Microfluidic cell detection system and detection method

Abstract

The invention relates to the technical field of biological detection, and discloses a microfluidic cell detection system, which comprises a cell channel and two electrode groups arranged on the cell channel, each electrode group at least comprises a reference electrode and a signal electrode, the distance between the signal electrode and the reference electrode is matched with the size of a cell, and the signal electrode is connected with the reference electrode. The electrode groups are connected to the control detection unit, the cell channel is a microfluidic channel and is used for single cell flow, the control detection unit applies an alternating current signal to the reference electrode, the control detection unit receives a feedback signal of the signal electrode, and the characteristics of cells flowing through the electrode groups are determined according to feedback signals of the two electrode groups. The invention further comprises a corresponding detection method. By processing signal data of the two groups of electrodes, electrical impedance response and response difference of a single cell under a specific frequency and flight time of the single cell passing through the two groups of electrodes are extracted, and the method can be used for obtaining information such as cell size, shape and internal substances.

Description

Technical Field

[0001] The present invention relates to the field of biological detection technology, and in particular to a microfluidic cell detection system and a detection method. Background Art

[0002] Microfluidics is a technology that manipulates fluids at the micrometer or even nanometer scale. It involves fields such as physics, chemistry, biology, and engineering. It can achieve precise manipulation of liquids, particles, or molecules in a tiny space and is widely used in analytical chemistry, biomedicine, environmental monitoring, and biomanufacturing.

[0003] Impedance microfluidics technology analyzes and manipulates fluids, particles or cells by measuring changes in electrical impedance in the fluid. It has the advantages of being label-free, high-throughput, high-sensitivity and strong real-time performance.

[0004] Traditional cell analysis methods such as fluorescence detection, staining, mass spectrometry, chromatography, etc. cannot reflect the characteristics of a single cell, or rely on expensive equipment. In addition, the labeled detection methods will affect the cells being tested, resulting in a waste of cell resources.

[0005] When using impedance microfluidics technology to detect cells, since it only analyzes the heterogeneity of the cell system based on the electrophysiological properties of the cells, it can quickly and accurately analyze the biophysical properties of a large number of cells without using any labels, thereby identifying rare abnormal cells in the cell population and separating them, which plays a vital role in early disease diagnosis and treatment evaluation in the biomedical field.

[0006] See the Chinese patent "A high-performance cell electrical impedance detection microelectrode" (publication number CN113804735A), which discloses a cell impedance detection technology that uses electrodes disposed on a chip substrate to detect the electrical impedance of cells in a microfluidic channel of a chip. The cell information obtained is limited, and it is difficult to distinguish cells with similar characteristics. Summary of the invention

[0007] The purpose of the present invention is to solve the above problems and to provide a microfluidic cell detection system and detection method. By processing two sets of electrode signal data, the electrical impedance response, response difference, and flight time of a single cell under a specific frequency are extracted, which can be used to obtain information such as cell size, shape, and internal substances.

[0008] The technical solution adopted by the present invention is: A microfluidic cell detection system, characterized in that it includes a cell channel and two electrode groups arranged on the cell channel, each electrode group includes at least a reference electrode and a signal electrode, the spacing between the signal electrode and the reference electrode matches the size of the cell, the electrode group is connected to a control detection unit, the cell channel is a microfluidic channel for the flow of a single cell, the control detection unit applies an AC signal to the reference electrode, the control detection unit receives a feedback signal from the signal electrode, and determines the characteristics of the cells flowing through the electrode group based on the feedback signals of the two electrode groups.

[0009] Furthermore, the electrode group includes two signal electrodes, which are arranged on both sides of the reference electrode, and the distance between the signal electrode and the reference electrode is 2 μm to 30 μm.

[0010] Furthermore, the distance between the two electrode groups is 0.1 mm to 10 mm.

[0011] Furthermore, in the cell flow direction, the height h2 of the front channel is greater than or equal to the height h1 of the rear channel, the width w2 of the front channel is less than or equal to the width w1 of the rear channel, and the two electrode groups are respectively arranged on the front channel and the rear channel.

[0012] Furthermore, the ranges of h1 and h2 are 10 μm to 300 μm, and h2 is 1.25 to 5 times of h1; the ranges of w1 and w2 are 10 μm to 300 μm, and w2 is 0.8 to 0.1 times of w1; and the flow rate of the front section channel is adapted to the flow rate of the rear section channel.

