Immunodetection system and method based on digital micro-fluidic chip

Abstract

The invention discloses an immunodetection system and method based on a digital micro-fluidic chip, the system comprises a micro-fluidic chip, a heating unit, a magnetic field loading unit, a fluorescence detection unit and a control unit, the micro-fluidic chip comprises a liquid injection area, a magnetic mixing area, a magnetic separation area, a detection area, a waste liquid area and an electrode array; the electrode array covers each area and drives liquid drops in the areas to move; the control unit is used for controlling the electrode array to drive the movement sequence and position of the liquid drops in each region according to an immunodetection process; wherein the heating unit is used for regulating and controlling the immune reaction temperature of liquid drops in the magnetic mixing area, and driving the liquid drops to continuously move in the magnetic mixing area through the electrode array covered by the magnetic mixing area, so that samples, magnetic beads and fluorescent microspheres in the liquid drops are fully mixed and react. The immunoreaction time is greatly shortened, the magnetic mixing uniformity is greatly improved, and the immunodetection efficiency and accuracy are improved.

Description

Background Art

[0002] Common immunoassay methods include enzyme-linked immunosorbent assay, immunochromatography, chemiluminescent immunoassay, fluorescent immunoassay, etc. The immunochromatographic method is widely used in disease screening and home self-examination. It has a simple operation method and a fast detection speed, but its sensitivity is generally lower than other detection methods, which can easily lead to false negative test results, that is, a negative test result cannot be used as a basis for excluding infection. Enzyme-linked immunosorbent assay, chemiluminescent detection and other methods have high sensitivity and good stability of test results. However, most of the current methods rely on large-scale pipetting systems for automated detection, which are not suitable for application scenarios such as on-site disease screening and rapid detection in emergency departments. Therefore, there is an urgent need to develop portable automated rapid immunoassay methods. Summary of the invention

[0003] In view of the problems existing in the prior art, the object of the present invention is to provide an immunoassay system and method based on a digital microfluidic chip, an electronic device and a computer-readable storage medium that have a high degree of automation and take into account both detection efficiency and accuracy.

[0004] To achieve the above-mentioned objectives, the first aspect of the present invention provides an immunoassay system based on a digital microfluidic chip, comprising a microfluidic chip, a heating unit, a magnetic field loading unit, a fluorescence detection unit and a control unit, wherein the microfluidic chip comprises an injection area, a magnetic mixing area, a magnetic separation area, a detection area, a waste liquid area and an electrode array; the heating unit is arranged in the magnetic mixing area, the magnetic field loading unit is arranged in the magnetic separation area, and the fluorescence detection unit is arranged in the detection area; the electrode array covers each area and drives the movement of droplets in the area; the control unit is used to control the movement order and position of the droplets driven by the electrode array in each area according to the immunoassay process; wherein the heating unit is used to regulate the immune reaction temperature of the droplets in the magnetic mixing area, and drive the droplets to move continuously in the magnetic mixing area through the electrode array covered by the magnetic mixing area, so that the samples, magnetic beads and fluorescent microspheres in the droplets are fully mixed and reacted.

[0005] Furthermore, a plurality of electrodes in the electrode array covering the magnetic mixing zone are arranged in a closed manner around the outer peripheral edge of the magnetic mixing zone, so that the droplets in the magnetic mixing zone can continue to move in the magnetic mixing zone under the drive of the plurality of electrodes.

[0006] Furthermore, a plurality of electrodes in the electrode array covering the magnetic mixing zone are arranged in a “mouth” shape.

[0007] Furthermore, the microfluidic chip comprises a plurality of liquid injection areas, a plurality of magnetic mixing areas and a plurality of magnetic separation areas, and the plurality of liquid injection areas, a plurality of magnetic mixing areas and a plurality of magnetic separation areas are connected to the same detection area and the same waste liquid area.

[0008] Furthermore, the electrode array covering the magnetic separation zone can drive the droplets to move bidirectionally toward the magnetic mixing zone or the detection zone under the control of the control unit.

