Terahertz trace molecule fingerprint spectrum detection method

Abstract

The invention relates to the technical field of trace molecule detection, and provides a terahertz trace molecule fingerprint spectrum detection method which comprises the following steps: collecting a time domain signal of a sample under the condition that the sample formed by compounding a sample layer and a substrate layer is placed in a terahertz wave radiation area for radiation; the sample layer is obtained by coating an analyte on a substrate layer formed on the basis of a selected substrate material; converting the time domain signal of the sample into a sample frequency domain signal based on fast Fourier transform; acquiring a transmission spectrum according to the sample frequency domain signal and a reference frequency domain signal acquired by the test air, and extracting an absorption fingerprint signal of the analyte from the transmission spectrum; and establishing a standard equation between the content of the analyte and the intensity of the fingerprint signal based on the absorption fingerprint signals of the analyte with different contents. The detection mode is low in required cost, short in detection time and simple to operate, can realize ultra-wide spectrum detection of analytes, and is beneficial to promotion of wide application and development of trace molecule fingerprint detection.

Description

Technical Field

[0001] The invention relates to the technical field of trace molecule detection, and in particular to a terahertz trace molecule fingerprint spectrum detection method. Background Art

[0002] The vibration and rotation modes within / between molecules of a substance are located in the terahertz band, showing unique fingerprint characteristics, making terahertz trace molecular fingerprint detection technology one of the important methods for characterizing physicochemical characteristics. At present, the commonly used terahertz trace molecular fingerprint detection methods include the tablet pressing method, which can be used to obtain the terahertz fingerprint information of the substance by mixing the analyte with a highly transparent substance in the terahertz band such as polyethylene and pressing it into a sheet sample with a certain thickness. However, due to the weak terahertz radiation power and the mismatch between the wavelength of the terahertz wave and the molecular size of the substance, the interaction between the terahertz wave and the analyte is often weak, making the detection limit of the conventional tablet pressing method at the level of tens of milligrams, making it difficult to achieve high-sensitivity detection of trace sample fingerprints.

[0003] There is also metasurface technology based on local enhancement of electric field, which can significantly enhance the interaction between terahertz waves and matter. By sensing the difference in the resonance peak amplitude envelope before and after the material is added to the metasurface, the fingerprint information of the material can be extracted, and high-sensitivity detection of trace sample fingerprints can be achieved. However, the coverage bandwidth of the resonance peak width spectrum is narrow when multiple metasurfaces or tuning methods (such as adjusting the incident angle of the terahertz wave) are used to achieve the coverage. In addition, the high preparation cost of metasurfaces and their long detection time have seriously affected the application and development of terahertz trace molecular fingerprint detection. Summary of the invention

[0004] The present invention provides a method for detecting terahertz trace molecular fingerprint spectrum, which is used to solve the defects of the prior art that the detection of terahertz trace molecular fingerprint spectrum requires high cost, long detection time and narrow coverage bandwidth, which affects the application and development of terahertz trace molecular fingerprint detection.

[0005] The present invention provides a method for detecting terahertz trace molecular fingerprint spectrum, comprising the following steps: When a sample formed by a composite of a sample layer and a substrate layer is placed in a terahertz wave radiation zone for radiation, a time domain signal of the sample is collected; the sample layer is obtained by coating an analyte on the substrate layer, and the substrate layer is formed based on a selected substrate material; Based on fast Fourier transform, convert the time domain signal into a sample frequency domain signal; Acquire a transmission spectrum according to the sample frequency domain signal and a reference frequency domain signal acquired from the test air, and extract the transmission spectrum to obtain an absorption fingerprint signal of the analyte; Based on the absorption fingerprint signals of the analyte at different contents, a standard equation between the content of the analyte and the fingerprint signal intensity is established.

[0006] According to the terahertz trace molecular fingerprint spectrum detection method provided by the present invention, the substrate material is a hard material or a flexible material; the hard material includes silicon and quartz; the flexible material includes polyimide, polydimethylsiloxane, cycloolefin copolymer, cycloolefin polymer and 4-methylpentene.

[0007] According to the terahertz trace molecular fingerprint spectrum detection method provided by the present invention, the base layer is cut into a preset size, and the preset size is larger than the spot size of the terahertz wave used for radiating in the terahertz wave radiation area.

[0008] According to the terahertz trace molecular fingerprint spectrum detection method provided by the present invention, the analyte has an absorption peak in the terahertz band; the analyte includes at least amino acid substances and sugar substances.

[0009] According to the terahertz trace molecular fingerprint spectrum detection method provided by the present invention, the manner of coating the analyte on the base layer comprises at least one of a solution dropping and drying method, a sublimation method and a spin coating method.

