Terahertz sensing system for detecting biochemical substances in solution

Abstract

The invention discloses a terahertz sensing system for detecting biochemical substances in a solution. The terahertz sensing system comprises a base; the shell is installed on the base, the shell is constructed to be of a groove-shaped structure, and the groove-shaped structure and the base form a containing space; the enrichment module is arranged in the accommodating space, divides the accommodating space into a first sample cell and a second sample cell, and comprises a filtering membrane with the thickness of 1 micron to 3 mm; a to-be-detected solution is injected into the first sample pool, the to-be-detected solution in the first sample pool penetrates through the filtering membrane to enter the second sample pool, and biochemical substances in the to-be-detected solution are enriched on the filtering membrane in the process that the solution in the first sample pool penetrates through the filtering membrane; wherein the terahertz wave passes through the shell and is incident on the filter membrane carrying the biochemical substances, a detection wave beam is obtained after passing through the filter membrane, the detection wave beam is a wave beam carrying biochemical substance information, and the wave beam carrying the biochemical substance information is used for realizing quantitative analysis on the biochemical substances in the solution to be detected.

Description

Technical Field

[0001] The invention relates to the field of terahertz detection, in particular to a terahertz sensing system for detecting biochemical substances in a solution. Background Art

[0002] Terahertz waves are electromagnetic waves with frequencies between 0.1 and 10 THz, which have the advantages of low energy, high safety, strong penetration, good coherence, and large amount of information. Many substances have unique physical and chemical properties in the terahertz band, which makes terahertz waves show a broad application prospect in many fields, such as radar, remote sensing, biomedical imaging and security detection.

[0003] Terahertz waves have the ability to penetrate a variety of non-metallic materials, such as paper, cloth, and plastic, which gives them significant advantages in non-destructive imaging and detection. At the same time, terahertz waves have low energy and will not cause damage to materials, so they are particularly popular in many fields such as biomedical and biochemical detection. However, the propagation of terahertz waves is not unimpeded, especially when encountering water molecules, their transmission efficiency will drop significantly. The frequency of terahertz radiation coincides with the vibration frequency of hydrogen bonds inside water molecules, causing water molecules to absorb and scatter terahertz radiation energy. Therefore, when terahertz waves are transmitted in an environment containing water molecules, they will experience significant attenuation, and the energy density decreases rapidly with increasing distance. This makes the use of terahertz waves to directly detect biochemical substances in aqueous solutions technically very limited. Summary of the invention

[0004] In view of this, the present invention provides a terahertz sensing system for detecting biochemical substances in a solution.

[0005] According to an embodiment of the present invention, a terahertz sensing system for detecting biochemical substances in a solution is provided, comprising:

[0006] Pedestal;

[0007] A housing is mounted on the base, wherein the housing is constructed as a groove-shaped structure, and the groove-shaped structure and the base form an accommodating space;

[0008] An enrichment module is disposed in the accommodating space, and the enrichment module divides the accommodating space into a first sample pool and a second sample pool. The enrichment module includes:

[0009] A filter membrane, wherein the thickness of the filter membrane is between 1 micron and 3 millimeters; the solution to be tested is injected into the first sample pool, and the solution in the first sample pool passes through the filter membrane and enters the second sample pool, and in the process that the solution in the first sample pool passes through the filter membrane, the biochemical substances in the solution to be tested are enriched on the filter membrane;

[0010] Among them, the terahertz wave passes through the shell and is incident on the filter membrane carrying the biochemical substance. After passing through the filter membrane, a detection beam is obtained. The detection beam is a beam carrying information of the biochemical substance. The beam carrying information of the biochemical substance is used to realize quantitative analysis of the biochemical substance in the solution to be tested.

[0011] According to an embodiment of the present invention, the enrichment module further comprises: a terahertz functional substrate, mounted on the base and located in the accommodating space,

[0012] The terahertz wave passes through the housing and is incident on the filter membrane carrying the biochemical substance, and a detection beam is obtained after passing through the filter membrane, including:

[0013] The terahertz wave passes through the housing and is incident on the filter membrane carrying the biochemical substance, and then passes through the filter membrane and is incident on the terahertz functional substrate, and is reflected and / or transmitted by the terahertz functional substrate, and the obtained reflected beam or transmitted beam is the detection beam.

[0014] According to an embodiment of the present invention, the terahertz functional substrate is a grating-coupled SPR sensor chip, a terahertz metasurface sensor chip based on a functional element sequence structure, a terahertz reflective lens or a terahertz transmissive lens;

[0015] When the terahertz functional substrate is a terahertz metasurface sensor chip based on a functional element sequence structure, the terahertz wave is reflected and / or transmitted on the terahertz functional substrate, and the obtained reflected beam or transmitted beam is the detection beam;

[0016] When the terahertz functional substrate is a grating-coupled SPR sensor chip, the terahertz wave is reflected on the terahertz functional substrate, and the obtained reflected beam is the detection beam;

[0017] When the terahertz functional substrate is a terahertz reflective lens, the terahertz wave is reflected on the terahertz functional substrate, and the obtained reflected beam is the detection beam;

[0018] When the terahertz functional substrate is a terahertz transmission lens, the terahertz wave is transmitted on the terahertz functional substrate, and the obtained transmission beam is the detection beam.

[0019] According to an embodiment of the present invention, a limiting groove is formed on the base, the terahertz functional substrate is installed in the limiting groove, and the depth of the limiting groove is less than or equal to the thickness of the terahertz functional substrate.

[0020] According to an embodiment of the present invention, the terahertz sensing system further includes:

[0021] A gasket is installed between the base and the shell, and the gasket is suitable for sealing the accommodating space formed by the groove structure and the base.

[0022] According to an embodiment of the present invention, when the solution to be tested is body fluid, and the biochemical substance in the solution to be tested is calcium ions in the body fluid, the first sample pool is filled with a reaction solution, the reaction solution contains a reaction substrate, and the anions in the reaction substrate react with the calcium ions to form a water-insoluble product containing the calcium ions, and the product is enriched on the filter membrane;

[0023] Preferably, the reaction substrate is an ionic compound, the cation of the ionic compound is selected from any one of the cations other than calcium ions included in body fluids, and the anion of the ionic compound is selected from carbonate ions, bicarbonate ions or sulfate ions.

