Graphene sensor based on anapole resonance and preparation method

Abstract

A graphene sensor based on Anapole resonance and a preparation method thereof. From top to bottom, the surface to the base is provided with an acetamiprid layer, a graphene layer, a metal resonance unit structure layer and a polyimide base layer; the polyimide base layer is connected with the metal resonance unit structure layer, the other side of the metal resonance unit structure layer is connected with the graphene layer, the other side of the graphene layer is connected with the acetamiprid layer, and the layers are tightly connected with each other; and a terahertz wave is incident from the surface to the polyimide base layer. The present application adopts a periodically arranged metal open ring to form a metasurface, which can not only detect the small changes of the dielectric environment on the surface of the metasurface structure, but also interact with the incident terahertz wave, excite the Anapole resonance in the metasurface, limit the electromagnetic field in the scattering source, so that the energy cannot be radiated outward, and the sensing performance of the sensor is improved.

Description

Technical Field

[0001] This invention relates to a graphene sensor based on Anapole resonance and its preparation method, belonging to the field of terahertz electromagnetic wave metasurface technology. Background Technology

[0002] Terahertz (THz) waves are increasingly becoming a mainstream technology for pesticide detection. THz spectroscopy provides a non-destructive and label-free sensing technique. However, due to the mismatch between the wavelength of terahertz radiation and the size of the analyte, the sensitivity of terahertz waves is limited when detecting trace amounts of analytes. Therefore, methods utilizing metamaterials to enhance the signal have been developed to increase the interaction between the terahertz wave and the analyte. The frequency and amplitude of the resonance peak change with the concentration of the analyte, thereby enabling the detection of low-concentration analytes.

[0003] The electromagnetic response of terahertz (THz) waves interacting with matter can be described by a series of electric, magnetic, and toroidal multipoles, generated by oscillating charges, toroidal currents, and polar currents, respectively. Adjusting the interactions between different multipoles is an effective means of controlling the electromagnetic radiation response. For example, by changing the far-field radiation power ratio of electric dipoles to magnetic dipoles, a directional radiation mode without backscattering can be obtained. Nonradiative anapole resonance is a unique optical state induced by the interference of electric and toroidal dipole moments. Like metamaterial unit structures, anapole modes confine the electromagnetic field within the scattering source, preventing energy from radiating outwards, and typically possess a very high quality factor. With these novel far-field and near-field properties, anapole modes have been applied in fields such as lasers, ultrasensitive sensors, and stealth information transmission. However, research on graphene metasurface sensing based on anapole resonances is still limited. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides a graphene sensor based on Anapole resonance and its preparation method.

[0005] A graphene sensor based on Anapole resonance is configured from the top surface down to the substrate as follows: an acetamiprid layer, a graphene layer, a metal resonant unit structure layer, and a polyimide substrate layer. The polyimide substrate layer is connected to the metal resonant unit structure layer, the other side of the metal resonant unit structure layer is connected to the graphene layer, and the other side of the graphene layer is connected to the acetamiprid layer. The layers are tightly connected. Terahertz waves are incident from the surface onto the polyimide substrate layer.

[0006] A method for fabricating a graphene sensor based on Anapole resonance includes the following steps:

[0007] Step 1: Spin-coat a polyimide substrate onto quartz glass.

[0008] Step 2: Deposit a metal structural unit layer on the front side of the polyimide layer.

[0009] Step 3: Prepare a graphene layer using chemical vapor deposition, and then transfer the graphene layer to the metal structural unit layer.

[0010] Step 4: Add acetamiprid solution to the surface of the graphene layer to obtain the acetamiprid layer.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] The metasurface, constructed by periodically arranged open metal rings, can detect minute changes in the dielectric environment of the metasurface structure. The interaction between the metasurface and the incident terahertz wave excites the Anapole resonance in the metasurface, confining the electromagnetic field inside the scattering source and preventing energy from radiating outward, thereby improving the sensor's sensing performance.

[0013] A sandwich-like structure design was introduced, which incorporates a graphene structural layer, a metal resonant unit structural layer, and a polyimide layer. This design is simple, easy to process, and has good ductility.