[0010] According to the terahertz trace molecular fingerprint spectrum detection method provided by the present invention, the transmission spectrum is extracted to obtain the absorption fingerprint signal of the analyte, including: Extracting the transmission spectrum based on a preset algorithm to obtain an absorption fingerprint spectrum of the analyte; the preset algorithm at least includes a wavelet denoising algorithm and a fast Fourier transform (FFT) filtering algorithm; The absorption fingerprint spectrum is subjected to a base removal operation to obtain an absorption fingerprint signal of the analyte.

[0011] According to the terahertz trace molecular fingerprint spectrum detection method provided by the present invention, when the sample formed by the composite of the sample layer and the substrate layer is placed in a terahertz wave radiation zone for radiation, the time domain signal of the sample is collected, including: When a sample formed by the composite of the sample layer and the substrate layer is placed in a terahertz wave radiation zone for radiation, collecting at least one transmitted time domain pulse and multiple reflected time domain pulses of the sample; A time domain signal of the sample is acquired according to the at least one transmitted time domain pulse and the multiple reflected time domain pulses.

[0012] The present invention also provides a terahertz trace molecular fingerprint spectrum detection device, comprising the following modules: A signal acquisition module, used for acquiring a time domain signal of a sample formed by a composite of a sample layer and a substrate layer when the sample is placed in a terahertz wave radiation zone for radiation; the sample layer is obtained by coating an analyte on the substrate layer, and the substrate layer is formed based on a selected substrate material; A signal conversion module, used for converting the time domain signal into a sample frequency domain signal based on fast Fourier transform; A signal extraction module, used to obtain a transmission spectrum according to the sample frequency domain signal and a reference frequency domain signal obtained from the test air, and extract the transmission spectrum to obtain an absorption fingerprint signal of the analyte; The fingerprint modeling module is used to establish a standard equation between the content of the analyte and the fingerprint signal intensity based on the absorption fingerprint signal of the analyte with different contents.

[0013] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, a method for detecting terahertz trace molecular fingerprint spectra as described in any one of the above is implemented.

[0014] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method for detecting the terahertz trace molecular fingerprint spectrum as described in any one of the above is implemented.

[0015] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the computer program implements any of the above-mentioned methods for detecting terahertz trace molecular fingerprint spectra.

[0016] The detection method of terahertz trace molecular fingerprint spectrum provided by the present invention is to coat the analyte on the substrate to form a sample layer, and use terahertz waves to radiate the sample layer and the substrate layer to form a composite sample, collect the time domain signal of the sample, and obtain the reference signal based on the test air to obtain the transmission spectrum of the analyte relative to the air, extract the absorption fingerprint signal of the analyte from it, and finally establish a standard equation between the content of the analyte and the fingerprint signal intensity according to the absorption fingerprint signal of the analyte with different contents. Compared with the detection method of the meta-structured surface, this method has lower detection cost and less detection time for the detection of terahertz trace molecular fingerprint spectrum, and is simple to operate. It can realize rapid and ultra-wide spectrum detection of analytes, which is conducive to promoting the wide application and development of the detection of terahertz trace molecular fingerprint spectrum. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic flow chart of the detection method of terahertz trace molecular fingerprint spectrum provided by the present invention.

[0019] Figure 2 It is a schematic diagram of the principle of the detection method of terahertz trace molecular fingerprint spectrum provided by the present invention.

[0020] Figure 3a It is a schematic diagram of the absorption fingerprint spectrum of tyrosine provided by the present invention.

[0021] Figure 3b It is a schematic diagram of the absorption fingerprint signal of tyrosine provided by the present invention.

[0022] Figure 3c This is a schematic diagram of the absorption fingerprint signal of tyrosine obtained by the tableting method.

[0023] Figure 4 It is a schematic diagram of the standard equation between the tyrosine content and the fingerprint signal intensity provided by the present invention.

[0024] Figure 5 It is a schematic diagram of the absorption fingerprint spectrum of substrate layers of different thicknesses provided by the present invention.

[0025] Figure 6a It is a schematic diagram of the absorption fingerprint spectrum of cystine provided by the present invention.

[0026] Figure 6b It is a schematic diagram of the absorption fingerprint spectrum of glutamate provided by the present invention.

[0027] Figure 7 It is a schematic structural diagram of a detection device for terahertz trace molecular fingerprint spectrum provided by the present invention.

