CN108827903B - Terahertz non-bi-anisotropic metamaterial label-free sensor and its preparation and application - Google Patents

Abstract

The invention relates to a terahertz non-bi-anisotropic metamaterial label-free sensor, preparation and application, and belongs to the technical field of biology. The flexible substrate polyimide structure comprises a flexible substrate polyimide, wherein a metal layer is arranged on the upper layer of the flexible substrate polyimide, the metal layer is a titanium metal layer which is located on the lower layer and is 20nm thick and a gold metal layer which is located on the upper layer and is 200nm thick, the titanium metal layer is on the flexible substrate polyimide, and the metal layer is a double-opening metal resonance ring. The invention has the advantages that the asymmetrical double-opening metal resonance ring is designed to realize the electromagnetic induction transparent resonance peak, cells are inoculated on the surface of the metamaterial through cell culture, finally the resonance frequency deviation of the device is detected by using a back transmission method, the theoretical sensitivity is up to 455GHz/RIU, the cancer cell concentration can be rapidly and preliminarily detected without marks, and the apoptosis tendency of the oral cancer cell HSC3 under different time of the action of the anti-cancer medicament can be obtained.

Description

Terahertz non-bi-anisotropic metamaterial label-free sensor and its preparation and application

technical field

The invention relates to a terahertz non-bi-anisotropic metamaterial label-free sensor, preparation and application thereof, and belongs to the field of biotechnology.

Background technique

Terahertz technology is currently attracting attention in public safety, communications, and biomedical applications. And terahertz metamaterials can achieve controllable electromagnetic response by designing the corresponding unit geometry, that is, people can flexibly control their electromagnetic properties only by designing the resonant structure. It has shown great application prospects in functional devices such as label-free sensors of structural materials, especially in the highly sensitive sensing and recognition of biological samples. Traditional flow cytometry can detect cell concentration markers, but the test time is long and the cost is high.

SUMMARY OF THE INVENTION

The invention provides a terahertz non-bi-anisotropic metamaterial label-free sensor, a preparation method and a method for testing the concentration and apoptosis trend of cancer cells, which solve the problems of long testing time and high cost of traditional flow cytometry labeling detection technology and Insufficient, the realization of the detection process time is short, the detection cost is low.

In order to realize the above-mentioned purpose of the invention, the technical scheme adopted in the present invention is,

Terahertz non-anisotropic metamaterial label-free sensor, the structure is as follows, including a flexible substrate polyimide, the flexible substrate polyimide is provided with a metal layer on the upper surface, the thickness of the flexible substrate polyimide is 25um, The metal layer is arranged on the upper surface of the flexible base polyimide at equal distances horizontally and vertically. The metal layer includes a titanium metal layer with a thickness of 20 nm and a gold metal layer with a thickness of 200 nm. The gold metal layer is on the top of the titanium metal layer. The titanium metal layer is in contact with the upper surface of the flexible base polyimide, the metal layer is an asymmetric double-opening metal resonator ring, and the double-opening metal resonance ring is evenly arranged on the upper surface of the flexible base polyimide;

The top-view shape of the double-opening metal resonator ring is two opposite “bow”-shaped metal rings. The two “bow”-shaped metal rings form a hollow “I” shape with two notches. The gap is located at the top edge of the “I” shape and On the bottom edge, the two notches are not on the same vertical line, and the line width of the "bow"-shaped metal ring is 3 µm.

Preferably, the distance between adjacent double-opening metal resonator rings is 12um, the length and width of the double-opening metal resonator ring are both 44 µm, the distance d of the slit in the middle of the double-opening metal resonator ring structure is 6um, and the distance g between the middle of the double-opening metal resonance ring structure is 4um, and the lateral distance between the centerlines of the two gaps is 28um.

