Multi-channel anti-magnetic suspension cell mass density detection microfluidic chip

Abstract

A kind of multi-channel anti-magnetic suspension cell mass density detection microfluidic chip, comprising: glass plate, microchannel module arranged on one side thereof, first magnetization enhancement component and second magnetization enhancement component, wherein: microchannel module is located between two magnetization enhancement components.The present application improves magnetic induction intensity gradient by magnetic field beam aggregation trapezoidal channel, reduces the concentration of paramagnetic solution required in cell suspension process, realizes non-contact, label-free detection of cell;Construct parallel independent multi-channel detection channel, capture the position information of cell suspended in magnetic field by image, so as to calculate the mass density of cell in independent multi-channel without measuring single cell mass and volume, effectively improve the detection flux of single measurement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cell detection, and specifically relates to a multi-path anti-magnetic suspension cell mass density detection microfluidic chip. BACKGROUND

[0002] The existing cell mass density detection methods mainly include density gradient centrifugation, microchannel resonance, quantitative phase imaging and fluorescence correlation spectroscopy. However, the density gradient centrifugation usually has low detection precision; the suspension microchannel resonance has high detection precision and real-time response, and can only measure the mass and density of a single cell in a single measurement process; and the detection methods based on optical principles have limitations such as cell damage, high equipment cost and difficult operation. SUMMARY

[0003] The present application proposes a multi-path anti-magnetic suspension cell mass density detection microfluidic chip to solve the problems of low detection precision, low detection throughput, high detection cost and complex operation in the existing cell mass density detection technology. The magnetic field bundle aggregation trapezoidal channel is used to improve the magnetic induction strength gradient and reduce the required paramagnetic solution concentration in the cell suspension process, so as to realize the non-contact and label-free detection of cells. The parallel independent multi-path detection channel is constructed, and the position information of the cells suspended in the magnetic field is captured by the image, so that the mass density of the cells in the independent multi-path can be calculated without measuring the mass and volume of the single cell, and the detection throughput is effectively improved in a single measurement.

[0004] The present application is realized by the following technical solutions:

[0005] The present application relates to a multi-path anti-magnetic suspension cell mass density detection microfluidic chip, which comprises a glass plate, a microchannel module arranged on one side of the glass plate, a first magnetization enhancement component and a second magnetization enhancement component, wherein the microchannel module is located between the two magnetization enhancement components.

[0006] The microchannel module is an I-shaped microchannel module, which comprises a magnetic field bundle aggregation trapezoidal channel and a plurality of detection channels arranged on the magnetic field bundle aggregation trapezoidal channel in sequence. The magnetic field bundle aggregation trapezoidal channel comprises a magnetic field bundle aggregation trapezoidal channel inlet, a magnetic field bundle aggregation trapezoidal unit array and a magnetic field bundle aggregation trapezoidal channel outlet. The magnetic field bundle aggregation trapezoidal channel inlet is connected to a mixed solution of ferromagnetic / ferromagnetic microparticles and ethanol, and the magnetic field bundle aggregation trapezoidal unit array is provided with a plurality of detection channels. The detection channel is a multi-path independent Z-shaped channel array, which comprises a detection channel inlet, a vertical detection area and a detection channel outlet connected in sequence. The detection channel inlet is connected to a mixed solution of cells and paramagnetic solution.

[0007] The vertical detection area is located between the two magnetic field beam converging trapezoidal units, and the centers of the detection channel entrance and the detection channel exit are respectively located at the intersection of the midpoint of the upper bottom of the magnetic field beam converging trapezoidal unit and the long axis of the microchannel module.

[0008] The first and second magnetization enhancement assemblies each comprise a magnetization enhancement assembly and a permanent magnet arranged thereon, wherein the first permanent magnet and the second permanent magnet are square permanent magnets with the same geometric characteristics and the same magnetization properties, and the magnetization directions are perpendicular to the plane of the glass plate.

[0009] The magnetic field beam converging trapezoidal channel outlet is provided with a flow stopping unit, and the gap of the flow stopping unit is smaller than the diameter of the ferromagnetic / ferromagnetic oxide microparticles, so as to ensure that the ferromagnetic / feromagnetic oxide microparticles can be deposited in the magnetic field beam converging trapezoidal channel.