[0028] Figure 8 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The embodiment of the present invention provides a method for detecting terahertz trace molecular fingerprint spectrum, which is based on Fabry-Perot resonance to enhance the interaction between terahertz waves and substances, and can achieve highly sensitive, ultra-wide spectrum and low-cost quantitative and qualitative detection of terahertz trace molecular fingerprints, and further simplify the detection operation and reduce the detection time, thereby promoting the widespread application and development of terahertz trace molecular fingerprint detection. Specifically, Figure 1 is a schematic diagram of the process of the terahertz trace molecular fingerprint spectrum detection method provided by the present invention, such as Figure 1 As shown, the method includes the following: Step 100, when a sample formed by a composite of a sample layer and a substrate layer is placed in a terahertz wave radiation zone for radiation, a time domain signal of the sample is collected; the sample layer is obtained by coating an analyte on the substrate layer, and the substrate layer is formed based on a selected substrate material; Step 200, based on fast Fourier transform, convert the time domain signal into a sample frequency domain signal; Step 300, obtaining a transmission spectrum according to the sample frequency domain signal and a reference frequency domain signal obtained from the test air, and extracting the transmission spectrum to obtain an absorption fingerprint signal of the analyte; Step 400: establishing a standard equation between the content of the analyte and the intensity of the fingerprint signal based on the absorption fingerprint signal of the analyte with different contents.

[0031] When a sample formed by combining a sample layer and a substrate layer is placed in a terahertz wave radiation zone for radiation, a time domain signal of the sample is collected, wherein the sample layer of the analyte is obtained by coating the analyte on the substrate layer, and the substrate layer is formed based on a selected substrate material.

[0032] Based on the fast Fourier transform, the time domain signal of the sample is converted into the sample frequency domain signal. Then, the transmission spectrum is obtained according to the sample frequency domain signal and the reference frequency domain signal obtained from the test air. The transmission spectrum is extracted to obtain the absorption fingerprint signal of the analyte.

[0033] Finally, based on the absorption fingerprint signals of analytes with different contents, a standard equation between the content of the analyte and the fingerprint signal intensity is established to complete the fingerprint detection of the analyte.

[0034] Optionally, the reference frequency domain signal is obtained by transforming the reference time domain signal based on Fourier fast transform, and the reference time domain signal is collected when the test air is radiated by terahertz waves.

[0035] In one embodiment, when a sample formed by combining a sample layer and a substrate layer is placed in a terahertz wave radiation zone for radiation, a time domain signal of the sample is collected, and a reference time domain signal of the air in the terahertz wave radiation zone is collected at the same time. Based on fast Fourier transform, the time domain signal of the sample is converted into a sample frequency domain signal, and the reference time domain signal is converted into a reference frequency domain signal. Then, according to the sample frequency domain signal and the reference frequency domain signal obtained by the transformation, a transmission spectrum is obtained, and the transmission spectrum is extracted to obtain an absorption fingerprint signal of the analyte.

[0036] Optionally, by calculating the ratio of the sample frequency domain signal to the reference frequency domain signal, a transmittance curve of the analyte relative to air is obtained, that is, a transmission spectrum.

[0037] The above operations are performed on analytes with different contents to obtain absorption fingerprint signals corresponding to analytes with different contents. According to the corresponding relationship between the analyte content and the absorption fingerprint signal, a standard equation between the analyte content and the fingerprint signal intensity is established.

[0038] Optionally, a standard equation between the analyte content and the fingerprint signal intensity is used to ensure the correspondence between the analyte content and the signal intensity of the absorption fingerprint signal. Based on the standard equation, for the analyte to be detected, after extracting its absorption fingerprint signal, the extracted absorption fingerprint signal is substituted into the established standard equation to detect the analyte content.

[0039] In one embodiment, a base material is selected to form a base layer, and different contents of analytes are coated on the base layer to form sample layers with different contents of analytes. Then, each sample layer is sequentially placed in a terahertz wave radiation zone for radiation, and the corresponding sample time domain signal and the reference time domain signal of air are collected. Based on fast Fourier transform, the collected sample time domain signal and reference time domain signal are converted into sample frequency domain signal and reference frequency domain signal.

[0040] Furthermore, according to the different analyte contents, the ratio of the sample frequency domain signal and the reference frequency domain signal of the analyte at each content is calculated to obtain the transmission spectrum of the analyte at different contents, and then the absorption fingerprint signal of the analyte at different contents is extracted from the transmission spectrum. Finally, based on the corresponding relationship between the analyte content and the extracted absorption fingerprint signal, a standard equation between the analyte content and the fingerprint signal intensity of the absorption fingerprint signal is established.

[0041] The specific process is as follows: 1. Select the base material to form the base layer; 2. Coating a certain amount of analyte on the base layer to obtain a sample layer; 3. Place the sample formed by combining the sample layer and the substrate layer in the terahertz wave radiation zone for radiation, and collect the time domain signal of the sample and the reference time domain signal of the air; 4. Perform fast Fourier transform on the sample time domain signal to obtain a sample frequency domain signal, and perform fast Fourier transform on the reference time domain signal to obtain a reference frequency domain signal; 5. Calculate the ratio of the sample frequency domain signal to the reference frequency domain signal to obtain the transmission spectrum of the analyte relative to air; 6. Extract the absorption fingerprint signal of the analyte from the transmission spectrum; 7. Repeat the above process 1-6 for different contents of analytes to obtain absorption fingerprint signals of different contents of analytes, thereby establishing a standard equation between the content of the analyte and the fingerprint signal intensity of the absorption fingerprint signal.

