阅读说明：本技术 一种石墨烯-超材料吸收器及其在检测抗生素中的应用 (graphene-metamaterial absorber and application thereof in detection of antibiotics ) 是由 刘建军 丁凡 范兰兰 于 2019-10-29 设计创作，主要内容包括：本发明公开了一种石墨烯-超材料吸收器,由石墨烯和超材料吸收器组成。所述超材料吸收器由若干个单吸收器形成阵列结构；每个单吸收器由底层、中间介质和顶层三层结构组成,其底层材料为铝、中间介质材料为高阻硅、顶层材料为金。本发明还包括所述石墨烯-超材料吸收器在检测抗生素中的应用。本发明可以突破传统抗生素检测方法中样品前处理过程复杂、分析周期长、有机溶剂消耗量大,且对操作者专业能力要求较高,不便于基层推广使用等瓶颈。采用石墨烯-超材料吸收器作为载体,可以实现快速无损的抗生素浓度表征。(The invention discloses graphene-metamaterial absorbers which consist of graphene and metamaterial absorbers, wherein each metamaterial absorber is of an array structure formed by a plurality of single absorbers, each single absorber is of a three-layer structure consisting of a bottom layer, a middle medium and a top layer, the bottom layer is made of aluminum, the middle medium is made of high-resistance silicon, and the top layer is made of gold.)

The graphene-metamaterial absorber is characterized by consisting of graphene and a metamaterial absorber;

the metamaterial absorber is of an array structure formed by a plurality of single absorbers;

each single absorber is composed of a bottom layer, an intermediate medium and a top layer, wherein the bottom layer is made of aluminum, the intermediate medium is made of high-resistance silicon, and the top layer is made of gold, the bottom layer and the intermediate medium are of square structures with the size of and are tightly attached to , the top layer is tightly attached to the upper surface of the intermediate medium and is composed of an inner square structure and an outer square structure which are located in the middle of the intermediate medium, the inner square structure is located in the outer square structure, the middle points of the inner square structure and the outer square structure are overlapped, the side length of the outer square structure is smaller than that of the intermediate medium, groups of opposite sides of the outer square structure are parallel to diagonal lines of the inner square structure, the other groups of opposite sides of the outer square structure are parallel to the other diagonal lines of the inner square structure, and openings are formed in the;

the graphene is tightly attached to the surfaces of the metamaterial absorber where the intermediate medium and the top layer are located.

2. The graphene-metamaterial absorber of claim 1, wherein the metamaterial absorber is fabricated by surface micromachining, and the method comprises coating a photoresist on side of a high-resistance silicon material, attaching an aluminum material to the aluminum material according to the size of the aluminum material, coating a photoresist on the side of the high-resistance silicon material, exposing and developing the pattern on the photoresist to form a top-layer structure pattern, performing thermal evaporation deposition on the high-resistance silicon material to uniformly deposit gold on the developed pattern, and finally dissolving and removing the high-resistance silicon to obtain a metamaterial absorber array.

3. The graphene-metamaterial absorber according to claim 2, wherein the graphene and metamaterial are bonded by clamping the metamaterial absorber with tweezers to bond the graphene, so that the graphene is tightly bonded on the surface of the metamaterial absorber where the middle medium and the top layer are located, then adding acetone to soak the graphene and the metamaterial absorber for several minutes, and finally placing the graphene and metamaterial absorber into an oven to be dried to obtain the graphene-metamaterial absorber.

4. The graphene-metamaterial absorber of claim 1, wherein the top layer and middle media have a side length of 80um, the bottom layer and top layer have a thickness of 0.5um, the middle media have a thickness of 12um, the inner square structure has a side length of 22.5um, the outer square structure has a side length of 50um, the outer square structure has an opening size of 5um, and the inner square structure and the outer square structure have a width of 5 um.

