Microfluidic and terahertz transmission line integrated cell sorting and detecting system and method thereof

Abstract

The invention belongs to the technical field of biomedical analysis, and relates to a cell sorting and detecting system integrating microfluidic control and a terahertz transmission line and a method thereof. A cell sorting area of the system comprises: a cell injection chamber for introducing a multi-cell mixed culture solution to be sorted; the microfluid channel is used for realizing primary cell sorting based on a magnetic field; the capture trap microstructure array is used for capturing the free MNPs and realizing the separation of the free MNPs and the target cells with the MNPs markers; the transmission line detection area comprises a fixing structure used for fixing a to-be-detected cell in a sensing area of the transmission line; the transmission line detection unit is used for detecting the characteristic spectrums of the labeled cells and the unlabeled cells in situ in real time; an outlet collection chamber is also included. High integration of cell sorting and electrical detection is achieved, high-sensitivity detection of terahertz waves and accurate sample control of microfluidics can be combined, and higher-throughput, lower-damage and more accurate sample analysis and sorting are achieved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biomedical analysis, and particularly relates to a cell sorting and detection system integrated with microfluidics and terahertz transmission lines and a method thereof. BACKGROUND

[0002] In the field of biomedicine, it is often necessary to carry out various analyses on specific types of target cells in a sample to be tested, and the key to successful analysis lies in whether the target cells can be sorted from the rest of the sample. At the same time, detection after cell sorting is of great significance for in-depth understanding of cell characteristics, functions, and disease diagnosis.

[0003] From the aspect of cell sorting, microfiltration is the most widely known cell sorting method. The most commonly used method is to sort cells according to their physical size, i.e., the microfluidic chip channel has a special size design, and smaller cells can pass through some narrow channels or sieves, while larger cells are intercepted. Microfiltration can be regarded as a passive cell sorting technique without relying on external action, i.e., without external force, the size difference of the cells themselves can complete the sorting.

[0004] However, this micro-membrane and micro-column screening method based on physical size often has the problem of limited sorting precision, i.e., the sizes of different types of cells may overlap, and the sizes of cells in the same type of cell population may also have certain differences. For example, in blood cells, lymphocytes and some smaller mononuclear cells are relatively close in size; it is difficult to accurately separate them using microfiltration, which may result in low cell purity after sorting. For some irregularly shaped cells, it is more difficult to filter and sort them simply by size; for example, nerve cells have complex protruding structures, and their size is complex to define, and in the microfiltration process, some cells may be incorrectly screened or blocked due to protrusions, making accurate sorting impossible. In addition, when processing a large number of cell samples with high cell density, cells tend to aggregate and form blockages, which affects the efficiency and recovery rate of cell sorting, and is not conducive to further cell analysis.

[0005] From the aspect of cell detection, cell detection technology can be broadly divided into two categories: one is invasive and non-active detection with certain toxic effects, and the other is non-invasive and active detection using near-field sensing technology.

[0006] Invasive detection techniques usually involve some degree of intervention or change to the cells, such as staining, are time-consuming, require a large number of samples, and the cells must be treated and fixed, which can cause certain toxicity to the cells and may affect the activity or cause the reaction of the cells, thereby affecting the detection results, and subsequent operation and detection cannot be performed on the inactivated cells. Non-invasive detection techniques can maintain the activity and function of the cells, and monitor the natural state of the cells in real time and continuously, and have significant advantages compared with invasive detection. However, the currently used techniques usually require complex equipment, and the sensitivity and resolution may be limited to a certain extent.

[0007] Terahertz wave cell sensing technology is a typical application of non-invasive cell sensing and detection technology, and is also a new field in biomedicine in recent years. When the terahertz signal passes through the biological molecules, the molecules will exhibit their unique spectral vibration characteristics in the terahertz band, thereby allowing us to analyze the terahertz characteristic fingerprint spectrum of the cell sample. Due to the propagation characteristics of terahertz waves in biological tissues, this technology has the advantages of non-invasive, non-invasive, real-time monitoring, and has shown great application prospects in the field of biological cell detection. However, due to the complexity of the current terahertz wave source, detector and equipment and technology for manipulating terahertz waves, and the high cost, it is not conducive to practical application, so there is still a distance for its scale and practicality.

