toroidal ring absorber and application thereof in detecting pesticide residues
阅读说明：本技术 一种回形环吸收器及其在检测农药残留物中的应用 (toroidal ring absorber and application thereof in detecting pesticide residues ) 是由 刘建军 丁凡 范兰兰 于 2019-10-29 设计创作，主要内容包括：本发明公开了一种回形环吸收器,由若干个单回形环吸收器拼装成阵列结构。每个单回形环吸收器包括底层和紧密贴合在所述底层上表面的单回形环结构；所述底层的材料是高阻硅,为正方形结构；所述单回形环结构的材料是金,由一个内正方形结构、一个外正方形结构以及两个外环臂构成。本发明还包括所述回形环吸收器在检测农药残留物中的应用。本发明可以突破传统农药残留检测方法数据处理复杂、无法快速检测、灵敏度低等瓶颈。采用回形环吸收器作为载体,可以实现快速无损检测,提高检测的灵敏度。(The invention discloses loop absorbers which are assembled into an array structure by a plurality of single loop absorbers, wherein each single loop absorber comprises a bottom layer and a single loop structure tightly attached to the upper surface of the bottom layer, the bottom layer is made of high-resistance silicon and is of a square structure, the single loop structure is made of gold and consists of inner square structures, outer square structures and two outer loop arms.)
1, loop absorbers, which are characterized in that a plurality of single loop absorbers are assembled into an array structure;
each single-loop absorber comprises a bottom layer and a single-loop structure closely attached to the upper surface of the bottom layer;
the bottom layer is made of high-resistance silicon and has a square structure;
the single-loop ring structure is made of gold and comprises inner square structures, outer square structures and two outer ring arms, the inner square structures are located in the outer square structures, the middle points of the inner square structures and the outer square structures coincide with the middle point of the bottom layer, 0 groups of opposite sides of the inner square structures and groups of opposite sides of the outer square structures are parallel to groups of opposite sides of the bottom layer, the other groups of opposite sides of the inner square structures and the other groups of opposite sides of the outer square structures are parallel to the other groups of opposite sides of the bottom layer, the side length of the outer square structures is smaller than that of the bottom layer, openings are formed in the middle portions of the sides, and the two outer ring arms are formed by extending two ends of the sides where the openings are located to the edges of the bottom layer.
2. The loop absorber of claim 1 wherein the openings of each row of single loop absorbers are on the same side of in the array configuration.
3. The toroidal ring absorber of claim 1, wherein said absorber is prepared by surface micromachining technology, comprising the steps of: firstly, coating photoresist on a high-resistance silicon substrate, and exposing and developing patterns on the photoresist to form a loop pattern; secondly, carrying out thermal evaporation deposition on the high-resistance silicon substrate to uniformly deposit metal gold on the annular ring pattern; and finally, dissolving and removing the high-resistance silicon to obtain the toroidal ring absorber.
4. The toroidal ring absorber of claim 1, wherein said bottom layer has a side length of 50un and a thickness of 17 um; the thickness of the single-loop ring structure is 0.5um, the side length of the inner square structure is 15um, the side length of the outer square structure is 35um, and the opening width of the outer square structure is 5 um; the width of interior square structure and outer square structure is 5 um.
5. The toroidal ring absorber of claim 1, wherein said bottom layer material is high-resistivity silicon with a dielectric constant of 11.7 and a conductivity of 2.5 x 10-4S/m。
6. The loop absorber of claim 1 wherein the single loop configuration of gold material has a conductivity of 4.52 x 10-7S/m。
7. Use of the toroidal ring absorbers of any of claims 1-6 and for detecting pesticide residues comprising the steps of:
(1) putting the loop absorber into a specific sample box, preparing sample solutions with different concentrations, respectively dripping the sample solutions on the absorber, and then fastening the sample box to ensure that the liquid film thickness in the sample box is degrees each time;
(2) placing a sample box to be tested in a terahertz time-domain transmission system to obtain terahertz spectrum information of the sample box;
(3) and analyzing the relation between the solutions of the samples with different concentrations and the red shift of the resonance frequency of the absorber, and distinguishing the samples with different concentrations through the red shift condition of the resonance peak, thereby realizing the high-sensitivity detection of the samples.