[0014] The doping intensity of the graphene is enhanced by acetamiprid, thereby altering the conductivity and dielectric environment, and consequently changing the transmittance of terahertz light waves, achieving ultrasensitive sensing. This graphene metasurface sensor has a detection limit of 10.72 fg / ml for acetamiprid and a modulation depth as high as 43.78%.

[0015] The ultrasensitive detection of acetamiprid is achieved by utilizing the unique electromagnetic properties of the Anapole resonance and the fact that a slight change in the dielectric environment causes the Fermi level of graphene to shift to the Dirac point. Attached Figure Description

[0016] When considered in conjunction with the accompanying drawings, the invention will be more fully and better understood, and its many accompanying advantages will become readily apparent, by referring to the following detailed description. However, the accompanying drawings, which are provided to further illustrate the invention and form part of this invention, are used to explain the invention and do not constitute an undue limitation thereof, as shown in the figures:

[0017] Figure 1a The side view of the graphene sensor structure based on Anapole resonance provided by the present invention.

[0018] Figure 1b The main view of the graphene sensor structure based on Anapole resonance provided by the present invention.

[0019] Figure 2 This is a schematic diagram of the metal resonant unit structure layer of the graphene sensor based on Anapole resonance provided by the present invention under a microscope.

[0020] Figure 3 This is a schematic diagram of the array arrangement of metal layer unit structures in the graphene sensor structure based on Anapole resonance provided by the present invention.

[0021] Figure 4 The transmission spectra of the graphene sensor based on Anapole resonance provided by this invention are shown under experimental and simulation conditions.

[0022] Figure 5a The surface current distribution of the graphene sensor based on Anapole resonance provided by this invention has a frequency of 0.47 THz.

[0023] Figure 5b The surface current distribution of the graphene sensor based on Anapole resonance provided by this invention has a frequency of 0.575 THz.

[0024] Figure 6a This is a schematic diagram of the direction of the toroidal polar moment (TD) generated by the graphene sensor based on Anapole resonance provided by the present invention.

[0025] Figure 6b This is a schematic diagram of the direction of the electric dipole moment (ED) generated by the graphene sensor based on Anapole resonance provided by the present invention.

[0026] Figure 7a The scattering power spectrum of the graphene sensor based on Anapole resonance provided by this invention.

[0027] Figure 7b The scattering power spectrum at the resonance of the graphene sensor structure based on Anapole resonance provided by this invention.

[0028] Figure 7c The phase spectrum of the graphene sensor based on Anapole resonance provided by this invention.

[0029] Figure 8a Modulation depth maps of the graphene sensor device based on Anapole resonance provided by this invention under the action of different concentrations of acetamiprid.

[0030] Figure 8b The transmission spectrum modulation depth map of the graphene sensor device based on Anapole resonance provided by the present invention under the action of different concentrations of acetamiprid.

[0031] Among them: 01-acetamiprid layer, 02-graphene layer, 03-metal resonant unit structure layer, 04-polyimide substrate layer and 05-incident terahertz wave. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0033] Obviously, many modifications and variations made by those skilled in the art based on the spirit of this invention fall within the scope of protection of this invention.

[0034] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when an element or component is referred to as “connected” to another element or component, it may be directly connected to the other element or component, or there may be intermediate elements or components. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0035] Those skilled in the art will understand that, unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art.

[0036] To facilitate understanding of the embodiments, further explanations and descriptions will be provided below, and the various embodiments do not constitute a limitation of the present invention.

[0037] Example 1: As Figure 1a and Figure 1b As shown, a graphene sensor based on Anapole resonance includes, in sequence: an acetamiprid layer 01, a graphene layer 02, a metal resonant unit structure layer 03, a polyimide substrate layer 04, and an incident terahertz wave 05. The polyimide substrate layer 04 is connected to the metal resonant unit structure layer 03, the other side of the metal resonant unit structure layer 03 is connected to the graphene layer 02, and the other side of the graphene layer 02 is connected to the acetamiprid layer 01. The layers are tightly connected, and the terahertz wave is incident on the polyimide substrate layer 04 from the surface of the sensor.