[0008] The microfluidic chip test system provides an integrated platform for cell sorting and electrical detection, and through efficient sorting and electrical detection of cells, it is expected to provide new methods and indicators for early diagnosis of diseases. For example, in cancer research, it can be used to detect electrical changes of abnormal cells such as circulating tumor cells, so as to achieve earlier and more accurate cancer diagnosis. However, the current microfluidic chip for cell detection has low integration, and generally can only realize single cell sorting or sample labeling function, and cannot realize real-time cell electrical property detection; after cell sorting and enrichment, separate equipment is needed for testing and analysis, the principle of the instrument is complex, the detection unit is large, and it is difficult to realize accurate detection of trace cells, and cannot be integrated on the chip with the microfluidic chip, which restricts the development of related technologies. SUMMARY

[0009] The present application aims to solve the above problems in the prior art, and provides a cell sorting and detection system and method integrating microfluidics and terahertz transmission lines. The present application integrates a terahertz high-frequency transmission line detection region and a microfluidic sorting region on a chip by using microfluidic chip technology, to realize a high-integration multifunctional integrated microanalysis platform.

[0010] The microfluidic sorting area can accurately control the liquid flow and the distribution and flow direction of biological samples such as cells in the liquid, and ensure that the sample can be accurately regulated to the optimal analysis area, so as to provide more accurate sample control for terahertz wave analysis; the terahertz transmission line detection area can provide a high-efficiency, rapid and non-invasive detection means for the microfluidic system, and can detect the sorted cells on the chip in real time, analyze and monitor the characteristics of the sample through the non-invasive high-frequency terahertz signal, and further extract the terahertz characteristic spectrum of various cells including target cells.

[0011] The integration can combine the high-sensitivity detection of terahertz waves and the accurate sample control of microfluidics, realize higher throughput, lower damage and more accurate sample analysis and sorting, and promote the further development of terahertz cell sensing detection and diagnosis technology.

[0012] The technical scheme of the present application is:

[0013] The present application provides a cell sorting and detection system integrating microfluidics and terahertz transmission lines, which comprises a cell sorting area and a transmission line detection area, and the cell sorting area comprises, in sequence:

[0014] A cell injection chamber for introducing a multi-cell mixed culture solution to be sorted;

[0015] A microfluidic channel for guiding the flow of the multi-cell mixed culture solution in the microfluidic channel to realize preliminary cell sorting based on a magnetic field;

[0016] A capture trap microstructure array for capturing free MNPs to separate the free MNPs from target cells labeled with MNPs;

[0017] The transmission line detection area comprises:

[0018] A fixing structure for fixing the cells to be tested in the sensing area of the transmission line;

[0019] A transmission line detection unit connected to a vector network analyzer through high-frequency microwave probes at both ends, for in-situ real-time detection of the characteristic spectrum of labeled cells and unlabeled cells, and feedback of the detection information to the vector network analyzer; and an outlet collection chamber for collecting cells that are not fixed after sorting.

[0020] Further, before introducing the multi-cell mixed culture solution into the chamber, the MNPs and the target cells are co-cultured in advance, and the MNPs are used for specific antibody recognition and labeling of the target cells.

[0021] Further, a permanent magnet or an electromagnet is arranged on one side of the microfluidic channel, and the flow route of the target cells labeled with MNPs is controlled by the magnetic field, so as to separate them from the unlabeled cells.

[0022] Further, the capture trap microstructure array comprises a plurality of magnetic bead capture traps, which allow small-sized free MNPs to enter and be fixed, thereby realizing further sorting with target cells labeled with MNPs.

[0023] Further, the substrate material of the system comprises a silicon wafer, high-purity quartz or a PET material, and the microfluidic channel adopts PDMS or SU-8 material.

[0024] Further, the transmission line detection unit is arranged on the microfluidic channel in the two regions close to and not close to the magnetic field, respectively.

[0025] Further, the two ends of the transmission line are connected to form an electrical connection, the transmission line detection unit is fed with a high-frequency terahertz electrical signal, and the electrical signal fed back from the transmission line is received; the high-frequency microwave probe is also connected to a vector network analyzer, and the vector network analyzer analyzes the electrical signal and obtains a characteristic spectrum; thereby realizing in-situ real-time detection of the characteristic spectrum of the target cells labeled with MNPs, unlabeled cells and empty transmission lines without cells.

