Terahertz metamaterial-based sensor and multi-residual pesticide detection device and method

Abstract

The application relates to the field of pesticide residue detection, in particular to a sensor based on terahertz metamaterial and a multi-residue pesticide detection device and method. The sensor based on terahertz metamaterial comprises a substrate and a plurality of double resonators arranged in a periodic array on the substrate; wherein the substrate has an Au layer, a Ti layer and a PI layer arranged in a stack; the double resonator comprises a herringbone structure and two linear structures, and each of the herringbone structure and the linear structure has a Ti layer and an Au layer arranged in a stack from the PI layer of the substrate to the Au layer away from the substrate; the middle positions of the upper horizontal line and the lower horizontal line of the herringbone structure are interrupted; each linear structure is located in one port of the herringbone structure, is parallel to the horizontal line of the herringbone structure, and is spaced from the outline surrounded by the herringbone structure by a gap. The application can realize synchronous detection of multiple pesticide residues, and has high sensitivity.

Description

Technical Field

[0001] The present invention relates to the field of pesticide residue detection, and particularly to a sensor based on terahertz metamaterial, a multi-residue pesticide detection device and a method. Background Art

[0002] At present when food safety has attracted much attention, the detection of pesticide residues in food is a key link to ensure public health. However, traditional detection methods such as enzyme inhibition method and colloidal gold method can only detect the targeted detection of 1-2 types of pesticides at a time. In the face of the current situation of compound pollution such as organophosphorus and pyrethroids, multiple samplings and step-by-step detections are required. The operation is cumbersome, the detection efficiency is low, and there are also deficiencies in real-time performance and sensitivity, and it is impossible to collect data in real time and perform quantitative analysis. When facing the large-scale food sampling inspection tasks in the market, it is difficult to meet the actual needs of efficient detection.

[0003] Terahertz wave is an electromagnetic wave with a frequency band ranging from 0.1 terahertz to 10 terahertz and a wavelength range of 0.03 mm to 3 mm, which has the characteristics of various photons and quasi-electrons. Terahertz metamaterial is based on the physical local electric field enhancement effect, and its resonance frequency will shift with the change of the dielectric constant of the待测物质 (substance to be measured). This characteristic makes it have great application potential in biological detection, especially in the highly sensitive recognition of pesticide residue substances.

[0004] Therefore, there is an urgent need to develop a residue pesticide detection technology based on terahertz metamaterial to solve the problems existing in the existing detection methods. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a sensor based on terahertz metamaterial, which can realize the synchronous detection of multiple pesticide residues and has high sensitivity.

[0006] To solve the above technical problem, the technical solution of the present invention is: A sensor based on terahertz metamaterial, comprising a substrate and a plurality of double resonators arranged in a periodic array on the substrate; wherein,

[0007] The substrate has an Au layer, a Ti layer and a PI layer arranged in a stacked manner;

[0008] The double resonator includes a "日" - shaped structure and two "一" - shaped structures, both of which have a Ti layer and an Au layer arranged in a stacked manner in sequence from the PI layer of the substrate towards the Au layer背离基底的方向 (direction away from the substrate);

[0009] The middle positions of the upper horizontal line and the lower horizontal line of the "日" - shaped structure are interrupted;

[0010] Each "一" - shaped structure is located in one of the "口" of the "日" - shaped structure, parallel to the horizontal line of the "日" - shaped structure, and there is a gap between it and the contour surrounding the "日" - shaped structure.

[0011] Further, the thickness of the Au layer is 14 μm, the thickness of the Ti layer is 10 nm, and the thickness of the Au layer is 200 nm.

[0012] Further, the length and width of the figure-eight structure are both denoted as h, the width of the upper and lower horizontal lines is denoted as a, the interruption length is f, the width of the middle horizontal line is denoted as c, the width inside the square is denoted as d, the length of the one-stroke structure is denoted as b, and the width is denoted as e; where

[0013] a = 7±2 μm, b = 40±4 μm, c = 5±2 μm, d = 46±4 μm, e = 5±2 μm, f = 18±2 μm, h = 60±5 μm.

