CN114100706B - Particle sorting method and system based on particle drift - Google Patents

Abstract

The invention discloses a particle sorting method and a system based on particle drift, which comprises the following steps: step 1: obtaining a calibration drift voltage of a target particle in the classified particles, comparing the calibration drift voltage with a preset drift voltage, if the calibration drift voltage is smaller than the preset drift voltage, executing the step 2, otherwise, executing the step 3; step 2: correcting the drift voltage until the calibrated drift voltage is greater than the preset drift voltage; and step 3: injecting the classified particles into the first microfluidic chip, and applying a drift voltage to the first microfluidic chip according to a preset drift voltage; and 4, step 4: and collecting the drifting particles after drifting, carrying out secondary sorting, and applying a preset drifting voltage to the first micro-fluidic chip to enable the particles needing to be separated, which are smaller than the target particle calibration drifting voltage in the classified particles, to be subjected to the external force of the preset drifting voltage and to be shifted in the first micro-fluidic chip, so as to realize the pretreatment of part of the particles needing to be separated.

Description

A particle sorting method and system based on particle drift

technical field

The invention belongs to the field of microfluidics, in particular to a particle sorting method and system based on particle drift.

Background technique

Microfluidic chip technology integrates basic operation units such as sample preparation, reaction, separation, and detection in biological, chemical, and medical analysis processes into a micron-scale chip to automatically complete the entire analysis process.

However, the existing inertial microfluidic technology utilizes the fluid inertia effect to induce particles to migrate in the flow channel under the action of inertial force to achieve precise control. It has the advantages of simple flow channel structure, convenient operation, and high control accuracy. However, the fluid inertia effect has a significant impact on the particle size. Due to strong dependence, it is difficult to precisely control particles with high concentrations and similar sizes, so pre-processing of the sorted particles is required.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a particle sorting method and system based on particle drift, which is used to solve the problem that the fluid inertia effect has a strong dependence on the particle appearance size, and it is difficult to accurately control the high concentration and similar size particles.

The object of the present invention can be realized through the following technical solutions:

A particle sorting method based on particle drift, comprising the following steps:

Step 1: Obtain the calibration drift voltage of the target particle in the classified particles, and compare the calibration drift voltage with the preset drift voltage. If the calibration drift voltage is less than the preset drift voltage, perform step 2, otherwise, perform step 3;

Step 2: Correct the drift voltage until the calibrated drift voltage is greater than the preset drift voltage;

Step 3: inject the classified particles into the first microfluidic chip, and apply a drift voltage to the first microfluidic chip according to the preset drift voltage;

Step 4: Collect the drifted particles and conduct secondary sorting.

Further, the preset drift voltage is up to the maximum withstand voltage of the first microfluidic chip.

Further, the calibrated drift voltage of the target particle is the voltage required for the target particle to generate the maximum offset under the action of the electric field.

Further, injecting the classified particles into the first microfluidic chip, and applying a drift voltage to the first microfluidic chip according to the preset drift voltage, specifically:

A drift channel is constructed in the first microfluidic chip, wherein one end of the drift channel is the particle injection end, the other end of the drift channel is the collection end, and the collection end is connected to the collection tank;

After the classified particles enter the drift channel in the first microfluidic chip through the injection end, a preset drift voltage is applied to the first microfluidic chip, and after a preset period of time, the drift particles in the collection tank are subjected to secondary sorting.

Further, the obtaining the calibrated drift voltage of the target particles in the classified particles is specifically as follows: injecting the target particles into the first microfluidic chip, loading the first microfluidic chip with drift piezoelectricity, and detecting whether there is in the collection tank. Target particles, until the target particles are not detected in the collection cell, the corresponding drift piezoelectricity is the calibration drift voltage. If the drift piezoelectricity loaded on the first microfluidic chip reaches the maximum withstand voltage, the target particles are still detected in the collection cell. , the maximum withstand voltage is the calibration drift voltage.