[0026] In the above steps, the empty transmission line without cells is used to detect the background characteristic spectrum, and the characteristic spectrum of the cells needs to be obtained by a difference algorithm after the characteristic spectrum of the background and the characteristic spectrum of the cells are compared, and the transmission line detection unit is the detection area of the system. The high-frequency microwave probe is an external component, which is connected to the two ends of the transmission line to form a reliable electrical connection, so that the transmission line detection unit can be fed with a high-frequency terahertz electrical signal, and the electrical signal fed back from the transmission line can be received. This electrical signal represents the characteristic spectrum information, and the high-frequency microwave probe is also connected to a vector network analyzer, and the vector network analyzer analyzes the electrical signal and obtains the characteristic spectrum.

[0027] The application also provides a cell sorting and detection method integrating microfluidics and terahertz transmission lines, comprising the following steps:

[0028] MNPs are used to specifically recognize and label target cells, and a mixed culture solution containing a plurality of cells is injected into a starting chamber and enters a microfluidic channel from the chamber;

[0029] The unlabeled cells flow along the microfluidic channel without an external magnetic field, flow through the transmission line detection area, and part of the unlabeled cells are fixed by the fixed structure in the sensing area of the transmission line. The high-frequency on-chip microwave probe is used for signal excitation and reception of the transmission line, and the vector network analyzer is used for deep analysis of the test signal to obtain the cell characteristic spectrum information. The unlabeled cells that are not fixed continue to flow and flow into an outlet collection chamber as an unlabeled cell sample.

[0030] The free MNPs and the cells labeled with the MNPs are attracted to the microfluidic channel close to the magnetic field region by an external magnetic field, the free MNPs are captured when flowing to the magnetic bead capture trap, the labeled cells continue to flow into the transmission line detection area, and part of the labeled cells are limited in the transmission line detection area by the fixed structure for characteristic spectrum detection; the transmission line is excited and received by a high-frequency on-chip microwave probe, the test signal is analyzed by a vector network analyzer to obtain the characteristic spectrum information of the labeled cells; the labeled cells not fixed continue to flow and flow into the outlet collection chamber as the labeled cell sample;

[0031] The characteristic spectrum of the labeled cells is compared with the characteristic spectrum of the unlabeled cells for analysis.

[0032] In the above method, the separation principle of the labeled cells and the free magnetic beads is that the target cells labeled with the MNPs and the free MNPs are in the same microfluidic channel close to the magnetic field, if the mixed sample is directly detected, a large number of free MNPs are easy to interfere with the detection of the target cells, and therefore the free MNPs need to be screened out. Since the diameter of the magnetic beads is much smaller than that of the labeled cells, when passing through the magnetic bead capture trap, the small-sized particles (i.e. the free MNPs) enter and are captured, and the large-sized cells (i.e. the target cells labeled with the MNPs) continue to flow to the cell detection area under the driving of the microfluidic channel. Similar to the unlabeled cells, part of the cells labeled with the magnetic beads are limited in the transmission line detection area by the fixed microstructure in the center of the microfluidic channel, the characteristic spectrum is detected by the high-frequency transmission line sensor, and is compared with the characteristic spectrum of the unlabeled cells for further analysis of the physiological state, and the rest of the labeled cells finally flow to the outlet collection chamber and are finally collected as the labeled sample.

[0033] The sorting and detection process of the system includes blank signal calibration, labeled / unlabeled cell sorting, and in-situ characteristic spectrum comparison. The blank signal calibration is to connect the vector network analyzer and high-frequency microwave probe with the transmission line detection unit before injecting the mixed cell sample into the system, and to inject culture solution without cells and magnetic beads as a blank liquid sample into the microfluidic system for a characteristic spectrum test. The blank culture solution pre-test eliminates environmental interference. This test signal is used as a blank signal for comparison with the subsequent cell detection signal. The in-situ characteristic spectrum comparison has two comparisons: first, the comparison between the cell detection signal and the blank signal without cells. Through such comparison, the characteristic spectrum peak frequency change caused by the presence of cells can be obtained from the characteristic spectrum data, so as to determine the frequency point of the terahertz dielectric response of the cells; second, the comparison between the two cell detection signals, that is, the comparison between the labeled cell detection signal and the unlabeled cell detection signal. This can further determine the difference in terahertz dielectric response between the two cells, and the difference reflected on the characteristic spectrum can be analyzed in combination with pathological diagnosis, so as to directly interpret the physiological state of the cells on the terahertz spectrum.