[0010] The present application relates to a kind of multi-pass type diamagnetic suspension cell mass density detection method based on above-mentioned device, the function relationship of the density of the measured object and its suspension height is obtained by calibrating detection device, after the measured cell is dispersed in gadolinium injection PBS buffer, it is injected into detection channel entrance, the suspension height information of cell in different detection channel vertical detection area is obtained by image acquisition technology, is substituted into function relationship, and the mass density information of cell in different detection channel is obtained.

[0011] The calibration includes:

[0012] Step 1: configure the known concentration of ferroferric oxide microparticle ethanol solution, and inject into the magnetic field beam converging trapezoidal channel entrance at a slow flow rate until the ferroferric oxide particles fill the magnetic field beam converging trapezoidal channel under the action of the flow stopping unit;

[0013] Step 2: sequentially install the first and second magnetization enhancement assemblies on both sides of the microchannel module;

[0014] Step 3: prepare the known concentration of gadolinium injection PBS buffer, and mix three different micron-level standard density particles with the gadolinium injection PBS buffer thoroughly;

[0015] Step 4: inject the gadolinium injection PBS buffer containing the three micron-level standard density particles into different detection channel entrances respectively, and calibrate the detection process by observing the suspension height of different micron-level standard density balls, which specifically includes:

[0016] 4.1) the standard density particles are stably suspended under the action of magnetic field and gravitational field, and the balance equation is wherein: is the magnetic susceptibility difference between the standard density particles and the gadolinium injection PBS buffer, is the vacuum permeability, is the magnetic induction intensity vector, is the magnetic induction intensity vector along Projection value along the axial direction, The volume of standard density particles, This represents the density difference between standard density particles and gadobutrol PBS buffer. It is the acceleration due to gravity;

[0017] 4.2) The magnetic induction intensity of the vertical detection area in the detection channel is along... Projection values ​​in the axial direction Simplify to follow A function of direction and position, namely: ,in: The equivalent linear coefficient of the magnetic field. The height at which the object to be tested is suspended;

[0018] 4.3) By observing the suspension height of three sets of standard density particles in the vertical detection area, the functional relationship between the density of the analyte and its suspension height is obtained as follows: ,in: These represent the particle size to be detected, density, and equivalent detection coefficient, respectively. .

[0019] Technical effect

[0020] This invention achieves flow-cylindrical filling of iron oxide micron-sized particles within the magnetic field-focusing trapezoidal unit by integrally fabricating a compact magnetic field-focusing trapezoidal unit, multi-pathway detection channels, and a flow-stopping unit using soft photolithography. Under the magnetization of a permanent magnet, the magnetic field-focusing trapezoidal unit effectively enhances the magnetic field strength and gradient. The resulting magnetic field distribution meets the requirements for parallel multi-pathway micro-channel antimagnetic levitation cell detection. Compared to existing technologies, this invention enables cell levitation in a label-free and non-contact manner. It integrates parallel, independent, multi-pathway detection channels, acquiring the positional information of suspended cells within the detection channels through image acquisition. Without measuring cell mass and volume, it calculates the mass density of suspended cells within multiple detection channels, thereby increasing detection throughput. Attached Figure Description

[0021] Figure 1 This is an isometric view of the overall structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the overall three-dimensional structure of the present invention;

[0023] Figure 3 This is a schematic diagram of the microchannel structure in this invention;

[0024] Figure 4 This is a cross-sectional schematic diagram of the present invention;

[0025] Figure 5 for Figure 4A magnified schematic diagram of a portion of the structure of A in the diagram;

[0026] In the figure: 1 Glass plate, 2 Microchannel module, 3 Magnetic field focusing trapezoidal channel inlet, 4 First magnetization enhancement component, 5 Magnetic field focusing trapezoidal channel, 6 Magnetic field focusing trapezoidal unit, 7 Detection channel, 8 Detection channel inlet, 9 Vertical detection area, 10 Detection channel outlet, 11 Magnetic field focusing trapezoidal channel outlet, 12 Second magnetization enhancement component, 13 First permanent magnet, 14 First high permeability alloy sheet, 15 Second permanent magnet, 16 Second high permeability alloy sheet, 17 Flow stop unit. Detailed Implementation

[0027] like Figure 1 As shown, this embodiment relates to a multi-path antimagnetic levitation cell mass density detection microfluidic chip, including: a glass plate 1, a microchannel module 2 disposed on one side thereon, a first magnetization enhancement component 4 and a second magnetization enhancement component 12, wherein: the microchannel module 2 is located between the two magnetization enhancement components.