Further, the drift voltage correction is performed, specifically:

S1: extract the value of the preset drift voltage and the value of the calibrated drift voltage;

S2: establish a plane coordinate system and mark (the preset drift voltage value, the value of the calibration drift voltage) as the first calculation point, and mark (the value of the calibration drift voltage, the preset drift voltage value) as the second calculation point;

S3: Calculate the distance between the first calculation point and the second calculation point, and mark it as the correction number;

S4: The preset drift voltage value is subtracted from the correction number to complete the drift voltage correction.

Further, the secondary sorting comprises the following steps:

The solution containing the drift particles in the collection tank is injected into the second microfluidic chip to complete the secondary sorting.

Further, the drift channel is in the shape of a coiled mosquito coil.

A particle sorting system based on particle drift, applicable to the above-mentioned particle sorting method based on particle drift, comprising:

a calibration module, the calibration module is used to calibrate the drift voltage of the target particles in the classified particles;

a comparison correction module, the comparison correction module is used for comparing the calibration drift voltage with the preset drift voltage, and if the calibration drift voltage is less than the preset drift voltage, the drift voltage correction is performed until the calibration drift voltage is greater than the preset drift voltage;

a first microfluidic chip module, the first microfluidic chip module is used for receiving classified particles and performing electronic drift according to a preset drift voltage;

The second microfluidic chip module, the second microfluidic chip module is used for secondary sorting of the solution containing drift particles.

Further, it also includes a host computer, the host computer is connected to the calibration module, the comparison correction module, the first microfluidic chip module and the second microfluidic chip module, and the host computer is used to display the calibration module, the comparison The operation data of the correction module, the first microfluidic chip module and the second microfluidic chip are corrected.

Compared with the prior art, the beneficial effects of the present invention are:

By applying a preset drift voltage to the first microfluidic chip, the particles to be separated which are smaller than the calibration drift voltage of the target particle are subjected to the external force F of the preset drift voltage, and the first microfluidic chip will be offset in the first microfluidic chip , impinging on the passage in the first microfluidic chip, to achieve pre-processing of some of the particles that need to be separated, so that the results of the secondary sorting are more accurate.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

Fig. 1 is the structural representation of the present invention;

Fig. 2 is the schematic diagram of the principle block diagram of the present invention;

3 is a schematic diagram of a second microfluidic chip;

FIG. 4 is a cross-sectional view of a second microfluidic chip.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Accordingly, the detailed descriptions of embodiments of the invention provided in the following drawings are not intended to limit the scope of the invention as claimed, but are merely representative of selected embodiments of the invention.

Traditionally, inertial microfluidic technology utilizes the inertial effect of fluid to induce particles to migrate under the action of inertial force in the flow channel to achieve precise control. It has the advantages of simple flow channel structure, convenient operation, and high control precision. However, the fluid inertia effect has a significant impact on the particle size. Due to strong dependence, it is difficult to precisely control particles with high concentrations and similar sizes, so pre-processing of the sorted particles is required.

Particle drift means that if a particle with an electric charge q is subjected to other external forces F in addition to the constant uniform magnetic field B in the magnetic field, the particle must move perpendicular to the magnetic field B in addition to the helical motion with the magnetic field line as the axis. This movement caused by the external force is called drift, so adding an external force F outside the microfluidic chip can make the particles move, so the sorted particles can be pre-processed.

Based on the above description, an embodiment of the present invention proposes a particle drift-based particle sorting method as shown in FIG. 1 , including the following steps:

Step 1: Obtain the calibration drift voltage of the target particle in the classified particles, and compare the calibration drift voltage with the preset drift voltage. If the calibration drift voltage is less than the preset drift voltage, perform step 2, otherwise, perform step 3;

Step 2: Correct the drift voltage until the calibrated drift voltage is greater than the preset drift voltage;

Step 3: inject the classified particles into the first microfluidic chip, and apply a drift voltage to the first microfluidic chip according to the preset drift voltage;

Step 4: Collect the drifted particles and conduct secondary sorting.