[0034] The beneficial effects of the present application are:

[0035] (1) Integration and high efficiency: The high integration of cell sorting and electrical detection is realized by integrating cell sorting and electrical detection in one microfluidic chip, combining magnetic nanoparticle (MNP) labeling, magnetic field sorting and microfluidic structure, realizing high-efficiency cell sorting, reducing the complex steps in traditional technology and improving the overall efficiency.

[0036] (2) Non-invasive detection: The use of terahertz waves for electrical characteristic analysis of sorted cells can obtain physiological state information of cells without causing physical or chemical damage to cells, maintaining cell activity, solving the problems of low efficiency, poor precision and insensitive cell detection signal in traditional cell sorting methods, and having the characteristics of high efficiency, precision and non-invasive.

[0037] (3) High sensitivity and real-time detection: With the help of high-frequency transmission line and advanced vector network analyzer, the physiological changes of trace cells can be accurately detected, and real-time detection can be realized.

[0038] (4) Biocompatibility of materials: The use of PDMS to make microfluidic channels ensures the friendliness to the cell environment and improves the detection reliability.

[0039] (5) Wide application prospect: the system has high integration degree and high throughput processing capacity, can complete multifunctional operations such as cell sorting and characteristic spectrum analysis on a single chip platform, and has wide application prospect in the fields of cell research, liquid biopsy, cancer screening, drug screening, biomedical research and personalized medicine, and is an innovative and practical technical scheme.

[0040] (6) The cell sorting and detection method provided by the application realizes the pre-separation of cells carrying magnetic bead markers and cells without carrying markers by introducing a magnetic field, not only depending on the difference in physical size of the cells, but also labeling the target cells with magnetic beads in advance, and guiding by magnetic force by using an external magnetic field, so that the pre-separation of the two is realized. And on the micro-flow channel close to the magnetic field, a plurality of micro-column array traps for capturing and collecting small magnetic nanoparticles are arranged, and a different idea from the traditional micro-filtration "small size passes, large size does not pass" is adopted, that is, the difference in physical size is reversely used to capture and limit the small size magnetic beads in the trap area, and the large size target cells keep flowing, and the method of cross-flow filtration is combined, so that the large size cells carrying magnetic bead markers effectively pass through the micro-column array trap area, thereby realizing the separation between the magnetic beads and the cells carrying magnetic bead markers, and effectively avoiding the blockage, improving the sorting throughput and accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 It is the overall schematic diagram of the cell sorting and detection system provided by the application;

[0042] Figure 2 It is the structure schematic diagram of the cell sorting area;

[0043] Figure 3 It is the schematic diagram of the force on the magnetic beads and cells under the magnetic field;

[0044] Figure 4 It is the schematic diagram of the capture trap microstructure array of the magnetic beads;

[0045] Figure 5 It is the structure schematic diagram of the transmission line detection area;

[0046] Figure 6 It is the overall flow chart of the cell sorting and detection method provided by the application; DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the application will be described clearly and completely in combination with the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0048] For a further understanding of the present application, reference will be made to the following description taken in conjunction with the accompanying drawings and examples.

[0049] Example 1

[0050] The present application relates to a cell sorting and detection system integrated with microfluidics and terahertz transmission lines, which is a microfluidic chip testing system integrated with cell sorting and electrical detection functions, aiming to provide an efficient and accurate cell screening and analysis platform.

[0051] As shown in Figure 1 , the entire system is made on a silicon wafer or high-purity quartz substrate, and is divided into two major areas: a cell sorting area and a transmission line detection area, which work together to achieve efficient cell sorting and electrical physiological characteristic analysis.

[0052] In the cell sorting area, the system innovatively combines the use of magnetic nanoparticles (MNPs) labeling, magnetic field assisted sorting, physical screening of micro-pillar array structure, and microfluidic operation, together forming an efficient and reliable cell sorting mechanism. The main microfluidic structure is made of polydimethylsiloxane (PDMS) material, which is widely used due to its good biocompatibility and processing performance.

[0053] As shown in Figure 2 , the cell sorting area includes:

[0054] A cell injection chamber for introducing a multi-cell mixed culture solution to be sorted.

[0055] A mixed culture solution containing multiple cells is injected into the starting chamber, and the target cells and magnetic beads are pre-cultured, using MNPs to recognize and label the target cells with antibodies. This process ensures that only target cells will be labeled with MNPs, resulting in a mixed culture solution of magnetic beads and multiple cells.