[0038] like Figure 2 As shown, the metal resonant unit structure layer 03 includes a basic metal unit, which includes a square-shaped resonant ring and two rectangular-shaped resonant metals.

[0039] like Figure 3As shown, when there are multiple basic metal units, they are arranged periodically along the x and y directions.

[0040] A method for fabricating a graphene sensor based on Anapole resonance includes the following steps:

[0041] Step 1) Spin-coat a polyimide substrate onto a 300μm thick quartz glass substrate, and then bake for 5 hours at 120℃ / 1 hour-200℃ / 1 hour-230℃ / 1 hour-250℃ / 2 hours for a total of 5 hours to obtain a 5μm thick polyimide substrate.

[0042] Step 2) Spin-coat two layers of photoresist LOR10B and AZ1500 onto the polyimide substrate; align the photoresist-coated polyimide substrate with the photomask on the lithography machine and expose it under ultraviolet light; use magnetron sputtering to grow a metal resonant unit structure layer on the area not covered by photoresist, and then strip the photoresist to complete the drawing and fabrication of a 0.2μm thick aluminum structure unit.

[0043] Step 3) A graphene layer was prepared using chemical vapor deposition, and then the graphene layer with a size of 1.0 cm × 1.0 cm was transferred to the metal structural unit layer; thus, the preparation of a graphene sensor with good uniformity was completed.

[0044] Step 4) Add acetamiprid solution to the surface of the graphene layer of the prepared sensor to obtain acetamiprid layer, and use terahertz time-domain spectrometry to further detect acetamiprid solutions of different concentrations.

[0045] The present invention also provides a preparation process for acetamiprid solution, including the following steps:

[0046] Step 1: Mix 100mg acetamiprid and 100ml acetone to prepare a standard solution.

[0047] Step 2: The standard solution was continuously diluted with acetone to obtain nine groups of acetamiprid concentrations of 0.12 fg / mL, 5.12 fg / mL, 0.21 fg / mL, 8.63 pg / mL, 353.09 pg / mL, 14.5 ng / mL, 595 ng / mL, 24.4 μg / mL and 1 mg / mL.

[0048] Step 3: Add 25 μL of 0.12 fg / mL acetamiprid solution four times and 5.12 fg / mL acetamiprid solution once to the surface of the sensor to obtain C1.

[0049] Step 4: After the water in the solution has completely evaporated, continue adding 5.12 fg / mL of acetamiprid solution to obtain an acetamiprid solution with concentration C2. Continue this process, adding solutions of different concentrations to obtain C2 solutions. i .

[0050] like Figure 4 As shown, the metasurface was simulated using both CST and COMSOL simulation software. A terahertz wave was incident perpendicularly on the upper surface of the sensor, and the electric field was along the y-direction E. y The magnetic field is along the x-direction H x Due to the high carrier concentration and conductivity of graphene, significant radiation losses occur, resulting in a decrease in the amplitude of the transmission curve. The transmission curves obtained from experiments and two simulation software programs match well, with only slight differences in amplitude intensity and frequency shift. These minor differences are due to errors in the fabrication of PI and the metal structure.

[0051] As shown in Figure 5, to better understand the resonance mechanism generated by this sensor, a and b show the corresponding surface current distributions on the xy plane at frequencies of 0.47 and 0.575 THz, respectively. At 0.47 THz, the left rectangle generates a counterclockwise circular current, producing a magnetic dipole moment MD along the +z axis. The circular current generated in the right rectangle is clockwise, with MD in the negative z-axis direction. These opposing MD moments are connected end-to-end, forming a circular dipole moment TD along the y-axis.

[0052] like Figure 6a , Figure 6b As shown, at 0.575 THz, the oscillating charge accumulated at the opening gap of the resonant ring forms an electric dipole moment ED, which is opposite to the direction of TD mentioned above.

