Micro-fluidic chip and antigen concentration detection system

Abstract

The invention belongs to the technical field of immunization and detection, and particularly relates to a micro-fluidic chip and an antigen concentration detection system. The chip comprises a first air hole, a second air hole, a second mixing flow channel, a third mixing flow channel, a second cleaning position bin, a detection area and a first waste liquid bin, and the second mixing flow channel is used for mixing a sample, an immunomagnetic bead and a fluorescent antibody to generate a magnetic bead sample antibody mixed microsphere; the tail end of the second mixing flow channel is connected with the head end of a third mixing flow channel through a second cleaning position bin, the tail end of the third mixing flow channel is connected with an inlet of a detection area, and an outlet of the detection area is connected with a first waste liquid bin; the second cleaning position bin is further connected to a second waste liquid bin and a second cleaning liquid injection device. The height of the detection area is smaller than the distance between the adjacent magnetic bead sample antibody mixed microspheres; by adopting the micro-fluidic chip disclosed by the invention, the efficiency of antigen concentration detection can be improved, and the production cost of the micro-fluidic chip is greatly saved.

Description

Technical Field

[0001] The invention belongs to the field of immunity and detection technology, and specifically relates to a microfluidic chip and an antigen concentration detection system. Background Art

[0002] The application of protein detection technologies such as immunohistochemistry and ELISA is very extensive, and it has achieved the detection of thousands of protein biomarkers. Single-molecule immunoassay technology has higher detection sensitivity and wider detection range. One of the core technologies in single-molecule immunoassay is antigen conjugate coplanar technology, which requires antigen conjugates such as magnetic bead solutions to be sucked into the detection area by positive pressure or negative pressure, and it is necessary to ensure that all particles are coplanar and evenly dispersed. The US patent specification with application announcement number US20100075407A1 discloses a chip, which uses centrifugal method to inject magnetic bead solution into the detection area, and micro-wells are set in the area. Each particle needs to fall into a micro-well to achieve coplanar and uniform dispersion of particles. The magnetic bead drop rate during the detection process using this chip is not high, and it is necessary to use oil layer or other reagents for flushing, which is cumbersome and wastes reagents; in addition, due to the setting of micro-wells, the production process of the chip is complicated, and the precision requirements for chip production equipment are also high, resulting in high production costs of the chip. The Chinese utility model patent specification with authorization announcement number CN17910491U discloses a magnetic bead tile chip, which uses positive pressure to inject magnetic beads and designs the depth of the detection area to be small enough to ensure the coplanarity and uniformity of the magnetic beads; however, when using this chip to detect antigen concentration, the process of generating magnetic bead sample antibody mixed microspheres and cleaning the mixed microspheres must be performed outside the chip. The whole process is time-consuming and complicated, and the volatilization of the mixed microsphere solution and the waste liquid generated by cleaning will cause aerosol pollution. Summary of the invention

[0003] The purpose of the present invention is to provide a microfluidic chip and an antigen concentration detection system to solve the technical problem that the existing microfluidic chip has a low hole-falling rate and needs to be flushed with an oil layer or other reagents, the steps are cumbersome and the reagents are wasted. It is also used to solve the technical problem that when detecting the antigen concentration, the process of generating magnetic bead sample antibody mixed microspheres and cleaning the mixed microspheres is time-consuming and complicated and will cause aerosol pollution.

[0004] In order to solve the above technical problems, the present invention provides a microfluidic chip, including a second mixing channel, a third mixing channel, a second cleaning position bin, a detection area and a first waste liquid bin, wherein the second mixing channel is used to mix samples, immunomagnetic beads and fluorescent antibodies to generate magnetic bead sample antibody mixed microspheres, the end of the second mixing channel is connected to the head end of the third mixing channel through the second cleaning position bin, and the second cleaning position bin is used to accommodate the magnetic bead sample antibody mixed microspheres and fix them, the end of the third mixing channel is connected to the inlet of the detection area, and the outlet of the detection area is connected to the first waste liquid bin; the second cleaning position bin is also connected to the second waste liquid bin and the second cleaning liquid injection device respectively; the height of the detection area is less than the spacing between adjacent magnetic bead sample antibody mixed microspheres; the first waste liquid bin and the second waste liquid bin are respectively provided with a first air hole and a second air hole, and the first air hole and the second air hole are used to change the air pressure in the internal space of the chip to control the flow direction of the liquid in the chip.