[0014] The present invention also relates to a multi-residual pesticide detection device, including:

[0015] A sensor based on terahertz metamaterials;

[0016] An independent cavity;

[0017] An inlet pipe, connecting to the liquid inlet of the independent cavity;

[0018] A transparent serpentine microfluidic channel, connecting to the liquid outlet of the independent cavity and located above the sensor based on terahertz metamaterials;

[0019] A terahertz wave generator, located above the transparent serpentine microfluidic channel, for emitting terahertz waves to the transparent serpentine microfluidic channel.

[0020] Further, the multi-residual pesticide detection device further includes a plurality of color reaction cavities, each color reaction cavity is filled with a corresponding color reaction reagent, and all are connected to the inlet pipe.

[0021] Further, the multi-residual pesticide detection device further includes a waste liquid pipe and a waste liquid collection cavity, the inlet of the waste liquid pipe is connected to the independent cavity and the plurality of color reaction cavities, and the outlet is connected to the waste liquid collection cavity.

[0022] Further, each color reaction cavity is provided with an insertion port for inserting a reagent module, and the color reaction reagent is added through the inserted reagent module.

[0023] The present invention also relates to a multi-residual pesticide detection method based on the multi-residual pesticide detection device, including:

[0024] The liquid to be detected reaches the independent cavity through the inlet pipe, and then enters the transparent serpentine microfluidic channel;

[0025] The terahertz wave generator emits terahertz waves towards the transparent serpentine microfluidic channel;

[0026] Sensors based on terahertz metamaterials captured spectral frequency shift signals of terahertz waves passing through a transparent serpentine microfluidic channel and being reflected by its own substrate;

[0027] By comparing each spectral frequency shift signal with the pre-calibrated standard spectral frequency shift signals of each pesticide residue, the type and concentration of each pesticide residue can be determined.

[0028] By adopting the above technical solution, the present invention has the following beneficial effects:

[0029] 1. Strong ability to detect multiple residues simultaneously: The sensor based on terahertz metamaterials in this invention can simultaneously detect multiple pesticide residues with a detection time of ≤5 minutes, which is more than 3 times more efficient than traditional methods and has strong real-time performance.

[0030] 2. High sensitivity and accuracy: Terahertz metamaterial-enhanced detection significantly improves sensitivity, up to 10 times that of traditional enzyme inhibition methods, and can detect trace residues close to the lower limit of GB 2763. Furthermore, through verification with the "terahertz frequency shift signal," it effectively avoids the false positive / false negative problem of single detection methods. In addition, the sensor of this invention has both a double U-shaped resonator (H-shaped structure) and a central rod-shaped resonator (I-shaped structure), which can achieve two resonance peaks, further increasing detection accuracy. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of a single dual resonator of the present invention on a substrate;

[0032] Figure 2 This is a schematic diagram of the terahertz metamaterial-based sensor of the present invention;

[0033] Figure 3 This is a flowchart illustrating the fabrication process of the terahertz metamaterial-based sensor of the present invention.

[0034] Figure 4 This is a physical image of the terahertz metamaterial-based sensor of the present invention;

[0035] Figure 5 The diagram shows the multimodal resonance characteristics of the sensor in the frequency band from 0.3THz to 2.5THz.

[0036] Figure 6 This is a diagram illustrating the absorption enhancement mechanism of the resonant peak in the terahertz band.

[0037] Figure 7 The graph shows the relationship between refractive index and absorption spectrum when the thickness of the analyte is 10 μm.

[0038] Figure 8 This is a graph showing the frequency shift as a function of refractive index.

