Aerosol detection method based on terahertz metasurface sensor and SARS-CoV-2

Abstract

The invention discloses an aerosol detection method based on a terahertz metasurface sensor and SARS-CoV-2, and belongs to the technical field of biological detection. The terahertz wave band metasurface sensor comprises a substrate and a metasurface structure attached to the substrate. The metasurface is designed on the basis of a Friedrich-Wintgen quasi bound state in a continuous medium F-W QBIC method and is formed by coupling an I-shaped resonator and a C-shaped resonator, an IC-shaped array at least comprises 1250 resonance ring units which are evenly distributed and equal in size, each resonance ring unit is in a capital letter I shape and a capital letter C shape, and the resonance ring units are used for achieving resonance under the terahertz wave band. The aerosol detection method comprises the following steps: generating aerosol by using an aerosol generator, collecting an aerosol sample by means of a negative pressure suction mode, analyzing a change rule of resonant frequency in a QBIC resonant mode, and constructing a standard equation of the content and the frequency of SARS-CoV-2; and according to the measured data, the detection of the SARS-CoV-2 is realized by combining a standard equation.

Description

Technical Field

[0001] The present invention relates to terahertz time-domain spectroscopy detection technology, and relates to a terahertz metasurface sensor and a SARS-CoV-2 aerosol detection method based on the same, belonging to the technical field of biological detection. Background Art

[0002] Infection with the novel coronavirus (SARS-CoV-2) can cause patients to suffer from coronavirus disease 2019 (COVID-19). Among them, SARS-CoV-2 is an RNA virus transmitted through the respiratory tract, with high infectivity and significant immune evasion ability. Rapid and accurate screening and isolation of positive patients are crucial for effectively organizing the spread of the virus, which makes the demand for highly sensitive detection technology extremely urgent.

[0003] In the prior art, quantitative real-time PCR (qRT-PCR) is the gold standard for infectious disease control. However, this technology is time-consuming and requires advanced infrastructure and skilled operators, and it is difficult to implement in environments with poor economy and infrastructure; rapid antigen testing (RAT) has low cost and simple operation but low sensitivity; although terahertz spectroscopy technology has the potential for rapid and quantitative detection, it is challenging to detect trace substances. Although terahertz spectroscopy combined with metamaterial (MM) technology can enhance the interaction between light and matter to achieve label-free detection of trace substances, most studies focus on detecting SARS-CoV-2 solutions, and there are few studies on SARS-CoV-2 aerosols. Moreover, the current detection relies on amplification technology, which affects the timeliness.

[0004] In view of this, the present invention proposes a metasurface design and preparation method based on the BIC theory and its application in the detection of SARS-CoV-2 aerosols to achieve a highly sensitive, rapid and direct detection method. Summary of the Invention

[0005] One of the objectives of the present invention is to provide a terahertz metasurface sensor capable of detecting various aerosol-transmitted viruses and other substances.

[0006] Another objective of the present invention is to provide a SARS-CoV-2 aerosol detection method based on the terahertz metasurface sensor. Without the need for additional labeling or enzymes, it can work at room temperature and pressure, directly detect SARS-CoV-2 aerosols, without complex pre-signal amplification steps, and can more truly reflect the actual situation of virus proteins in aerosols.

[0007] The objectives of the present invention are achieved through the following technical solutions:

[0008] The terahertz band metasurface sensor disclosed by the present invention includes a substrate and a metasurface structure attached to the substrate; the metasurface is designed based on the Friedrich-Wintgen quasi-bound state in a continuum F-W QBIC method and is composed of two different resonators of "I" shape and "C" shape. Among them, the "IC" shape array includes at least 1250 uniformly arranged and equal-sized resonator ring units. The resonator ring units are in the shapes of capital letters "I" and "C", and the resonator ring units are used to achieve resonance in the terahertz band.

[0009] Among them, the substrate material is selected from one of polyimide, high-resistance silicon or quartz, and the thickness is 0.1 - 0.5 mm; preferably, the substrate material is quartz glass with a size of 3×3 cm. 2 , and the thickness is 0.5 mm. The material of the metal meta-atom resonator unit is selected from one of gold, copper, aluminum, etc., and the thickness is 200 nm; preferably, the material of the metal meta-atom resonator unit is gold with a thickness of 200 nm.