[0056] A microfluidic channel for guiding the flow of the multi-cell mixed culture solution inside the chip.

[0057] The above-mentioned microfluidic channel can be designed in various shapes according to actual conditions, and can contain multiple branches, thereby enabling the integration of other cell sorting techniques such as flow cytometry and dielectrophoresis, different target cell sorting on each microfluidic channel, and finally near-field detection using transmission lines.

[0058] As shown in Figure 3 , by setting permanent magnets or electromagnets that can change the magnetic field strength and direction next to the microfluidic channel, the flow path of the target cells with magnetic bead markers can be controlled using the magnetic field, allowing the target cells to be accurately and efficiently sorted from the mixed solution.

[0059] When the cells labeled with MNPs flow in the microfluidic channel with the culture solution, the free MNPs and the cells carrying MNPs are attracted by the external magnetic field and deflected to the microfluidic channel close to the magnetic field region. The unlabeled cells continue to flow along the microfluidic channel without the external magnetic field, thereby realizing the preliminary sorting of cells based on the magnetic field assistance.

[0060] However, not only the cells carrying the MNP label can flow to the microfluidic channel close to the magnetic field region, but also the free MNPs not labeled on the cells flow into the microfluidic channel close to the magnetic field region with the labeled cells under the action of the magnetic field, which inevitably causes a large amount of consumption and waste of free MNPs. Moreover, since the magnetic properties of MNPs are positively correlated with the number of MNPs, the more the number of magnetic beads, the more serious the drift and distortion of the characteristic spectrum of the cells to be detected in the process of transmission line near-field sensing of cells. Therefore, in order to improve the accuracy of cell detection as much as possible, it is necessary to separate the free MNPs from the cells carrying the label as much as possible.

[0061] To solve this problem, the embodiment adds a reverse screening using the size difference between magnetic beads and cells in the cell sorting area, as shown in Figure 4 The free MNPs are captured and fixed in the trap structure as much as possible by using the capture trap microstructure array that only allows small-sized magnetic beads to enter, thereby realizing further separation of free MNPs from cells carrying the label.

[0062] The capture trap microstructure array is used to capture the excess free MNPs and separate them from the cells carrying the magnetic bead label. The shape of the capture trap microstructure array is parallel to the direction of liquid flow, which belongs to the method of cross-flow filtration, and the small-sized magnetic beads are screened out and the large-sized cells flow through the microstructure, thereby effectively avoiding the problem of blockage of the microfluidic channel.

[0063] The capture trap microstructure array includes a plurality of magnetic bead capture traps. In specific embodiments, the number and arrangement of the magnetic bead capture traps can be set as needed, which can be single row or multiple rows arranged in an array. Its shape can be upstream opening and downstream sealing according to the direction of liquid flow, which is used for in-situ capture and collection of MNPs; or the upstream opening is provided for the MNPs to enter, and the downstream is connected to a specific microfluidic channel, which connects multiple capture traps to a unified MNP collection area, which can solve the problem of overflow after the capture trap is full, and also facilitates the recovery of excess MNPs.

[0064] As shown in Figure 5 The transmission line detection area includes:

[0065] A fixing structure is arranged near the transmission line resonant structure to fix the cells to be detected, so that a better near-field sensing effect is achieved.

[0066] A transmission line detection unit is arranged to be connected to a vector network analyzer through a high-frequency microwave probe arranged at both ends of the transmission line detection unit, so that the characteristic spectrum of the labeled cells, the unlabeled cells and the empty transmission line without cells can be detected in situ and in real time, and the information is fed back to the vector network analyzer.

[0067] A plurality of outlet collection chambers are arranged to collect the cells that are not fixed after being sorted.

[0068] When the unlabeled cells flow through the cell detection area, part of the cells are limited in the sensing area of the transmission line by the fixing structure arranged at the center of the microfluidic channel, and the high-frequency microwave probe is used to excite and receive signals on the chip, and the characteristic spectrum of the cells is detected and analyzed by the vector network analyzer, and the remaining cells flow to the outlet collection chamber and are finally collected as unlabeled samples.

[0069] The characteristic spectrum of the labeled cells, the unlabeled cells and the empty transmission line without cells can be detected in situ and in real time by arranging the transmission line detection unit on the microfluidic channel near the magnetic field and the microfluidic channel away from the magnetic field, and the electrical characteristic information of the cell culture solution, the cells and the magnetic beads is compared and analyzed by using a differential algorithm or a de-embedding algorithm, so that the physiological state and potential pathological characteristics of the target cells are further revealed, and the detection accuracy is improved.