[0039] Figure 9 Structural schematic diagram of the multi-residual pesticide detection device of the present invention;

[0040] 1. Sensor based on terahertz metamaterial; 2. Independent cavity; 3. Inlet flow pipe; 4. Transparent serpentine microfluidic channel; 5. Color reaction cavity; 6. Waste liquid pipe; 7. Waste liquid collection cavity. Specific embodiments

[0041] In order to make the content of the present invention easier to be clearly understood, the present invention will be further described in detail below according to specific embodiments in conjunction with the accompanying drawings.

[0042] Embodiment 1

[0043] As Figure 1 and Figure 2 shown, a sensor 1 based on terahertz metamaterial includes a substrate and a plurality of double resonators arranged in a periodic array on the substrate; wherein,

[0044] The substrate has an Au layer, a Ti layer and a PI layer arranged in a stacked manner;

[0045] The double resonator includes a rectangle structure and two straight bar structures both having a Ti layer and an Au layer arranged in sequence from the PI layer of the substrate towards the Au layer背离 the substrate;

[0046] The middle positions of the upper horizontal line and the lower horizontal line of the rectangle structure are interrupted;

[0047] Each straight bar structure is located in one of the openings of the rectangle structure, parallel to the horizontal line of the rectangle structure, and there is a gap between it and the contour surrounding the rectangle structure.

[0048] Preferably, the thickness of the Au layer is 14 μm, the thickness of the Ti layer is 10 nm, and the thickness of the Au layer is 200 nm.

[0049] Preferably, the length and width of the rectangle structure are both denoted as h, the width of the upper horizontal line and the lower horizontal line is denoted as a, the interrupted length is f, the width of the middle horizontal line is denoted as c, the width inside the opening is denoted as d, the length of the straight bar structure is denoted as b, and the width is denoted as e; wherein,

[0050] a = 7 ± 2 μm, b = 40 ± 4 μm, c = 5 ± 2 μm, d = 46 ± 4 μm, e = 5 ± 2 μm, f = 18 ± 2 μm, h = 60 ± 5 μm.

[0051] More preferably, a = 7 μm, b = 40 μm, c = 5 μm, d = 46 μm, e = 5 μm, f = 18 μm, h = 60 μm, and the period l = 72 µm. This size is based on simulation. It should be noted that there may be some inaccuracies in the translation of "背离" as it is not a very common and exact match in this context. It might be better to use a more appropriate expression like "away from" or "facing away from" depending on the specific meaning intended in the original text. Also, some of the technical terms might need further verification and adjustment according to the actual field of patent technology.

[0052] like Figure 3 As shown, the fabrication method of this terahertz metamaterial-based sensor 1 includes:

[0053] First, a polyimide layer (PI layer) is spin-coated onto a silicon substrate. Then, the polyimide layer is imidized by baking at 110 °, 200 °, and 250 ° for 1 hour, 2 hours, and 2.5 hours, respectively.

[0054] Then, 10 nm Ti and 200 nm Au are deposited on the surface of the PI layer to obtain the Ti layer and Au layer, forming a metal substrate;

[0055] The metal substrate is then peeled off from the silicon substrate, and multiple dual resonators arranged in a periodic array are fabricated on the other surface of the PI layer.

[0056] Finally, the sample was divided into 10mm × 10mm pieces using a Disco cutter. The completed metamaterial is shown in the image below. Figure 4 As shown.

[0057] It is important to note that during the preparation of metamaterials, to prevent Ti from being corroded by acetone solution, the sample needs to be coated with a resin and protected with a thermally foamed film. Detailed parameters are as follows.

[0058] Step 1, spin coating PI

[0059] The second step involves depositing a film on one side to prepare the metal substrate.

[0060]

[0061] Step 3: Metal substrate peeling

[0062] Soak in acetone and sonicate for 5 minutes.

[0063] Step 4, photolithography

[0064]

[0065] Fifth step: deposit a film on the other side to fabricate a periodic array of dual resonators.