[0010] Preferably, the "I" shape structure is composed of a removed straight line segment, and the "C" shape structure is composed of a removed structure in the shape of an open ring.

[0011] Further preferably, the size of the metal meta-atom resonator unit is 200×400 μm, the length of each "I" shape structure is 110 μm, the outer diameter of each "C" shape structure is 160 μm, the inner diameter is 130 μm, and the opening width is 20 μm.

[0012] The above-mentioned metamaterial structure can be obtained through ultraviolet lithography technology and Lift-off technology. For example, a finite element simulation software is used for design and simulation, and a mask processing drawing is drawn using a plate-making software. Through the ultraviolet lithography technology, an effective and usable terahertz metasurface sensor in the shape of "IC" is processed.

[0013] The parameters of the resonator ring unit include periodicity w, slit length a, length l of the "I" shape meta-atom, inner and outer radii r1 and r2 of the "C" shape meta-atom, and opening width g.

[0014] The SARS-CoV-2 aerosol detection method based on a terahertz metasurface sensor is realized based on the said sensor. The SARS-CoV-2 aerosol detection method based on a terahertz metasurface sensor is as follows: Prepare a SARS-CoV-2 solution with a standard concentration, generate aerosol using an aerosol generator, and collect aerosol samples by means of negative pressure inhalation to carry out detection work. Collect 0.1 - 1.4 THz spectral data, deeply analyze the variation law of the resonance frequency in the QBIC resonance mode, and then construct a standard equation for the content and frequency of SARS-CoV-2. Based on the measured data, combine the standard equation of the content and frequency of SARS-CoV-2 to achieve the detection of SARS-CoV-2.

[0015] The SARS-CoV-2 aerosol detection method based on a terahertz metasurface sensor is realized based on the said sensor. The SARS-CoV-2 aerosol detection method based on a terahertz metasurface sensor includes the following steps:

[0016] Step 1: Prepare a standard solution of SARS-CoV-2 with deionized water;

[0017] Step 2: Pour the standard solution of SARS-CoV-2 into the aerosol generating device as the sample to be measured; Use the terahertz frequency-domain spectroscopy system, and in the reflection measurement mode, collect the terahertz spectral data of air at room temperature as the reference signal, and the terahertz spectral data of different amounts of aerosol samples as the sample signal to obtain the reference amplitude Iref(v) and the sample amplitude Isam(v);

[0018] Step 3: In the range of 0.1 - 1.4 THz, use the amplitude information to obtain the reflectivity of the SARS-CoV-2 sample through R(v) = Isam(v) / Iref(v), and establish a standard equation for the content and reflectivity of SARS-CoV-2;

[0019] Step 4: According to the above frequency-reflectivity curve, obtain the frequencies f corresponding to the resonance peaks of different amounts of SARS-CoV-2 respectively, and establish a standard equation for the content and frequency of SARS-CoV-2;

[0020] Step 5: Subtract the frequency f corresponding to different amounts of SARS-CoV-2 samples from the frequency f0 of the deionized water sample to obtain the corresponding frequency offset Δf, and establish a standard equation for the content and frequency offset of SARS-CoV-2;

[0021] Step 6: Replace the standard solution in Step 2 with the sample solution to be measured, and measure the sample solution to be measured according to Steps 2 - 5.

[0022] Preferably, the concentration of the standard solution of SARS-CoV-2 prepared in Step 1 is 1 ng / mL; the measurement conditions of the terahertz frequency-domain spectroscopy system in Step 2 are: 20-25 °C, relative humidity <40%.

[0023] Preferably, the standard equation of the content and frequency of SARS-CoV-2 established in Step 4 is:

[0024] SARS-CoV-2: f = 8.92*10 -5 x 2 -0.12x + 41.33, 650 < f < 705

[0025] The standard equation of the content and frequency shift of SARS-CoV-2 established in Step 5 is:

[0026] SARS-CoV-2: Δf = 42*lg x + 2.334;

[0027] In the formula: x is the volume of the standard solution added, with the unit of ng / mL, and Δf has the unit of GHz. f is the frequency corresponding to the resonance peak of SARS-CoV-2; Δf is the frequency shift obtained by subtracting the SARS-CoV-2 sample from the deionized water sample.