[0024] According to an embodiment of the present invention, the terahertz sensing system further includes: a pump body, which is suitable for pumping the solution to be tested into the first sample pool; the pump body is also suitable for pumping the solution that passes through the filter membrane and enters the second sample pool into the first sample pool, so that the solution circulates in the first sample pool and the second sample pool, thereby achieving equilibrium in the enrichment of biochemical substances in the solution to be tested on the filter membrane.

[0025] According to an embodiment of the present invention, the terahertz sensing system further includes:

[0026] A terahertz generation module, adapted to generate the terahertz wave;

[0027] A terahertz detection module, adapted to detect the detection beam;

[0028] A processing module is adapted to process the electrical signal output by the terahertz detection module, and determine whether the enrichment of the biochemical substances in the solution to be tested on the filter membrane has reached equilibrium based on the change of the detection beam measured each time the pump body pumps the solution into the first sample pool. The processing module is also adapted to obtain information about the biochemical substances based on information about the detection beam in the equilibrium state.

[0029] According to an embodiment of the present invention, a boss is formed on the bottom of the groove of the groove-shaped structure, and the boss is configured to abut against the filter membrane to cooperate with the base to fix the positions of the filter membrane and the terahertz functional substrate and to enable the filter membrane and the terahertz functional substrate to form a close contact, and the area of ​​the boss is larger than the area of ​​the terahertz functional substrate.

[0030] According to an embodiment of the present invention, the material of the boss of the housing is a terahertz transparent material; the filter membrane is a porous material with high terahertz wave transmittance; the information of the biochemical substance includes the composition, concentration, mass and refractive index of the biochemical substance.

[0031] According to an embodiment of the present invention, when the solution to be tested passes through the above-mentioned filter membrane from the first sample pool and enters the second sample pool, since the filter membrane is very thin, with a thickness of 1 micron to 3 mm, and the filter membrane is a porous filter membrane, the filter membrane of this thickness achieves effective enrichment of biochemical substances, and the amount of water attached to it is much less than that of a water film of the same thickness, which greatly reduces the scattering and absorption effect of water molecules on terahertz waves. Since water molecules are a strong absorber in the terahertz band, their presence will significantly affect the transmission and reflection characteristics of terahertz waves, thereby interfering with the terahertz detection of biological substances. By using a thinner filter membrane, the amount of attached water is reduced, or methanol, ethanol or glycerol is pumped in after the enrichment of biochemical substances on the filter membrane reaches equilibrium, and the water molecules contained in the filter membrane are removed by the dehydration effect of methanol, ethanol and glycerol, thereby ensuring that the interference of terahertz waves when penetrating the filter membrane is minimized, and the signal-to-noise ratio of the detection signal is improved. In addition, reducing the interference of water molecules on terahertz waves not only improves the sensitivity of detection, but also enhances the stability and reliability of the entire sensing system. Because the fluctuation of water molecule content may cause fluctuations in the detection results, by controlling the amount of water on the filter membrane, this fluctuation can be significantly reduced, making the detection results more stable and reliable. In addition, the filter membrane in the embodiment of the present invention is separated from the terahertz functional substrate, so the filter membrane is easy to replace, and the terahertz functional substrate can be reused. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0033] Figure 1 A three-dimensional diagram of a terahertz sensing system provided according to an embodiment of the present invention is shown;

[0034] Figure 2 A cross-sectional view of a terahertz sensing system for detecting biochemical substances in a solution provided in an embodiment of the present invention is shown;

[0035] Figure 3 A perspective view of a housing of a terahertz sensing system provided according to an embodiment of the present invention is shown;

[0036] Figure 4 A three-dimensional diagram of a base of a terahertz sensing system provided according to an embodiment of the present invention is shown;

[0037] Figure 5A cross-sectional view of a terahertz sensing system including a terahertz metasurface sensing chip based on a functional element sequence structure provided according to an embodiment of the present invention is shown;

[0038] Figure 6 A cross-sectional view of a terahertz sensing system including a grating-coupled SPR sensing chip provided according to an embodiment of the present invention is shown;

[0039] Figure 7 A cross-sectional view of a terahertz sensing system including a terahertz reflective lens provided according to an embodiment of the present invention is shown;

[0040] Figure 8 A cross-sectional view of a terahertz sensing system suitable for a terahertz reflection measurement mode is shown, in which a central through hole of a housing provided by an embodiment of the present invention is sealed by a boss made of a terahertz transparent material;

[0041] Fig. 9 A cross-sectional view of a terahertz sensing system suitable for terahertz transmission measurement mode is shown, in which a central through hole of a base is sealed by a terahertz transparent substrate and a central through hole of a housing is sealed by a terahertz transparent boss according to an embodiment of the present invention.

[0042] Description of Reference Numerals

[0043] 1- Base

[0044] 11-Limiting slot

[0045] 12- Second through hole

[0046] 2- Shell

[0047] 21-Boss

[0048] 22-First through hole

[0049] 3-Enrichment module

[0050] 31-Filter membrane

[0051] 32-Terahertz functional substrate

[0052] 32a-Terahertz supersurface sensor chip

[0053] 32b-grating coupled SPR sensor chip

[0054] 32c-Terahertz reflective lens

[0055] 32d-Terahertz transmission lens

[0056] 4-First sample pool

[0057] 41-First liquid inlet

[0058] 42-Second liquid inlet

[0059] 5- Second sample pool

[0060] 51-Liquid outlet

[0061] 6a, 6b-fastening screws DETAILED DESCRIPTION

[0062] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0063] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0064] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0065] When using expressions such as "at least one of A, B, and C, etc.", it should generally be interpreted as the meaning of the expression generally understood by those skilled in the art. For example, "a system having at least one of A, B, and C" should include but not be limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc. When using expressions such as "at least one of A, B, or C, etc.", it should generally be interpreted as the meaning of the expression generally understood by those skilled in the art. For example, "a system having at least one of A, B, or C" should include but not be limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.

[0066] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only reference directions of the drawings and are not intended to limit the scope of protection of the present invention. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or configurations will be omitted when they may cause confusion in the understanding of the present invention.

[0067] Figure 1 A three-dimensional diagram of a terahertz sensing system provided according to an embodiment of the present invention is shown.

[0068] Figure 2A cross-sectional view of a terahertz sensing system for detecting biochemical substances in a solution provided according to an embodiment of the present invention is shown.