[0009] The second aspect of the present invention provides an immunoassay method based on a digital microfluidic chip, using the above-mentioned immunoassay system, the method comprises the following steps:

[0010] 1) Injecting samples, immune capture magnetic beads and fluorescent microsphere solution into the microfluidic chip;

[0011] 2) driving the mixed solution to move to the magnetic mixing area for immune response operation;

[0012] 3) After the immune reaction is completed, the reaction mixture is driven to move to the magnetic separation area for magnetic bead enrichment operation;

[0013] 4) After the magnetic beads are enriched, a cleaning solution is injected into the microfluidic chip to perform a magnetic bead re-dissolution and cleaning operation;

[0014] 5) After the magnetic beads are re-dissolved and cleaned, a buffer solution is injected into the microfluidic chip to re-dissolve the magnetic beads and the magnetic bead mixture is driven to move to the detection area for fluorescent immunoassay.

[0015] Further, step 2) comprises:

[0016] The temperature of the magnetic mixing zone is adjusted to the immune response temperature;

[0017] driving the mixed solution to move to the magnetic mixing zone;

[0018] The mixed liquid is driven to continuously move in the magnetic mixing zone during the immune response time;

[0019] After the immune response time is reached, the mixed solution is driven to move to the magnetic separation area.

[0020] Further, step 3) includes:

[0021] Loading a magnetic field in the magnetic separation area, adsorbing and positioning the magnetic beads in the mixed solution after the immune reaction in the magnetic separation area;

[0022] After driving the supernatant in the mixed solution to move to the waste liquid area, the magnetic field loaded in the magnetic separation area is removed.

[0023] Further, step 4) includes:

[0024] After the enrichment is completed, a cleaning solution is injected into the microfluidic chip and moved to the magnetic separation area to re-dissolve the magnetic beads, and the re-dissolved magnetic bead mixture is driven to move to the magnetic mixing area to mix the magnetic beads;

[0025] After mixing the magnetic beads, the magnetic bead supernatant mixture is driven to move to the magnetic separation area for magnetic bead enrichment;

[0026] Repeat the above cleaning operation 2-3 times and then proceed to step 5).

[0027] A third aspect of the present invention provides an electronic device, comprising:

[0028] Processor; and

[0029] A memory having computer-readable instructions stored therein, wherein the computer-readable instructions implement the above method when executed by the processor.

[0030] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the above method when executed by a processor.

[0031] The present invention arranges a liquid injection area, a magnetic mixing area, a magnetic separation area, a detection area and a waste liquid area on a microfluidic chip, and automatically realizes a series of operations such as immune response, magnetic bead enrichment, cleaning, and detection through control of a control unit in combination with electrode arrays covered in each area. The immune response time and magnetic mixing uniformity are greatly shortened through the cooperation of a heating unit and the electrode array covered in the magnetic mixing area, thereby improving the efficiency and accuracy of immune detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 A schematic diagram of an immunoassay system based on a digital microfluidic chip according to an embodiment of the present invention;

[0034] Figure 2 for Figure 1 Schematic diagram of the use of the immunoassay system for pathogenic microorganism immunoassay;

[0035] Figure 3 The present invention is a flowchart of an immunoassay method based on a digital microfluidic chip according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0037] like Figure 1As shown, the immunoassay system based on the digital microfluidic chip of the present invention comprises a microfluidic chip, a heating unit, a magnetic field loading unit, a fluorescence detection unit and a control unit, wherein the microfluidic chip comprises a liquid injection area 1, a magnetic mixing area (temperature control area) 2, a magnetic separation area 3, a detection area 4, a waste liquid area 5 and an electrode array; the heating unit is arranged in the magnetic mixing area 2, the magnetic field loading unit is arranged in the magnetic separation area 3, and the fluorescence detection unit is arranged in the detection area 4; the electrode array covers each area and drives the movement of the droplets in the area; the control unit is used to control the movement sequence and position of the droplets driven by the electrode array in each area according to the immunoassay process; wherein the heating unit is used to regulate the immune reaction temperature of the droplets in the magnetic mixing area 2, and the droplets are driven to move continuously in the magnetic mixing area 2 by the electrode array covered by the magnetic mixing area 2, so that the sample, magnetic beads and fluorescent microspheres in the droplets are fully mixed and reacted. Specifically, an injection port is arranged on the liquid injection area, and the injection port can realize the injection of solutions such as sample, magnetic beads, fluorescent microsphere solution, cleaning solution and buffer solution into the microfluidic chip. The heating unit includes a heat spreader and a temperature control module. The heating unit can be set at the bottom of the magnetic mixing zone. The heat spreader of the heating unit is in direct contact with the chip. The temperature of the heat spreader is adjusted by the temperature control module, and then the temperature of the magnetic mixing zone is adjusted to the immune reaction temperature. The magnetic field loading unit includes a magnet and a linear motor. The magnet is controlled by the linear motor to keep its distance from the top of the chip, and the magnet is controlled to be close to the top of the chip to achieve the loading of the external magnetic field, and the magnet is controlled to be away from the top of the chip to achieve the withdrawal of the external magnetic field. The fluorescence detection unit includes an optical fiber probe and a fluorescence signal amplification system. The optical fiber probe is fixed on the top of the detection zone, and a large beam diameter quartz multimode optical fiber with a numerical aperture of 0.23NA is used for excitation light transmission and emission light collection. The optical fiber is small in size and easy to install. Under the requirement of small and portable equipment, it cooperates with the fluorescent microsphere signal amplification system to achieve high-sensitivity immune detection. The electrode array includes multiple electrodes laid in each zone. The multiple electrodes are laid according to the moving path of the droplets in each zone to ensure that the droplets injected into the chip can move between zones under the drive of the electrode array.