5. The graphene-metamaterial absorber according to claim 1, wherein the material has a high resistivity of silicon with a dielectric constant of 11.7 and a conductivity of 2.5 x 10^-4S/m。

6. The graphene-metamaterial absorber of claim 1, wherein the material gold has a conductivity of 4.52 x 10^-7S/m, the conductivity of the material aluminum is 3.45 multiplied by 10^-7S/m。

7. Use of the graphene-metamaterial absorber of any one of claims 1-6 to for detecting antibiotics, comprising the steps of:

(1) fully cleaning the heterostructure of the graphene-metamaterial absorber by using deionized water;

(2) dripping antibiotic solutions with different concentrations on the surface of the graphene-metamaterial absorber, drying the solution by blowing, and detecting the solution, wherein each concentration is repeated for three times;

(3) analyzing the blue shift relation of the resonant frequency of the sample solution with different concentrations and the graphene-metamaterial absorber, and representing different concentrations and different types of antibiotics through the blue shift relation of the resonant peak of the graphene-metamaterial absorber and the change relation of the antibiotic concentration.

8. The use of the graphene-metamaterial absorbers as claimed in claim 7, wherein the cleaned graphene-metamaterial absorber of step (1) is air-dried for 40min at room temperature.

9. The application of the graphene-metamaterial absorber in detecting antibiotics according to claim 7, wherein the detection mode in step (2) is a reflection type, a calibration light source is aligned to the center of a sample point on the surface of the metamaterial absorber before detection, a terahertz time-domain spectrometer is used for scanning a sample four times, the terahertz time-domain spectrum of the sample on the surface of the metamaterial absorber is obtained after the spectral lines scanned four times are averaged, and then the obtained time-domain spectrum information is subjected to Fourier transform to obtain the characteristic information of the sample in the frequency domain.

Technical Field

The invention relates to the technical field of antibiotic concentration detection, in particular to graphene-metamaterial absorbers and application thereof in antibiotic detection.

Background

Nevertheless, due to the problems of the continuous improvement of the drug resistance level of antibiotics, the reduction of the research and development investment of related drugs, and the gradual reduction of antibiotic pharmaceutical companies, diseases caused by bacterial infection cannot be effectively treated, thereby seriously threatening the physical health of residents.

in general, antibiotic concentration is positively correlated with drug efficacy, but too high antibiotic concentration increases drug resistance of germs, too low concentration does not achieve therapeutic effect, and thus it is important to set reasonable antibiotic concentration, thus, it is important to measure the concentration of different antibiotic drugs.

Disclosure of Invention

In order to overcome the defects of the existing antibiotic detection, the invention provides graphene-metamaterial absorbers and application thereof in detecting antibiotics.

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

the graphene-metamaterial absorber is composed of graphene and a metamaterial absorber.

The metamaterial absorber is of an array structure formed by a plurality of single absorbers;

each single absorber is composed of a bottom layer, an intermediate medium and a top layer, wherein the bottom layer is made of aluminum, the intermediate medium is made of high-resistance silicon, the top layer is made of gold, the bottom layer and the intermediate medium are square structures with the size of and are tightly attached to , the top layer is tightly attached to the upper surface of the intermediate medium and is composed of an inner square structure and an outer square structure, the inner square structure is located in the outer square structure, the middle points of the inner square structure and the outer square structure are overlapped, the side length of the outer square structure is smaller than that of the intermediate medium, groups of opposite sides of the outer square structure are parallel to diagonals of the inner square structure, the other groups of opposite sides of the outer square structure are parallel to the other diagonals of the inner square structure, and the center of each side of the outer square structure is provided with an opening.

The graphene is tightly attached to the surfaces of the metamaterial absorber where the intermediate medium and the top layer are located.