[0042] After establishing a standard equation between the content of the analyte and the fingerprint signal intensity, for the analyte to be detected with an unknown content, a substrate material is selected to form a substrate layer, and then the analyte to be detected is coated on the substrate layer to obtain a sample layer. The sample formed by the composite of the sample layer and the substrate layer is placed in the terahertz wave radiation zone for radiation, and the sample time domain signal corresponding to the analyte to be detected and the reference time domain signal of the air in the terahertz wave radiation zone are collected. Based on the fast Fourier transform, the collected sample time domain signal is converted into a sample frequency domain signal, and the collected reference time domain signal is converted into a reference frequency domain signal, and the ratio of the sample frequency domain signal to the reference frequency domain signal is calculated to obtain the transmittance curve of the sample corresponding to the analyte to be detected relative to the air, that is, the transmission spectrum. The absorption fingerprint signal of the analyte to be detected is extracted from the transmission spectrum, and finally the fingerprint signal intensity of the extracted absorption fingerprint signal is substituted into the established standard equation to calculate the content of the analyte to be detected.

[0043] In this embodiment, the analyte is coated on the substrate layer to form a sample layer, and the sample formed by the composite of the sample layer and the substrate layer is irradiated with terahertz waves, the sample signal is collected, and the reference signal is obtained based on the test air to obtain the transmission spectrum of the analyte relative to the air, from which the absorption fingerprint signal of the analyte is extracted. Compared with the detection method of the meta-surface, the required detection cost is lower, the detection time is less, and the operation is simple. It can achieve rapid and ultra-wide spectrum detection of the analyte, which is conducive to promoting the widespread application and development of terahertz trace molecular fingerprint detection.

[0044] Optionally, the substrate material may be a hard material or a flexible material, wherein the hard material includes at least silicon and quartz, and the flexible material includes at least polyimide, dimethylsiloxane, cycloolefin copolymer, cycloolefin polymer and 4-methylpentene.

[0045] Optionally, the base layer is reusable, and the base layer is cut into a preset size, and the preset size corresponds to a size larger than the spot size of the terahertz wave used for radiating in the terahertz wave radiation area. Optionally, the selected base material is cut into a preset size to form the base layer.

[0046] Optionally, the analyte is a substance having an absorption peak in the terahertz band, including but not limited to amino acid substances and sugar substances.

[0047] Optionally, the method of coating the analyte onto the base layer includes at least one of a solution dropping and drying method, a sublimation method and a spin coating method, which can be specifically determined according to the morphology of the analyte.

[0048] Optionally, when collecting the time domain signal of the sample containing the analyte, specifically obtaining a single-transmission time domain pulse and multiple-reflection time domain pulses of the sample, step 100 may further include: Step 101, when a sample formed by combining a sample layer and a substrate layer is placed in a terahertz wave radiation zone for radiation, a single transmission time domain pulse and multiple reflection time domain pulses of the sample are collected; Step 102: Acquire a time domain signal of the sample according to the once transmitted time domain pulse and the multiple reflected time domain pulses.

[0049] When a sample formed by the composite of the sample layer and the substrate layer is placed in a terahertz wave radiation zone for radiation, at least one transmitted time domain pulse and multiple reflected time domain pulses of the sample are collected, and a time domain signal of the sample is acquired based on the collected at least one transmitted time domain pulse and multiple reflected time domain pulses.

[0050] Optionally, when extracting the absorption fingerprint signal of the analyte from the transmission spectrum, the transmission spectrum is extracted based on a preset algorithm and a base removal operation to obtain the absorption fingerprint signal of the analyte. The preset algorithm includes a wavelet denoising algorithm, a fast Fourier transform (FFT) filtering algorithm, and the like.

[0051] Based on this, in step 300, the transmission spectrum is extracted to obtain the absorption fingerprint signal of the analyte, which may also include: Step 301, extracting the transmission spectrum based on a preset algorithm to obtain an absorption fingerprint spectrum of the analyte; the preset algorithm includes a wavelet denoising algorithm, a fast Fourier transform (FFT) filtering algorithm, etc.; Step 302: performing a base removal operation on the absorption fingerprint spectrum to obtain an absorption fingerprint signal of the analyte.

[0052] First, the transmission spectrum is extracted based on a preset algorithm to obtain the absorption fingerprint spectrum of the analyte, and the preset algorithms used include wavelet denoising algorithm, fast Fourier transform FFT filtering algorithm, etc. Further, the absorption fingerprint spectrum is de-basised to obtain the absorption fingerprint signal of the analyte.