[0038] like Figure 2As shown, the present invention adopts double antibody sandwich immunoassay, takes magnetic beads as solid phase carriers, modifies capture antibodies onto magnetic beads through the reaction of streptavidin and biotin to prepare immune capture magnetic beads, modifies detection antibodies onto the surface of fluorescent microspheres to prepare fluorescent detection microspheres, and starts immune reaction after the sample to be tested is mixed with the immune capture magnetic beads and the fluorescent detection microspheres. When the sample is positive, the target antigen (N protein) in the sample reacts with the capture antibody on the surface of the immune capture magnetic beads and the detection antibody on the surface of the fluorescent detection microspheres to form a "sandwich" complex of magnetic beads-capture antibody-antigen-detection antibody-fluorescent microspheres. After magnetic separation and washing away the free (not involved in the reaction) antigens, fluorescent detection microspheres and impurities, the fluorescent signal is detected by the optical module. The collected fluorescent signal is the signal of the fluorescent microspheres bound to the magnetic beads through the immune reaction, which is positively correlated with the concentration of the target antigen in the sample; when the sample is negative, there is no target antigen in the sample, and the "sandwich" complex of magnetic beads-capture antibody-antigen-detection antibody-fluorescent microspheres cannot be formed. After magnetic separation and washing, all fluorescent microspheres and impurities are removed, and the fluorescent microspheres are not bound to the immune magnetic beads. The detection value obtained by deducting the background fluorescent signal from the fluorescent signal collected by the optical module is the immune detection signal value. Qualitative detection can be performed by setting a threshold. When the immune detection signal value is lower than the threshold, the sample is judged to be negative; when it is higher than the threshold, the sample is judged to be positive. A standard curve can also be made using the test results of a series of standard substances with known concentrations to perform quantitative testing on unknown samples.

[0039] In one embodiment of the present invention, multiple electrodes in the electrode array covering the magnetic mixing zone 2 are arranged in a closed manner around the outer edge of the magnetic mixing zone 2, and the middle position of the magnetic mixing zone 2 is not covered with electrodes, that is, droplets only exist in the positions covering the electrodes in the outer circle of the magnetic mixing zone and can move under the drive of the electrodes, and there are no droplets in the positions in the middle of the magnetic mixing zone that are not covered with electrodes, so that the droplets in the magnetic mixing zone 2 can continue to move in the magnetic mixing zone 2 under the drive of multiple electrodes. Since the movement of the droplets of the present invention is driven by the electrode arrays covering each area, and the immune reaction of the magnetic beads, capture antibodies, etc. in the mixed solution also requires a certain amount of time, keeping the mixed solution entering the magnetic mixing zone in a continuously mixed state can increase the efficiency of the immune reaction, and the control unit can be used to control the electrode array to continuously drive the droplets, so that the mixed solution is in a continuously mixed state. In this embodiment, the multiple electrodes in the electrode array of the magnetic mixing zone are designed to be arranged with closed peripheral edges. On the one hand, the mixed liquid can continue to move along the multiple electrode arrangement positions in the magnetic mixing zone, ensuring that the magnetic beads and the sample to be tested are fully mixed during the immune reaction; on the other hand, the mixed liquid can be kept in a continuously mixed state without increasing the area of ​​the magnetic mixing zone, which is more conducive to the miniaturization and portability of the entire device.