[0028] Preferably, the minimum detection limit of SARS-CoV-2 aerosol is 0.1 ng / mL.

[0029] Beneficial effects:

[0030] 1. The terahertz metasurface sensor and the SARS-CoV-2 aerosol detection method disclosed in the present invention are designed based on the Friedrich-Wintgen quasi-bound state in a continuum F-W QBIC method. The metasurface is composed of two different resonators, namely "I"-shaped and "C"-shaped, coupled together. An aerosol generator is used to generate aerosol, and the aerosol sample is collected by means of negative pressure inhalation for detection. No additional labeling or enzymes are required, and it can work at room temperature and pressure without complex pre-signal amplification steps, directly detecting SARS-CoV-2 aerosol.

[0031] 2. The terahertz metasurface sensor and SARS-CoV-2 aerosol detection method disclosed in the present invention utilizes a terahertz frequency domain spectroscopy system and adopts a reflection measurement mode to collect terahertz spectrum data of air at room temperature as a reference signal, and introduces terahertz spectrum data of different amounts of aerosol samples as sample signals to obtain a reference amplitude Iref(v) and a sample amplitude Isam(v); within the range of 0.1 to 1.4 THz, the amplitude information is used to obtain the reflectivity of the SARS-CoV-2 sample through R(v)=Isam(v) / Iref(v), and the relationship between the content of SARS-CoV-2 and the reflectivity is established. Standard equation; according to the above frequency-reflectivity curve, the frequencies f corresponding to the resonance peaks of different amounts of SARS-CoV-2 are obtained, and the standard equation of SARS-CoV-2 content and frequency is established; the frequency f corresponding to different amounts of SARS-CoV-2 samples is subtracted from the frequency f0 of the deionized water sample to obtain the corresponding frequency offset Δf, and the standard equation of SARS-CoV-2 content and frequency offset is established; based on the data obtained by the measurement, combined with the standard equation of SARS-CoV-2 content and frequency, SARS-CoV-2 can be detected, which can more truly reflect the actual situation of viral proteins in aerosols.

[0032] 3. The terahertz metasurface sensor and SARS-CoV-2 aerosol detection method disclosed in the present invention can achieve aerosol detection of SARS-CoV-2 with a concentration as low as 0.1ng / mL by deeply analyzing the change law of the resonant frequency in the QBIC resonant mode and constructing a standard equation for the content and frequency of SARS-CoV-2. It can effectively detect extremely low concentrations of viral proteins. The present invention can produce an obvious resonant frequency response to slight changes in the concentration of S protein, with a sensitivity of 1.42GHz / lg(ng·mL- 1 ).

[0033] 4. This has significant advantages over existing technologies. For example, qRT-PCR technology usually takes hours or even days to get test results. The terahertz metasurface sensor and SARS-CoV-2 aerosol detection method disclosed in the present invention can complete the detection in just 1 minute by simulating the patient's exhalation, which helps to take prevention and control measures in time and reduce the risk of virus transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the meta-atom structure and parameters of the terahertz supersurface of the present invention.

[0035] Figure 2 It is a reflection spectrum diagram of the structural parameter changes of the terahertz metasurface of the present invention and a schematic diagram of the FW QBIC mode fitting results.

[0036] Figure 3 Schematic diagram of the reflectivity spectrum test results of the terahertz metasurface sensor of the present invention.

[0037] Figure 4 Schematic diagram of the process of the terahertz metasurface sensor of the present invention for detecting SARS-CoV-2 aerosol.

[0038] Figure 5 Schematic diagram of the relationship between the frequency deviation and concentration of the terahertz metasurface sensor of the present invention for detecting SARS-CoV-2 aerosol.

[0039] Figure 6 Schematic diagram of the results of the terahertz metasurface sensor of the present invention for detecting SARS-CoV-2 aerosol.

[0040] Figure 7 Schematic diagram of the terahertz metasurface sensor of the present invention for detecting other proteins. Detailed implementation manners

[0041] First, the present invention conducts simulation design and preparation on the metasurface to obtain a highly sensitive terahertz metasurface sensor. Secondly, a detection method is formed by testing the SARS-CoV-2 sample through a terahertz frequency domain system.

[0042] The present invention will be further described below in conjunction with the drawings and embodiments.