[0053] In one embodiment, for terahertz ultra-wide spectrum trace fingerprint detection, a 1000 μm thick high-resistance silicon wafer is cut into 6×6 mm 2 The square was used as the base layer. The tyrosine solution was dripped onto the silicon wafer and dried to obtain the sample layer. The dosage was 3.54 μg / mm 2 , 7.08μg / mm 2 , 10.62μg / mm 2 and 14.15 μg / mm 2 . The time domain signals of samples corresponding to different doses are collected, and the time domain signals obtained by testing air are used as reference time domain signals. The corresponding frequency domain signals are obtained by fast Fourier transform, and then the transmission spectrum is obtained. The absorption fingerprint signals corresponding to different doses of tyrosine solutions are obtained from the transmission spectrum by using wavelet denoising algorithm and conventional de-basing operation, and a standard equation between tyrosine content and fingerprint signal intensity of the absorption fingerprint signal is established, thereby realizing quantitative and qualitative detection of tyrosine.

[0054] In another embodiment, in order to evaluate the effect of substrate thickness on the terahertz broadband trace fingerprint detection effect, high-resistance silicon wafers with thicknesses of 100 μm, 500 μm, and 1000 μm were cut into 6×6 mm 2 The same dose of tyrosine solution was dripped onto silicon wafers of different thicknesses and dried to obtain sample layers corresponding to substrate layers of different thicknesses. For example, the dose used was 14.15 μg / mm 2 The sample time domain signals of each sample layer are collected, and the time domain signals obtained by the test air are used as the reference time domain signals. The corresponding frequency domain signals are obtained by fast Fourier transform, and then the transmission spectrum is obtained. The wavelet denoising algorithm is used to extract the absorption fingerprint signals corresponding to the same dose of analyte at different substrate thicknesses from the transmission spectrum.

[0055] In one embodiment, in order to evaluate the universality of the terahertz trace molecular fingerprint spectroscopy detection method, a 1000 μm thick high-resistance silicon wafer was cut into 6×6 mm 2The square is used as the base layer. The cystine and glutamic acid solutions are dropped on the silicon wafer and dried to obtain the sample layers corresponding to the different analytes. The time domain signals of the samples formed by the composite of each sample layer and the base layer are collected, and the time domain signals obtained by the test air are used as the reference time domain signals. The corresponding frequency domain signals are obtained by fast Fourier transform, and then the transmission spectrum is obtained. The absorption fingerprint signals of different analytes are extracted from the transmission spectrum using the wavelet denoising algorithm.

[0056] In one embodiment, the detection method of terahertz trace molecular fingerprint spectrum provided by the embodiment of the present invention is based on the Fabry-Perot resonant cavity for qualitative and quantitative detection of terahertz trace fingerprints, and its implementation principle is as follows: Figure 2 As shown, in Figure 2 In the figure, 201 is a terahertz wave radiation area, 202 is a sample layer coated on a base layer 203, and 204 is a terahertz wave receiving area.

[0057] Select a suitable base material, such as hard materials such as silicon and quartz, or flexible materials such as polyimide, polydimethylsiloxane, cycloolefin copolymer, cycloolefin polymer and 4-methylpentene, and cut it into a fixed size according to a preset size as a base layer.

[0058] By using the solution drop drying method, sublimation method and spin coating method, a substance containing amino acids or sugars with absorption peaks in the terahertz band is coated on the substrate to form a sample layer. Figure 2 In the manner shown, the sample is placed in the terahertz wave radiation area 201 for radiation, and the time domain signal of the sample is collected in the terahertz wave receiving area 204, and the time domain signal of the air is collected as a reference time domain signal. When collecting the sample time domain signal, the time domain pulse of the analyte is obtained once and the time domain pulse of multiple reflections is obtained. Exemplarily, the time domain signal obtained needs to be greater than 3 time domain pulses.

[0059] Furthermore, based on the fast Fourier transform, the sample time domain signal is converted into a sample frequency domain signal, the reference time domain signal is converted into a reference frequency domain signal, and the ratio of the sample frequency domain signal to the reference frequency domain signal is calculated to obtain the transmission spectrum of the analyte relative to air. The absorption fingerprint spectrum of the analyte is extracted by using wavelet denoising algorithm, FFT filtering algorithm, etc. and conventional debasing operation.

[0060] In one embodiment, based on the Fabry-Perot cavity for qualitative and quantitative detection of terahertz trace fingerprints, a 1000 μm thick silicon wafer is first cut into 6×6 mm 2 The size of the substrate was used as the base layer, and then tyrosine was mixed with ultrapure water, and the tyrosine solution was dripped onto the silicon wafer to obtain the sample layer. The dosages used were 3.54 μg / mm 2 , 7.08μg / mm2 , 10.62μg / mm 2 and 14.15 μg / mm 2 After rapid drying, the terahertz time-domain spectroscopy system is used to obtain the terahertz time-domain signal of the corresponding sample. E sam ( t ), the terahertz spectrum information obtained by testing air is used as the reference time domain signal E ref ( t ). Using fast Fourier transform, we can obtain the sample time domain signals respectively. E sam ( t ) E sam ( ω ), and the reference time domain signal E ref ( t ) E ref ( ω ), and by calculating T = E sam ( ω ) / E ref ( ω ), obtain the transmittance curve of the sample relative to air, that is, the transmission spectrum, and use the wavelet denoising algorithm to extract the absorption fingerprint signal of the corresponding substance.