By applying a preset drift voltage to the first microfluidic chip, the particles to be separated which are smaller than the calibration drift voltage of the target particle are subjected to the external force F of the preset drift voltage, and the first microfluidic chip will be offset in the first microfluidic chip , impinges on the passage in the first microfluidic chip, and realizes the pretreatment of part of the particles that need to be separated;

The present invention is described in detail below in conjunction with the accompanying drawings;

As shown in FIG. 1 , the first microfluidic chip is a microfluidic chip with a regular shape, wherein the regular shape is a rectangle, a circle, a diamond, etc. In one embodiment, the first microfluidic chip is A rectangular hamburger structure, wherein the upper layer is an upper field voltage plate, the middle layer is a microfluidic chip, and the lower layer is a lower field voltage plate. A drift channel is machined inside, the cross section of the drift channel is circular, and the uneven carbon nanotube coating is coated in the drift channel. On the one hand, the drifted particles can be captured. It will affect the penetration of the applied electric field, so in this embodiment, the drift channel is coated with an uneven carbon nanotube coating, and the drift channel is in the shape of a coiled mosquito coil. On the one hand, the coiled mosquito coil-shaped drift channel can reduce the first The area of a microfluidic chip, on the other hand, the disc mosquito coil-shaped drift channel has several arc-shaped bends, which can make particles that are much larger than the target particle size to be separated due to excessive acceleration in the arc-shaped bends. The centrifugal force at the channel is greater than the centrifugal force at the straight line, and then hits the arc-shaped curve to realize the pretreatment of large-sized particles. One end of the drift channel is the particle injection end, and the other end of the drift channel is the collection end, and the collection end and the collection tank In which, the collecting tank is pre-filled with liquid for decelerating and collecting the drifting particles. Generally, supercooled water is selected as the liquid.

Please refer to FIG. 2, as shown in FIG. 2, step 1: Obtain the calibrated drift voltage of the target particle in the classified particles, and compare the calibrated drift voltage with the preset drift voltage. If the calibrated drift voltage is less than the preset drift voltage, execute Step 2, on the contrary, perform step 3, wherein, the calibration drift voltage of the target particle is the voltage required for the target particle to generate the maximum offset under the action of the electric field, and the maximum offset is the corresponding distance when the target particle hits the drift channel. The drift voltage is the maximum withstand voltage of the first microfluidic chip, the target particles are injected into the first microfluidic chip, the drift piezoelectricity is loaded on the first microfluidic chip, and whether there is a target particle in the collection pool is detected until the collection When no target particles are detected in the cell, the corresponding drift piezoelectricity is the calibration drift voltage. If the drift piezoelectricity loaded on the first microfluidic chip reaches the maximum withstand voltage, and the target particles are still detected in the collection cell, the maximum withstand voltage The voltage is the calibration drift voltage;

Step 2: Correct the drift voltage until the calibrated drift voltage is greater than the preset drift voltage. Specifically, S1: extract the preset drift voltage value and the value of the calibrated drift voltage; S2: establish a plane coordinate system and set (the preset drift voltage) value, the value of the calibration drift voltage) is marked as the first calculation point, (the value of the calibration drift voltage, the preset drift voltage value) is marked as the second calculation point; S3: Calculate the distance between the first calculation point and the second calculation point , and marked as the correction number; S4: the preset drift voltage value minus the correction number to complete the drift voltage correction, in which, the triangular graph of the first calculation point and the second calculation point is constructed, and the correction number can be quickly calculated by the Pythagorean theorem ;

Step 3: inject the classified particles into the first microfluidic chip, and apply a drift voltage to the first microfluidic chip according to the preset drift voltage, when the classified particles enter the drift channel in the first microfluidic chip through the injection end Afterwards, a preset drift voltage is applied to the first microfluidic chip, and after a preset period of time, the drift particles in the collection tank are subjected to secondary sorting.

Please refer to FIG. 3. As shown in FIG. 3, the second microfluidic chip consists of an upper substrate and a lower substrate; the upper substrate and the lower substrate are sealed and bonded together to form a second microfluidic chip; the upper substrate Equipped with a liquid inlet hole, an inertial flow channel and an outlet liquid hole;

Among them, the liquid inlet hole and the outlet liquid hole are both connected with the outside world, which are used for the introduction and export of the solution containing drift particles; the liquid inlet hole is connected with the inertial flow channel, and then divided into two branches, one branch is connected with the first outflow liquid The hole is communicated, and the other branch is communicated with the second outflow hole.