A method for preparing a label-free sensor of a terahertz non-bi-anisotropic metamaterial includes the following preparation steps,

(1) Spin-coat 25 μm polyimide film on the cleaned Si substrate;

(2) Coating photoresist AZ5214 on the polyimide film and drying;

(3) Expose the photoresist with a photolithography machine;

(4) developing and drying the exposed photoresist;

(5) The thickness of 20nm titanium and 200nm gold are deposited by evaporation on the surface of the developed polyimide pattern;

(6) Soak the metal-deposited Si substrate in acetone solution for 10 minutes, and peel off the remaining photoresist;

(7) Removal of the substrate: The Si substrate deposited with metal was soaked in hydrofluoric acid for 10 minutes to peel off the substrate and the polyimide film.

Preferably, the following steps are included:

1) First clean the Si substrate, the size of the Si substrate is 10mm × 10mm, the thickness is 500μm, respectively, with acetone, alcohol, ultrasonic cleaning, each time is 15 minutes, and finally rinsed with deionized water 3-5 times to remove Organic contamination on the surface keeps the polished surface of the substrate clean.

2) Then spin-coat a polyimide solution with a viscosity of 3600 (centipoise) on the cleaned silicon wafer, and place the spin-coated polyimide solution in a vacuum drying oven for curing. Bake for 1 hour each at 120°C, 200°C and 230°C, then bake for another 2 hours at 250°C, and finally cool to room temperature and take out;

3) On the polyimide film, spin-coat a 1 μm-thick reversal photoresist AZ5214, and pre-bake at 95°C for 90 seconds;

4) Place the photoresist-coated substrate and the prepared mask on the lithography machine and align them, attach the Si substrate to the mask, observe with the microscope on the lithography machine, and adjust the exposure time. The exposure time is 9.8 seconds, exposure 4 times, then reverse baking is carried out after exposure, bake for 1 minute at 110 ° C, then reverse exposure for 45 seconds, and finally utilize developer to develop, the time is 45 seconds, and post-bake is carried out after developing, The baking temperature is 90℃, and the time is 10 minutes;

5) Deposit 20nm thick titanium and 200nm thick gold by evaporation on the exposed polyimide film;

6) Put the above-mentioned vapor-deposited Si substrate into an acetone solution for stripping to remove the remaining photoresist AZ5214 and the first layer of metal on the photoresist, soak for about 20 minutes, and then remove the remaining photoresist AZ5214 and the first layer metal on the photoresist. Propanol and deionized water cleaning;

7) Soak the polyimide film on the Si substrate in a 1:10 hydrofluoric acid solution for about 10 minutes, then take it out, peel off the polyimide film from the silicon substrate, and at a temperature of 90°C Cured for about 10 minutes.

6. The method for preparing a terahertz non-bi-anisotropic metamaterial label-free sensor according to claim 5, wherein in step (2), the polyimide solution is spin-coated twice to obtain a thickness of 25 μm For the polyimide film, after the first coating of polyimide, it is first baked at 120 ° C and 200 ° C for 1 hour, and then the second coating of polyimide is cured.

A method for testing cancer cell concentration and apoptosis trend using a terahertz non-amphitropic metamaterial label-free sensor includes the following steps,

1) First, the cancer cells were seeded in the unlabeled sensor of terahertz non-bi-anisotropic metamaterials, and the cancer cells were digested from the petri dish with trypsin; After sterilization of the label-free sensor of the terahertz non-bi-anisotropic metamaterial, it was placed at the bottom of the culture plate and the single cell suspension was inoculated into the culture plate, and then placed in a 37°C, 5% carbon dioxide cell incubator for culture ;

2) Put the above label-free sensor of terahertz non-anisotropic metamaterial seeded with cancer cells into a terahertz time-domain spectrometer for detection. The terahertz beam is set to be incident from the polyimide layer, and then from the metal The optical path set out from the layer is set for detection, and the electromagnetic response characteristics of the transmitted wave are obtained;

3) Seed different concentrations of HSC3 oral cancer cells on the terahertz non-biisotropic metamaterial label-free sensor, and detect the resonance frequency of the terahertz non-bi anisotropic metamaterial label-free sensor compared to the cell-free concentration The resonance frequency offset is obtained to obtain the concentration detection curve;

4) Add the anticancer drug cisplatin at a concentration of 1 μM to the label-free sensor of terahertz non-bi-anisotropic metamaterial cultured with a certain concentration of HSC3 oral cancer cells, and detect the terahertz non-bi-anisotropic at different times. The resonant frequency of the heterosexual metamaterials label-free sensor was compared with the resonant frequency offset of the cell-free concentration, and the apoptosis curve of oral cancer cells was obtained.