[0061] The dosage was 14.15 μg / mm 2 The transmittance curve of tyrosine solution and the absorption fingerprint signal extracted by wavelet denoising algorithm are shown in Figure 3a As shown; the absorption fingerprint signal obtained by removing the base operation is as follows Figure 3b As shown, it can be Figure 3c The absorption fingerprint signal of tyrosine obtained by the tableting method is compared with that shown in the figure, and a standard equation between the dosage of the analyte and the fingerprint signal intensity of the absorption fingerprint signal is established, such as Figure 4 According to the above method, Fabry-Perot resonance can be used for qualitative and quantitative detection of terahertz trace fingerprints, and the dosage obtained by experimental testing can be as low as 3.54μg / mm 2 , which proves the effectiveness of the terahertz trace molecular fingerprint spectroscopy detection method provided by the embodiment of the present invention.

[0062] In one embodiment, different substrate thicknesses are used to evaluate terahertz trace fingerprint detection. Specifically, silicon wafers of different thicknesses, such as 100 μm, 500 μm, and 1000 μm, are first cut into 6×6 mm 2The size of the substrate was changed to form a substrate with different thicknesses. Tyrosine was then mixed with ultrapure water and dripped onto the substrate with different thicknesses of 100 microns, 500 microns and 1000 microns, respectively, with a dosage of 14.15 μg / mm 2 After rapid drying, the terahertz time-domain spectroscopy system is used to obtain the terahertz time-domain signals of samples corresponding to substrate layers of different thicknesses. E sam ( t ), the terahertz spectrum information obtained by testing air is used as the reference time domain signal E ref ( t ). Using fast Fourier transform, we can obtain the sample time domain signals respectively. E sam ( t ) E sam ( ω ), and the reference time domain signal E ref ( t ) E ref ( ω ), and by calculating T = E sam ( ω ) / E ref ( ω ), obtain the transmittance curve of the sample relative to air, and use the wavelet denoising algorithm to extract the corresponding material absorption fingerprint spectrum. Among them, the absorption fingerprint spectrum of the substrate layer with a thickness of 100 microns and 500 microns is as follows Figure 5 As shown in the figure, the Fabry-Perot resonance corresponding to the 100-micron-thick substrate layer is sparse and difficult to extract using the wavelet denoising algorithm, so it is not marked. In addition, the absorption fingerprint spectrum corresponding to the 1000-micron-thick substrate layer is shown in the figure. Figure 3a As shown, the corresponding absorption fingerprint signal is Figure 3b As shown. Figure 3c By comparing the absorption fingerprint spectrum of tyrosine obtained by the tableting method shown, it can be determined that the thicker substrate layer has better fidelity in peak shape and frequency for the absorption peak of the extracted analyte.

[0063] In another embodiment, the universality of the terahertz trace molecular fingerprint spectroscopy detection method provided in the embodiment of the present invention is evaluated, and the same method is used to detect two analytes other than tyrosine. Specifically, a 1000 micron thick silicon wafer is first cut into 6×6 mm 2The size of the substrate was used as the base layer, and then cystine and glutamic acid were mixed with ultrapure water and dripped on the surface of the base layer respectively, wherein the dosage was 14.15 μg / mm 2 After rapid drying, the terahertz time-domain spectroscopy system is used to obtain the terahertz time-domain signal of the corresponding sample. E sam ( t ), and the terahertz spectrum information obtained from the test air as the reference time domain signal E ref ( t ). Using fast Fourier transform, we can obtain the sample time domain signals respectively. E sam ( t ) frequency domain signal frequency domain signal E sam ( ω ), and the reference time domain signal E ref ( t ) E ref ( ω ). By calculating T = E sam ( ω ) / E ref ( ω ), obtain the transmittance curve of the sample relative to air, and use the wavelet denoising algorithm to extract the corresponding material absorption fingerprint spectrum. Among them, the absorption fingerprint spectra of cystine and glutamic acid are as follows: Figure 6a and Figure 6b According to the above method, the absorption fingerprint spectra of different analytes and different doses of the same analyte can be extracted, and then the absorption fingerprint signal of the analyte can be obtained. It can be seen that the detection method of terahertz trace molecular fingerprint spectrum provided by the embodiment of the present invention can realize terahertz trace fingerprint detection based on the Fabry-Perot resonance enhancement mechanism, and has excellent universality.