[0066]

[0067] Step 6, zone designation

[0068]

[0069] Step 7: Spread the adhesive evenly and protect it.

[0070] Step 8, Separation

[0071] A thermally expanded polyimide (PI) film is applied, followed by HF immersion and release. Photoresist is then dropped onto a small silicon wafer that has released PI. The PI film, removed from the thermally expanded polyimide film, is then applied face-up onto the wafer. Liquid surface tension is used to ensure a relatively smooth application of the PI film onto the silicon wafer, followed by drying. Finally, acetone immersion is performed, completing the metamaterial fabrication.

[0072] To verify the effectiveness of this terahertz metamaterial-based sensor 1, simulations were performed.

[0073] Numerical simulation of the metamaterial structure was performed using the tetrahedral mesh frequency domain solver in the Computer Simulation Technology (CST) Studio Suite. The steps can be summarized as follows:

[0074] ① Unit structure setup: The metamaterial unit structure was constructed using the Periodicstructure module in the Microve & RF / Optical module of CST software;

[0075] ② Background Material Settings: Using the software's database, parameters for materials such as gold (Au), titanium (Ti), and polyimide film (PI) were set. In our simulation, the substrate was chosen as a lossless dielectric material, polyimide film. Specifically, the dielectric constant of PI is ε = 3.5, the conductivity of Au is 4.561 × 10⁷ S / m, and the conductivity of Ti is 2.38 × 10⁶ S / m.

[0076] ③ Structural Model Establishment: The structural model is established through the combination of basic structures and Boolean operations, and the metamaterial unit structure is constructed as shown in the figure. It is mainly composed of three parts: a substrate layer (PI), a Ti layer and an Au layer. Ti and Au films are deposited on the upper surface of the substrate layer. In the designed ring metamaterial, the thicknesses of the polyimide film, Au and Ti are 14μm, 200nm and 10nm, respectively.

[0077] ④ Parameter settings: The frequency range is 0-2.5THz. Select unit cell boundary conditions in the x and y directions, and select open (add space) in the z direction. The periodic boundary conditions are excited by port, and the unit cell boundary conditions are excited by Floquetmodes.

[0078] ⑤ Solver selection: Select a frequency domain solver for numerical solution to obtain simulation results.

[0079] Figure 5It is a multimodal resonance characteristic diagram presented by the sensor within the frequency band of 0.3 THz to 2.5 THz. The resonance characteristics mainly include resonance peak 1 that appears at 0.53 THz and resonance peak 2 that appears at 2.30 THz. The absorption rate of the resonance peaks can reach 0.99, having a stronger absorption rate.

[0080] The absorption enhancement mechanism of the resonance peaks in the terahertz band is as Figure 6 shown. From Figure 6 it can be seen the electric field distributions of the two resonance peaks. Among them, the electric field, magnetic field, and surface current of resonance peak 1 are mainly concentrated on the U-shaped rod (the structure of a rectangle with a cross in the middle), while the electric field, magnetic field, and surface current of resonance peak 2 are mainly concentrated on the central resonance rod (the structure of a single line). Combining with the current distribution diagram, it can be seen that both resonance peaks are caused by Fano resonance.

[0081] Figure 7 It shows the relationship between the refractive index and the absorption spectrum when the thickness of the analyte is 10 μm. As the refractive index of the analyte changes from 1.0 to 1.9, the resonance peaks of the analyte shift to the left in turn, but the absorption rates of the two absorption peaks decrease from 0.99 to 0.94.

[0082] The implementation mechanism of the metamaterial sensor is to add the material to be measured in the space around the metamaterial, making it affect the environmental parameters of the space, and then causing the resonance change of the sensor. The sensitivity and quality factor are important parameters for evaluating the performance of the metamaterial sensor. The curve of the frequency shift extracted from Figure 7 versus the refractive index is as Figure 8 shown. It shows that as the refractive index of the analyte increases, the frequency shift of the superconducting material sensor increases linearly, and the resonance position of the superconducting material is sensitive to the dielectric environment.