[0053] like Figure 7a As shown, to further analyze the roles of TD and ED in all resonances, the scattering power of different multipoles was calculated by summing the contributions of all scattering dipoles in Cartesian coordinates. ED, TD, MD, the magnetic quadpole MQ, and the electric quadpole EQ were identified as the five largest contributors. Octopuses and higher-order multipoles had negligible influence on the scattering power. Figure 7a As shown, at 0.47 THz, the ED resonance generated by this metasurface dominates, with the ED exhibiting the largest far-field power. At 0.575 THz, the contributions of both ED and TD dominate the far-field scattering power of this metasurface. Figure 7b The magnified local images clearly show that the scattering powers of ED and TD are the same. For example... Figure 7c As shown, in the case of P = ikT, the destructive interference between TD and ED leads to the suppression of far-field scattering. TD and ED have the same scattering power but opposite directions, thus the metasurface produces a nonradiative anapole resonance.

[0054] Acetamiprid (ACE) is one of the most widely used novel neonicotinoid insecticides. Some studies have shown that ACE can lead to decreased cell viability by inhibiting cell proliferation and promoting apoptosis, and acetamiprid is toxic to TM3 interstitial stromal cells of the testes. Therefore, a method for rapid detection of low concentrations of acetamiprid is needed.

[0055] An anapole resonance-based graphene sensor was used as a detection platform for ACE, and 11 different concentrations of ACE solutions were tested: 10.72 fg / ml (C1), 15.84 fg / ml (C2), 20.96 fg / ml (C3), 26.08 fg / ml (C4), 31.20 fg / ml (C5), 36.32 fg / ml (C6), 41.44 fg / ml (C7), 0.26 pg / ml (C8), 0.47 pg / ml (C9), and 9.52 pg / ml (C1). 10 and 18.15 pg / ml C 11 To improve the reliability of the data, all experimental data reported in this invention are the average of three tests.

[0056] like Figure 8a As shown, the sensor detects the transmission spectra of ACE at different concentrations. At f1 = 0.36 THz, the transmission coefficient of the sensor increases with increasing concentration from C1 to C9; when the concentration increases from C9 to C... 11 At f2 = 0.55 THz, the transmission coefficient of the sensor remains essentially constant. At f2 = 0.55 THz, with changes in concentration, the transmission coefficient of the sensor first increases by C1-C9, then remains constant by C9-C. 11 When the concentration is C9, the anapole resonance response is strongest, and the sensor's maximum transmission coefficient approaches 100%. This phenomenon is caused by the initial Fermi level E of graphene. F Located in the valence band, slightly off the Dirac point; as ACE concentration increases, E F Gradually, it shifts from the valence band to the Dirac point. When the ACE concentration increases to 0.47 pg / ml C9, E F The transfer to the Dirac point. The E of graphene. F The closer to the Dirac point, the lower the conductivity and the smaller the loss of graphene; therefore, the transmission coefficient reaches its maximum at f2. When the detected concentration reaches saturation, the transmission curve of the sensor no longer changes significantly. The sensor operates at different concentrations C1-C... 11 The change in modulation depth is defined as ΔT = (T Cc -T Bare )%, of which T Cc T Bare It is the transmittance at the resonance point when there is no analyte. For example... Figure 8bAs shown, with increasing ACE concentration, the sensor exhibits a small change in ΔT at f1, but a larger change in ΔT at the peak f2, thus achieving ultrasensitive detection. When the ACE concentration is 0.47 pg / ml (C9), ΔT reaches its maximum value, at which point ΔT... max =43.78%. At the lowest concentration of C11 0.72 fg / ml, ΔT = 7.12%, which is still a relatively high detection level for metasurface sensors.

[0057] Therefore, it can be confirmed that this invention proposes and experimentally verifies a graphene sensor based on Anapole resonance, which can be used for ultrasensitive qualitative detection of ACE in the terahertz region. The physical mechanism of Anapole resonance excitation was studied by comparing the electromagnetic responses of electric dipoles and cyclic dipoles. The unique electromagnetic properties of the Anapole mode and slight changes in the dielectric environment lead to the Eo of graphene. F The fact that it moves to the Dirac point, combined with this, enables ultrasensitive detection of ACE. The sensor has a detection limit of 10.72 fg / ml and a modulation depth of 43.78% for acetamiprid, laying a solid foundation for the quantitative detection of trace amounts in chemical and biological sensing.