[0028] like Figure 2 As shown, the microchannel module 2 is I-shaped and includes: a magnetic field focusing trapezoidal channel 5 and several detection channels 7 arranged sequentially on it.

[0029] like Figure 3 As shown, the magnetic field focusing trapezoidal channel 5 includes: a magnetic field focusing trapezoidal channel inlet 3, a magnetic field focusing trapezoidal unit array 6, and a magnetic field focusing trapezoidal channel outlet 11, wherein: the magnetic field focusing trapezoidal channel inlet 3 is filled with a mixed solution of ferromagnetic / ferrite micron particles and ethanol, and the magnetic field focusing trapezoidal unit array 6 is provided with several detection channels 7.

[0030] like Figure 3 As shown, the quantity relationship between the detection channel 7 and the magnetic field focusing trapezoidal unit 6 satisfies M=1 / 4*N, where M represents the number of detection channels and N represents the number of magnetic field focusing trapezoidal units.

[0031] like Figure 3 As shown, the detection channel 7 is a multi-channel independent Z-shaped channel array, including: a detection channel inlet 8, a vertical detection area 9 and a detection channel outlet 10 connected in sequence. The detection channel inlet 8 is filled with a mixture of cells and paramagnetic solution.

[0032] like Figure 3 As shown, the vertical detection area 9 is located between the two magnetic field focusing trapezoidal units 6, and the centers of the detection channel inlet 8 and the detection channel outlet 10 are located at the intersection of the midpoint of the upper bottom of the magnetic field focusing trapezoidal unit 6 and the long axis of the microchannel module 2, respectively.

[0033] like Figure 3As shown, the magnetic field focusing trapezoidal channel inlet 3, magnetic field focusing trapezoidal channel outlet 11, detection channel inlet 8, and detection channel outlet 10 are all circular.

[0034] In this embodiment, the number of detection channels 7 is preferably 12, and the size of the vertical detection area 9 in the detection channel is preferably l×w×h=1800 μm ×200 μm×50 μm.

[0035] like Figure 4 As shown, the first and second magnetization enhancement components 4 and 12 each include a magnetization enhancement component and a permanent magnet disposed thereon, wherein: the first permanent magnet 13 and the second permanent magnet 15 are both square permanent magnets with the same geometric features and the same magnetization properties, and the magnetization direction is perpendicular to the plane of the glass plate 1.

[0036] Preferably, both the first permanent magnet 13 and the second permanent magnet 15 are magnetized along the thickness direction, and square rare earth neodymium iron boron permanent magnets with a magnetic property grade of N42 and a diameter of l×w×h=50.8 mm ×12.7 mm×6.35 mm are selected.

[0037] Preferably, the thickness of the first high-permeability alloy sheet 14 and the second high-permeability alloy sheet 16 is the same as the height of the magnetic field focusing trapezoidal channel 5 and the detection channel 7, and their lengths are greater than or equal to the length of the magnetic field focusing trapezoidal unit 6 array.

[0038] The first high-permeability alloy sheet 14 and the second high-permeability alloy sheet 16 are preferably 50 μm high-permeability permalloy sheets.

[0039] The distances from both sides of the microchannel module 2 to the first high-permeability alloy sheet 14 and the second high-permeability alloy sheet 16 are 500 μm-1000 μm to ensure that the magnetic induction intensity gradient meets the levitation requirements.

[0040] like Figure 5 As shown, a flow-stopping unit 17 is provided at the outlet 11 of the magnetic field focusing trapezoidal channel. The gap of the flow-stopping unit 17 is smaller than the diameter of the ferromagnetic / ferrooxy micron particles, ensuring that the ferromagnetic / ferrooxy micron particles can be deposited in the magnetic field focusing trapezoidal channel 5.