[0069] like Figure 1 and Figure 2 As shown, the terahertz sensing system comprises a base 1, a housing 2, and an enrichment module 3. The housing 2 is mounted on the base 1, and the housing 2 and the base 1 are assembled and installed by fastening screws 6a and 6b.

[0070] Figure 3 A three-dimensional view of a housing of a terahertz sensing system provided according to an embodiment of the present invention is shown.

[0071] Figure 4 A three-dimensional diagram of a terahertz sensing system base provided according to an embodiment of the present invention is shown.

[0072] Combination Figure 2 , Figure 3 and Figure 4 As shown, the housing 2 is constructed as a groove-shaped structure, and the groove-shaped structure and the base 1 form an accommodating space.

[0073] Continue to refer Figure 2 The enrichment module 3 is arranged in the accommodation space, and the enrichment module 3 divides the accommodation space into a first sample pool and a second sample pool. The enrichment module 3 includes a filter membrane 31, and the thickness of the filter membrane is between 1 micron and 3 mm. The solution in the first sample pool passes through the filter membrane 31 and enters the second sample pool. During the process of the solution in the first sample pool passing through the filter membrane 31, the biochemical substances in the solution to be tested are enriched on the filter membrane 31.

[0074] The terahertz wave passes through the housing 2 and is incident on the filter membrane 31 carrying the biochemical substance. After passing through the filter membrane 31, a detection beam is obtained. The detection beam is a beam carrying information about the biochemical substance. The beam carrying information about the biochemical substance is used to realize quantitative analysis of the biochemical substance in the solution to be tested.

[0075] According to an embodiment of the present invention, the filter membrane 31 preferably has a flexible porous filter membrane with high terahertz transmittance, such as filter paper, and a rigid filter membrane with high terahertz transmittance (such as porous ceramic) can also be selected. In the process of the solution to be tested passing through the filter membrane 31 from the first sample pool 4 and entering the second sample pool 5, since the filter membrane is very thin, with a thickness between 1 micron and 3 mm, and the filter membrane is a porous filter membrane, the filter membrane 31 of this thickness can effectively enrich the biochemical substances, and the amount of water attached to it is much less than that of the water film of the same thickness, which greatly reduces the scattering and absorption effect of water molecules on terahertz waves. Since water molecules are a strong absorber in the terahertz band, their presence will significantly affect the transmission and reflection characteristics of terahertz waves, thereby interfering with the terahertz detection of biological substances. By using a thinner filter membrane to reduce the amount of attached water, or by pumping in methanol, ethanol or glycerol after the enrichment of biochemical substances on the filter membrane reaches equilibrium, and using the dehydration effect of methanol, ethanol and glycerol to reduce the water molecules contained in the filter membrane, it is possible to minimize the interference of the terahertz wave when penetrating the filter membrane, thereby improving the signal-to-noise ratio of the detection signal. In addition, reducing the interference of water molecules on terahertz waves not only improves the sensitivity of detection, but also enhances the stability and reliability of the entire sensing system. Because fluctuations in the content of water molecules may lead to fluctuations in the detection results, by controlling the amount of water on the filter membrane, this fluctuation can be significantly reduced, making the detection results more stable and reliable.

[0076] According to an embodiment of the present invention, the enrichment module 3 further includes: a terahertz functional substrate 32, and a terahertz functional substrate 33 is mounted on the base 1 and located in the accommodating space. Since the filter membrane 31 included in the enrichment module 3 is separated from the terahertz functional substrate 32, the filter membrane 31 in the embodiment of the present invention is easy to replace, and the terahertz functional substrate 32 can be reused.

[0077] The terahertz wave passes through the housing 21 and is incident on the filter membrane 31 carrying the biochemical substance, and a detection beam carrying the biochemical substance information is obtained after passing through the filter membrane 31, including: the terahertz wave passes through the housing 2 and is incident on the filter membrane 31 carrying the biochemical substance, and after passing through the filter membrane 31, it is incident on the terahertz functional substrate 32, is reflected by the terahertz functional substrate 32 and / or is transmitted by the terahertz functional substrate 3, and the obtained reflected beam or transmitted beam is the detection beam carrying the biochemical substance information.

[0078] According to an embodiment of the present invention, the terahertz functional substrate 32 is a grating-coupled SPR sensor chip, a terahertz metasurface sensor chip based on a functional element sequence, a terahertz reflective lens, or a terahertz transmissive lens.

[0079] When the terahertz functional substrate 32 is a terahertz metasurface sensor chip based on a functional element structure, the terahertz wave is reflected and / or transmitted on the terahertz functional substrate 32, and the obtained reflected beam or transmitted beam is the detection beam.

[0080] Figure 5 A cross-sectional view of a terahertz sensing system including a terahertz metasurface sensing chip based on a functional element structure provided according to an embodiment of the present invention is shown.

[0081] like Figure 5 As shown, when the terahertz functional substrate 32 is a terahertz metasurface sensor chip 32a based on a functional element sequence, the terahertz wave passes through the housing 2 and is incident on the filter membrane 31 carrying the biochemical substance, and then passes through the filter membrane 31 and is incident on the terahertz metasurface sensor chip 32a for reflection and / or transmission. The terahertz metasurface sensor chip 32a generates artificial surface plasmons under the irradiation of the terahertz wave beam, and the artificial surface plasmons interact with the filter membrane 31, and the information of the biochemical substance enriched in the filter membrane 31 is transmitted to the reflected beam and the transmitted beam through the coupled emission mechanism of the artificial surface plasmon, thereby obtaining a reflected beam or a transmitted beam carrying the information of the biochemical substance. When the terahertz functional substrate 32 is a terahertz metasurface sensor chip 32a based on a functional element sequence, the thickness of the filter membrane needs to be less than the resonance wavelength of the artificial surface plasmons generated by the terahertz metasurface sensor chip 32a. This is because the effective depth of action between the artificial surface plasmon excited by the terahertz wave on the terahertz supersurface sensor chip 32a and the filter membrane 31 is limited to the penetration depth of the artificial surface plasmon, and the penetration depth of the artificial surface plasmon is less than its resonance wavelength. When the thickness of the filter membrane 31 is greater than the resonance wavelength of the artificial surface plasmon on the terahertz supersurface sensor chip 32a, the detection sensitivity of the terahertz supersurface sensor chip 32a will decrease. Therefore, in order to improve the detection sensitivity of the terahertz supersurface sensor chip 32a, the thickness of the filter membrane 31 needs to be less than the resonance wavelength of the artificial surface plasmon generated by the terahertz supersurface sensor chip 32a. Secondly, when the thickness of the filter membrane 31 is close to or equal to the wavelength of the terahertz wave, an interference effect may also occur. The interference effect will cause the amplitude and phase of the terahertz wave to change, thereby affecting the sensing result. In order to avoid the influence of this interference effect on the sensing performance, the thickness of the filter membrane also needs to be less than the wavelength of the terahertz wave. Furthermore, when the terahertz functional substrate 32 is a terahertz metasurface sensor chip 32a based on a functional element sequence, the thickness of the filter membrane 31 is preferably between 1 micron and 500 microns, for example, it can be 1 micron, 50 microns, 100 microns, 150 microns, 200 microns, 250 microns, 300 microns, 350 microns, 400 microns, 450 microns, or 500 microns.