[0083] From the calculation results of the sensitivity, it is found that the maximum theoretical sensitivities of resonance peak 1 and resonance peak 2 are close to 110 GHz and 440 GHz / RIU respectively; the maximum FOM values are 2.99 and 4.71 respectively; the maximum quality factor Q values are 11.86 and 28.36 respectively.

[0084] Example 2

[0085] As Figure 9 shown, a multi-residual pesticide detection device includes:

[0086] The sensor 1 based on terahertz metamaterial of Example 1;

[0087] Independent cavity 2;

[0088] Inflow pipeline 3, connecting to the liquid inlet of the independent cavity 2;

[0089] A transparent serpentine microfluidic channel 4, connected to the liquid outlet of the independent cavity 2, is located above the sensor 1 based on terahertz metamaterials;

[0090] The terahertz wave generator is located above the transparent serpentine microfluidic channel 4 and is used to emit terahertz waves into the transparent serpentine microfluidic channel 4.

[0091] Preferably, such as Figure 9 As shown, the multi-residue pesticide detection device also includes multiple colorimetric reaction chambers 5, each of which is filled with a corresponding colorimetric reaction reagent and is connected to the inlet pipe 3.

[0092] By reacting the solution with the colorimetric reagent in the colorimetric reaction chamber 5, the residual pesticides in the solution can be visualized and verified against the detection structure of the sensor.

[0093] Preferably, such as Figure 9 As shown, the multi-residue pesticide detection device also includes a waste liquid pipe 6 and a waste liquid collection chamber 7. The inlet of the waste liquid pipe 6 is connected to an independent chamber 2 and multiple colorimetric reaction chambers 5, and the outlet is connected to the waste liquid collection chamber 7.

[0094] This facilitates cleaning of the device and avoids interference between different solutions. Furthermore, it allows the device to be reused multiple times.

[0095] Preferably, each colorimetric reaction chamber is provided with an insertion port for inserting reagent modules, through which colorimetric reaction reagents are added.

[0096] This makes it easy to add colorimetric reagents into the colorimetric reaction chamber. The reagent module can be replaced separately, reducing the cost of single-sample testing to 1.5-2 yuan, which is more than 60% lower than that of disposable chips, and also reduces consumable pollution.

[0097] Furthermore, the reagent module supports changing the type of colorimetric reaction reagent to meet the colorimetric requirements of various pesticides and adapt to different detection throughput and detection range needs.

[0098] Multi-residue pesticide detection methods based on multi-residue pesticide residue detection devices include:

[0099] The liquid to be tested reaches the independent cavity 2 through the inlet pipe 3, and then enters the transparent serpentine microfluidic channel 4;

[0100] The terahertz wave generator emits terahertz waves toward the transparent serpentine microfluidic channel 4;

[0101] Sensor 1, based on terahertz metamaterials, captured the spectral frequency shift signal of terahertz waves passing through a transparent serpentine microfluidic channel and being reflected by its own substrate;

[0102] By comparing each spectral frequency shift signal with the pre-calibrated standard spectral frequency shift signals of each pesticide residue, the type and concentration of each pesticide residue can be determined.

[0103] The following section provides a detailed description of this embodiment, using a specific pesticide residue detection process as an example.

[0104] Pesticide residue testing process

[0105] Taking the simultaneous detection of organophosphates (chlorpyrifos), pyrethroids (cyhalothrin), and fungicides (carbendazim) in tomato samples as an example, the specific steps are as follows:

[0106] 1. Sample pretreatment: Take 10g of fresh tomato sample, remove the peel and put it into a homogenizer, add 20mL of phosphate buffer (pH7.4, 0.01mol / L), homogenize for 2min; transfer the homogenate to a centrifuge tube, centrifuge at 5000rpm for 5min, and take the supernatant as the sample to be tested.