[0041] In this embodiment, the gap between two adjacent square units of the flow-stopping unit 17 is 5 μm;

[0042] This embodiment relates to a multi-channel antimagnetic levitation cell mass density detection method based on the above-mentioned device, including:

[0043] Step 1: Prepare a 2 mg / mL iron oxide micronized ethanol solution and inject it into the magnetic field focusing trapezoidal channel inlet 3 at a slow flow rate until the iron oxide particles fill the magnetic field focusing trapezoidal channel 5 under the action of the flow stop unit 17.

[0044] The ferromagnetic / ferrite micron particles are preferably 8 μm in diameter.

[0045] Step 2: Install the first magnetization enhancement component 4 and the second magnetization enhancement component 12 sequentially on both sides of the microchannel module 2;

[0046] Step 3: Prepare a gadobutrol PBS buffer solution of a certain concentration, and thoroughly mix three different micron-sized standard density particles with the gadobutrol PBS buffer solution;

[0047] Step 4: Inject gadobutrol PBS buffer containing three micron-sized standard density particles into different detection channel inlets 8. The detection process is calibrated by observing the suspension height of the different micron-sized standard density spheres. Specifically, this includes:

[0048] 4.1) Standard density particles are stably suspended under the influence of a magnetic field and a gravitational field, and their equilibrium equation is: ,in: This represents the difference in magnetic susceptibility between standard density particles and gadobutrol PBS buffer. The permeability of free space, It is the magnetic induction intensity vector. The magnetic induction intensity vector along Projection value along the axial direction, The volume of standard density particles, This represents the density difference between standard density particles and gadobutrol PBS buffer. It is the acceleration due to gravity;

[0049] 4.2) Due to the design of the trapezoidal channel 5, the magnetic induction intensity of the vertical detection area 9 in the detection channel 7 is concentrated along... Projection values ​​in the axial direction Simplify to follow A function of direction and position, namely: ,in: The equivalent linear coefficient of the magnetic field. The height at which the object to be tested is suspended;

[0050] 4.3) By observing the suspension height of three sets of standard density particles in the vertical detection area 9, the functional relationship between the density of the analyte and its suspension height is obtained as follows: ,in: These represent the particle size to be detected, density, and equivalent detection coefficient, respectively. .

[0051] Step 5: Prepare a gadobutrol PBS buffer solution of a specific concentration and mix the cells to be tested thoroughly with the gadobutrol PBS buffer solution.

[0052] Step 6: Inject gadobutrol PBS buffer containing the test cells into the inlet 8 of the detection channel and observe the suspension state of the test cells in the detection channel 7: if the test cells gradually sink to the bottom of the detection channel 7 over time, a slightly higher concentration of gadobutrol PBS buffer needs to be prepared; if the test cells gradually float to the top of the detection channel 7 over time, a slightly lower concentration of gadobutrol PBS buffer needs to be prepared.

[0053] Step 7: Obtain the suspension height information of cells in the vertical detection area 9 within different detection channels 7 using image acquisition technology, and substitute it into the functional relationship in step 4.3) to obtain the mass density information of cells in different detection channels.

[0054] In summary, this invention achieves flow-cylindrical filling of iron oxide micron-sized particles within the magnetic field-focusing trapezoidal unit by integrally fabricating a compact magnetic field focusing trapezoidal unit, multi-channel detection channels, and flow-stopping unit using soft photolithography. Under the magnetization effect of the permanent magnet, the magnetic field focusing trapezoidal unit effectively enhances the magnetic field strength and gradient. The resulting magnetic field distribution meets the requirements of parallel multi-channel microfluidic antimagnetic levitation cell detection, effectively improving detection throughput and efficiency.

[0055] The above-described specific implementations can be partially adjusted by those skilled in the art in different ways without departing from the principles and purpose of the present invention. The scope of protection of the present invention is defined by the claims and is not limited to the above-described specific implementations. All implementation schemes within the scope of the claims are bound by the present invention.