[0005] The beneficial effects are as follows: since the height of the detection zone is less than the spacing between the adjacent magnetic bead sample antibody mixed microspheres, the problem of the mixed microspheres overlapping up and down in the detection zone to affect the counting can be avoided, and there is no need to set up multiple microwells in the chip and drop the mixed microspheres therein, and there is no need to use oil layers or other reagents to rinse the mixed microspheres after they enter the detection zone; the use of the microfluidic chip of the present invention for antigen concentration detection can make the operation steps of the entire process simpler, improve the efficiency of antigen concentration detection, and greatly save the production cost of the microfluidic chip. Samples, immunomagnetic beads and fluorescent antibodies can be mixed in the second mixing channel to generate mixed microspheres, and the generated mixed microspheres can be cleaned in the second cleaning position bin, and the generated waste liquid will flow into the second waste liquid bin; the process of generating magnetic bead sample antibody mixed microspheres and cleaning the mixed microspheres is carried out in the chip and the waste liquid will not contact the outside air, thereby avoiding the problem of aerosol pollution caused by the volatilization of waste liquid or mixed microsphere solution.

[0006] Preferably, it also includes a first mixing channel, a first cleaning position bin, a first cleaning liquid injection device and a fluorescent antibody injection device, the first mixing channel is used to mix samples and immunomagnetic beads, the end of the first mixing channel is connected to the head end of the second mixing channel through the first cleaning position bin, the first cleaning position bin is used to accommodate and fix the mixed microspheres generated after the sample and the immunomagnetic beads are mixed; the first cleaning position bin is also connected to the outlet of the first cleaning liquid injection device and the second waste liquid bin, respectively, and the outlet of the fluorescent antibody injection device is connected to the head end of the second mixing channel.

[0007] Its beneficial effects are as follows: by setting up the first cleaning position chamber and the first cleaning liquid injection device, other impurities in the sample except the antigen magnetic bead mixed microspheres can be cleaned first in the first cleaning chamber, which is cleaner than washing in one cleaning chamber as a whole; after cleaning in the first cleaning chamber, the fluorescent antibody and the antigen magnetic bead mixed microspheres are combined, so that the binding rate of the fluorescent antibody, the immune magnetic beads and the antigen is higher.

[0008] Preferably, it also includes a third waste liquid bin, a first mixing flow channel, a first cleaning position bin, a first cleaning liquid injection device and a fluorescent antibody injection device. The first mixing flow channel is used to mix samples and immunomagnetic beads. The end of the first mixing flow channel is connected to the head end of the second mixing flow channel through the first cleaning position bin, and the first cleaning position bin is used to accommodate and fix the mixed microspheres generated by mixing the sample and the immunomagnetic beads. The first cleaning position bin is also respectively connected to the outlet of the first cleaning liquid injection device and the third waste liquid bin. A third air hole is opened on the third waste liquid bin, and the third air hole is used to change the air pressure in the internal space of the chip to control the flow direction of the liquid in the chip.

[0009] Preferably, it further comprises a sample hole, an immunomagnetic bead injection device and a fluorescent antibody injection device, and the head end of the second mixing channel is respectively connected to the sample hole, the outlet of the immunomagnetic bead injection device and the outlet of the fluorescent antibody injection device.

[0010] The beneficial effect is that by connecting the head end of the second mixing channel to the sample hole, the outlet of the immunomagnetic bead injection device and the outlet of the fluorescent antibody injection device respectively, it is easier to inject the three into the second mixing channel for incubation.