[0082] When the terahertz functional substrate 32 is a grating-coupled SPR sensor chip, the terahertz wave is reflected on the terahertz functional substrate, and the obtained reflected beam is the detection beam.

[0083] According to an embodiment of the present invention, a grating-coupled SPR sensor chip includes at least one sensor unit, each of which includes a substrate and a surface plasma wave generating component located on the substrate; the surface plasma wave generating component includes a grating and a sensitive layer; wherein the grating is located on the substrate and the sensitive layer is located on the grating; or, the sensitive layer is located on the substrate and the grating is located on the sensitive layer. Preferably, the sensitive layer is a narrow bandgap semiconductor film, and the narrow bandgap semiconductor film is a III-V semiconductor film, a IV-VI semiconductor film, or a graphene film; preferably, the III-V semiconductor film is an indium antimonide film.

[0084] Figure 6 A cross-sectional view of a terahertz sensing system including a grating-coupled SPR sensing chip provided according to an embodiment of the present invention is shown.

[0085] like Figure 6As shown, when the terahertz functional substrate 32 is a grating-coupled SPR sensor chip 32b, the terahertz wave passes through the housing 2 and is incident on the filter membrane 31 carrying the biochemical substance, and after passing through the filter membrane 31, it is incident on the grating-coupled SPR sensor chip 32b and is reflected. The grating-coupled SPR sensor chip 32b generates a surface plasma wave under the irradiation of the terahertz beam and the wave vector compensation of the grating, and the surface plasmon wave interacts with the filter membrane 31 located within its penetration depth, and the information of the biochemical substance enriched in the filter membrane 31 is transmitted to the reflected beam through the grating-coupled emission mechanism of the surface plasmon wave, thereby obtaining a reflected beam carrying the information of the biochemical substance, and realizing the detection of the biochemical substance in the solution. The detection device of the biochemical substance provided in the embodiment of the present invention can realize the detection of the biochemical substance in the solution without destroying the biochemical substance molecules. The thickness of the filter membrane needs to be less than the resonant wavelength of the surface plasmon generated by the grating-coupled SPR sensor chip 32b. This is because the effective depth of action of the surface plasmon excited by the terahertz wave on the grating coupling type SPR sensor chip 32b and the filter membrane 31 is limited to the penetration depth of the surface plasmon, and the penetration depth of the surface plasmon is less than its resonance wavelength. When the thickness of the filter membrane 31 is greater than the resonance wavelength of the surface plasmon on the grating coupling type SPR sensor chip 32b, the detection sensitivity of the grating coupling type SPR sensor chip 32b will decrease. Therefore, in order to improve the detection sensitivity of the grating coupling type SPR sensor chip 32b, the thickness of the filter membrane 31 needs to be less than the resonance wavelength of the surface plasmon generated by the grating coupling type SPR sensor chip 32b. When the terahertz functional substrate 32 is a grating coupling type SPR sensor chip 32b, in order to ensure the stability and accuracy of the sensing performance of the grating coupling type SPR sensor chip 32b, the thickness of the filter membrane 31 needs to be less than the wavelength of the terahertz wave. This helps to reduce losses, avoid interference effects, and achieve precise control and detection of terahertz waves. Furthermore, when the terahertz functional substrate 32 is a grating-coupled SPR sensor chip 32b, the thickness of the filter membrane 31 is preferably between 10 microns and 500 microns, for example, 10 microns, 50 microns, 100 microns, 150 microns, 200 microns, 250 microns, 300 microns, 350 microns, 400 microns, 450 microns, 500 microns.

[0086] Figure 7 A cross-sectional view of a terahertz sensing system including a terahertz reflective lens provided according to an embodiment of the present invention is shown.

[0087] like Figure 7 As shown, when the terahertz functional substrate 32 is a terahertz reflective lens 32c, the terahertz wave is reflected on the terahertz functional substrate, and the obtained reflected beam is the detection beam.

[0088] According to an embodiment of the present invention, Figure 7 The terahertz reflective lens 32c can also be replaced with a terahertz transmission lens 32d. According to an embodiment of the present invention, when the terahertz functional substrate 32 in the enrichment module 3 is a terahertz transmission lens, the terahertz wave passes through the housing 2 and is incident on the filter membrane 31 carrying the biochemical substance. After passing through the filter membrane 31 and the terahertz transmission lens 32d, a transmission beam carrying the biochemical substance information is obtained. The transmission beam is the detection beam. According to the Lambert-Beer law, the terahertz detection sensitivity based on the terahertz reflective lens 32c increases with the increase of the thickness of the filter membrane. Therefore, when the terahertz functional substrate 32 is a terahertz reflective lens 32c, the thickness of the filter membrane is preferably between 100 microns and 3 mm, for example, it can be 100 microns, 200 microns, 300 microns, 400 microns, 500 microns, 600 microns, 700 microns, 800 microns, 900 microns, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm.

[0089] According to an embodiment of the present invention, when the filter membrane 31 is a rigid porous membrane, a flexible buffer layer is required to make the filter membrane 31 fit tightly with the terahertz functional substrate 32, while protecting the terahertz functional substrate 32 from possible damage caused by the rigid membrane. The thickness of the buffer layer should be much smaller than the penetration depth of the terahertz surface plasma wave or the penetration depth of the artificial surface plasmon, so as to minimize the influence of the buffer layer on the detection sensitivity of the terahertz wave sensing system.