[0013] Furthermore, the frequency of the alternating current applied to the reference electrode is 10 kHz to 10 MHz, and the voltage amplitude is 0.01V to 3V.

[0014] A microfluidic cell detection method, characterized in that: Single cells are continuously transported at intervals in the cell channel. When the cells pass through the electrode group respectively, the control detection unit records the feedback signal of the signal electrode of the electrode group, compares and analyzes the feedback signal with the characteristic signal, and obtains various parameters of the cell.

[0015] Furthermore, the control detection unit records feedback information from the two electrode groups to obtain the time it takes for a single cell to pass through the two electrode groups, and calculates the movement speed of the cell.

[0016] Furthermore, two electrode groups are respectively arranged on the front channel and the rear channel of different heights and widths, and the control detection unit records feedback information of the two electrode groups to obtain density and shape parameters of the cells.

[0017] Furthermore, the control and detection unit analyzes multiple parameters of the cells, including type, phenotype, state, activity, and metabolic output, by comparing the change in the inter-electrode impedance of the electrode group with the characteristic signal.

[0018] The beneficial effects of the present invention are: (1) The dual-electrode group mode can achieve electrode signal compensation and reduce signal interference errors; (2) Channel design at different heights enables measurement of cell shape, density and other parameters; (3) The electrode's dual signal electrodes simultaneously measure multiple groups of impedances of a cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Attached Figure 1 is a top view of the microfluidic detection system of the present invention; Attached Figure 2 is a side view of the microfluidic detection system of the present invention; Attached Figure 3 is a schematic diagram of the electrode set; Attached Figure 4 It is a graph of impedance changes when cells pass through the channels of two electrode groups; Attached Figure 5 It is a graph of flight time and impedance changes of different cells between two electrode groups. DETAILED DESCRIPTION

[0020] The specific implementation modes of the microfluidic cell detection system and detection method of the present invention are described in detail below with reference to the accompanying drawings.

[0021] The microfluidic cell detection system of this patent establishes a cell microfluidic channel and an electrode group in the chip, so that when the cells flow through the cell channel, the high-frequency electrodes of the two electrode groups measure the feedback signal, thereby obtaining various parameters of the cells.

[0022] See attached Figure 1 , 2 Two electrode groups are arranged on the path of the cell channel, the spacing between the two electrode groups is 0.1mm to 10mm, and the cell channel is arranged in a stepped shape in the width and height directions.

[0023] In the cell flow direction, the height h2 of the front channel is greater than or equal to the height h1 of the rear channel, the width w2 of the front channel is less than or equal to the width w1 of the rear channel, and the two electrode groups are respectively arranged on the front channel and the rear channel. The range of h1 and h2 is 10 μm to 300 μm, and h2 is 1.25 to 5 times of h1; the range of w1 and w2 is 10 μm to 300 μm, and w2 is 0.8 to 0.1 times of w1.

[0024] The actual application size of the cell channel is matched front to back, so that the flow rate of the front channel is adapted to the flow rate of the rear channel.

[0025] See attached Figure 3 Each electrode group includes two signal electrodes, which are arranged on both sides of the reference electrode. The distance between the signal electrode and the reference electrode is 2μm to 30μm. This size is comparable to the size of the cells to be tested. The frequency of the alternating current applied to the reference electrode is 10 kHz to 10 MHz, and the voltage amplitude is 0.01V to 3V. The control detection unit receives the current signal fed back from the signal electrode. The current signals of the first electrode and the third electrode are amplified and converted into voltage signals through a transimpedance amplifier and then differentially processed. The differential signals are then demodulated, including bandpass filtering, conditioning and amplification of the differential signals, and then multiplication and low-pass filtering with the AC reference signal and the AC reference signal with a 90° phase shift, respectively, to calculate the real and imaginary parts of the electrode impedance and convert them into impedance values.

[0026] The control detection unit compares the obtained impedance data with the data in the pre-established cell detection database, thereby determining various parameters of the detected cells.

[0027] Since two electrode groups are arranged on the cell channel, the time taken for the cell to pass through the two electrode groups can be determined based on the signals of the cell on the two electrode groups, thereby calculating the movement speed of the cell in the cell channel.

[0028] In addition, due to the difference in cell channel heights at the two electrode groups, when cells flow from the rear channel to the front channel, after entering the front channel, due to their shape or density, the cells float upward in the channel at a relatively high height. The difference in the measured values ​​of the two electrode groups can be used to calculate parameters such as the shape or density of the cells.