[0011] Preferably, it also includes a first buffer injection device and a second buffer injection device, the outlet of the first buffer injection device is connected to the first cleaning position bin, and the second buffer injection device is connected to the second cleaning position bin.

[0012] The beneficial effect is that by setting up the buffer injection device, the buffer can be injected to dissolve and protect the mixed microspheres after the mixed microspheres are washed.

[0013] Preferably, it further comprises a second buffer injection device, and the second cleaning bin is also connected to the outlet of the second buffer injection device.

[0014] The beneficial effect is that by setting up the buffer injection device, the buffer can be injected to dissolve and protect the mixed microspheres after the mixed microspheres are washed.

[0015] To solve the above technical problems, the present invention also provides an antigen concentration detection system, including a concentration calculation device and the microfluidic chip of the present invention; the concentration calculation device is used to count the magnetic beads in the detection area and deduce the concentration of the antigen in the sample.

[0016] The beneficial effects are as follows: since the height of the detection area of ​​the microfluidic chip is less than the spacing between the adjacent magnetic bead sample antibody mixed microspheres, the problem of the mixed microspheres overlapping up and down in the detection area to affect the counting can be avoided, and there is no need to set up multiple microwells in the chip and drop the mixed microspheres therein, and there is no need to use oil layers or other reagents to rinse the mixed microspheres after they enter the detection area; the antigen concentration detection system of the present invention is used to detect the antigen concentration, which can make the operation steps of the whole process simpler, improve the efficiency of antigen concentration detection, and greatly save the production cost of the microfluidic chip. Samples, immune magnetic beads and fluorescent antibodies can be mixed in the second mixing channel to generate mixed microspheres, and the generated mixed microspheres can be cleaned in the second cleaning position bin, and the generated waste liquid will flow into the second waste liquid bin; the process of generating magnetic bead sample antibody mixed microspheres and cleaning the mixed microspheres is carried out in the chip and the waste liquid will not contact the outside air, thereby avoiding the problem of aerosol pollution caused by the volatilization of waste liquid or mixed microsphere solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of a first microfluidic chip of the present invention;

[0018] Figure 2 is a schematic structural diagram of a second microfluidic chip of the present invention;

[0019] Figure 3 It is a schematic structural diagram of the third microfluidic chip of the present invention.

[0020] Explanation of the accompanying drawings: 1 is the sample hole; 2 is the first vesicle; 3 is the first mixing channel; 4 is the third vesicle; 5 is the first cleaning position chamber; 6 is the second vesicle; 7 is the fifth vesicle; 8 is the fourth vesicle; 9 is the second mixing channel; 10 is the second cleaning position chamber; 11 is the third mixing channel; 12 is the detection area; 13 is the first waste liquid chamber; 14 is the second waste liquid chamber; 15 is the first air hole; 16 is the second air hole; 17 is the third waste liquid chamber; 18 is the third air hole; 19 is the first waste liquid channel; 20 is the second waste liquid channel; 21 is the sixth vesicle. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0022] Microfluidic chip embodiment:

[0023] Embodiment 1:

[0024] like Figure 1 As shown, the microfluidic chip in this embodiment includes a sample hole 1, an immunomagnetic bead injection device, a fluorescent antibody injection device, a second mixing channel 9, a second buffer injection device, a second cleaning liquid injection device, a second cleaning position bin 10, a third mixing channel 11, a detection area 12, a first waste liquid bin 15 and a second waste liquid bin 14, and the first waste liquid bin 15 and the second waste liquid bin 14 are respectively provided with a first pore 15 and a second pore 16; the head end of the second mixing channel 9 is respectively connected to the sample hole 1, the immunomagnetic bead injection device and the fluorescent antibody injection device, the end of the second mixing channel 9 is connected to the head end of the first mixing channel 11 through the second cleaning position bin 10, the end of the first mixing channel 11 is connected to the inlet of the detection area 12, and the outlet of the detection area 12 is connected to the first waste liquid bin 13; the second cleaning position bin 10 is connected to the second waste liquid bin 14 through the second waste liquid channel, and the second cleaning position bin 10 is also respectively connected to the second buffer injection device and the second cleaning liquid injection device. The immunomagnetic bead injection device uses a first vesicle 2 containing immunomagnetic beads, the fluorescent antibody injection device uses a second vesicle 6 containing fluorescent antibodies, the second cleaning solution injection device uses a fourth vesicle 8 containing cleaning solution, and the second buffer injection device uses a fifth vesicle 7 containing buffer, and the buffer can be PBS buffer. The height of the detection area 12 is less than the spacing between adjacent magnetic bead sample antibody mixed microspheres.