[0107] 2. Sample Injection and Distribution: Use a pipette to draw 1 mL of the sample to be tested and inject it into the sample well of the inlet channel; start the detection program through the data processing module, and the fluid control unit drives the microvalve. After the sample enters through the S-shaped mixing microchannel (inlet pipe 3), it is distributed from multiple independent microchannels at a rate of 100 μL / channel to five colorimetric reaction chambers 5 and one independent chamber 2 (the first and second colorimetric reaction chambers 5 detect chlorpyrifos, the third and fourth colorimetric reaction chambers 5 detect cyhalothrin, and the fifth colorimetric reaction chamber 5 detects carbendazim).

[0108] 3. Isothermal reaction and signal acquisition: The temperature control unit maintains the reaction chamber temperature at 25℃±1℃. The data processing module simultaneously starts the terahertz monitoring unit (including the terahertz wave generator and the terahertz metamaterial-based sensor 1. The light output port of the terahertz wave generator is generally 18-12mm away from the terahertz metamaterial-based sensor) for real-time monitoring and continuous acquisition for 5 minutes.

[0109] First and second colorimetric reaction chambers 5 (chlorpyrifos detection): Chlorpyrifos in the sample inhibits acetylcholinesterase activity, reducing the decomposition of thioacetylcholine, weakening the DTNB colorimetric reaction, and the system color changes from colorless to yellow;

[0110] (1) Acetylcholinesterase catalyzes the decomposition of thioacetylcholine

[0111]

[0112] (2) Chlorpyrifos inhibits the irreversible reaction of AChE.

[0113]

[0114] (3) DTNB colorimetric reaction

[0115]

[0116] The third and fourth colorimetric reaction chambers 5 (cyhalothrin detection): Cyhalothrin in the sample competes with colloidal gold-labeled cyhalothrin antigen for binding to monoclonal antibodies. Based on the immune competitive reaction and the gold-labeled probe (Au-Ag*), the system will turn red; the higher the cyhalothrin content, the less Ab-Au-Ag* is generated, and the lighter the red color.

[0117]

[0118] Fifth colorimetric reaction chamber 5 (carbendazim detection): Carbendazim in the sample competes with HRP-labeled carbendazim antigen for binding to specific antibodies. The core colorimetric reaction is the HRP-catalyzed TMB oxidation reaction, and the system color changes from colorless to blue. The higher the carbendazim content, the less HRP-Ag'* binds in the immune competitive reaction, and the lighter the blue color.

[0119] Carbendazim detection of HRP enzymatic colorimetric reaction

[0120]

[0121] Independent cavity 2: The sample flows directly into the integrated array area of ​​the terahertz detection window through the transparent serpentine microfluidic channel 4, and the terahertz signal is acquired in real time for 5 minutes to obtain the baseline signal.

[0122] 4. Results Output and Judgment: After 5 minutes, the following will be displayed on the touch screen: reaction time-color gradient, real-time monitoring signal curve collected by sensor 1 based on terahertz metamaterial, to determine whether the sample contains organophosphates (chlorpyrifos), pyrethroids (cyhalothrin), or fungicides (carbendazim); the test data and curves can be exported via USB interface.

[0123] After the test is completed, start the chip regeneration program. Specific steps are as follows:

[0124] 1. The fluid control unit drives the micro infusion pump to inject 0.1 mol / L NaOH solution into each reaction chamber (independent chamber 2 and five colorimetric reaction chambers 5), soak for 30 seconds, and rinse the inner wall of the reaction chamber to remove residual reagents and samples;

[0125] 2. Inject deionized water and rinse twice. After each rinse, use a miniature vacuum pump to extract the waste liquid into the waste liquid collection chamber.

[0126] 3. Introduce nitrogen gas to dry the inside of the reaction chamber, completing the regeneration process. The chip can then be used for the next test.