In step 3), HSC3 oral cancer cells were cultured at concentrations of 1×10 ⁵ cells/ml, 4×10 ⁵ cells/ml, and 7×10 ⁵ cells/ml. After culturing for 24 hours, they were removed from the medium and the surface was removed with filter paper. Moisture, after it is fully dried, use a terahertz time-domain spectrometer to test the resonance frequency offset.

In step 4), the cell concentration of HSC3 oral cancer cells to which 1 μM concentration of anticancer drug cisplatin was added was 2×10 ⁶ cells/ml, and the cells were treated for 24, 48 and 72 hours respectively. Take out and remove the surface moisture with filter paper, and use the terahertz time-domain spectrometer to test the resonance frequency offset after it is fully dried.

The advantage of the present invention is that compared with the previous structure, the terahertz cancer cell sensor of this structure is designed with an asymmetric double-opening metal resonant ring to realize the electromagnetically induced transparent resonance peak, and the loss at the resonance response frequency is only related to the material itself. Cells are seeded on the surface of the metamaterial, and finally the resonant frequency shift of the device is detected by the back transmission method. The theoretical sensitivity is as high as 455GHz/RIU. apoptosis trend.

Description of drawings

FIG. 1 is a schematic top view of the label-free sensor of terahertz non-bi-anisotropic metamaterials;

FIG. 2 is a schematic three-dimensional structure diagram of a label-free sensor of a terahertz non-bi-anisotropic metamaterial;

Figure 3 is a micrograph of a label-free sensor of a terahertz non-bi-anisotropic metamaterial,

Fig. 4 is the physical picture of the unlabeled sensor of terahertz non-bi-anisotropic metamaterial;

FIG. 5 is a schematic diagram of a terahertz non-bi-anisotropic metamaterial label-free sensor using a back-transmission method to detect a device resonance frequency shift;

Fig. 6 is the transmission resonance curves of different concentrations of HSC3 cancer cells tested by the label-free sensor of terahertz non-amphitropic metamaterials;

Fig. 7 is the resonance frequency shift under different cancer cell concentrations tested for the label-free sensor of the terahertz non-amphitropic metamaterial;

Figure 8 shows the resonant frequency shift of the anti-cancer drug cisplatin for different times under certain cell concentration conditions and the cell survival rate tested by the biological CCK-8 method as tested by the label-free sensor of terahertz non-biisotropic metamaterials curve.

Detailed ways

Below in conjunction with the accompanying drawings and specific embodiments, the present invention will be further clarified. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of use of the present invention. Modifications of all equivalent forms fall within the scope defined by the appended claims of this application.

The terahertz non-bi-anisotropic metamaterial label-free sensor of the present invention is an asymmetric double-opening metal resonant ring, which can generate electromagnetically induced transparent resonance peaks, inoculate cells on its surface through cell culture, and finally use a back transmission method. The detection device resonant frequency shift is used to test the concentration of cancer cells. As shown in Figure 5.

The terahertz non-biisotropic metamaterial label-free sensor of the present invention is specifically an electromagnetically induced transparent Fano resonant metamaterial. By utilizing its electromagnetic response characteristics, the electromagnetically induced transparent peak line type is only compatible with metal materials. Therefore, any linear changes in resonance characteristics can be considered to be caused by external substances, and the sensitivity of the sensor is relatively large. Based on the above analysis, we designed the flexible substrate polyimide (PI)-based terahertz high-sensitivity cancer cell sensor. The structure is shown in Figure 1. The overall structure of the sensor includes two layers, the upper metal layer and the lower The dielectric layer of polyimide is used as a flexible substrate to support the upper metal structure. In the structure claimed in this patent application, the metal layer structure is composed of two bow-shaped double-opening metal resonator rings, as shown in FIG. 1 and FIG. 2 .