[0025] By connecting the head end of the second mixing channel to the sample hole, the outlet of the immunomagnetic bead injection device and the outlet of the fluorescent antibody injection device respectively, it is easier to inject the three into the second mixing channel for incubation.

[0026] The working process of the microfluidic chip in this embodiment is as follows:

[0027] 1) Inject the sample into the second mixing channel 9 through the syringe and the sample hole 1, and squeeze the first vesicle 2 and the second vesicle 6 at the same time to make the immunomagnetic beads and the fluorescent antibody enter the second mixing channel 9. After the sample is injected, the needle tip of the syringe does not move away and blocks the first pore 15.

[0028] After the sample, immunomagnetic beads and fluorescent antibodies are mixed in the second mixing channel 9, incubation begins to generate magnetic bead sample antibody mixed microspheres.

[0029] 2) After the magnetic bead sample antibody mixed microspheres enter the second cleaning chamber 10, they are fixed by a magnet, the second pores 16 are opened, and the fourth vesicles 8 are squeezed to allow the cleaning solution therein to enter the second cleaning chamber 10 to clean the magnetic bead sample antibody mixed microspheres.

[0030] The waste liquid generated by cleaning flows into the second waste liquid tank 14 through the second waste liquid channel.

[0031] 3) After the cleaning is completed, the fixation of the magnetic bead sample antibody mixed microspheres is released, the second pore 16 is blocked and the first pore 15 is opened, negative pressure suction is performed through the first pore 15, and at the same time, the fifth vesicle 7 is squeezed to allow the buffer solution therein to enter the second cleaning chamber 10.

[0032] As the buffer solution enters the second cleaning chamber 10, the formed magnetic bead sample antibody mixed microsphere solution will enter the detection zone 12 through the third mixing channel 11. Since the depth of the detection zone 12 is less than the spacing between adjacent magnetic bead sample antibody mixed microspheres, after the magnetic bead sample antibody mixed microspheres and the buffer solution fill the detection zone 12, the magnetic beads will be spread in the detection zone 12. Excess liquid will enter the first waste liquid chamber 13.

[0033] 4) After the detection area 12 is filled with the magnetic bead sample antibody mixed microsphere solution, the magnetic beads and microspheres in the detection area 12 are counted to obtain the concentration of the antigen in the sample.

[0034] The detection area 12 can be photographed by a camera and the magnetic beads and microspheres can be counted using image recognition technology.

[0035] Since the height of the detection zone is less than the spacing between the adjacent magnetic bead sample antibody mixed microspheres, the problem of the mixed microspheres overlapping up and down in the detection zone to affect the counting can be avoided, and there is no need to set up multiple microwells in the chip and drop the mixed microspheres therein, and there is no need to use oil layers or other reagents to rinse the mixed microspheres after they enter the detection zone; the use of the microfluidic chip of the present invention for antigen concentration detection can make the operation steps of the entire process simpler, improve the efficiency of antigen concentration detection, and greatly save the production cost of the microfluidic chip. Samples, immunomagnetic beads and fluorescent antibodies can be mixed in the second mixing channel to generate mixed microspheres, and the generated mixed microspheres can be cleaned in the second cleaning position bin, and the generated waste liquid will flow into the second waste liquid bin; the process of generating magnetic bead sample antibody mixed microspheres and cleaning the mixed microspheres is carried out in the chip and the waste liquid will not contact the outside air, thereby avoiding the problem of aerosol pollution caused by the volatilization of waste liquid or mixed microsphere solution.