[0127] Calibration test:

[0128] 1. Sensitivity verification: Prepare a standard sample containing chlorpyrifos and test it according to the above procedure. The terahertz signal can clearly distinguish the standard sample containing chlorpyrifos from the blank sample, which meets the sensitivity requirements.

[0129] 2. Repeatability verification: The same chip was used to repeatedly test the standard sample containing carbendazim 20 times. The relative standard deviation (RSD) of the test results was small, which proved that the device has stable performance for repeated use.

[0130] 3. Accuracy verification: Ten commercially available tomato samples were tested using this device and gas chromatography-mass spectrometry (GB23200.113-2018). The deviation between the two methods was ≤4%, proving that the device is accurate and reliable.

[0131] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A sensor based on terahertz metamaterial, characterized in that it includes a substrate and a plurality of double resonators arranged in a periodic array on the substrate; wherein the substrate has an Au layer, a Ti layer and a PI layer arranged in a stacked manner; the double resonator includes a figure-eight structure and two one-shaped structures, both of which have a Ti layer and an Au layer arranged in sequence from the PI layer of the substrate towards the Au layer背离 the substrate; the middle positions of the upper and lower horizontal lines of the figure-eight structure are interrupted; each one-shaped structure is located within one of the openings of the figure-eight structure, parallel to the horizontal line of the figure-eight structure, and there is a gap between it and the contour surrounding the figure-eight structure.

2. The sensor based on terahertz metamaterial according to claim 1, characterized in that the thickness of the Au layer is 14μm, the thickness of the Ti layer is 10 nm, and the thickness of the Au layer is 200 nm.

3. The sensor based on terahertz metamaterial according to claim 1, characterized in that the length and width of the figure-eight structure are both denoted as h, the width of the upper and lower horizontal lines is denoted as a, the interruption length is f, the width of the middle horizontal line is denoted as c, the width within the opening is denoted as d, the length of the one-shaped structure is denoted as b, and the width is denoted as e; wherein a = 7±2μm, b = 40±4μm, c = 5±2μm, d = 46±4μm, e = 5±2μm, f = 18±2μm, h =60±5μm.

4. A multi-residual pesticide detection device, characterized in that it includes: the sensor based on terahertz metamaterial according to any one of claims 1-3; an independent cavity; an inlet pipe, connecting the liquid inlet of the independent cavity; a transparent serpentine microfluidic channel, connecting the liquid outlet of the independent cavity and located above the sensor based on terahertz metamaterial; a terahertz wave generator, located above the transparent serpentine microfluidic channel, for emitting terahertz waves towards the transparent serpentine microfluidic channel.

5. The multi-residual pesticide detection device according to claim 4, characterized in that it further includes a plurality of color reaction cavities, each color reaction cavity is filled with a corresponding color reaction reagent, and all are connected to the inlet pipe.

6. The multi-residual pesticide detection device according to claim 5, characterized in that it further includes a waste liquid pipe and a waste liquid collection cavity, the inlet of the waste liquid pipe is connected to the independent cavity and the plurality of color reaction cavities, and the outlet is connected to the waste liquid collection cavity.

7. The multi-residual pesticide detection device according to claim 5, characterized in that each color reaction cavity is provided with an insertion port for inserting a reagent module, and the color reaction reagent is added through the insertion of the reagent module.

8. A multi-residual pesticide detection method based on the multi-residual pesticide detection device according to any one of claims 4-7, characterized in that it includes: the liquid to be detected reaches the independent cavity through the inlet pipe, and then enters the transparent serpentine microfluidic channel; the terahertz wave generator emits terahertz waves towards the transparent serpentine microfluidic channel; the sensor based on terahertz metamaterial captures the spectral frequency shift signal of the terahertz wave passing through the transparent serpentine microfluidic channel and reflected by its own substrate; the spectral frequency shift signals are compared with the standard spectral frequency shift signals of each pesticide residue calibrated in advance to determine the types and concentrations of each pesticide residue.

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