[0064] In this embodiment, the detection method of terahertz trace molecular fingerprint spectroscopy based on Fabry-Perot resonance is low-cost and the substrate material is reusable, which greatly reduces the operating cost of trace molecular fingerprint detection. Compared with metasurface detection, it is simple to operate, does not require complex professional training, and has a short detection time.

[0065] Furthermore, high-sensitivity qualitative and quantitative detection of analytes, as well as ultra-wide spectrum detection, can be achieved, and can be extended to other bands. It is applicable to substances with fingerprint information in the terahertz band, has high universality, reduces detection limitations, and is conducive to promoting the application and popularization of terahertz trace molecular fingerprint detection technology.

[0066] The following is a description of a detection device for terahertz trace molecular fingerprint spectrum provided by the present invention. The detection device for terahertz trace molecular fingerprint spectrum described below and the detection method for terahertz trace molecular fingerprint spectrum described above can correspond to each other.

[0067] Reference Figure 7 The terahertz trace molecular fingerprint spectrum detection device provided by the embodiment of the present invention comprises: The signal acquisition module 10 is used to collect the time domain signal of the sample when the sample formed by the composite of the sample layer and the substrate layer is placed in the terahertz wave radiation zone for radiation; the sample layer is obtained by coating the analyte on the substrate layer, and the substrate layer is formed based on the selected substrate material; A signal conversion module 20, configured to convert the time domain signal into a sample frequency domain signal based on a fast Fourier transform; A signal extraction module 30, for obtaining a transmission spectrum according to the sample frequency domain signal and a reference frequency domain signal obtained from the test air, and extracting the transmission spectrum to obtain an absorption fingerprint signal of the analyte; The fingerprint modeling module 40 is used to establish a standard equation between the content of the analyte and the fingerprint signal intensity based on the absorption fingerprint signals of the analyte with different contents.

[0068] In one embodiment, the substrate material is a hard material or a flexible material; the hard material includes silicon and quartz; the flexible material includes polyimide, polydimethylsiloxane, cycloolefin copolymer, cycloolefin polymer and 4-methylpentene.

[0069] In one embodiment, the base layer is cut into a preset size, and the preset size is larger than the spot size of the terahertz wave radiated in the terahertz wave radiation area.

[0070] In one embodiment, the analyte has an absorption peak in the terahertz band; the analyte includes at least amino acid substances and sugar substances.

[0071] In one embodiment, the method of coating the analyte on the base layer includes at least one of a solution dropping and drying method, a sublimation method and a spin coating method.

[0072] In one embodiment, the signal acquisition module 10 is further used for: When a sample formed by the composite of the sample layer and the substrate layer is placed in a terahertz wave radiation zone for radiation, collecting at least one transmitted time domain pulse and multiple reflected time domain pulses of the sample; A time domain signal of the sample is acquired according to the at least one transmitted time domain pulse and the multiple reflected time domain pulses.

[0073] In one embodiment, the signal extraction module 30 is further used to: Extracting the transmission spectrum based on a preset algorithm to obtain an absorption fingerprint spectrum of the analyte; the preset algorithm includes but is not limited to a wavelet denoising algorithm and a fast Fourier transform (FFT) filtering algorithm; The absorption fingerprint spectrum is subjected to a base removal operation to obtain an absorption fingerprint signal of the analyte.

[0074] Figure 8 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 8 As shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830 and a communication bus 840, wherein the processor 810, the communication interface 820 and the memory 830 communicate with each other through the communication bus 840. The processor 810 may call the logic instructions in the memory 830 to execute the steps of the terahertz trace molecular fingerprint spectrum detection method, for example including: When a sample formed by a composite of a sample layer and a substrate layer is placed in a terahertz wave radiation zone for radiation, a time domain signal of the sample is collected; the sample layer is obtained by coating an analyte on the substrate layer, and the substrate layer is formed based on a selected substrate material; Based on fast Fourier transform, convert the time domain signal into a sample frequency domain signal; Acquire a transmission spectrum according to the sample frequency domain signal and a reference frequency domain signal obtained from the test air, and extract the transmission spectrum to obtain an absorption fingerprint signal of the analyte; Based on the absorption fingerprint signals of the analyte at different contents, a standard equation between the content of the analyte and the fingerprint signal intensity is established.

[0075] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0076] On the other hand, the present invention further provides a computer program product, the computer program product includes a computer program, the computer program can be stored in a non-transitory computer-readable storage medium, and when the computer program is executed by a processor, the computer can execute the steps of the terahertz trace molecular fingerprint spectrum detection method provided by the above methods, for example, including: When a sample formed by a composite of a sample layer and a substrate layer is placed in a terahertz wave radiation zone for radiation, a time domain signal of the sample is collected; the sample layer is obtained by coating an analyte on the substrate layer, and the substrate layer is formed based on a selected substrate material; Based on fast Fourier transform, convert the time domain signal into a sample frequency domain signal; Acquire a transmission spectrum according to the sample frequency domain signal and a reference frequency domain signal acquired from the test air, and extract the transmission spectrum to obtain an absorption fingerprint signal of the analyte; Based on the absorption fingerprint signals of the analyte at different contents, a standard equation between the content of the analyte and the fingerprint signal intensity is established.