[0036] Embodiment 2:

[0037] like Figure 2As shown, the microfluidic chip in this embodiment is added with a first mixing channel 3, a first cleaning position chamber 5 and a first cleaning liquid injection device compared with the microfluidic chip in the first embodiment. The sample hole 1 and the immunomagnetic bead injection device are respectively connected to the head end of the first mixing channel 3, the end of the first mixing channel 3 is connected to the head end of the second mixing channel 9 through the first cleaning position bin 5, the first cleaning position bin 5 is connected to the second waste liquid bin 14 through the first waste liquid channel 19, the first cleaning position bin 5 is also connected to the outlet of the first cleaning liquid injection device, and the head end of the second mixing channel 9 is also connected to the outlet of the fluorescent antibody injection device; the end of the second mixing channel 9 is connected to the head end of the third mixing channel 11 through the second cleaning position bin 10, the second cleaning position bin 10 is connected to the second waste liquid bin 14 through the second waste liquid channel 20, and the second cleaning position bin 10 is also connected to the outlet of the second cleaning liquid injection device and the outlet of the second buffer injection device respectively; the end of the third mixing channel 11 is connected to the inlet of the detection area 12, and the outlet of the detection area 12 is connected to the first waste liquid bin 13; the first waste liquid bin 13 and the second waste liquid bin 14 are respectively provided with a first air hole 15 and a second air hole 16. The immunomagnetic bead injection device uses a first vesicle 2 containing immunomagnetic beads, the fluorescent antibody injection device uses a second vesicle 6 containing fluorescent antibodies, the first cleaning liquid injection device and the second cleaning liquid injection device respectively use a third vesicle 4 containing cleaning liquid and a fourth vesicle 8 containing cleaning liquid, and the second buffer injection device uses a fifth vesicle 7 containing buffer. The height of the detection area 12 is less than the spacing between adjacent magnetic bead sample antibody mixed microspheres.

[0038] The working process and working principle of the microfluidic chip in this embodiment are as follows:

[0039] 1) injecting a sample into the first mixing channel 3 through a syringe and a sample hole 1, and at the same time using an extrusion column of the device to squeeze the first vesicle 2 to inject immunomagnetic beads into the first mixing channel 3, so that the sample and the immunomagnetic beads are mixed in the first mixing channel 3 to form a sample-magnetic bead mixture; after the sample is injected, the tip of the syringe does not move away to block the sample hole 1.

[0040] 2) After the sample magnetic bead mixture flows into the first cleaning chamber 5, the magnetic beads in the first cleaning chamber 5 are fixed by a magnet, the first pore 15 is blocked by the instrument pore control column 1, and the third vesicle 4 is squeezed by the equipment squeezing column to clean the sample magnetic bead mixture to remove components other than the antigen in the sample, and the generated waste liquid enters the waste liquid chamber 14 through the first waste liquid channel 19.

[0041] To ensure the cleaning effect, the amount of reagent 6 needs to be sufficient and the extrusion speed needs to be controlled.

[0042] 3) After the cleaning is completed, the magnetic beads in the first cleaning chamber 5 are released, the second air hole 16 is blocked, and the sample magnetic bead mixture is sucked by negative pressure through the first air hole 15, and the second vesicle 6 is squeezed to mix the fluorescent antibody and the washed magnetic beads into the second mixing channel 9 for mixed incubation to generate magnetic bead sample antibody mixed microspheres.

[0043] After the fluorescent antibody is mixed with the washed magnetic beads, it will combine with the antigen on the magnetic beads, making the antigen fluorescently labeled and easier to identify.