[0070] In the sensing and detection of cells, the present application proposes a method for near-field sensing and characteristic spectrum extraction of the electrical characteristics of cells by using the transmission line on the chip, the high-frequency microwave probe and the vector network analyzer.

[0071] The electrical detection technology can be used for the detection of other biological samples such as bacteria, viruses and specific molecules by using the transmission line characteristic spectrum analysis method.

[0072] The detection signal source and the analyzer can use an external vector network analyzer to detect through a coaxial connecting line and a high-frequency microwave probe, or use an integrated circuit made on the chip or use an advanced packaging technology to prepare a bump and a pad at the port of the transmission line, and then stack and package a special integrated circuit externally to directly use the on-chip signal source and the detection and analysis circuit for detection, so that the complex device and the calibration process of the probe test are avoided.

[0073] Embodiment 2

[0074] The present application relates to a cell sorting and detection method integrating microfluidics and terahertz transmission lines, as shown in Figure 6 The present application relates to a cell sorting and detection method integrating microfluidics and terahertz transmission lines, as shown in

[0075] The target cells are labeled by MNPs, and a mixed culture containing various cells is injected into the starting chamber, and the cells flow along the microfluidic channel;

[0076] The cells not labeled by MNPs continue to flow along the microfluidic channel under the action of the microfluidic force, and the unlabeled cells flow through the transmission line detection area, and part of the unlabeled cells are limited in the sensing area of the transmission line by the fixed structure, and the high-frequency on-chip microwave probe is used for signal excitation and reception of the limited cells, and the characteristic spectrum information of the cells is obtained by deep analysis of the test signal by the vector network analyzer, and the unlabeled cells not fixed continue to flow and flow into the outlet collection chamber as the unlabeled cell sample.

[0077] The target cells with MNPs are attracted to the microfluidic channel close to the magnetic field area with the free MNPs under the external magnetic field, and when flowing to the magnetic bead capture trap, the magnetic beads can smoothly enter the magnetic bead capture trap and be captured due to the diameter of the magnetic beads being much smaller than that of the labeled cells, while the large-sized cells cannot enter the magnetic bead capture trap and continue to flow along the microfluidic channel and then enter the cell detection area.

[0078] When the cells flow through the transmission line detection area, part of the labeled cells are limited in the transmission line detection area by the fixed structure for characteristic spectrum detection, the high-frequency on-chip microwave probe is used for signal excitation and reception of the transmission line, and the characteristic spectrum information of the labeled cells is obtained by analyzing the test signal by the vector network analyzer; the labeled cell characteristic spectrum is compared and analyzed with the unlabeled cell characteristic spectrum; and the unlabeled cells not fixed continue to flow and finally flow into the outlet collection chamber as the labeled cell sample for subsequent research.

[0079] At this time, the high-frequency on-chip microwave probe is used for signal excitation and reception of the transmission line, and the presence of the cells affects the electromagnetic characteristics of the high-frequency transmission line, so that the transmission signal carries the electrical characteristic information of the cells, and the characteristic spectrum information of the cells can be obtained by deep analysis of the test signal by the vector network analyzer. These information is crucial for understanding the physiological state and characteristics of the cells, and subsequent tests of a large number of samples and pathological diagnosis can be used to summarize the correlation between the cell characteristic spectrum and the physiological state, so as to realize the pathological diagnosis and analysis of the cells by the transmission line near-field sensing.

[0080] The cell sorting and detection method provided by the application comprises the following steps: before the microfluidic chip system is connected with cells, blank cell culture solution is connected in advance, and a transmission line blank signal test is performed in the transmission line detection area of two microchannels, so as to obtain the frequency spectrum characteristics of the transmission line itself under the influence of the cell culture solution, the surrounding microflow channel and the fine cell fixing structure. The data will be used as blank data for comparison with subsequent cell tests. Then, the system is connected with cells and magnetic beads are labeled, after preliminary sorting by a magnetic field, the characteristic spectrum of unlabeled cells is detected, and then the cells with magnetic beads are detected, so as to accurately extract the influence of the magnetic beads on the characteristic spectrum of the cells by comparing the difference between the characteristic spectrum data of the cells with and without magnetic beads, and further compare and analyze the difference between the characteristic spectrum of the two kinds of cells, so as to judge the difference in physiological characteristics.

