure array by utilizing polylactic acid microspheres through a self-assembly technology to obtain a polylactic acid micro-colloid sphere template; secondly, spin coating a TiN layer and a magnetron sputtering Ag layer; and thirdly, depositing the graphene layer by electron cyclotron plasma sputtering. The graphene layer and the TiN-Ag layer in the graphene/TiN-Ag composite material have the composite effect, so that the substrate can realize Raman enhancement under various excitation wavelengths, the dependence of the substrate on an excitation light source is overcome to a certain extent, and the Raman analysis application range of the substrate is widened.)

1. The graphene/TiN-Ag composite material is characterized by comprising a two-dimensional structure array template formed on a silicon chip and formed by arranging polylactic acid microspheres, TiN-Ag layers and graphene layers are alternately deposited on the template, and the deposition thicknesses of the TiN-Ag layers and the graphene layers are 50-100nm and 2-10nm respectively.

2. The graphene/TiN-Ag composite material according to claim 1, wherein the molar ratio of TiN and Ag in the TiN-Ag layer is 10 (1-2).

3. The graphene/TiN-Ag composite material of claim 1, wherein the graphene layer is deposited by electron cyclotron plasma sputtering.

4. The graphene/TiN-Ag composite material according to claim 1, wherein the preparation method of the graphene/TiN-Ag composite material comprises the following steps:

firstly, preparing a two-dimensional periodic structure array by utilizing polylactic acid microspheres through a self-assembly technology to obtain a polylactic acid micro-colloid sphere template;

secondly, spin coating a TiN layer and a magnetron sputtering Ag layer;

and thirdly, depositing the graphene layer by electron cyclotron plasma sputtering.

5. The graphene/TiN-Ag composite material according to claim 4, wherein the first step is specifically:

(1) soaking the silicon wafer in 1-3% sodium dodecyl sulfate solution for 12-36 hours to make the silicon wafer have hydrophilic property;

(2) preparing an ethanol solution of polylactic acid microspheres, and mixing the polylactic acid microspheres and the ethanol solution according to the mass-to-volume ratio of 1: 0.5-2, and then carrying out ultrasonic treatment to uniformly disperse the polylactic acid microspheres and the ethanol solution;

(3) dripping the solution of the polylactic acid ethanol on a hydrophilic silicon wafer, spreading the liquid evenly, inserting the liquid into water in an inclined way, and diffusing the liquid on the water surface to form a single-layer closely-arranged structural array;

(4) and fishing the silicon wafer with the cleaned silicon wafer after the liquid surface is static, sucking the redundant water by using filter paper, and placing the silicon wafer in an inclined mode until the silicon wafer is completely dried to obtain the silicon wafer with the polylactic acid bead array.

6. The graphene/TiN-Ag composite material according to claim 4, wherein the second step is specifically:

and dispersing TiN into absolute ethyl alcohol, adding PVP, heating to 80 ℃, and stirring for 3 hours to obtain a mixture, so that TiN is doped in the PVP. Placing the silicon wafer with the polylactic acid bead array in a spin coater, spin-coating the mixture into the silicon wafer with the polylactic acid bead array, and drying to obtain the silicon wafer with the polylactic acid bead array containing TiN; loading silicon wafer into magnetron sputtering cavity, vacuumizing to make background air pressure reach 10^-4Below Pa, setting the flow rate of argon as working gas to make the working pressure reach 10^-2Carrying out magnetron sputtering on an Ag layer after Pa; the power of the Ag target is 100W, the co-sputtering time is 10-30min, and the polylactic acid microsphere template after the TiN-Ag layer is deposited is obtained.

7. The graphene/TiN-Ag composite material according to claim 4, wherein the third step is specifically:

transferring the polylactic acid microsphere template with the TiN-Ag layer deposited in the second step into an electron cyclotron plasma sputtering deposition chamber through a transition chamber, vacuumizing to 3 x 10 < -4 > Pa, and introducing argon to keep the air pressure at 1 x 10 < -2 > Pa; applying current to a magnetic coil and introducing microwaves, generating argon plasma through the coupling action of a magnetic field and the microwaves, applying target bias voltage of-200V to-500V to bombard a carbon target, applying bias voltage of +100V to +200V to a TiN-Ag layer, and performing sputtering deposition for 1-5 min.

Technical Field

The invention belongs to the technical field of surface enhanced Raman scattering spectroscopy (SERS) detection, and particularly relates to a graphene/TiN-Ag composite material and a preparation method thereof.

Background

Surface-enhanced Raman scattering (SERS) has been used in the fields of biomedicine, environmental monitoring, food safety, and the like because of its high detection sensitivity, high analysis speed, and no water-based interference, and can realize nondestructive detection of samples. The preparation of the high-activity SERS substrate is a key problem which restricts the application of the surface enhanced Raman scattering technology. The traditional SERS substrate generally adopts precious metals such as gold, silver, copper and the like, but the substrate materials have high cost, the metal surface needs roughening treatment to have higher SERS activity, and the rough substrate is mostly unstable and is easy to be interfered by other substances, so that the substrate has poor stability.

In a specific SERS assay, the resonance frequency of the surface plasmon varies with the kind, size, shape, etc. of the metal nanoparticle, and thus, a surface enhanced raman signal can be obtained by controlling these factors. Among them, the roughness of the substrate surface of the placed analyte is an important factor for the generation of surface plasmon and the enhancement of raman signal. In practical applications, users also find that the dependence on the excitation light source is strong only by relying on the surface plasmon resonance property of the noble metal nanoparticles, and thus, the application limitation is serious.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a graphene/TiN-Ag composite material and a preparation method thereof.