[0090] Continue to refer Figure 2 and Figure 4 According to an embodiment of the present invention, a limiting groove 11 is formed on the base 1, and the terahertz functional substrate 32 is installed in the limiting groove 11, and the depth of the limiting groove 11 is less than or equal to the thickness of the terahertz functional substrate 32.

[0091] According to an embodiment of the present invention, referring to Figure 2 , Figure 3 , Figure 5~Figure 7 A boss 21 is formed on the bottom of the groove structure. Figure 2 , Figure 3 , Figure 5~Figure 7The middle boss is formed by the housing 2, and the bottom of the groove of the groove structure extends toward the filter membrane 31. The boss 21 is constructed to abut against the filter membrane 31 when the groove structure is combined with the base 1, so as to cooperate with the base 1 to fix the position of the filter membrane 31 and the terahertz functional substrate 32, and make the filter membrane 31 and the terahertz functional substrate 32 form a close contact. The design of the boss 21 enables it to directly abut against the filter membrane 31 when the groove structure is combined with the base 1, and work together with the base 1 to accurately fix the position of the filter membrane 31 and the terahertz functional substrate 32, and form a first sample pool 4 and a second sample pool 5. The liquids in the two sample pools can only circulate with each other through the filter membrane. This mechanical fixing method ensures the stability of the sensor element during the detection process and avoids measurement errors caused by position offset or looseness.

[0092] The boss 21 achieves close contact between the filter membrane 31 and the terahertz functional substrate 32 by pressing them. This close contact is crucial to ensure that the terahertz wave can effectively penetrate the filter membrane and interact with the surface plasmon of the grating-coupled SPR sensor chip 32b or interact with the artificial surface plasmon of the terahertz metasurface sensor chip 32a based on the functional element sequence. Close contact also reduces the scattering and absorption of terahertz waves by air gaps or impurities, and improves the transmission efficiency and quality of the signal. The close contact and fixation between the boss 21 and the filter membrane 31 and the terahertz functional substrate 32 helps to reduce the loosening or damage of components caused by vibration or impact. This design improves the durability and long-term stability of the system, allowing the sensing system to maintain stable performance under various environmental conditions.

[0093] According to an embodiment of the present invention, Figure 2 , Figure 3 , Figure 5~Figure 7 The terahertz wave directly penetrates the housing 2 and enters the accommodation space, or a first through hole 22 may be opened on the housing, and the terahertz wave may enter the accommodation space from the first through hole 22. When the terahertz wave directly penetrates the housing 2 and enters the accommodation space, the housing is a terahertz transparent material.

[0094] Figure 8 A cross-sectional view of a terahertz sensing system suitable for terahertz reflection measurement mode is shown, in which a central through hole of a housing provided by an embodiment of the present invention is sealed by a boss made of a terahertz transparent material.

[0095] like Figure 8As shown, a first through hole 22 is provided in the center of the housing 2. The first through hole 22 has a gradually decreasing trumpet shape in the direction toward the filter membrane, and the port coaxially connected to the small opening of the trumpet-shaped first through hole 22 is the limiting hole of the boss 21, and the aperture of the limiting hole is larger than the small opening diameter of the trumpet-shaped through hole, so that an annular platform is formed at the connection between the two for supporting the boss 21.

[0096] According to an embodiment of the present invention, the material used for the boss 21 is a terahertz transparent material, and its thickness is less than the thickness of the housing 2. Compared with the terahertz wave directly penetrating the housing 2 to enter the accommodating space, the first through hole 22 is opened in the center of the housing 2 to minimize the transmission loss and scattering loss of the terahertz wave during the incidence and reflection. When the first through hole 22 is opened in the center of the housing 2, the boss 21 is not an integrated structure with the housing 2. The boss 21 is a separate component made of a terahertz transparent material. The boss 21 is fixed to the annular platform of the first through hole 22 opened in the center of the housing 2 by a commercially available adhesive, and the first through hole 22 is sealed and blocked.

[0097] According to an embodiment of the present invention, when a first through hole 22 is provided in the center of the housing 2, the material of the housing is a non-terahertz transparent material. When the terahertz wave is incident obliquely, the housing 2 can absorb the terahertz wave that does not enter the first through hole 22 to reduce interference with the detection beam. The inclination angle of the flare of the first through hole 22 can be determined according to the incident angle of the terahertz wave to minimize interference with the detection beam.

[0098] According to the embodiment of the present invention, when the first through hole 22 is opened in the center of the housing 2, the diameter of the small opening of the trumpet-shaped first through hole 22 needs to be smaller than the diameter of the boss 21, so as to allow an annular platform for supporting the boss 21 to be formed at the connection between the limiting hole and the trumpet-shaped small opening of the boss 21. When the boss 21 is fixed in the limiting hole to seal the first through hole 22, in addition to using a commercially available adhesive to bond the boss 21 to the annular platform, a gasket may also be provided between the annular platform and the boss 21 for sealing.

[0099] Fig. 9 A cross-sectional view of a terahertz sensing system suitable for terahertz transmission measurement mode is shown, in which a central through hole of a base is sealed by a terahertz transparent substrate and a central through hole of a housing is sealed by a terahertz transparent boss according to an embodiment of the present invention.

[0100] like Fig. 9 As shown, the base 1 has a second through hole 12 in the center, which is coaxially connected to the limiting groove 11. The diameter of the second through hole 12 is smaller than the diameter of the limiting groove 11, so that an annular platform is formed at the connection to support the terahertz functional substrate 32. Fig. 9The terahertz functional substrate 32 arranged in the limiting groove 11 is a terahertz transmission lens 32d. Of course, the terahertz functional substrate 32 in the limiting groove 11 can also be a terahertz metasurface sensor chip 32a based on a functional element sequence. The terahertz functional substrate 32 is fixed in the limiting groove and the second through hole 12 is sealed. When sealing, in addition to using a commercially available adhesive to bond the terahertz functional substrate 32 to the annular platform, a gasket can also be set between the annular platform and the terahertz functional substrate 32 for sealing. At this time, the filter membrane 31 is placed on the terahertz functional substrate 32, and the filter membrane 31 is pressed tightly by the boss 21 of the housing 2, so that the filter membrane 31 is in close contact with the terahertz functional substrate 32 to ensure that the solution to be tested can only flow from the first sample pool 4 into the second sample pool 5 through the filter membrane 31.