[0077] In another aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the terahertz trace molecular fingerprint spectrum detection method provided by the above methods, for example, including: When a sample formed by a composite of a sample layer and a substrate layer is placed in a terahertz wave radiation zone for radiation, a time domain signal of the sample is collected; the sample layer is obtained by coating an analyte on the substrate layer, and the substrate layer is formed based on a selected substrate material; Based on fast Fourier transform, convert the time domain signal into a sample frequency domain signal; Acquire a transmission spectrum according to the sample frequency domain signal and a reference frequency domain signal obtained from the test air, and extract the transmission spectrum to obtain an absorption fingerprint signal of the analyte; Based on the absorption fingerprint signals of the analyte at different contents, a standard equation between the content of the analyte and the fingerprint signal intensity is established.

[0078] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0079] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting terahertz trace molecular fingerprint spectroscopy, characterized in that: include: When a sample formed by combining the sample layer and the substrate layer is placed in a terahertz wave radiation zone for radiation, a time domain signal of the sample is collected; The sample layer is obtained by coating the analyte on the base layer, and the base layer is formed based on a selected base material; Based on fast Fourier transform, convert the time domain signal into a sample frequency domain signal; Acquire a transmission spectrum according to the sample frequency domain signal and a reference frequency domain signal obtained from the test air, and extract the transmission spectrum to obtain an absorption fingerprint signal of the analyte; Based on the absorption fingerprint signals of the analyte at different contents, a standard equation between the content of the analyte and the fingerprint signal intensity is established.

2. The method for detecting terahertz trace molecular fingerprint spectroscopy according to claim 1, characterized in that: The substrate material is a hard material or a flexible material; the hard material includes silicon and quartz; the flexible material includes polyimide, polydimethylsiloxane, cycloolefin copolymer, cycloolefin polymer and 4-methylpentene.

3. The method for detecting terahertz trace molecular fingerprint spectrum according to claim 1, characterized in that: The base layer is cut into a preset size, and the preset size is larger than the spot size of the terahertz wave used for radiating in the terahertz wave radiation area.

4. The method for detecting terahertz trace molecular fingerprint spectrum according to claim 1, characterized in that: The analyte has an absorption peak in the terahertz band; the analyte includes at least amino acid substances and sugar substances.

5. The method for detecting terahertz trace molecular fingerprint spectrum according to claim 1, characterized in that: The method of coating the analyte on the base layer includes at least one of a solution dropping and drying method, a sublimation method and a spin coating method.

6. The method for detecting terahertz trace molecular fingerprint spectrum according to claim 1, characterized in that: Extracting the transmission spectrum to obtain an absorption fingerprint signal of the analyte includes: Extracting the transmission spectrum based on a preset algorithm to obtain an absorption fingerprint spectrum of the analyte; the preset algorithm at least includes a wavelet denoising algorithm and a fast Fourier transform (FFT) filtering algorithm; The absorption fingerprint spectrum is subjected to a base removal operation to obtain an absorption fingerprint signal of the analyte.

7. The method for detecting terahertz trace molecular fingerprint spectrum according to claim 1, characterized in that: When the sample formed by the composite of the sample layer and the substrate layer is placed in a terahertz wave radiation zone for radiation, collecting the time domain signal of the sample includes: When a sample formed by the composite of the sample layer and the substrate layer is placed in a terahertz wave radiation zone for radiation, collecting at least one transmitted time domain pulse and multiple reflected time domain pulses of the sample; A time domain signal of the sample is acquired according to the at least one transmitted time domain pulse and the multiple reflected time domain pulses.

8. A terahertz trace molecular fingerprint spectrum detection device, characterized in that: include: A signal acquisition module, used for acquiring a time domain signal of a sample formed by a composite of a sample layer and a substrate layer when the sample is placed in a terahertz wave radiation zone for radiation; the sample layer is obtained by coating an analyte on the substrate layer, and the substrate layer is formed based on a selected substrate material; A signal conversion module, used for converting the time domain signal into a sample frequency domain signal based on fast Fourier transform; A signal extraction module, used to obtain a transmission spectrum according to the sample frequency domain signal and a reference frequency domain signal obtained from the test air, and extract the transmission spectrum to obtain an absorption fingerprint signal of the analyte; The fingerprint modeling module is used to establish a standard equation between the content of the analyte and the fingerprint signal intensity based on the absorption fingerprint signal of the analyte with different contents.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method for detecting terahertz trace molecular fingerprint spectrum according to any one of claims 1 to 7 is implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for detecting terahertz trace molecular fingerprint spectrum according to any one of claims 1 to 7 is implemented.

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