[0043] Embodiment 1, Design and preparation of a terahertz metasurface sensor based on Friedrich-Wintgen quasi-bound states in the continuum (F-W QBIC).

[0044] As Figure 4 shown, the terahertz band metasurface sensor disclosed in this embodiment includes a substrate and a metasurface structure attached to the substrate; the metasurface is designed based on the Friedrich-Wintgen quasi-bound state in the continuum F-W QBIC method and is composed of two different resonators, namely "I"-shaped and "C"-shaped, where the "IC" array contains at least 1250 uniformly arranged and equal-sized resonator ring units, and the resonator ring units are in the shapes of capital letters "I" and "C", and the resonator ring units are used to achieve resonance in the terahertz band.

[0045] The substrate material is quartz glass, with a size of 3×3 cm 2 , and a thickness of 0.5 mm.

[0046] The material of the metal atomic resonator unit is gold, with a thickness of 200 nm.

[0047] The removed "IC" - shaped form. The "I" - shaped structure is composed of a removed straight - line segment, and the "C" - shaped structure is composed of a removed structure in the shape of an open - ring.

[0048] The removed "IC" - shaped form has a unit size of w μm, the length of the "I" - shaped structure is l μm, the width of the structure is a μm, the outer radius of the "C" - shaped structure is r 1 μm, and the inner radius is r 2 μm, and the opening width is g μm. Preferably, for the removed "IC" - shaped form, the unit size is 200×400 μm, the length of the "I" - shaped structure is 110 μm, the outer diameter of the "C" - shaped structure is 160 μm, the inner diameter is 130 μm, and the opening width is 20 μm.

[0049] As Figure 2 , the design principle of a metasurface sensor disclosed in the present invention is based on the bound state in the continuum (BIC) theory. It can be seen that by adjusting the length l of the "I" - shaped element atoms, the BIC phenomenon can be achieved under the condition of l = 135 μm, that is, at a specific frequency, the resonance peak "disappears", forming a bound - state mode with a Q - value approaching infinity.

[0050] The Q - value is a basic value describing the quality of the sensor. The higher the value, the better the performance of the sensor. The calculation formula is Q = f 0 / FWHM, where f 0 is the resonance - peak position and FWHM is the full - width at half - maximum at this point. As Figure 2 , it can be seen that by adjusting the length l of the "I" - shaped element atoms, the closer it is to the condition of l = 135 μm, the lower the FWHM, down to 10 to the negative N - th power, while the change of f 0 is relatively small. Therefore, the Q - value approaches infinity.

[0051] According to the preferred "IC" - shaped form, it is a Friedrich - Wintgen quasi - bound state in the continuum (F - WQBIC) mode. To further confirm this mode, the spectral data is fitted by the following formula,

[0052]

[0053] where k represents the near - field coupling rate between two resonance modes (ω 1 and ω 2 ). γ e1 and γ e2 are their radiation damping rates. As is well known, when two resonance frequencies are close, the right - hand side of the equation is zero. Therefore, on the left - hand side, k = 0 or γ e1 =γ e2According to the fitting results, k approaches zero before reaching the BIC point, and at the BIC point (l = 135 μm), k = 0. This is in line with the F-WBIC theory, and the fitting accuracy is approximately 99%.

[0054] The metasurface sensor is obtained by ultraviolet lithography technology and Lift-off technology. According to the preferably "IC" shape, its terahertz test results are as Figure 3 shown. The resonant peak of the F-W QBIC mode is at 681.56 GHz.

[0055] Example 2, a method for direct detection of SARS-CoV-2 aerosol based on terahertz metasurface.

[0056] As Figure 4 shown, the method for detecting SARS-CoV-2 aerosol based on the terahertz metasurface sensor disclosed in this example is specifically implemented as follows:

[0057] S1: Take a SARS-CoV-2 sample, and then inject deionized water to form a standard solution, obtaining a 1 mg / mL standard solution required for the experiment.

[0058] S2: Immerse the metasurface in dithiodiethanol for 24 hours to form a dense carboxyl (-COOH) layer, immerse the metasurface in a mixture of N-hydroxysuccinimide (NHS) and 1-ethyl-3-carbodiimide (EDC) for 0.5 hours to activate the surface, immerse the metasurface in SARS-CoV-2 antibody for 0.5 hours to form a recognition layer, and wash the metasurface with phosphate (PBS) solution between each step.