[0044] 4) After the magnetic bead sample antibody mixed microspheres enter the second cleaning position chamber 10, they are fixed by a magnet, the first pore 15 is blocked and the second pore 16 is unblocked, the fourth vesicle 8 is squeezed to allow the cleaning liquid therein to enter the second cleaning position chamber 10 to clean the magnetic bead sample antibody mixed microspheres, and the generated waste liquid enters the waste liquid chamber 14 through the second waste liquid channel 20.

[0045] To ensure the cleaning effect, the amount of cleaning liquid in the fourth vesicle 8 needs to be sufficient, and the extrusion speed needs to be controlled during extrusion.

[0046] 5) After cleaning is completed, the second pore 16 is blocked, and the cleaned magnetic bead sample antibody mixed microspheres are suctioned under negative pressure through the first pore 15, while the fifth vesicle 7 is squeezed to allow the buffer solution therein to enter the second cleaning position chamber 10 and mix with the magnetic bead sample antibody mixed microspheres, so that the magnetic bead sample antibody mixed microspheres and the buffer solution enter the detection area 12 through the third mixing channel 11.

[0047] Since the height of the detection zone 12 is smaller than the spacing between adjacent magnetic bead sample antibody mixed microspheres, after the magnetic bead sample antibody mixed microspheres and the buffer solution fill the detection zone 12 , the magnetic beads will be spread out in the detection zone 12 .

[0048] 6) Count the magnetic beads and microspheres in the detection area 12 to obtain the concentration of the antigen in the sample.

[0049] The detection area 12 can be photographed by a camera and the magnetic beads and microspheres can be counted using image recognition technology.

[0050] By setting up the first cleaning position chamber and the first cleaning liquid injection device, other impurities in the sample except the antigen magnetic bead mixed microspheres can be cleaned first in the first cleaning chamber, which is cleaner than washing in one cleaning chamber as a whole; after cleaning in the first cleaning chamber, the fluorescent antibody and the antigen magnetic bead mixed microspheres are combined, so that the binding rate of the fluorescent antibody, the immune magnetic beads and the antigen is higher.

[0051] The technical effects of the microfluidic chip of this embodiment have been described in the first embodiment and will not be repeated here.

[0052] Embodiment three:

[0053] like Figure 3 As shown, the microfluidic chip in this embodiment has a substantially similar structure to that in the second embodiment. The difference between the two is that the microfluidic chip in this embodiment further includes a third pore 18 and a first buffer injection device, and the first cleaning position bin 5 is also connected to the third waste liquid bin 17. The connection relationship between the two waste liquid bins and the two cleaning position bins is different from that of the microfluidic chip in the first embodiment, and the other parts are the same as those of the microfluidic chip in the first embodiment. The first buffer injection device uses a sixth vesicle 21 containing a buffer. The third pore 18 is provided on the third waste liquid bin 17, the first cleaning position bin 5 is connected to the third waste liquid bin 17 through the first waste liquid channel 19, and the second cleaning position bin is connected to the second waste liquid bin 14 through the second waste liquid channel 20. The height of the detection area 12 is less than the spacing between adjacent magnetic bead sample antibody mixed microspheres.

[0054] The working principle and working process of the microfluidic chip in this embodiment are as follows:

[0055] 1) injecting a sample into the first mixing channel 3 through a syringe and a sample hole 1, and at the same time using an extrusion column of the device to squeeze the first vesicle 2 to inject immunomagnetic beads into the first mixing channel 3, so that the sample and the immunomagnetic beads are mixed in the first mixing channel 3 to form a sample-magnetic bead mixture; after the sample is injected, the tip of the syringe does not move away to block the sample hole 1.

[0056] 2) After the sample magnetic bead mixture flows into the first cleaning chamber 5, the magnetic beads in the first cleaning chamber 5 are fixed by a magnet, the first pore 15 and the second pore 16 are blocked by the instrument pore control column, the third pore 18 is opened, and the third vesicle 4 is squeezed by the device squeezing column to wash the sample magnetic bead mixture and remove components other than antigens in the sample.