Claims

1. A multi-channel antimagnetic levitation cell mass density detection microfluidic chip, characterized in that, include: A glass plate, a microchannel module disposed on one side thereof, a first magnetization enhancement component and a second magnetization enhancement component, wherein: the microchannel module is located between the two magnetization enhancement components, and the magnetization direction is perpendicular to the plane of the glass plate; The microchannel module is I-shaped, comprising: a magnetic field focusing trapezoidal channel and several detection channels arranged sequentially thereon. The magnetic field focusing trapezoidal channel includes: a magnetic field focusing trapezoidal channel inlet, a magnetic field focusing trapezoidal unit array, and a magnetic field focusing trapezoidal channel outlet. The magnetic field focusing trapezoidal channel inlet is supplied with a mixed solution of iron oxide microparticles and ethanol. The magnetic field focusing trapezoidal unit array has several detection channels. The magnetic field focusing trapezoidal channel outlet is equipped with a flow-stopping unit, allowing the iron oxide microparticles to deposit within the magnetic field focusing trapezoidal channel. The detection channels are multi-channel independent Z-shaped channel arrays, including: a detection channel inlet, a vertical detection area, and a detection channel outlet connected sequentially. The detection channel inlet is supplied with a mixture of cells and a paramagnetic solution. The vertical detection area is located between two magnetic field focusing trapezoidal units. The centers of the detection channel inlet and outlet are located at the intersection of the midpoint of the upper base of the magnetic field focusing trapezoidal unit and the long axis of the microchannel module, respectively.

2. The multi-channel antimagnetic levitation cell mass density detection microfluidic chip according to claim 1, characterized in that, The first and second magnetization enhancement components each include a magnetization enhancement component and a permanent magnet disposed thereon, wherein the permanent magnets are square permanent magnets with the same geometric features and the same magnetization properties.

3. The multi-channel antimagnetic levitation cell mass density detection microfluidic chip according to claim 1, characterized in that, The gap of the flow-stopping unit is smaller than the diameter of the iron oxide micron particles.

4. A method for detecting the mass density of multi-channel antimagnetically levitated cells based on any one of the multi-channel antimagnetically levitated cell mass density detection microfluidic chips according to claims 1-3, characterized in that, The functional relationship between the density of the analyte and its suspension height was obtained by calibration. The cells to be tested were dispersed in gadobutrol PBS buffer and injected into the inlet of the detection channel. The suspension height information of the cells in the vertical detection area in different detection channels was obtained by image acquisition technology. Substituting the information into the functional relationship, the mass density information of the cells in different detection channels was obtained. The calibration includes: Step 1: Prepare an ethanol solution of iron oxide micron-sized particles with a known concentration, and inject it into the inlet of the magnetic field-focused trapezoidal channel at a slow flow rate until the iron oxide particles fill the magnetic field-focused trapezoidal channel under the action of the flow-stopping unit. Step 2: Install the first and second magnetization enhancement components sequentially on both sides of the microchannel module; Step 3: Prepare a gadobutrol PBS buffer with a known concentration, and thoroughly mix three different micron-sized standard density particles with the gadobutrol PBS buffer; Step 4: Inject gadobutrol PBS buffer containing three micron-sized standard density particles into different detection channel inlets. The detection process is calibrated by observing the suspension height of the standard spheres at different micron-sized densities. Specifically, this includes: 4.1) Standard density particles are stably suspended under the influence of a magnetic field and a gravitational field, and their equilibrium equation is: ,in: This represents the difference in magnetic susceptibility between standard density particles and gadobutrol PBS buffer. The permeability of free space, It is the magnetic induction intensity vector. The magnetic induction intensity vector along Projection value along the axial direction, The volume of standard density particles, This represents the density difference between standard density particles and gadobutrol PBS buffer. It is the acceleration due to gravity; 4.2) The magnetic induction intensity of the vertical detection area in the detection channel is along... Projection values ​​in the axial direction Simplify to follow A function of direction and position, namely: ,in: The equivalent linear coefficient of the magnetic field. The height at which the object to be tested is suspended; 4.3) By observing the suspension height of three sets of standard density particles in the vertical detection area, the functional relationship between the density of the analyte and its suspension height is obtained as follows: ,in: The density of the particles to be detected. The density of gadobutrol PBS buffer and the equivalent detection coefficient are given. .

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