The inertial flow channel is an Archimedes spiral structure, the inner diameter of the inlet of the flow channel is 10mm, and the outer diameter of the outlet of the flow channel is 30mm. The cross-section of the runner is rectangular, and its width and height are 300 μm and 50 μm, respectively.

In this embodiment, the upper substrate of the second microfluidic chip is fabricated by standard soft lithography technology, the material is polydimethylsiloxane, the lower substrate is a glass cover glass, and the upper substrate and the lower substrate pass oxygen The plasma cleaning process performs irreversible bonding.

Please refer to Figure 4. As shown in Figure 4, during the secondary sorting, first, the solution containing drift particles is injected into the second microfluidic chip using a precision syringe pump, and the flow rate is set to 450 μL/min. The solution containing drift particles enters the inertial flow channel through the liquid inlet hole, and is randomly distributed at the cross section A-A at the inlet of the inertial flow channel. Since the inertial flow channel is in the shape of an Archimedes spiral, the microfluidic flow in the flow channel generates two countercurrent secondary flow vortices perpendicular to the main flow direction, so the solution containing drift particles is simultaneously affected by the inertial flow channel in the flow channel. The inertial lift force induced by the wall and the secondary flow drag force produced by the solution turning in the helical flow channel. Then, under the influence of inertial lift FL and secondary flow drag force FD, the solution containing drifting particles gradually produces inertial focusing effect and laterally migrates to different equilibrium positions. It is slightly close to the inner wall of the flow channel, but the distance between the equilibrium positions of the two kinds of particles is small, and the precise separation of the two kinds of particles cannot be realized. When the lift force dominates bypassing the turbulent obstacle, it quickly focuses to the near inner wall of the flow channel, while the small-sized particles are dominated by the drag force of the turbulent flow and migrate to the outer wall when bypassing the turbulent obstacle, so that the large-sized particles and the small-sized particles migrate to the outer wall surface. The balance position is increased. Finally, the large-sized particles communicated and flowed out through the first outlet liquid hole; the small-sized particles communicated and flowed out through the first outlet liquid hole to realize the secondary sorting of particles of different sizes. The size particles are pre-processed, so the application can be classified more accurately when it is subjected to secondary sorting.

In addition to the above, the present application also proposes a particle drift-based particle sorting system for more accurate sorting of particles of different sizes, including:

a calibration module, the calibration module is used to calibrate the drift voltage of the target particles in the classified particles;

a comparison correction module, the comparison correction module is used for comparing the calibration drift voltage with the preset drift voltage, and if the calibration drift voltage is less than the preset drift voltage, the drift voltage correction is performed until the calibration drift voltage is greater than the preset drift voltage;

a first microfluidic chip module, the first microfluidic chip module is used for receiving classified particles and performing electronic drift according to a preset drift voltage;

a second microfluidic chip module, the second microfluidic chip module is used for secondary sorting of the solution containing drift particles;

Also includes a host computer, the host computer is connected to the calibration module, the comparison correction module, the first microfluidic chip module and the second microfluidic chip module, and the host computer is used to display the calibration module, the comparison correction module, Operation data of the first microfluidic chip module and the second microfluidic chip.

To sum up, the present application provides a particle sorting method and system based on particle drift. By applying a preset drift voltage to the first microfluidic chip, the particles that need to be separated are smaller than the target particle calibration drift voltage. The particles are subjected to the external force F of the preset drift voltage, deflected in the first microfluidic chip, and collided with the passage in the first microfluidic chip, so that part of the particles that need to be separated can be pre-processed, so that the secondary separation can be achieved. The selection result is more precise.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " rear, left, right, vertical, horizontal, top, bottom, inside, outside, clockwise, counterclockwise, etc., or The positional relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as a limitation of the present invention.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. In the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations; the preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details and do not limit the invention to specific embodiments only. Obviously, many modifications and variations are possible in light of the content of this specification. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is to be limited only by the claims and their full scope and equivalents.