[0057] To ensure the cleaning effect, the amount of reagent 6 needs to be sufficient and the extrusion speed needs to be controlled. The generated waste liquid enters the third waste liquid bin 17 through the first waste liquid channel 19.

[0058] 3) After the cleaning is completed, the magnetic beads in the first cleaning chamber 5 are released, the second pores 16 and the third pores 18 are blocked, the sample magnetic bead mixture is sucked under negative pressure through the first pores 15, the second vesicles 6 are squeezed to mix the fluorescent antibodies and the washed magnetic beads, and at the same time, the sixth vesicles 21 are squeezed to allow the buffer solution to enter the first cleaning chamber 5, and the fluorescent antibodies, buffer solution and the washed magnetic beads enter the second mixing channel 9 for mixed incubation to generate magnetic bead sample antibody mixed microspheres.

[0059] After the fluorescent antibody is mixed with the washed magnetic beads, it will combine with the antigen on the magnetic beads, making the antigen fluorescently labeled and easier to identify.

[0060] 4) After the magnetic bead sample antibody mixed microspheres enter the second cleaning position chamber 10, they are fixed by a magnet, the first pore 15 is blocked and the second pore 16 is unblocked, the fourth vesicle 8 is squeezed so that the cleaning liquid therein enters the second cleaning position chamber 10 to clean the magnetic bead sample antibody mixed microspheres, and the generated waste liquid enters the second waste liquid chamber 14 through the second waste liquid channel 20.

[0061] To ensure the cleaning effect, the amount of cleaning liquid in the fourth vesicle 8 needs to be sufficient, and the extrusion speed needs to be controlled during extrusion.

[0062] 5) After cleaning is completed, the second pore 16 is blocked, and the cleaned magnetic bead sample antibody mixed microspheres are suctioned under negative pressure through the first pore 15, while the fifth vesicle 7 is squeezed to allow the buffer solution therein to enter the second cleaning position chamber 10 and mix with the magnetic bead sample antibody mixed microspheres, so that the magnetic bead sample antibody mixed microspheres and the buffer solution enter through the third mixing channel 11 and fill the detection area 12.

[0063] Since the depth of the detection zone 12 is less than the spacing between adjacent magnetic bead sample antibody mixed microspheres, after the magnetic bead sample antibody mixed microspheres and the buffer solution fill the detection zone 12, the magnetic beads will be spread out in the detection zone 12. Excess liquid will enter the first waste liquid tank 13.

[0064] 6) Count the magnetic beads and microspheres in the detection area 12 to obtain the concentration of the antigen in the sample.

[0065] The detection area 12 can be photographed by a camera and the magnetic beads and microspheres can be counted using image recognition technology.

[0066] The technical effects of the microfluidic chip of this embodiment have been described in the first embodiment and will not be repeated here.

[0067] Antigen concentration detection system embodiment:

[0068] The antigen concentration detection system of the present invention comprises a concentration calculation device and a microfluidic chip of the present invention; the concentration calculation device is used to count the magnetic beads in the detection area and deduce the concentration of the antigen in the sample. The method for counting the magnetic beads in the detection area is to take a picture of the detection area with a camera and count the magnetic beads using image recognition technology.

[0069] Since the height of the detection area of ​​the microfluidic chip is less than the spacing between the adjacent magnetic bead sample antibody mixed microspheres, the problem of the mixed microspheres overlapping up and down in the detection area to affect the counting can be avoided, and there is no need to set up multiple microwells in the chip and drop the mixed microspheres therein, and there is no need to use oil layers or other reagents to rinse the mixed microspheres after they enter the detection area; the use of the antigen concentration detection system of the present invention for antigen concentration detection can make the operation steps of the entire process simpler, improve the efficiency of antigen concentration detection, and greatly save the production cost of the microfluidic chip. Samples, immune magnetic beads and fluorescent antibodies can be mixed in the second mixing channel to generate mixed microspheres, and the generated mixed microspheres can be cleaned in the second cleaning position bin, and the generated waste liquid will flow into the second waste liquid bin; the process of generating magnetic bead sample antibody mixed microspheres and cleaning the mixed microspheres is carried out in the chip and the waste liquid will not contact the outside air, thereby avoiding the problem of aerosol pollution caused by the volatilization of waste liquid or mixed microsphere solution.