[0059] S3: Pour the standard solution of SARS-CoV-2 into an aerosol generating device to generate aerosol, and collect the aerosol as a sample to be measured by means of simulating breathing for 1 minute.

[0060] S4: Use a terahertz frequency-domain spectroscopy system for testing. The indoor temperature is 20 - 25 °C, and the humidity is less than 40%.

[0061] (1) In the reflection measurement mode, collect the terahertz spectral data of air at room temperature as a reference signal, and the terahertz spectral data of aerosol samples with different amounts as sample signals, obtaining the reference amplitude Iref(v) and the sample amplitude Isam(v).

[0062] (2) Within the selected characteristic frequencies, using the amplitude information, obtain the reflectivity of the SARS-CoV-2 sample through R(v) = (Isam(v) / Iref(v)) 2 and establish a curve of the frequency of SARS-CoV-2 versus the reflectivity.

[0063] (3) Obtain the frequencies f corresponding to the resonance peaks of different amounts of SARS-CoV-2 according to the above frequency-reflectivity curve, and establish a curve of the content of SARS-CoV-2 versus frequency.

[0064] (4) Subtract the frequency f or reflectivity R corresponding to different amounts of SARS-CoV-2 samples from the frequency f 0 or reflectivity R 0 of the sample soaked with SARS-CoV-2 antibody to obtain the corresponding frequency offset Δf or reflectivity ΔR, and establish a curve of the content of SARS-CoV-2 versus frequency offset.

[0065] The fitting functions for the frequency f at the lowest point of the SARS-CoV-2 transmission spectrum in steps (2), (3), and (4) are: f = 8.92×10 -5 x 2 -0.12x + 41.33, 650 < f < 705; the fitting functions for the frequency offset Δf and reflectivity ΔR at the lowest point of the SARS-CoV-2 transmission spectrum are: Δf = 1.42×lg x + 2.334 and ΔR = 3.1×10 -3 *lg x + 0.004;

[0066] In the above formula: x is the volume of the standard product solution added, with the unit of ng / mL, and the unit of Δf is GHz.

[0067] According to the above method, the lowest detection limit of SARS-CoV-2 aerosol is 0.1 ng / mL.

[0068] Figure 5 This is a schematic diagram of the relationship between the frequency shift and concentration of SARS-CoV-2 detected by the terahertz metasurface sensor of the present invention. Among them, Figure 5 (b) is Figure 5 (a)'s enlarged view. As the concentration of SARS-CoV-2 increases, the detected frequency offset also increases accordingly, and SARS-CoV-2 as low as 0.1 ng / mL can be detected.

[0069] Figure 6 This is a schematic diagram of the results of detecting SARS-CoV-2 aerosol by the terahertz metasurface sensor of the present invention. It can be seen that as the concentration of SARS-CoV-2 increases from 0.1 ng / mL to 1 mg / mL, the data points in the figure, that is, the frequency shift caused by the SARS-CoV-2 solution passing through the terahertz metasurface sensor, also increase accordingly. The slope in the image represents the sensitivity of the sensor, reaching 1.42 GHz / lg(ng·mL -1 ).

[0070] Comparative Example 1: Use a terahertz metasurface sensor to detect other proteins.

[0071] Comparative Example 1 is to verify the qualitative detection of SARS-CoV-2 by the terahertz metasurface sensor.

[0072] Comparative Example 1 is intended to identify the qualitative ability of the terahertz metasurface sensor by introducing aerosols of different proteins (BSA, bovine serum albumin, NSE, neuron-specific enolase, HB, hemoglobin, OVA, ovalbumin).

[0073] The solution preparation in Comparative Example 1 is the same as that in Example 2. The solution mass is 1 mg / mL.

[0074] The detection result of Comparative Example 1 is as Figure 7 shown, it can be seen that the terahertz metasurface sensor can achieve qualitative detection of SARS-CoV-2.

[0075] In summary, the present invention has the advantages of high sensitivity, rapidity, direct detection, etc., and can meet the requirements of public health monitoring for the detection of SARS-CoV-2 S protein aerosol.