8. The application of the kinds of toroidal ring absorbers in the detection of pesticide residues according to claim 7, wherein the sample box of step (1) is made of tetrafluoroethylene and comprises an upper cover plate and a lower cover plate, a circular groove with the thickness of 0.5mm is formed in the middle area of the lower cover plate, sealed vacuum rubber rings are embedded in the edges of the groove, and screw holes are correspondingly formed in the edges of the upper cover plate and the lower cover plate, so that the two cover plates can be fixed through screws and bolts, and the sealed vacuum rubber rings of the lower cover plate are tightly attached to the upper cover plate.
9. The use of kinds of loop absorbers for detecting pesticide residues according to claim 7, wherein the sample solution in step (1) is a mixed solution of pesticide to be detected and absolute ethyl alcohol with different concentrations.
10. The use of kinds of loop absorbers in the detection of pesticide residues according to claim 7, wherein the terahertz time-domain transmission system in step (2) is a THz-TDS test system box, and the box is dry air.
Technical Field
The invention relates to the technical field of pesticide detection, in particular to toroidal ring absorbers and application thereof in detecting pesticide residues.
Background
At present, the analysis and detection of pesticide residue mainly depend on large-scale instruments, and chromatographic analysis is a common pesticide residue detection method and comprises gas chromatography, liquid chromatography, high performance liquid chromatography and the like. The essence of chromatography is that the mixture of different substances in a solid phase is eluted using a mobile phase by utilizing the selective distribution of the different substances in different phases, and the different substances in the mixture move along the solid phase at different speeds, finally achieving the separation effect. The immunoassay method is a method of detecting by using a binding reaction of an antibody and an antigen, and includes radioimmunoassay, enzyme-linked immunoassay, fluorescence polarization immunoassay, and the like. The prior pesticide residue detection technology has the following defects:
1. although chromatography can reach very low detection lower limit and obtain very high detection precision, the pretreatment work of a sample to be detected by the method is complex, an operator needs to have skilled operation skills, and rapid detection cannot be carried out.
2. Although the enzyme inhibition method is simple to operate and suitable for field detection, the enzyme inhibition method can only be used for detecting specific types of pesticides at present, has low detection precision and can only carry out qualitative analysis.
3. Although the immunoassay method can detect the pesticide ( antibodies can only be applied to the detection of pesticides), the antibodies are difficult to prepare and have insufficient stability, and the antibodies are required to be stored under specific conditions.
Disclosure of Invention
The invention aims to overcome the defects of the existing pesticide residue detection, and provides loop absorbers and application thereof in pesticide residue detection.
In order to achieve the purpose, the invention adopts the following technical scheme:
kinds of loop absorbers, which are assembled into an array structure by a plurality of single loop absorbers.
Each single-loop absorber comprises a bottom layer and a single-loop ring structure tightly attached to the upper surface of the bottom layer, the bottom layer is made of high-resistance silicon and is of a square structure, the single-loop ring structure is made of gold and comprises inner square structures, outer square structures and two outer loop arms, the inner square structures are located in the outer square structures, the middle points of the inner square structures and the middle points of the outer square structures are overlapped with the middle point of the bottom layer, 0 groups of opposite sides of the inner square structures and groups of opposite sides of the outer square structures are parallel to groups of opposite sides of the bottom layer, the other groups of opposite sides of the inner square structures and the other groups of opposite sides of the outer square structures are parallel to the other groups of opposite sides of the bottom layer, the side length of the outer square structures is smaller than that of the bottom layer, openings are arranged in the middle positions of sides of the outer square structures, and the two outer loop arms are formed by extending two ends of sides.
, in the array structure, the openings of each row of single loop absorbers are on the same side .