Claims

1. A microfluidic chip, characterized in that: The invention comprises a second mixing channel, a third mixing channel, a second cleaning position bin, a detection zone and a first waste liquid bin, wherein the second mixing channel is used to mix samples, immune magnetic beads and fluorescent antibodies to generate magnetic bead sample antibody mixed microspheres, the end of the second mixing channel is connected to the head end of the third mixing channel through the second cleaning position bin, and the second cleaning position bin is used to accommodate and fix the magnetic bead sample antibody mixed microspheres, the end of the third mixing channel is connected to the inlet of the detection zone, and the outlet of the detection zone is connected to the first waste liquid bin; the second cleaning position bin is also connected to the second waste liquid bin and the second cleaning liquid injection device respectively; the height of the detection zone is less than the spacing between adjacent magnetic bead sample antibody mixed microspheres; the first waste liquid bin and the second waste liquid bin are respectively provided with a first air hole and a second air hole, and the first air hole and the second air hole are used to change the air pressure in the internal space of the chip to control the flow direction of the liquid in the chip.

2. The microfluidic chip according to claim 1, characterized in that: It also includes a first mixing flow channel, a first cleaning position bin, a first cleaning liquid injection device and a fluorescent antibody injection device. The first mixing flow channel is used to mix samples and immunomagnetic beads. The end of the first mixing flow channel is connected to the head end of the second mixing flow channel through the first cleaning position bin. The first cleaning position bin is used to accommodate and fix mixed microspheres generated after the sample and the immunomagnetic beads are mixed. The first cleaning position bin is also connected to the outlet of the first cleaning liquid injection device and the second waste liquid bin, respectively, and the outlet of the fluorescent antibody injection device is connected to the head end of the second mixing flow channel.

3. The microfluidic chip according to claim 1, characterized in that: It also includes a third waste liquid bin, a first mixing flow channel, a first cleaning position bin, a first cleaning liquid injection device and a fluorescent antibody injection device. The first mixing flow channel is used to mix samples and immunomagnetic beads. The end of the first mixing flow channel is connected to the head end of the second mixing flow channel through the first cleaning position bin, and the first cleaning position bin is used to accommodate and fix mixed microspheres generated after the sample and the immunomagnetic beads are mixed. The first cleaning position bin is also respectively connected to the outlet of the first cleaning liquid injection device and the third waste liquid bin. A third air hole is opened on the third waste liquid bin. The third air hole is used to change the air pressure in the internal space of the chip to control the flow direction of the liquid in the chip.

4. The microfluidic chip according to claim 1, characterized in that: It also includes a sample hole, an immunomagnetic bead injection device and a fluorescent antibody injection device. The head end of the second mixing channel is connected to the sample hole, the outlet of the immunomagnetic bead injection device and the outlet of the fluorescent antibody injection device respectively.

5. The microfluidic chip according to claim 2 or 3, characterized in that: It also includes a first buffer injection device and a second buffer injection device, wherein the outlet of the first buffer injection device is connected to the first cleaning position bin, and the outlet of the second buffer injection device is connected to the second cleaning position bin.

6. The microfluidic chip according to claim 1 or 4, characterized in that: It also includes a second buffer injection device, and the second cleaning position bin is also connected to the outlet of the second buffer injection device.

7. An antigen concentration detection system, characterized in that: It comprises a concentration calculating device and the microfluidic chip as claimed in any one of claims 1 to 6; the concentration calculating device is used to count the magnetic beads in the detection area and deduce the concentration of the antigen in the sample.

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