Claims (8)

1. A particle sorting method based on particle drift is characterized by comprising the following steps:

step 1: obtaining a calibration drift voltage of a target particle in the classified particles, comparing the calibration drift voltage with a preset drift voltage, if the calibration drift voltage is smaller than the preset drift voltage, executing the step 2, otherwise, executing the step 3;

and 2, step: correcting the drift voltage until the calibrated drift voltage is greater than the preset drift voltage;

and step 3: injecting the classified particles into the first microfluidic chip, and applying a drift voltage to the first microfluidic chip according to a preset drift voltage;

and 4, step 4: collecting the drifting particles after drifting, and carrying out secondary sorting;

the preset drift voltage is the maximum bearing voltage of the first microfluidic chip;

the calibration drift voltage of the target particles is the voltage required by the target particles to generate the maximum deviation under the action of the electric field.

2. The particle sorting method based on the particle drift of claim 1, wherein the classified particles are injected into the first microfluidic chip, and a drift voltage is applied to the first microfluidic chip according to a preset drift voltage, specifically:

constructing a drift channel in the first microfluidic chip, wherein one end of the drift channel is a particle injection end, the other end of the drift channel is a collection end, and the collection end is connected with a collection pool;

and after the classified particles enter the drift channel in the first micro-fluidic chip through the injection end, applying a preset drift voltage to the first micro-fluidic chip, and after a preset time period, carrying out secondary sorting on the drift particles in the collecting tank.

3. The particle sorting method based on particle drift of claim 1, wherein the calibration drift voltage of the target particles in the sorted particles is obtained, specifically, the target particles are injected into a first microfluidic chip, a drift piezoelectric is loaded on the first microfluidic chip, whether the target particles exist in the collection pool is detected, until the target particles cannot be detected in the collection pool, the corresponding drift piezoelectric is the calibration drift voltage, and if the drift piezoelectric loaded on the first microfluidic chip reaches the maximum withstand voltage and the target particles are still detected in the collection pool, the maximum withstand voltage is the calibration drift voltage.

4. The particle sorting method based on particle drift according to claim 1, wherein the performing drift voltage correction specifically comprises:

s1: extracting a preset drift voltage value and a calibrated drift voltage value;

s2: establishing a plane coordinate system and marking (a preset drift voltage value, a calibrated drift voltage value) as a first calculation point, (a calibrated drift voltage value, a preset drift voltage value) as a second calculation point;

s3: calculating the distance between the first calculation point and the second calculation point, and marking as a correction number;

s4: and subtracting the correction number from the preset drift voltage value to finish the drift voltage correction.

5. The method for sorting particles based on particle drift according to claim 1, wherein the secondary sorting comprises the following steps:

and injecting the solution containing the drifting particles in the collecting pool into the second microfluidic chip to finish secondary sorting.

6. The particle sorting method based on particle drift of claim 2, wherein the drift channel is in the shape of mosquito coil.

7. A particle sorting system based on particle drift, which is suitable for use in a particle sorting method based on particle drift according to any one of claims 1 to 6, and which comprises:

the calibration module is used for calibrating drift voltage of target particles in the classified particles;

the comparison and correction module is used for comparing the calibration drift voltage with a preset drift voltage, and correcting the drift voltage if the calibration drift voltage is smaller than the preset drift voltage until the calibration drift voltage is larger than the preset drift voltage;

the first micro-fluidic chip module is used for receiving the classified particles and performing electronic drift according to a preset drift voltage;

and the second microfluidic chip module is used for carrying out secondary sorting on the solution containing the drifting particles.

8. The particle sorting system based on particle drift of claim 7, further comprising an upper computer, wherein the upper computer is in communication connection with the calibration module, the comparison and correction module, the first microfluidic chip module and the second microfluidic chip module, and is used for displaying operation data of the calibration module, the comparison and correction module, the first microfluidic chip module and the second microfluidic chip.

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