, the metamaterial absorber is prepared by surface micromachining technology, which comprises coating photoresist on side of high-resistance silicon material, attaching aluminum material on the aluminum material according to size, coating photoresist on side of the high-resistance silicon material, exposing and developing the pattern on the photoresist to form a top layer structure pattern, performing thermal evaporation deposition on the high-resistance silicon material to uniformly deposit metal gold on the developed pattern, and finally dissolving and removing the high-resistance silicon to obtain the metamaterial absorber array.

, the process of attaching the graphene and the metamaterial comprises the steps of clamping the metamaterial absorber by using tweezers to attach the graphene, enabling the graphene to be tightly attached to the surfaces of the metamaterial absorber where the middle medium and the top layer are located, adding acetone to soak the graphene for a plurality of minutes, and finally placing the graphene and the metamaterial absorber in an oven to be dried to obtain the graphene-metamaterial absorber.

step by step, the length of side of top layer and middle medium is 80um, and the thickness of bottom and top layer is 0.5um, and the thickness of middle medium is 12um, the length of side of interior square structure is 22.5um, the length of side of outer square structure is 50um, the edge opening size of outer square structure all is 5um, the width of interior square structure and outer square structure is 5 um.

step, theThe high-resistivity silicon material has dielectric constant of 11.7 and conductivity of 2.5 × 10^-4S/m。

, the material has gold conductivity of 4.52 × 10^-7S/m, the conductivity of the material aluminum is 3.45.8 multiplied by 10^-7S/m。

The invention also discloses an application of the graphene-metamaterial absorber in detecting antibiotics, which comprises the following steps:

(1) fully cleaning the heterostructure of the graphene-metamaterial absorber by using deionized water;

(2) dripping antibiotic solutions with different concentrations on the surface of the graphene-metamaterial absorber, drying the solution by blowing, and detecting the solution, wherein each concentration is repeated for three times;

(3) analyzing the blue shift relation of the resonant frequency of the sample solution with different concentrations and the graphene-metamaterial absorber, and representing different concentrations and different types of antibiotics through the blue shift relation of the resonant peak of the graphene-metamaterial absorber and the change relation of the antibiotic concentration.

, air-drying the cleaned graphene-metamaterial absorber in the step (1) for 40min at room temperature.

, the detection mode in the step (2) is a reflection type, before detection, the calibration light source is aligned to the center of the sample point on the surface of the metamaterial absorber, the sample is scanned four times by using the terahertz time-domain spectrometer, the four scanned spectral lines are averaged to obtain the terahertz time-domain spectrum of the sample on the surface of the metamaterial absorber, and then the obtained time-domain spectrum information is subjected to Fourier transform to obtain the characteristic information of the sample in the frequency domain.

Fig. 6 shows a working principle diagram of a graphene-metamaterial absorber heterostructure in a terahertz wave band in a reflection mode. In the figure, Aluminum (Aluminum), Silicon (Silicon), Gold (Gold), Graphene (Graphene) and molecules (Molecular) are arranged from bottom to top in sequence. The graphene-metamaterial absorber constructed by the research has strong interaction with incident terahertz waves. The detection object is added to interact with an electric field excited by the metamaterial absorber, and the interaction with the graphene can change the Fermi level of the graphene, so that the heterostructure of the graphene-metamaterial absorber is very sensitive to substances added on the surface.

10pL of absolute ethanol solution is dripped on the surface of the graphene-metamaterial heterostructure, and heterostructure reflectivity spectral lines before and after dripping of a sample are collected, and the result is shown in figure 8. As can be seen from the figure, after the absolute ethanol solution sample was added, the reflectance at the resonance peak position of the graphene-metamaterial absorber heterostructure decreased with an increase in the resonance peak quality factor. Different from direct detection by using a metamaterial, the method for detecting the sample by using the graphene-metamaterial absorber heterostructure can cause blue shift (the resonant peak moves towards a high-frequency direction) of the resonant peak of the graphene-metamaterial absorber heterostructure, namely after the graphene is transferred on the surface of the metamaterial absorber, the substance to be detected is detected again, so that the quality factor of the resonant peak of the metamaterial absorber is increased, and the resonant frequency is increased. When the metamaterial absorber is used for directly detecting a sample, the quality factor of the resonant peak of the metamaterial absorber is reduced, the resonant frequency is reduced, and the red shift of the resonant frequency is caused at the same time, as shown in fig. 9.