[0058] Example 2: Figure 1a , Figure 1b , Figure 3 , Figure 4 Figure 5 Figure 6a , Figure 6b , Figure 7a , Figure 7b , Figure 7c , Figure 8a and Figure 8b As shown, a graphene sensor based on Anapole resonance and its preparation method are presented.

[0059] An anapole resonance-based graphene sensor comprises an acetamiprid layer (01), a graphene layer (02), a metal resonant unit structure layer (03), and a polyimide substrate layer (04). The non-radiative anapole mode originates from the interference effect of electric dipole moments and ring dipole moments. This mode enhances the interaction between the incident terahertz wave (05) and the matter, resulting in a strong electric field enhancement effect within the matter. This graphene sensor quantitatively detects the insecticide acetamiprid, lowering the detection limit for acetamiprid and increasing the modulation depth of the sensor. This ultrasensitive detection is achieved by utilizing the unique electromagnetic properties of the anapole resonance and the fact that even slight changes in the dielectric environment cause the Fermi level of graphene to shift to the Dirac point. The anapole resonance provides a platform for effectively controlling far-field radiation and near-field enhancement in optics, laying a solid foundation for quantitative detection in chemical and biological sensing.

[0060] A graphene sensor based on Anapole resonance is configured from the top surface down to the substrate as follows: acetamiprid layer 01, graphene layer 02, metal resonant unit structure layer 03, and polyimide substrate layer 04. The polyimide substrate layer 04 is connected to the metal resonant unit structure layer 03, the other side of the metal resonant unit structure layer 03 is connected to the graphene layer 02, and the other side of the graphene layer 02 is connected to the acetamiprid layer 01. Terahertz waves 05 are incident from the surface onto the polyimide substrate layer 04.

[0061] The metal resonant unit structure layer includes a basic aluminum structural unit; there are multiple basic metal units arranged in an array periodically; terahertz waves are incident perpendicularly on the sensor surface; the basic metal unit includes a split resonant ring, which consists of a square-shaped resonant ring and two rectangular-shaped resonant metals, with a spacing set between the two rectangular metals.

[0062] The graphene layer consists of three layers, with dimensions of 1.0cm × 1.0cm and a thickness of 1nm.

[0063] The thickness of the metal resonator unit structure layer is 200 nm, and the electrical conductivity of aluminum is 3.56 × 10⁻⁶. 7 S / m; The thickness of the polyimide substrate is 5 μm, the dielectric constant is 3.1, the permeability is 1, and the loss tangent is 0.05.

[0064] The period p of the metal structure unit is 200 μm; the two side lengths w1 and w2 of the square resonant ring are 160 μm and 110 μm respectively; the width h of the two rectangular resonant metals is 20 μm and the length l is 50 μm; the spacing d between the two rectangular metals is set to 10 μm.

[0065] A method for fabricating a graphene sensor based on Anapole resonance includes the following steps:

[0066] Step 1: Spin-coat a polyimide substrate onto quartz glass.

[0067] Step 2: Deposit a metal structural unit layer on the front side of the polyimide layer.

[0068] Step 3: Prepare a graphene layer using chemical vapor deposition, and then transfer the graphene layer to the metal structural unit layer.

[0069] Step 4: Add acetamiprid solution to the surface of the graphene layer to obtain the acetamiprid layer.

[0070] Step 2 specifically includes the following steps:

[0071] Step 2.1: Spin-coat two layers of photoresist LOR10B and AZ1500 onto the polyimide substrate.

[0072] Step 2.2: Align the polyimide substrate coated with photoresist with the photomask on the lithography machine and expose it under ultraviolet light.

[0073] Step 2.3: Using magnetron sputtering, grow a metal resonant unit structure layer on the area not covered by photoresist, and then strip the photoresist.

[0074] Step 4 also includes the preparation and addition of acetamiprid solution to obtain an acetamiprid layer.

[0075] Step 4.1: Mix 100 mg of acetamiprid and 100 ml of acetone to prepare a standard solution.

[0076] Step 4.2: The standard solution was continuously diluted with acetone to obtain nine groups of acetamiprid concentrations of 0.12 fg / mL, 5.12 fg / mL, 0.21 fg / mL, 8.63 pg / mL, 353.09 pg / mL, 14.5 ng / mL, 595 ng / mL, 24.4 μg / mL and 1 mg / mL.