[0101] According to an embodiment of the present invention, when the terahertz functional substrate 32 disposed in the limiting groove 11 of the base 1 is a terahertz transmission lens 32d, the terahertz generation module emits collimated terahertz waves to pass through the housing 2, the filter membrane 31 and the terahertz transmission lens 32d to generate a transmission beam, which is a detection beam carrying information of biochemical substances. Here, the information of biochemical substances carried by the detection beam comes from the direct interaction between the terahertz beam and the biochemical substances enriched on the filter membrane 31. The detection beam carrying information of biochemical substances is directly detected by the terahertz detection module, and the output signal of the terahertz detection module is processed by the processing module to obtain information of biochemical substances. According to the Lambert-Beer law, the terahertz detection sensitivity based on the terahertz transmission lens 32d increases with the increase of the thickness of the filter membrane. Therefore, when the terahertz functional substrate 32 is a terahertz transmission lens 32d, the thickness of the filter membrane is preferably between 100 μm and 3 mm, for example, it can be 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, or 3 mm.

[0102] According to an embodiment of the present invention, when the terahertz functional substrate 32 disposed in the limiting groove 11 of the base 1 is a terahertz metasurface sensor chip 32a based on a functional element sequence, the terahertz generation module emits collimated terahertz waves through the terahertz lens, passes through the housing 2 and the filter membrane 31, and converges on the terahertz metasurface sensor chip 32a based on a functional element sequence, thereby generating artificial surface plasmons, and the artificial surface plasmons interact with the filter membrane 31 containing biochemical substance information to obtain a transmission beam carrying the biochemical substance information. After the transmission beam is emitted from the second through hole 12 and collimated by the terahertz lens, it is received by the terahertz detection module, and the resonance frequency of the terahertz metasurface sensor chip 32a based on the functional element sequence or the transmission wave intensity of a given frequency is measured, thereby realizing the quantitative analysis of the biochemical substances in the solution to be tested.

[0103] above Figure 2 , Figure 3 , Figure 5~Figure 9 The area of ​​the middle boss 21 is larger than the area of ​​the terahertz functional substrate 32 , so that the terahertz functional substrate 32 is completely pressed and the force is balanced.

[0104] According to an embodiment of the present invention, the terahertz sensing system further includes: a gasket (not shown in the figure), which is installed between the base 1 and the housing 2, and the gasket is suitable for sealing the accommodating space formed by the groove structure and the base 1. The gasket is pre-set in a limiting groove (not shown in the figure) opened on the base 1 or in a limiting groove (not shown in the figure) opened on the housing 2.

[0105] According to an embodiment of the present invention, the gasket is used to seal the portion where the groove structure is connected to the base 1. The height of the gasket determines the degree of compression of the boss 21 on the filter membrane 31 and the terahertz functional substrate 32.

[0106] According to an embodiment of the present invention, the solution to be tested may be, for example, physiological saline, and the biological substance may be, for example, DNA, protein, etc. DNA and protein are macromolecular substances, and the filter membrane 31 may be used to directly filter the macromolecular substances to achieve the enrichment of the macromolecular substances.

[0107] According to an embodiment of the present invention, in order to achieve complete enrichment of DNA and protein in the filter membrane 31, the terahertz sensing system further includes a pump body, which is suitable for pumping the solution to be tested into the first sample pool 4, and the solution in the first sample pool is the solution to be tested; the pump body is also suitable for pumping the solution that passes through the filter membrane and enters the second sample pool 5 into the first sample pool 4, so that the solution circulates in the first sample pool 4 and the second sample pool 5, and then the biochemical substances (such as DNA, protein) in the solution to be tested are completely attached to the filter membrane. The pump body can be, for example, a peristaltic pump. Through the action of the pump body, the solution to be tested can repeatedly flow through the filter membrane, which greatly increases the contact opportunity and contact time between the biochemical substances and the surface of the filter membrane 31. This continuous and sufficient contact promotes the attachment of biochemical substances to the filter membrane, thereby improving the sensitivity and accuracy of the detection. The pump body can quickly distribute the biochemical substances in the solution to be tested to the entire filter membrane 31, reducing the problem of uneven distribution of substances or prolonged attachment time caused by the solution standing. Therefore, the total time required for detection is shortened. The circulating pumping of the pump body not only promotes the adhesion of biochemical substances, but also avoids the occurrence of precipitation and stratification, ensuring the stability and uniformity of the solution to be tested during the detection process. This helps to reduce the measurement error caused by the change of the state of the solution to be tested and improve the reliability of the test results. By recycling the solution to be tested, the demand for original samples is reduced. This is especially important for precious or difficult to obtain samples, which can reduce experimental costs while ensuring the detection effect.

[0108] According to an embodiment of the present invention, the solution to be tested may also be, for example, a body fluid, and the biochemical substance in the solution to be tested may be, for example, a calcium ion in the body fluid. When the solution to be tested is a body fluid, and the biochemical substance in the solution to be tested is a calcium ion in the body fluid, the first sample pool 4 is also filled with a reaction solution, the reaction solution includes a reaction substrate, and the anions in the reaction substrate react with the calcium ions to form a water-insoluble product including calcium ions, and the product is enriched on the filter membrane. According to an embodiment of the present invention, the cations in the reaction substrate are selected from any one of the other cations included in the body fluid except the calcium ion, and the anions of the reaction substrate are selected from carbonate ions, bicarbonate ions or sulfate ions. The reaction substrate may be, for example, sodium carbonate, sodium sulfate, and the like.

[0109] According to an embodiment of the present invention, when the solution to be tested is body fluid and the biochemical substance is calcium ions, the pump body is also used to pump the reaction solution into the first sample pool 4. At this time, the solution in the first sample pool 4 includes the reaction solution and the body fluid, and under the action of the pump body, the solution after the reaction of the reaction solution and the body fluid circulates between the first sample pool 4 and the second sample pool, so that the enrichment of the product including calcium ions on the filter membrane 31 reaches equilibrium.

[0110] According to an embodiment of the present invention, a liquid inlet is provided on the first sample pool 4 of the terahertz sensor system, and the number of the liquid inlets may be, for example, one or two (a first liquid inlet 41 and a second liquid inlet 42), for delivering an external solution to the first sample pool 4. A liquid outlet 51 is provided on the second sample pool 5 of the terahertz sensor system, for delivering the solution in the second sample pool 5 to the outside of the second sample pool 5.