The top-view shape of the double-opening metal resonator ring is two opposite “bow”-shaped metal rings. The two “bow”-shaped metal rings form a hollow “I” shape with two notches. The gap is located at the top edge of the “I” shape and On the bottom edge, the two notches are not on the same vertical line.

The main reason for choosing this structure is that the strong radiation loss (bright mode) and sub-radiation loss (dark mode) formed by it can interfere with each other, and the resonance response reflected in the spectrum will generate electromagnetically induced transparent peaks, the structure is easy to fabricate, and the sensitivity high. In order to determine the specific parameters of the structure, the electromagnetic field software CST based on the finite element time-domain difference algorithm is used to simulate the simulation. Determine specific parameters. The thickness of the polyimide in Figure 1 is 10 µm, and the metal structure layer includes titanium with a thickness of 20 nm and gold with a thickness of 200 nm. The relevant parameters of the double-open metal resonator are: p=50 μm, w=44 μm, t=25 μm, d=6 μm, g=4 μm , s=28 μm.

Fabrication of label-free sensors of terahertz non-bi-anisotropic metamaterials;

The actual production is carried out according to the structural parameters of the terahertz sensor as shown in Figure 1 and Figure 2. The specific steps are as follows:

(1) Spin coating 25μm thick polyimide film

First clean the silicon substrate, the size of the silicon wafer is 10mm × 10mm, the thickness is 500μm, respectively, with acetone, alcohol, ultrasonic cleaning, each time is 15 minutes, and finally rinsed with deionized water 3-5 times to remove the surface organic Contamination cleans the polished surface of the substrate.

(2) Then spin-coat a polyimide solution with a viscosity of 3600 (centipoise) on the cleaned silicon wafer. In order to obtain a polyimide film with a uniform thickness, place the spin-coated PI solution in a vacuum drying oven to cure. The curing process is to bake for 1 hour at 120°C, 200°C and 230°C respectively, then bake for 2 hours at 250°C, and finally cool to room temperature and take out. The method of increasing the thickness of PI film by multiple overlapping gluing is used. After the first gluing, bake for 1 hour at 120 °C and 200 °C respectively, and then glue and cure. The purpose of this is to avoid the film thickness. There is an air gap in between. If a relatively thick PI film is spin-coated, in order to make all the water in the solution evaporate, the baking time can be longer to respond, so that the film performance after curing is relatively stable.

(3) Spin coating reverse photoresist

On the polyimide film, a 1 μm thick reversal photoresist AZ5214 was spin-coated and prebaked at 95°C for 90 seconds.

(4) UV exposure and development

Place the substrate coated with photoresist and the prepared mask (MASK) on the photolithography machine and align it, stick the substrate and MASK closely, observe with the microscope on the photolithography machine, and adjust the exposure time, the exposure time is 9.8 seconds, 4 exposures. After exposure, a reverse bake was performed at 110°C for 1 minute. Then reverse exposure for 45 seconds, and finally develop with developing solution for 45 seconds. After developing, post-baking is performed, and the baking temperature is 90° C. and the time is 10 minutes.

(5) Evaporated layer metal and peeling

20 nm thick titanium and 200 nm thick gold were deposited by evaporation on the exposed polyimide film.

(6) Soak the vapor-deposited metal sample in acetone solution for stripping to remove the remaining photoresist AZ5214 and the first layer of metal on the photoresist, and the soaking time is about 20 minutes. Then rinse with isopropanol and deionized water.

After steps (5) and (6), a layer of metal structure can be obtained.

(7) Silicon substrate peeling off

The method of removing the polyimide film from the silicon substrate is to soak the polyimide film on the silicon substrate in a 1:10 hydrofluoric acid solution for about 10 minutes, then take it out and carefully remove the polyimide film. The film was peeled off from the silicon substrate and cured at a temperature of 90°C for about 10 minutes.