[0077] Step 4.3: Add 25 μL of 0.12 fg / mL acetamiprid solution four times and 5.12 fg / mL acetamiprid solution once to the sensor surface to obtain C1.

[0078] Step 4.4: After the water in the solution has completely evaporated, continue adding 5.12 fg / mL of acetamiprid solution to obtain an acetamiprid solution with concentration C2. Continue this process, adding solutions of different concentrations to obtain C2 solutions. i .

[0079] The resonance amplitude difference method was used to sense and detect acetamiprid solutions of different concentrations. The resonance amplitude difference is the difference between the maximum peak value and the minimum peak value at the resonance of the transmission spectrum of the metasurface structure.

[0080] Example 3: As Figure 1a , Figure 1b , Figure 3 , Figure 4 Figure 5 Figure 6a , Figure 6b , Figure 7a , Figure 7b , Figure 7c , Figure 8a and Figure 8b As shown, a graphene sensor detection method based on Anapole resonance is presented. This method utilizes the resonance amplitude difference method to sense and detect acetamiprid solutions of different concentrations. The resonance amplitude difference is the difference between the maximum and minimum peak values ​​at the resonance point of the transmission spectrum of the metasurface structure. This ultrasensitive detection is achieved by leveraging the unique electromagnetic properties of Anapole resonance and the fact that even slight changes in the dielectric environment cause the Fermi level of graphene to shift to the Dirac point.

[0081] An Anapole resonance-based graphene sensor comprises, in sequence: an acetamiprid layer, a graphene layer, a metal resonant unit structure layer, and a polyimide substrate layer; the surface of the graphene layer is covered with the acetamiprid layer; the metal resonant unit structure layer comprises basic metal units.

[0082] The principle of this invention is as follows: Under terahertz wave excitation, the metal resonant unit structure layer generates anapole resonance response, confining the electromagnetic field inside the scattering source, thus preventing energy from radiating outwards. When acetamiprid covalently adsorbs onto the graphene layer, the graphene layer is doped. The covalent adsorption between acetamiprid and the graphene layer alters the conductivity of the graphene, affecting the dielectric environment of the terahertz wave phase. In operation, by adjusting the concentration parameter of acetamiprid, the doping intensity of the graphene is adjusted to change the conductivity and the degree of dielectric environment, thereby altering the transmission coefficient of the terahertz wave and achieving ultrasensitive sensing.

[0083] The graphene layer is covered with an acetamiprid layer. The metal resonant unit structure layer consists of basic aluminum structural units. The aluminum metal units are multiple and arranged in an array-like periodic pattern.

[0084] The basic metal unit includes a split resonant ring, which consists of a square-shaped resonant ring and two rectangular resonant metals with a spacing between them.

[0085] The graphene layer consists of three layers, with dimensions of 1.0cm × 1.0cm and a thickness of 1nm.

[0086] The thickness of the metal resonator unit structure layer is 200 nm, and the electrical conductivity of aluminum is 3.56 × 10⁻⁶. 7 S / m; The thickness of the polyimide substrate is 5 μm, the dielectric constant is 3.1, the permeability is 1, and the loss tangent is 0.05.

[0087] The period p of the metal structure unit is 200 μm; the two side lengths w1 and w2 of the square resonant ring are 160 μm and 110 μm respectively; the width h of the two rectangular resonant metals is 20 μm and the length l is 50 μm; the spacing d between the two rectangular metals is set to 10 μm.

[0088] As described above, embodiments of the present invention have been explained in detail. However, many modifications are possible without departing substantially from the inventive points and effects of the present invention, which will be apparent to those skilled in the art. Therefore, all such modifications are also included within the scope of protection of the present invention.

Claims

1. A graphene sensor based on Anapole resonance, characterized in that, The layers are arranged sequentially from the top surface to the substrate: acetamiprid layer, graphene layer, metal resonant unit structure layer, and polyimide substrate layer. The polyimide substrate layer is connected to the metal resonant unit structure layer, the other side of the metal resonant unit structure layer is connected to the graphene layer, and the other side of the graphene layer is connected to the acetamiprid layer. The layers are tightly connected to each other. Terahertz waves are incident from the surface onto the polyimide substrate layer.