[0040] In one embodiment of the present invention, multiple electrodes in the electrode array covering the magnetic mixing zone 2 are arranged in a "mouth" shape. However, the arrangement of multiple electrodes is not limited thereto, and may also be other closed shapes such as a circle or a triangle.

[0041] In one embodiment of the present invention, the microfluidic chip comprises a plurality of the injection areas, a plurality of magnetic mixing areas 2 and a plurality of magnetic separation areas 3, and the plurality of injection areas, a plurality of magnetic mixing areas 2 and a plurality of magnetic separation areas 3 are connected to the same detection area 4 and the same waste liquid area 5. For example, Figure 1 The embodiment includes 4 injection areas, 4 magnetic mixing areas and 4 magnetic separation areas, so that 4 types of samples to be tested can be immunodetected simultaneously through 4 channel experiments, further improving the efficiency of immunodetection.

[0042] In one embodiment of the present invention, the electrode array covering the magnetic separation zone 3 can drive the droplets to move bidirectionally toward the magnetic mixing zone 2 or the detection zone 4 under the control of the control unit. By driving the droplets to the magnetic mixing zone for multiple cleaning operations by the electrode array, impurities or non-reactants are washed away, which can further improve the accuracy of immunoassay. In addition, by driving the droplets to move bidirectionally toward the magnetic mixing zone or the detection zone by the electrode array, the number of electrodes arranged in the electrode array can be reduced, which reduces the manufacturing cost on the one hand, and reduces the space occupied by the electrodes on the other hand, reduces the size of the microfluidic chip, and is more conducive to the miniaturization and convenience requirements of the chip.

[0043] like Figure 3 As shown, the present invention also provides an immunoassay method based on a digital microfluidic chip, using the above-mentioned immunoassay system, the method comprises the following steps:

[0044] Step S110: injecting samples, immune capture magnetic beads and fluorescent microsphere solution into the microfluidic chip;

[0045] Step S120: driving the mixed solution to move to the magnetic mixing area to perform immune reaction operation;

[0046] Step S130: After the immune reaction is completed, the mixed solution after the reaction is driven to move to the magnetic separation area for magnetic bead enrichment operation;

[0047] Step S140: After the magnetic beads are enriched, a cleaning solution is injected into the microfluidic chip to perform a magnetic bead redissolution and cleaning operation;

[0048] Step S150: After the magnetic beads are re-dissolved and cleaned, a buffer solution is injected into the microfluidic chip to re-dissolve the magnetic beads and the magnetic bead mixture is driven to move to the detection area for fluorescent immunoassay.

[0049] In one embodiment of the present invention, step S120 includes:

[0050] The temperature of the magnetic mixing zone is adjusted to the immune response temperature;

[0051] driving the mixed solution to move to the magnetic mixing zone;

[0052] The mixed liquid is driven to continuously move in the magnetic mixing zone during the immune response time;

[0053] After the immune response time is reached, the mixed solution is driven to move to the magnetic separation area.

[0054] In one embodiment of the present invention, step S130 includes:

[0055] Loading a magnetic field in the magnetic separation area, adsorbing and positioning the magnetic beads in the mixed solution after the immune reaction in the magnetic separation area;

[0056] After driving the supernatant in the mixed solution to move to the waste liquid area, the magnetic field loaded in the magnetic separation area is removed.

[0057] In one embodiment of the present invention, step S140 includes:

[0058] After the enrichment is completed, a cleaning solution is injected into the microfluidic chip and moved to the magnetic separation area to re-dissolve the magnetic beads, and the re-dissolved magnetic bead mixture is driven to move to the magnetic mixing area to mix the magnetic beads;

[0059] After mixing the magnetic beads, the magnetic bead supernatant mixture is driven to move to the magnetic separation area for magnetic bead enrichment;

[0060] After repeating the above cleaning operation 2-3 times, proceed to step S150.

[0061] All droplet operation actions (driving, temperature control, magnetic separation, magnetic mixing, and fluorescence signal detection) in the present invention can be written into a fixed process by software. The droplet operation software process is called according to the above steps and started with one button to realize the automation of the entire immunoassay process.

[0062] In order to enable those skilled in the art to more clearly understand the scheme of the present invention, two immunoassay examples are listed for illustration.