After the above procedures, the label-free sensor of terahertz metamaterials as shown in Figure 3 and Figure 4 can be obtained, and the size of the entire sensor is 10 mm × 10 mm. Compared with the previous structure, the terahertz sensor of this structure has single electromagnetic response information, and the theoretical sensitivity is as high as 455 GHz/RIU.

The most important application aspect of the label-free sensor of the terahertz non-bi-anisotropic meta-material with the label-free property of the terahertz meta-material designed in the present invention is biological sensing. The concentration of cancer cells and the tendency of apoptosis were tested by using this terahertz non-bi-anisotropic metamaterial label-free sensor. The test process includes the following steps.

1) First, the HSC3 oral cancer cells were inoculated in the non-di-anisotropic metamaterial label-free sensor of terahertz, and the cancer cells were digested from the petri dish with trypsin; then the cells were homogeneously blown with the medium to form a single-cell suspension ; After sterilizing the terahertz non-bi-anisotropic metamaterial unlabeled sensor, place it at the bottom of the culture plate and inoculate the single cell suspension into the culture plate, and put it into a 37°C, 5% carbon dioxide cell incubator cultivated in

2) Put the above-mentioned terahertz non-ambiisotropic metamaterial label-free sensor seeded with HSC3 oral cancer cells into a terahertz time-domain spectrometer for detection, and the terahertz beam is set to be incident from the polyimide layer, and then The optical path emitted from the metal layer is set for detection, and the electromagnetic response characteristics of the transmitted wave are obtained, as shown in FIG. 5 .

3) HSC3 oral cancer cells with the concentration of 1×10 ⁵ cell/ml, 4×10 ⁵ cell/ml and 7×10 ⁵ cell/ml were inoculated on the label-free sensor of terahertz non-biisotropic metamaterial After culturing for 24 hours, take it out from the culture medium and remove the surface water with filter paper. After it is fully dried, use a terahertz time-domain spectrometer to detect the resonant frequency of the label-free sensor of the terahertz non-amphitropic metamaterial compared with that in the cell-free concentration. Resonance frequency offset, Figure 7 shows the transmission spectrum of cultured HSC3 oral cancer cells measured by a terahertz time-domain spectrometer in a nitrogen atmosphere dry at room temperature (humidity less than 4%). It can be seen from Fig. 7 that under the three different concentrations of cancer cells, the resonant frequency shifts are 50 GHz, 68 GHz, and 90 GHz, respectively, compared with the cell-free metamaterials. Figure 6 shows the transmission resonance curves of different concentrations of HSC3 cancer cells tested by the label-free sensor of the terahertz non-amphitropic metamaterial.

4) The anticancer drug cisplatin at a concentration of 1 μM was added to the terahertz non-bi-anisotropic metamaterial unlabeled sensor cultured with HSC3 oral cancer cells with a cell concentration of 2×10 ⁶ cells/ml, respectively acting on 24, 48 and 72 hours, after the action time is completed, take out from the culture medium and remove the surface water with filter paper, and use a terahertz time-domain spectrometer to detect the terahertz non-bi-anisotropic metamaterial label-free sensor resonance frequency compared to the cell-free concentration Resonance frequency shift and oral cancer cell apoptosis curves under. Figure 8 shows the tested resonance frequency offset and the cell viability curve tested by the biological CCK-8 method. The trend of the curve obtained by the concentration of anticancer drugs and the different time of action was consistent with the cell survival rate measured by the biological CCK-8 kit method.

At the same time, we also simulated the test results of the samples to be tested with different refractive index parameters, and defined the sensitivity of the terahertz sensor as: Δ f /Δ n , where Δ f is the frequency offset. Through calculation, it is obtained that the theoretical sensitivity of the terahertz sensor of the present invention reaches 455 GHz/RIU. In conclusion, we designed and fabricated a label-free terahertz metamaterial sensor on a flexible polyimide substrate with label-free properties of terahertz metamaterials, which can respond to pure electric fields, with high sensitivity and label-free detection. Label-free detection of cell concentration and the changing trend of cell concentration under the influence of external factors can be performed initially and rapidly. Therefore, it can be widely used in the field of terahertz biosensing and recognition.