[0081] In summary, the application combines cell sorting and electrical detection technology innovatively, and provides a high-efficiency, accurate and real-time microfluidic chip test system for cell biology research and clinical application.

[0082] The above description is only the preferred embodiments of the application, and is not intended to limit the application. Although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art can modify the technical solutions described in the foregoing embodiments or replace some of the technical features equivalently. Any modification, equivalent replacement, modification, etc. within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A cell sorting and detection system integrating microfluidics and terahertz transmission lines, characterized in that, The system includes a cell sorting area and a transmission line detection area, wherein the cell sorting area comprises, in sequence: Cell injection chamber is used to introduce multi-cell mixed culture medium to be sorted; Microfluidic channels are used to guide the flow of multi-cell mixed culture media within the microfluidic channels to achieve preliminary cell sorting based on magnetic fields. A trap microstructure array is used to capture free MNPs, enabling the separation of free MNPs from target cells labeled with MNPs; The transmission line detection area includes: A fixation structure is used to fix the cells to be tested in the sensing area of ​​the transmission line; The transmission line detection unit is connected to the vector network analyzer at both ends via high-frequency microwave probes. It is used to detect the characteristic spectra of labeled and unlabeled cells in situ in real time and to feed the detection information back to the vector network analyzer. The outlet collection chamber is used to collect cells that have not been fixed after sorting.

2. The system according to claim 1, characterized in that, Before injecting the multi-cell mixed culture medium into the chamber, MNPs and target cells are co-cultured in advance, and MNPs are used to perform specific antibody recognition and labeling on the target cells.

3. The system according to claim 1, characterized in that, A permanent magnet or electromagnet is provided on one side of the microfluidic channel to manipulate the flow path of target cells labeled with MNPs using a magnetic field, thereby separating them from unlabeled cells.

4. The system according to claim 1, characterized in that, The capture trap microstructure array includes multiple magnetic bead capture traps that allow small-sized free MNPs to enter and be immobilized, thereby enabling further sorting with target cells labeled with MNPs.

5. The system according to claim 1, characterized in that, The substrate material of the system includes silicon wafers, high-purity quartz or PET material, and the microfluidic channels are made of PDMS or SU-8 material.

6. The system according to claim 1, characterized in that, The transmission line detection unit is respectively set on the microchannels in the regions near the magnetic field and the regions not near the magnetic field.

7. The system according to claim 6, characterized in that, A high-frequency microwave probe is used to connect the two ends of a transmission line to form an electrical connection, feeding a high-frequency terahertz electrical signal into the transmission line detection unit and receiving the electrical signal fed back from the transmission line. The high-frequency microwave probe is also connected to a vector network analyzer, which analyzes the electrical signal and obtains the characteristic spectrum. This enables in-situ real-time detection of the characteristic spectrum of target cells with MNPs labels, unlabeled cells, and cell-free empty transmission lines.

8. A cell sorting and detection method integrating microfluidics and terahertz transmission lines, characterized in that, Includes the following steps: MNPs are used to specifically identify and label target cells with antibodies, and a mixed culture medium containing multiple cells is injected into the starting chamber and enters the microfluidic channel from the chamber; Unlabeled cells flow along a microchannel without an external magnetic field under the action of microfluidics, passing through the transmission line detection area. Some unlabeled cells are confined to the sensing area of ​​the transmission line by a fixation structure. The transmission line is excited and received by a high-frequency on-chip microwave probe. The test signal is analyzed by a vector network analyzer to obtain cell characteristic spectrum information. The unfixed unlabeled cells continue to flow and flow into the outlet collection chamber as unlabeled cell samples. Free MNPs and MNP-labeled cells are attracted by an external magnetic field and deflected towards a microchannel near the magnetic field region. When they flow into the magnetic bead trap, the free MNPs are captured, while the labeled cells continue to flow into the transmission line detection area. Some labeled cells are fixed in the transmission line detection area by a fixation structure for characteristic spectrum detection. A high-frequency on-chip microwave probe is used to excite and receive signals from the transmission line, and the test signals are analyzed by a vector network analyzer to obtain the characteristic spectrum information of the labeled cells. The unfixed labeled cells continue to flow into the outlet collection chamber as labeled cell samples. The signature profiles of labeled cells were compared and analyzed with those of unlabeled cells.

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