[0111] According to the embodiment of the present invention, the filter membrane 31 has a high transmittance of terahertz waves. The filter membrane is preferably a filter paper commonly used in experiments, and the thickness of the filter membrane can be adjusted by stacking multiple layers of filter paper.

[0112] According to an embodiment of the present invention, the information of the biochemical substance includes the composition, concentration, quality and refractive index of the biochemical substance.

[0113] According to an embodiment of the present invention, the terahertz sensing system further includes a terahertz generation module (not shown in the figure) and a terahertz detection module (not shown in the figure). The terahertz generation module is suitable for generating terahertz waves. The terahertz detection module is suitable for real-time measurement of the detection beam, and is particularly suitable for detecting the evolution of the detection beam over time during the process in which the pump body pumps the solution to be tested into the first sample pool 4. The position of the terahertz generation module is configured to enable the generated terahertz wave to pass through the housing 2 without passing through the two sample pools, and directly incident on the filter membrane 31, thereby avoiding the influence of the solutions in the two sample pools on the terahertz wave.

[0114] According to a specific embodiment of the present invention, the terahertz wave generated by the terahertz generation module can be, for example, a single-frequency terahertz wave, and the terahertz functional substrate 32 is a grating-coupled SPR sensor chip 32b. The terahertz generation module includes a terahertz source and a modulation unit. The terahertz wave generated by the terahertz source can be, for example, a single-frequency terahertz linearly polarized parallel beam, and the modulation unit is suitable for modulating the single-frequency terahertz linearly polarized parallel beam so that the modulated single-frequency terahertz linearly polarized parallel beam resonates with the grating-coupled SPR sensor chip 32b. The modulation device includes a driving component or a focusing component. The driving component is suitable for rotating the terahertz source to adjust the incident angle of the terahertz beam incident on the grating-coupled SPR sensor chip 32b, so that the single-frequency terahertz linearly polarized parallel beam resonates with the grating-coupled SPR sensor chip 32b. When the single-frequency terahertz linearly polarized parallel beam resonates with the grating-coupled SPR sensor chip 32b, the incident angle of the single-frequency terahertz linearly polarized parallel beam is the resonance angle. The focusing component is suitable for focusing the single-frequency terahertz linearly polarized parallel beam to obtain a focused beam, and the focused beam is incident on the grating-coupled SPR sensor chip 32b at a preset angle. The focusing component is adjusted so that the focus of the focused beam is located on the surface of the grating-coupled SPR sensor chip 32b, and a certain wave vector component of the focused beam resonates with the grating-coupled SPR sensor chip 32b, and the incident angle of the wave vector component that resonates with the grating-coupled SPR sensor chip 32b is the resonance angle.

[0115] According to another embodiment of the present invention, the terahertz wave generated by the terahertz generation module can be, for example, a broadband terahertz linearly polarized parallel beam, and the terahertz functional substrate 32 is a grating-coupled SPR sensor chip 32b. The broadband terahertz linearly polarized parallel beam is incident on the grating-coupled SPR sensor chip 32b at a preset angle, so that a certain frequency component of the broadband terahertz linearly polarized parallel beam resonates with the grating-coupled SPR sensor chip 32b, and the frequency component of the broadband terahertz linearly polarized parallel beam resonating with the terahertz SPR sensor chip 32b is the resonant frequency.

[0116] According to an embodiment of the present invention, the terahertz sensing system also includes: a processing module (not marked), which is suitable for processing the output signal of the terahertz detection module, and determining whether the enrichment of the biochemical substances in the solution to be tested on the filter membrane has reached equilibrium based on the change of the detection beam measured each time the pump body pumps the solution into the first sample pool. The processing module is also suitable for obtaining information about the biochemical substances based on the information of the detection beam in the equilibrium state.

[0117] According to an embodiment of the present invention, when the terahertz functional substrate is a grating-coupled SPR sensor chip 32b, the processing module is suitable for obtaining the surface plasma wave resonance information of the grating-coupled SPR sensor chip 32b based on the spectrum information of the reflected beam measured in the process of the pump body pumping the solution into the first sample pool. When the resonance information remains unchanged over time (that is, the difference between the resonance information obtained by two consecutive measurements is less than a preset value), it is determined that the enrichment of the biochemical substance in the solution to be tested on the filter membrane has reached equilibrium. The processing device is also suitable for obtaining the information of the biochemical substance based on the resonance information under a predetermined state; wherein the resonance information is the incident angle or incident frequency corresponding to the resonance coupling between the terahertz beam and the grating-coupled SPR sensor chip 32b.

[0118] According to an embodiment of the present invention, when the terahertz functional substrate is a terahertz metasurface sensor chip 32a based on a functional elemental structure, the processing module is suitable for obtaining the resonance information of the artificial surface plasmon of the terahertz metasurface sensor chip 32a based on the functional elemental structure according to the spectrum information of the reflected beam or the spectrum information of the transmitted beam measured in the process of the pump body pumping the solution into the first sample pool, and when the resonance information remains unchanged over time, it is determined that the enrichment of the biochemical substances in the solution to be tested on the filter membrane reaches an equilibrium state, and the processing device is also suitable for obtaining the information of the biochemical substances according to the resonance information under a predetermined state; wherein the resonance information is the incident frequency of the terahertz wave corresponding to the resonance coupling between the terahertz beam and the terahertz metasurface sensor chip 32a based on the functional elemental structure or the reflected wave intensity or the transmitted wave intensity of the terahertz wave of a given frequency.

[0119] The following combination Figure 1 A specific embodiment is cited to illustrate the use of the terahertz sensing system provided by the embodiment of the present invention to detect the concentration of calcium ions in body fluids.

[0120] Step 1: The terahertz wave emitted by the terahertz generation module irradiates the upper surface of the housing 2 at a preset incident angle, then passes through the housing 2 and the filter membrane 31 and is incident on the grating-coupled SPR sensor chip 32b and is reflected. The reflected wave beam passes through the filter membrane 31 and the housing 2 and is received by the terahertz detection module, and the resonance angle or resonance frequency of the grating-coupled SPR sensor chip 32b when the two sample cells are in an unloaded state is measured;

[0121] Step 2: The reaction solution with known substrate concentration is pumped into the first sample pool from the first liquid inlet 41, and the reaction solution penetrates into the filter membrane 31 from the first side of the porous filter membrane 31, and then seeps out from the second side opposite to the first side of the filter membrane 31, and then is pumped out from the liquid outlet 51 of the second sample pool 5. The solution pumped out from the second sample pool 5 is pumped into the first sample pool 4, and the cycle is repeated multiple times. Under the condition that the predetermined state is maintained according to the resonance information obtained by the processing module, the resonance angle or resonance frequency of the grating coupled SPR sensor chip 32b is measured again.