[0063] Implementation Case 1: Immunoassay for Novel Coronavirus Nucleocapsid Protein (N Protein)

[0064] The digital microfluidic chip immunoassay system is connected to an external power supply for power supply, the host computer software is opened, 8 μL of the sample to be tested is injected into each of the four injection holes, and then 1 μL of N protein immune capture magnetic beads and detection fluorescent microspheres are injected in sequence, and the droplets are driven to the temperature control area;

[0065] The temperature control was turned on at 37°C, and a 10 μL droplet of the total reaction system continued to move along the "return" electrode structure in the temperature control area for 20 minutes.

[0066] Loading magnetic field, driving droplets to magnetic separation area, completing magnetic enrichment, driving supernatant to waste liquid area, discharging through liquid outlet, and evacuating magnetic field;

[0067] Inject 10 μL of washing solution through the injection hole, drive to the magnetic separation area, re-dissolve the magnetic beads, drive the magnetic bead solution to the magnetic mixing area, move along the "return" electrode structure, mix the magnetic beads, drive to the magnetic separation area, complete magnetic enrichment, drive the supernatant to the waste liquid area, discharge through the outlet hole, and evacuate the magnetic field;

[0068] Repeat the above steps to drive the supernatant to the waste liquid area for discharge;

[0069] Inject 10 μL of PBS buffer, drive to the magnetic separation area, re-dissolve the magnetic beads, drive the magnetic bead solution to the magnetic mixing area, move along the "return" electrode structure, mix the magnetic beads, drive to the signal detection area, detect the fluorescent signal, and complete the detection;

[0070] By comparing the detected fluorescence signal value with the threshold, qualitative detection of the new coronavirus can be achieved.

[0071] Implementation Case 2: Immunoassay for C-reactive Protein (CRP), an Inflammatory Indicator

[0072] The digital microfluidic chip immunoassay system is connected to an external power supply for power supply, the host computer software is opened, 8 μL of the sample to be tested is injected into each of the four injection holes, and then 1 μL of CRP immune capture magnetic beads and detection antibodies are injected in sequence, and the droplets are driven to the temperature control area;

[0073] The temperature control was turned on at 37°C, and a 10 μL droplet of the total reaction system continued to move along the "return" electrode structure in the temperature control area for 10 minutes.

[0074] Loading magnetic field, driving droplets to magnetic separation area, completing magnetic enrichment, driving supernatant to waste liquid area, discharging through liquid outlet, and evacuating magnetic field;

[0075] Inject 10 μL of washing solution through the injection hole, drive to the magnetic separation area, re-dissolve the magnetic beads, drive the magnetic bead solution to the magnetic mixing area, move along the "return" electrode structure, mix the magnetic beads, drive to the magnetic separation area, complete magnetic enrichment, drive the supernatant to the waste liquid area, discharge through the outlet hole, and evacuate the magnetic field;

[0076] Inject fluorescent microspheres labeled with secondary antibodies through the injection holes, drive to the magnetic separation area, re-dissolve the magnetic beads, drive the magnetic bead solution to the magnetic mixing area, turn on the 37°C temperature control, and drive the droplets to move continuously along the "return" electrode structure for 10 minutes;

[0077] Loading magnetic field, driving droplets to magnetic separation area, completing magnetic enrichment, driving supernatant to waste liquid area, discharging through liquid outlet, and evacuating magnetic field;

[0078] Inject 10 μL of washing solution through the injection hole, drive to the magnetic separation area, re-dissolve the magnetic beads, drive the magnetic bead solution to the magnetic mixing area, move along the "return" electrode structure, mix the magnetic beads, drive to the magnetic separation area, complete magnetic enrichment, drive the supernatant to the waste liquid area, discharge through the outlet hole, and evacuate the magnetic field;

[0079] Repeat the above steps to drive the supernatant to the waste liquid area for discharge;

[0080] Inject 10 μL of PBS buffer, drive to the magnetic separation area, re-dissolve the magnetic beads, drive the magnetic bead solution to the magnetic mixing area, move along the "return" electrode structure, mix the magnetic beads, drive to the signal detection area, detect the fluorescent signal, and complete the detection;

[0081] By substituting the fluorescence signal detection value into the standard curve, quantitative detection of CRP can be achieved.