[0076] The above specific description further details the purpose, technical solution and beneficial effects of the invention. It should be understood that the above is only a specific embodiment of the present invention and is not used to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A terahertz band metasurface sensor, characterized in that: The invention comprises a substrate and a metasurface structure attached to the substrate; the metasurface is designed based on the Friedrich-Wintgen quasi-bound state in continuous medium FW QBIC method, and is coupled by two different resonators of "I" shape and "C" shape, wherein the "IC"-shaped array comprises at least 1250 uniformly arranged and equal-sized resonant ring units, the resonant ring units are in the shape of capital letters "I" and "C", and the resonant ring units are used to achieve resonance in the terahertz band.

2. The sensor according to claim 1, characterized in that The "I"-shaped structure consists of a straight line segment, and the "C"-shaped structure consists of an open circular ring structure.

3. The sensor according to claim 1, characterized in that The base material is quartz glass, the size is 3×3cm 2 , thickness is 0.5mm; the material of the "IC" shaped array is gold.

4. The sensor according to any one of claims 1 to 3, characterized in that: The resonant ring unit parameters include periodicity w, slit length a, I-shaped meta-atom length l, C-shaped meta-atom inner and outer radii r1 and r2, and opening width g.

5. A SARS-CoV-2 aerosol detection method based on a terahertz metasurface sensor, implemented based on the sensor according to any one of claims 1 to 3; characterized in that: The implementation method is as follows: prepare a SARS-CoV-2 solution of standard concentration, use an aerosol generator to generate aerosol, and collect aerosol samples by negative pressure inhalation to carry out detection; collect 0.1-1.4THz spectral data, deeply analyze the change law of the resonance frequency in the QBIC resonance mode, and then construct a standard equation for the content and frequency of SARS-CoV-2; based on the data obtained from the measurement, combined with the standard equation for the content and frequency of SARS-CoV-2, the detection of SARS-CoV-2 is realized.

6. A SARS-CoV-2 aerosol detection method based on a terahertz metasurface sensor, implemented based on the sensor according to any one of claims 1 to 3; characterized in that: The following steps are involved: Step 1: Prepare the SARS-CoV-2 standard solution with deionized water; Step 2: Pour the SARS-CoV-2 standard solution into the aerosol generator as the sample to be tested; use the terahertz frequency domain spectroscopy system to collect the terahertz spectrum data of air at room temperature in the reflection measurement mode as the reference signal, and pass the terahertz spectrum data of different amounts of aerosol samples as the sample signal to obtain the reference amplitude Iref(v) and the sample amplitude Isam(v); Step 3: Using the amplitude information in the range of 0.1 to 1.4 THz, the reflectivity of the SARS-CoV-2 sample is obtained through R(v)=Isam(v) / Iref(v), and a standard equation for the content and reflectivity of SARS-CoV-2 is established; Step 4: According to the above frequency-reflectivity curve, the frequencies f corresponding to the resonance peaks of different amounts of SARS-CoV-2 are obtained, and a standard equation of SARS-CoV-2 content and frequency is established; Step 5: Subtract the frequency f corresponding to different amounts of SARS-CoV-2 samples from the frequency f0 of the deionized water sample to obtain the corresponding frequency offset Δf, and establish a standard equation for the SARS-CoV-2 content and frequency offset; Step 6: Replace the standard solution in step 2 with the sample solution to be tested, and measure the sample solution to be tested according to steps 2 to 5.

7. The method according to claim 6, characterized in that The concentration of the SARS-CoV-2 standard solution prepared in step 1 is 1 ng / mL; the measurement conditions of the terahertz frequency domain spectroscopy system in step 2 are: 20-25°C, relative humidity <40%.

8. The method according to claim 7, characterized in that The standard equation for the content and frequency of SARS-CoV-2 established in step 4 is: SARS-CoV-2: f=8.92*10 -5 x 2 -0.12x+41.33, 650<f<705 The standard equation for the content and frequency shift of SARS-CoV-2 established in step 5 is: SARS-CoV-2: Δf=42*lg x+2.334; Where: x is the volume of the added standard solution, the unit is ng / mL, Δf is the unit of GHz; f is the frequency corresponding to the resonance peak of SARS-CoV-2; Δf is the frequency shift obtained by subtracting the SARS-CoV-2 sample from the deionized water sample.

9. The method according to claim 8, characterized in that The minimum detection limit of SARS-CoV-2 aerosol is 0.1ng / mL.

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