[0122] Step 3: The calcium ion solution to be measured is pumped into the first sample pool 4 from the second liquid inlet 42 to react with the reaction substrate in the first sample pool 5. The solution containing the reaction product penetrates into the filter membrane from the first side of the filter membrane 31, and then seeps out from the second side of the filter membrane 31, and then is pumped out from the liquid outlet 51 of the second sample pool 5. The resonance angle or resonance frequency of the grating coupling type SPR sensor chip 32 is measured again when the resonance information obtained by the processing module is kept in a predetermined state, and the concentration of the calcium ion solution to be measured is obtained by obtaining the change in the resonance angle or the resonance frequency.

[0123] The embodiments of the present invention are described above. However, these embodiments are only for the purpose of illustration, and are not intended to limit the scope of the present invention. Although each embodiment is described above, it does not mean that the measures in each embodiment cannot be used in combination. The scope of the present invention is defined by the attached claims and their equivalents. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A terahertz sensing system for detecting biochemical substances in a solution, comprising: Pedestal; The housing is mounted on the base, the housing is constructed as a groove structure, and the groove structure and the base form a containing space ； An enrichment module is disposed in the accommodating space, and the enrichment module divides the accommodating space into a first sample pool and a second sample pool. The enrichment module includes: A filter membrane, wherein the thickness of the filter membrane is between 1 micron and 3 millimeters; the solution to be tested is injected into the first sample pool, and the solution in the first sample pool passes through the filter membrane and enters the second sample pool, and in the process that the solution in the first sample pool passes through the filter membrane, the biochemical substances in the solution to be tested are enriched on the filter membrane; Among them, the terahertz wave passes through the shell and is incident on the filter membrane carrying the biochemical substance. After passing through the filter membrane, a detection beam is obtained. The detection beam is a beam carrying information of the biochemical substance. The beam carrying information of the biochemical substance is used to realize quantitative analysis of the biochemical substance in the solution to be tested.

2. The terahertz sensing system according to claim 1, wherein: The enrichment module further includes: a terahertz functional substrate, which is mounted on the base and located in the accommodating space, The terahertz wave passes through the housing and is incident on the filter membrane carrying the biochemical substance, and a detection beam is obtained after passing through the filter membrane, including: The terahertz wave passes through the housing and is incident on the filter membrane carrying the biochemical substance, and then passes through the filter membrane and is incident on the terahertz functional substrate, and is reflected and / or transmitted by the terahertz functional substrate, and the obtained reflected beam or transmitted beam is the detection beam.

3. The terahertz sensing system according to claim 2, wherein: The terahertz functional substrate is a grating-coupled SPR sensor chip, a terahertz metasurface sensor chip based on a functional element sequence, a terahertz reflective lens or a terahertz transmissive lens; When the terahertz functional substrate is a terahertz metasurface sensor chip based on a functional element sequence structure, the terahertz wave is reflected and / or transmitted on the terahertz functional substrate, and the obtained reflected beam or transmitted beam is the detection beam; When the terahertz functional substrate is a grating-coupled SPR sensor chip or a terahertz reflective lens, the terahertz wave is reflected on the terahertz functional substrate, and the obtained reflected beam is the detection beam; When the terahertz functional substrate is a terahertz transmission lens, the terahertz wave is transmitted on the terahertz functional substrate, and the obtained transmission beam is the detection beam.

4. The terahertz sensing system according to claim 1, wherein: A limiting groove is formed on the base, the terahertz functional substrate is installed in the limiting groove, and the depth of the limiting groove is less than or equal to the thickness of the terahertz functional substrate.

5. The terahertz sensing system according to claim 1, wherein: Also includes: A gasket is installed between the base and the shell, and the gasket is suitable for sealing the accommodating space formed by the groove structure and the base.

6. The terahertz sensing system according to claim 1, wherein: When the solution to be tested is body fluid, and the biochemical substance in the solution to be tested is calcium ions in the body fluid, the first sample pool is filled with a reaction solution, the reaction solution contains a reaction substrate, anions in the reaction substrate react with the calcium ions to form a water-insoluble product containing the calcium ions, and the product is enriched on the filter membrane; Preferably, the reaction substrate is an ionic compound, the cation of the ionic compound is selected from any one of the cations other than calcium ions included in body fluids, and the anion of the ionic compound is selected from carbonate ions, bicarbonate ions or sulfate ions.

7. The terahertz sensing system according to claim 1, further comprising: A pump body, wherein the pump body is suitable for pumping the solution to be tested into the first sample pool; the pump body is also suitable for pumping the solution that passes through the filter membrane and enters the second sample pool into the first sample pool, so that the solution circulates in the first sample pool and the second sample pool, thereby achieving a balance in the enrichment of the biochemical substances in the solution to be tested on the filter membrane.

8. The terahertz sensing system according to claim 7, wherein: The terahertz sensing system further comprises: A terahertz generation module, adapted to generate the terahertz wave; A terahertz detection module, adapted to detect the detection beam; A processing module is adapted to process the electrical signal output by the terahertz detection module, and determine whether the enrichment of the biochemical substances in the solution to be tested on the filter membrane has reached equilibrium based on the change of the detection beam measured each time the pump body pumps the solution into the first sample pool. The processing module is also adapted to obtain information about the biochemical substances based on information about the detection beam in the equilibrium state.

9. The terahertz sensing system according to claim 2, wherein: A boss is formed on the bottom of the groove of the groove-shaped structure, and the boss is configured to abut against the filter membrane to cooperate with the base to fix the positions of the filter membrane and the terahertz functional substrate and make the filter membrane and the terahertz functional substrate form close contact, and the area of ​​the boss is larger than the area of ​​the terahertz functional substrate.

10. The terahertz sensing system according to claim 1, wherein: The material of the boss of the housing is a terahertz transparent material; The filter membrane is a porous material with high terahertz wave transmittance; The information of the biochemical substance includes the composition, concentration, mass and refractive index of the biochemical substance.

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