The research shows that the detection of the outer molecules of the graphene-metamaterial absorber heterostructure is obviously different from that of -like metamaterials, because the outer molecules and the large pi bonds of graphene have strong interaction, the Fermi level of the graphene is moved to a Dirac cone due to the interaction, the carrier concentration of the graphene is reduced, the reduction of the conductivity of the graphene leads to the enhancement of the resonant peak of the metamaterial absorber and the occurrence of a blue shift phenomenon.

The method can break through the bottlenecks that the sample pretreatment process is complex, the analysis period is long, the organic solvent consumption is large, the requirement on the professional ability of an operator is high, the use of is inconvenient to carry out by the basic level, and the like in the traditional antibiotic detection method, and the rapid and nondestructive antibiotic concentration characterization is realized by adopting the -step graphene transfer metamaterial absorber as a carrier.

For a better understanding and practice, the invention is described in detail below with reference to the accompanying drawings.

Drawings

Fig. 1 is a schematic structural diagram of a graphene-metamaterial absorber according to the present invention.

Fig. 2 is a schematic side view of a graphene-metamaterial absorber according to the present invention.

Fig. 3 is a top view of the structure of the metamaterial absorber of the present invention.

Figure 4 is a top view of a single absorber of the present invention.

Figure 5 is a dimensional diagram of a single absorber of the present invention.

Figure 6 is a dimensional diagram of a single absorber of the present invention.

FIG. 7 is a schematic diagram of the principle of external molecule detection by reflection mode of a single-layer graphene-metamaterial absorption device in a terahertz wave band.

FIG. 8 is a terahertz reflection spectrum of the graphene-metamaterial for detecting absolute ethyl alcohol.

FIG. 9 is a terahertz reflection spectrum of the metamaterial for detecting absolute ethyl alcohol.

Fig. 10 is a schematic diagram of the metamaterial absorber transferring graphene and a reflection wave-front diagram of the metamaterial absorber with or without single-layer graphene.

FIG. 11 shows terahertz reflectance spectra of erythromycin at different concentrations in a graphene-metamaterial absorber according to the present invention.

FIG. 12 is a graph of different concentrations of erythromycin characterized by the amount of frequency shift of resonance peaks in the graphene-metamaterial absorber according to the present invention.

Fig. 13 is a midecamycin terahertz reflection spectrum at different concentrations on the graphene-metamaterial absorber of the present invention.

FIG. 14 is a graph of different concentrations of midecamycin characterized by the amount of frequency shift of the resonance peak on the graphene-metamaterial absorber according to the present invention.

Fig. 15 is a terahertz reflection spectrum of josamycin at different concentrations on the graphene-metamaterial absorber according to the present invention.

Fig. 16 is a graph of different concentrations of josamycin represented by the frequency shift of the resonance peak on the graphene-metamaterial absorber.

FIG. 17 shows the sensitivity of the blue shift value of the resonant peak of the graphene-metamaterial absorber to the variation of the concentrations of three antibiotics.

FIG. 18 is a linear fit plot of the shift in resonance peak frequency of the graphene-metamaterial absorber of the present invention.

Main figure letter description:

an MMA metamaterial absorber; an MMA + Graphene-metamaterial absorber; AE (anhydrous ethanol)

Description of the main elements:

110 bottom layer 120 middle dielectric 130 top layer 131 inner square structure 132 outer square structure

133 opening 140 graphene layer

Detailed Description

All materials, reagents and equipment selected for use in the present invention are well known in the art, but do not limit the practice of the invention, and other reagents and equipment known in the art as are suitable for use in the practice of the following embodiments of the invention.