Claims (8)

1. a terahertz non-double anisotropic metamaterial label-free sensor, is characterized in that, the structure is as follows, including flexible base polyimide, flexible base polyimide is provided with the metal layer on the upper surface, flexible base The thickness of the polyimide is 25µm, and the metal layers are arranged at equal distances horizontally and vertically on the upper surface of the flexible substrate polyimide. The metal layers include a titanium metal layer with a thickness of 20nm and a gold metal layer with a thickness of 200nm. The gold metal layer is in the titanium metal layer. Above the layer, the titanium metal layer contacts the upper surface of the flexible base polyimide, the metal layer is an asymmetric double-opening metal resonance ring, and the double-opening metal resonance ring is evenly arranged on the upper surface of the flexible base polyimide; The top-view shape of the double-opening metal resonator ring is two opposite “bow”-shaped metal rings. The two “bow”-shaped metal rings form a hollow “I” shape with two notches. The gap is located at the top edge of the “I” shape and On the bottom edge, the two notches are not on the same vertical line, and the line width of the "bow"-shaped metal ring is 3 µm. 2. The terahertz non-bi-anisotropic metamaterial label-free sensor according to claim 1, wherein the adjacent double-slit metal resonator rings are separated by 12 µm, and the length and width w of the double-slit metal resonator rings are both 44 µm, The distance d of the slit in the middle of the double-slit metal resonator structure is 6 µm, the distance g between the middle of the double-slit metal resonator structure is 4 µm, and the lateral distance s between the centerlines of the two gaps is 28 µm. 3. The preparation of the terahertz non-bi-anisotropic metamaterial label-free sensor according to claim 1, characterized in that it comprises the following preparation steps, (1) Spin-coat 25 μm polyimide film on the cleaned Si substrate; (2) spin-coating 1 μm photoresist AZ5214 on the polyimide film and drying; (3) Expose the photoresist with a photolithography machine; (4) developing and drying the exposed photoresist; (5) The thickness of 20nm titanium and 200nm gold are deposited by evaporation on the surface of the developed polyimide pattern; (6) Soak the metal-deposited Si substrate in acetone solution for 10 minutes, and peel off the remaining photoresist; (7) Removing the substrate, soaking the metal-deposited Si substrate in hydrofluoric acid for 10 minutes to peel off the substrate and the polyimide film. 4. The preparation method of terahertz non-bi-anisotropic metamaterial label-free sensor according to claim 3, wherein, 1) First clean the Si substrate, the size of the Si substrate is 10mm × 10mm, the thickness is 500μm, respectively, with acetone, alcohol, ultrasonic cleaning, each time is 15 minutes, and finally rinsed with deionized water 3-5 times to remove The organic pollutants on the surface make the polishing surface of the substrate clean; 2) Then spin-coat a polyimide solution with a viscosity of 3600 centipoise on the cleaned silicon wafer, and put the spin-coated polyimide solution in a vacuum drying oven for curing. The curing process is performed at a temperature of 120 Bake for 1 hour at ℃, 200℃ and 230℃, then bake for 2 hours at 250℃, and finally cool to room temperature and take out; 3) On the polyimide film, spin-coat a 1 μm-thick reversal photoresist AZ5214, and pre-bake at 95°C for 90 seconds; 4) Place the photoresist-coated substrate and the prepared mask on the lithography machine and align them, attach the Si substrate to the mask, observe with the microscope on the lithography machine, and adjust the exposure time. The exposure time is 9.8 seconds, exposure 4 times, then reverse baking is carried out after exposure, bake for 1 minute at 110 ° C, then reverse exposure for 45 seconds, and finally utilize developer to develop, the time is 45 seconds, and post-bake is carried out after developing, The baking temperature is 90℃, and the time is 10 minutes; 5) Deposit 20nm thick titanium and 200nm thick gold by