, the absorber is prepared by surface micromachining technology, which comprises coating photoresist on high-resistance silicon substrate, exposing and developing the photoresist pattern to form a loop pattern, thermally evaporating the high-resistance silicon substrate to deposit gold metal on the loop pattern, and dissolving off the high-resistance silicon to obtain the loop absorber.
, the side length of the bottom layer is 50un, the thickness is 17um, the thickness of the single-loop ring structure is 0.5um, the side length of the inner square structure is 15um, the side length of the outer square structure is 35um, the opening width of the outer square structure is 5um, and the widths of the inner square structure and the outer square structure are 5 um.
, the bottom layer material has high-resistance silicon with dielectric constant of 11.7 and conductivity of 2.5 × 10-4S/m。
, the conductivity of the gold material of the single loop structure is 4.52 x 10-7S/m。
The invention also comprises the application of the loop absorber in detecting pesticide residues, comprising the following steps:
(1) putting the absorber into a specific sample box, preparing sample solutions with different concentrations, respectively dripping the sample solutions on the absorber, and then fastening the sample box to ensure that the liquid film thickness in the sample box is degrees each time;
(2) placing a sample box to be tested in a terahertz time-domain transmission system to obtain terahertz spectrum information of the sample box;
(3) and analyzing the relation between the solutions of the samples with different concentrations and the red shift of the resonance frequency of the absorber, and distinguishing the samples with different concentrations through the red shift condition of the resonance peak, thereby realizing the high-sensitivity detection of the samples.
, the sample box in step (1) is made of tetrafluoroethylene and consists of an upper cover plate and a lower cover plate, a circular groove with the thickness of 0.5mm is arranged in the middle area of the lower cover plate, sealing vacuum rubber rings are embedded in the edges of the groove, screw holes are correspondingly arranged in the edges of the upper cover plate and the lower cover plate, and the two cover plates can be fixed through screws and bolts, so that the sealing vacuum rubber rings of the lower cover plate are tightly attached to the upper cover plate.
, the sample solution in step (1) is a mixed solution of pesticides to be tested and absolute ethyl alcohol with different concentrations.
, the terahertz time-domain transmission system in the step (2) is a THz-TDS test system box, and dry air is filled in the box.
The invention has the advantages that the bottlenecks of complex data processing, incapability of quick detection, low sensitivity and the like of the traditional pesticide residue detection method can be broken through, and the quick nondestructive detection is realized by adopting the loop absorber as the carrier. The detection sensitivity is improved, and the detection limit reaches 0.213 mg/L.
For a better understanding and practice, the invention is described in detail below with reference to the accompanying drawings.
Drawings
Fig. 1 is a top view of a toroidal ring absorber of example 1.
Fig. 2 is a top view of the single loop absorber of example 1.
Fig. 3 is a side view of the single loop ring absorber of example 1.
Fig. 4 is a dimensional diagram of a single loop absorber in example 1.
Fig. 5 is a dimensional diagram of a single loop absorber in example 1.
FIG. 6 is a plot of dielectric constant ε and the red shift of the resonant peak of the loop absorber in example 2.
Fig. 7 is a graph comparing experimental and simulation results for the toroidal ring absorber of example 2.
FIG. 8 is a schematic view showing the structure of an upper plate cover of a sample cartridge in example 3.
FIG. 9 is a schematic view showing the structure of the lower plate cover of the sample cartridge in example 3.
FIG. 10 is a terahertz transmission spectrum of a mixed solution of toxaphene and absolute ethyl alcohol in different concentrations in example 3.
Figure 11 is a spectrum of the transmitted light of the different concentrations of toxaphene in example 3 at the absorber resonance low frequency peak.
FIG. 12 is a graph comparing the linear fit of the frequency shift of the low frequency resonance peak to the concentration of toxaphene in example 3 with experimental results.
Figure 13 is a graph of the transmission spectrum of toxaphene at the absorber resonance high frequency peaks for different concentrations of toxaphene in example 3.
FIG. 14 is a graph of the linear fit of the frequency shift of the high frequency resonance peak to the concentration of toxaphene in example 3, compared to experimental results.
Description of the main elements:
110
210
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.