[0029] Due to the dual-electrode mode of the two electrode groups and the different channel heights at the two electrode groups, the signals of the two groups of electrodes can compensate each other to extract the electrical impedance response of a single cell at a specific frequency, the response difference, and the flight time through the two groups of electrodes, thereby realizing a high-throughput, label-free detection method for analyzing multiple parameters such as cell type, phenotype, state, activity, and metabolic output. Example

[0030] The cells flow through the first electrode group and the second electrode group respectively through the cell channel, and the impedance change values ​​of the two electrode groups are collected. After demodulating the voltage change values, the information change when the cells pass through the two electrode groups is analyzed.

[0031] See attached Figure 4 , attached Figure 4It is a graph of impedance changes when cells pass through two electrode group channels. The horizontal axis is time and the vertical axis is the demodulated signal voltage value of the electrode group feedback impedance.

[0032] Cells with different morphological parameters have different impedances to the electrode group. Based on different feedback waveforms, various parameters of the cells can be analyzed and judged. It can be seen that when passing through the electrode group, two impedance fluctuations, positive and negative, are generated.

[0033] See attached Figure 5 , attached Figure 5 This is a diagram of the flight time and impedance change of different cells between two electrode groups. The horizontal axis in the figure is the demodulated signal voltage value of the feedback impedance of the electrode group, and the vertical axis is the flight time of the cells between the two electrode groups.

[0034] Based on the flight time of cells in the cell channel and the impedance fluctuation feedback when the cells pass through the two electrode groups, it is easy to analyze the type of cells and achieve cell classification.

[0035] The above are only preferred embodiments of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A microfluidic cell detection system, characterized in that: It includes a cell channel and two electrode groups arranged on the cell channel, each electrode group includes at least a reference electrode and a signal electrode, the spacing between the signal electrode and the reference electrode matches the size of the cell, the electrode group is connected to a control detection unit, the cell channel is a microfluidic channel for the flow of a single cell, the control detection unit applies an AC signal to the reference electrode, the control detection unit receives a feedback signal from the signal electrode, and determines the characteristics of the cells flowing through the electrode group according to the feedback signals of the two electrode groups.

2. The microfluidic cell detection system according to claim 1, characterized in that: The electrode group includes two signal electrodes, which are arranged on both sides of the reference electrode, and the distance between the signal electrode and the reference electrode is 2 μm to 30 μm.

3. The microfluidic cell detection system according to claim 1, characterized in that: The distance between the two electrode groups is 0.1 mm to 10 mm.

4. The microfluidic cell detection system according to any one of claims 1 to 3, characterized in that: In the cell flow direction, the height h2 of the front channel is greater than or equal to the height h1 of the rear channel, the width w2 of the front channel is less than or equal to the width w1 of the rear channel, and the two electrode groups are respectively arranged on the front channel and the rear channel.

5. The microfluidic cell detection system according to claim 4, characterized in that: The range of h1 and h2 is 10 μm to 300 μm, and h2 is 1.25 to 5 times of h1; The range of w1 and w2 is 10 μm to 300 μm, and w2 is 0.8 to 0.1 times of w1; The flow rate of the front section channel is adapted to the flow rate of the rear section channel.

6. The microfluidic cell detection system according to any one of claims 1 to 3, characterized in that: The reference electrode is applied with an alternating current with a frequency of 10 kHz to 10 MHz and a voltage amplitude of 0.01V to 3V.

7. A microfluidic cell detection method, using the microfluidic cell detection system according to any one of claims 1 to 6, characterized in that: Single cells are continuously transported at intervals in the cell channel. When the cells pass through the electrode group respectively, the control detection unit records the feedback signal of the signal electrode of the electrode group, compares and analyzes the feedback signal with the characteristic signal, and obtains various parameters of the cell.

8. The microfluidic cell detection method according to claim 7, characterized in that: The control detection unit records the feedback information of the two electrode groups to obtain the time for a single cell to pass through the two electrode groups, and calculates the movement speed of the cell.

9. The microfluidic cell detection method according to claim 7, characterized in that: The two electrode groups are respectively arranged on the front channel and the rear channel of different heights and widths. The control detection unit records the feedback information of the two electrode groups to obtain the density and shape parameters of the cells.

10. The microfluidic cell detection method according to claim 7, characterized in that: The control detection unit analyzes multiple parameters of the cell, including type, phenotype, state, activity, and metabolic output, by comparing the change in the inter-electrode impedance of the electrode group with the characteristic signal.

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