evaporation on the exposed polyimide film; 6) Put the above-mentioned vapor-deposited Si substrate into an acetone solution for stripping to remove the remaining photoresist AZ5214 and the first layer of metal on the photoresist, soak for about 20 minutes, and then remove the remaining photoresist AZ5214 and the first layer metal on the photoresist. Propanol and deionized water cleaning; 7) Soak the polyimide film on the Si substrate in a 1:10 hydrofluoric acid solution for about 10 minutes, then take it out, peel off the polyimide film from the silicon substrate, and at a temperature of 90°C Cured for about 10 minutes. 5 . The method for preparing a label-free sensor of terahertz non-anisotropic metamaterials according to claim 4 , wherein in step (2), the polyimide solution is spin-coated twice to obtain a thickness of 25 μm. 6 . For the polyimide film, after the first coating of polyimide, it is first baked at 120 ° C and 200 ° C for 1 hour, and then the second coating of polyimide is cured. 6. A method for testing the concentration of cancer cells and the trend of apoptosis using the terahertz non-bi-anisotropic metamaterial label-free sensor in claim 1, characterized in that, comprising the following steps: 1) First, the HSC3 oral cancer cells were inoculated in the non-di-anisotropic metamaterial label-free sensor of terahertz, and the cancer cells were digested from the petri dish with trypsin; then the cells were homogeneously blown with the medium to form a single-cell suspension ; After sterilizing the terahertz non-bi-anisotropic metamaterial unlabeled sensor, place it at the bottom of the culture plate and inoculate the single cell suspension into the culture plate, and put it into a 37°C, 5% carbon dioxide cell incubator cultivated in 2) Put the above-mentioned terahertz non-ambiisotropic metamaterial label-free sensor seeded with HSC3 oral cancer cells into a terahertz time-domain spectrometer for detection, and the terahertz beam is set to be incident from the polyimide layer, and then The optical path set out from the metal layer is set for detection, and the electromagnetic response characteristics of the transmitted wave are obtained; 3) Seed different concentrations of HSC3 oral cancer cells on the terahertz non-biisotropic metamaterial label-free sensor, and detect the resonance frequency of the terahertz non-bi anisotropic metamaterial label-free sensor compared to the cell-free concentration The resonance frequency offset is obtained to obtain the concentration detection curve; 4) Add the anticancer drug cisplatin at a concentration of 1 μM to the label-free sensor of terahertz non-bi-anisotropic metamaterial cultured with a certain concentration of HSC3 oral cancer cells, and detect the terahertz non-bi-anisotropic at different times. The resonant frequency of the heterosexual metamaterials label-free sensor was compared with the resonant frequency offset of the cell-free concentration, and the apoptosis curve of oral cancer cells was obtained. 7 . The method for testing the concentration of cancer cells and the trend of apoptosis using a label-free sensor for terahertz non-bi-anisotropic metamaterials according to claim 6 , wherein the culture concentration in step 3) is 1×10 ⁵ cells/ml , 4×10 ⁵ cells/ml and 7×10 ⁵ cells/ml of HSC3 oral cancer cells were cultured for 24 hours and removed from the culture medium and the surface moisture was removed with filter paper, and the resonance was tested by a terahertz time-domain spectrometer after being fully dried. frequency offset. 8 . The method for testing the concentration of cancer cells and the trend of apoptosis by a label-free sensor of terahertz non-bi-anisotropic metamaterials according to claim 6 , wherein the anticancer drug cisplatin at a concentration of 1 μM is added in step 4). The cell concentration of HSC3 oral cancer cells was 2×10 ⁶ cells/ml, and the cells were treated for 24, 48 and 72 hours respectively. After the action time was completed, the cells were taken out from the culture medium and the surface water was removed with filter paper. Test resonance frequency offset in a Hertz time-domain spectrometer.