The graphene/TiN-Ag composite material comprises a two-dimensional structure array template formed on a silicon chip and formed by arranging polylactic acid microspheres, TiN-Ag layers and graphene layers are alternately deposited on the template, and the deposition thicknesses of the TiN-Ag layers and the graphene layers are 50-100nm and 2-10nm respectively.

Wherein, the TiN-Ag layer is formed by that the molar ratio of TiN to Ag is 10 (1-2).

Wherein the graphene layer is obtained by electron cyclotron plasma sputtering deposition.

The preparation method of the graphene/TiN-Ag composite material comprises the following steps:

firstly, preparing a two-dimensional periodic structure array by utilizing polylactic acid microspheres through a self-assembly technology to obtain a polylactic acid micro-colloid sphere template;

and secondly, spin coating a TiN layer and magnetron sputtering an Ag layer.

And thirdly, depositing the graphene layer by electron cyclotron plasma sputtering.

Wherein, the first step is specifically as follows:

(1) soaking the silicon wafer in 1-3% sodium dodecyl sulfate solution for 12-36 hours to make the silicon wafer have hydrophilic property;

(2) preparing an ethanol solution of polylactic acid microspheres, and mixing the polylactic acid microspheres and the ethanol solution according to the mass volume ratio of 1g to 0.5-2 mL, and then carrying out ultrasonic treatment to uniformly disperse the polylactic acid microspheres and the ethanol solution;

(3) dripping the solution of the polylactic acid ethanol on a hydrophilic silicon wafer, spreading the liquid evenly, inserting the liquid into water in an inclined way, and diffusing the liquid on the water surface to form a single-layer closely-arranged structural array;

(4) and fishing the silicon wafer with the cleaned silicon wafer after the liquid surface is static, sucking the redundant water by using filter paper, and placing the silicon wafer in an inclined mode until the silicon wafer is completely dried to obtain the silicon wafer with the polylactic acid bead array.

Wherein, the second step is specifically as follows:

and dispersing TiN into absolute ethyl alcohol, adding PVP, heating to 80 ℃, and stirring for 3 hours to obtain a mixture, so that TiN is doped in the PVP. Placing the silicon wafer with the polylactic acid bead array in a spin coater, spin-coating the mixture into the silicon wafer with the polylactic acid bead array, and drying to obtain the silicon wafer with the polylactic acid bead array containing TiN;

loading silicon wafer into magnetron sputtering cavity, vacuumizing to make background air pressure reach 10^-4Below Pa, setting the flow rate of argon as working gas to make the working pressure reach 10^-2Carrying out magnetron sputtering on an Ag layer after Pa; the power of the Ag target is 100W, the co-sputtering time is 10-30min, and the polylactic acid microsphere template after the TiN-Ag layer is deposited is obtained.

Wherein, the third step is specifically as follows:

transferring the polylactic acid microsphere template with the TiN-Ag layer deposited in the second step into an electron cyclotron plasma sputtering deposition chamber through a transition chamber, vacuumizing to 3 x 10 < -4 > Pa, and introducing argon to keep the air pressure at 1 x 10 < -2 > Pa; applying current to a magnetic coil and introducing microwaves, generating argon plasma through the coupling action of a magnetic field and the microwaves, applying target bias voltage of-200V to-500V to bombard a carbon target, applying bias voltage of +100V to +200V to a TiN-Ag layer, and performing sputtering deposition for 1-5 min.

The invention has the following beneficial effects:

1. the polylactic acid microspheres are utilized to prepare a two-dimensional periodic structure array through a self-assembly technology, and a polylactic acid colloid sphere template is obtained to be used as a substrate for subsequent sputtering deposition, so that the obtained graphene/TiN-Ag composite material has original micron-scale or micro-nano-scale roughness, and the signal intensity of detected probe molecules can be enhanced.

2. TiN is coupled with Ag, so that the composite material disclosed by the invention has excellent SERS performance, and the composite material disclosed by the invention has good sample uniformity and can be used as an SERS substrate material.

3. The subsequent TiN-Ag layer and the graphene layer are both subjected to sputtering deposition, the quality and the thickness of the film layer are controllable, the method is simple and convenient, batch preparation is easy, and the cost is low.

4. By electron cyclotron plasma sputtering deposition, a stable graphene layer can be obtained on the surface of the TiN-Ag layer, and the adhesion stability of the graphene layer on the TiN-Ag layer is high. And the deposited graphene layer is graphene nanocrystalline, so that the graphene nano-crystal has excellent conductivity and can further remarkably enhance the signal intensity of the detected probe molecules.

5. Due to the compounding effect of the graphene layer and the TiN-Ag layer in the graphene/TiN-Ag composite material, the substrate can realize Raman enhancement under various excitation wavelengths, the dependence of the substrate on an excitation light source is overcome to a certain extent, and the Raman analysis application range of the substrate is widened.

Drawings

Fig. 1 is an SEM image of the graphene/TiN-Ag composite prepared in example 1.

FIG. 2 is a Raman spectrum of the graphene/TiN-Ag composite material prepared in example 4 as a SERS active substrate for detecting 2, 2' -dithiodipyridine (the laser excitation wavelength is 632.8nm, and the integration time is 10 s).

Detailed Description

The present invention will be described in detail with reference to specific examples. Of course, the described embodiments are merely inventive in part, and not in whole. Other examples, which can be obtained by one of ordinary skill in the art without inventive efforts based on the embodiments of the present invention, fall within the scope of the present invention.