2. The graphene sensor based on Anapole resonance according to claim 1, characterized in that, The metal resonant unit structure layer includes a basic aluminum structural unit; there are multiple basic aluminum structural units arranged in an array periodically; terahertz waves are incident perpendicularly on the sensor surface; the basic aluminum structural unit includes a split resonant ring, which consists of a square resonant ring and two rectangular resonant metals, with a spacing set between the two rectangular metals.

3. A graphene sensor based on Anapole resonance according to claim 1, characterized in that, The graphene layer consists of three layers, with dimensions of 1.0 cm × 1.0 cm and a thickness of 1 nm.

4. A graphene sensor based on Anapole resonance according to claim 1, characterized in that, The thickness of the metal resonator unit structure layer is 200 nm, and the electrical conductivity of aluminum is 3.56 × 10⁻⁶. 7 S / m; The thickness of the polyimide substrate is 5 μm, the dielectric constant is 3.1, the permeability is 1, and the loss tangent is 0.

05.

5. A graphene sensor based on Anapole resonance according to claim 1, characterized in that, The period of the metal structural unit in the metal resonant unit structural layer p It is 200 μm.

6. A graphene sensor based on Anapole resonance according to claim 2, characterized in that, The two side lengths of the square resonant ring w 1 For 160 μm and w 2 The width is 110 μm; the width of the two rectangular resonant metals is... h It is 20 μm long l The spacing is 50 μm; a distance is set between the two rectangular metal parts. d It is 10 μm.

7. A method for fabricating a graphene sensor based on Anapole resonance, characterized in that, Includes the following steps: Step 1: Spin-coat a polyimide substrate onto quartz glass; Step 2: Deposit a metal structural unit layer on the front side of the polyimide layer; Step 3: Prepare a graphene layer using chemical vapor deposition, and then transfer the graphene layer to the metal structural unit layer; Step 4: Add acetamiprid solution to the surface of the graphene layer to obtain the acetamiprid layer.

8. The method for fabricating a graphene sensor based on Anapole resonance according to claim 7, characterized in that, Step 2 specifically includes the following steps: Step 2.1: Spin-coat two layers of photoresist LOR10B and AZ1500 onto the polyimide substrate; Step 2.2: Align the polyimide substrate coated with photoresist with the photomask on the photolithography machine and expose it under ultraviolet light; Step 2.3: Using magnetron sputtering, grow a metal resonant unit structure layer on the area not covered by photoresist, and then strip the photoresist.

9. The method for fabricating a graphene sensor based on Anapole resonance according to claim 7, characterized in that, Step 4 also includes the preparation and addition of the acetamiprid solution to obtain the acetamiprid layer. Step 4.1: Prepare a standard solution by mixing 100 mg of acetamiprid and 100 ml of acetone; Step 4.2: The standard solution was continuously diluted with acetone to obtain nine groups of acetamiprid concentrations of 0.12 fg / mL, 5.12 fg / mL, 0.21 fg / mL, 8.63 pg / mL, 353.09 pg / mL, 14.5 ng / mL, 595 ng / mL, 24.4 μg / mL and 1 mg / mL; Step 4.3: Add 25 μL of 0.12 fg / mL acetamiprid solution four times and 5.12 fg / mL acetamiprid solution once to the sensor surface to obtain C1; Step 4.4: After the water in the solution has completely evaporated, continue adding 5.12 fg / mL of acetamiprid solution to obtain an acetamiprid solution with concentration C2. Continue this process, adding solutions of different concentrations to obtain C2 solutions. i .

10. The detection method of a graphene sensor based on Anapole resonance according to claim 2, characterized in that, The resonance amplitude difference method was used to sense and detect acetamiprid solutions of different concentrations. The resonance amplitude difference is the difference between the maximum peak value and the minimum peak value at the resonance of the transmission spectrum of the metasurface structure. The ultrasensitive detection is achieved by utilizing the unique electromagnetic properties of the Anapole resonance and the fact that a slight change in the dielectric environment will cause the Fermi level of graphene to move to the Dirac point.

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