[0082] In summary, the present invention can realize rapid automated immune detection. On the one hand, it does not rely on any professional detection personnel, precision detection instruments and professional laboratories, and has flexible usage scenarios, and can achieve on-site detection and instant testing, while reducing the cost of detection and improving the repeatability and stability of detection; on the other hand, the fully enclosed chip and equipment system can well protect the safety of operators and the environment when detecting contagious pathogenic microorganisms, avoiding pollution and potential risks of disease transmission; and because the system and method are based on a small system reaction on the chip, the reaction efficiency is improved by continuous driving of droplets during the immune reaction process, and highly sensitive qualitative and quantitative detection can be completed within half an hour, and the detection speed is fast.

[0083] In addition, in an exemplary embodiment of the present disclosure, an electronic device capable of implementing the above method is also provided, including a processor; and a memory, wherein computer-readable instructions are stored in the memory, and the computer-readable instructions implement the above method when executed by the processor.

[0084] It will be appreciated by those skilled in the art that various aspects of the present invention may be implemented as systems, methods or program products. Therefore, various aspects of the present invention may be specifically implemented in the following forms, namely: complete hardware embodiments, complete software embodiments (including firmware, microcode, etc.), or embodiments combining hardware and software aspects, which may be collectively referred to herein as "circuits", "modules" or "systems".

[0085] The electronic device is presented in the form of a general-purpose computing device. The components of the electronic device may include, but are not limited to: at least one processing unit, at least one storage unit, a bus connecting different system components (including the storage unit and the processing unit), and a display unit.

[0086] The storage unit stores program codes, which can be executed by the processing unit, so that the processing unit performs the steps according to various exemplary embodiments of the present invention described in the above “Exemplary Method” section of this specification. For example, the processing unit can perform the following steps: Figure 3 Steps S110 to S150 shown in FIG.

[0087] The storage unit may include a readable medium in the form of a volatile memory unit, such as a random access memory unit (RAM) and / or a cache memory unit, and may further include a read-only memory unit (ROM).

[0088] The storage unit may also include a program / utility having a set (at least one) of program modules, such program modules including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0089] The bus may represent one or more of several types of bus structures, including a memory unit bus or memory unit controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

[0090] The electronic device can also communicate with one or more external devices (such as keyboards, pointing devices, Bluetooth devices, etc.), and can also communicate with one or more devices that enable users to interact with the electronic device, and / or communicate with any device (such as routers, modems, etc.) that enables the electronic device to communicate with one or more other computing devices. This communication can be carried out through an input / output (I / O) interface. In addition, the electronic device can also communicate with one or more networks (such as local area networks (LANs), wide area networks (WANs) and / or public networks, such as the Internet) through a network adapter. As shown in the figure, the network adapter communicates with other modules of the electronic device through a bus. It should be understood that, although not shown in the figure, other hardware and / or software modules can be used in conjunction with the electronic device, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems, etc.

[0091] Through the description of the above embodiments, it is easy for those skilled in the art to understand that the example embodiments described here can be implemented by software, or by software combined with necessary hardware. Therefore, the technical solution according to the embodiment of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, and includes several instructions to enable a computing device (which can be a personal computer, a server, a terminal device, or a network device, etc.) to execute the method according to the embodiment of the present disclosure.

[0092] In an exemplary embodiment of the present disclosure, a computer-readable storage medium is also provided, on which a program product capable of implementing the above method of the present specification is stored. In some possible embodiments, various aspects of the present invention can also be implemented in the form of a program product, which includes a program code, and when the program product is run on a terminal device, the program code is used to enable the terminal device to perform the steps according to various exemplary embodiments of the present invention described in the above "Exemplary Method" section of the present specification.

[0093] The program product for implementing the above method according to an embodiment of the present invention may adopt a portable compact disk read-only memory (CD-ROM) and include program code, and may be run on a terminal device, such as a personal computer. However, the program product of the present invention is not limited thereto, and in this document, a readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, apparatus, or device.

[0094] The program product may use any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0095] Computer readable signal media may include data signals propagated in baseband or as part of a carrier wave, in which readable program code is carried. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Readable signal media may also be any readable medium other than a readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0096] The program code embodied on the readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination of the foregoing.

[0097] Program code for performing the operations of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., through the Internet using an Internet service provider).

[0098] In addition, the above-mentioned figures are only schematic illustrations of the processes included in the method according to an exemplary embodiment of the present invention, and are not intended to be limiting. It is easy to understand that the processes shown in the above-mentioned figures do not indicate or limit the time sequence of these processes. In addition, it is also easy to understand that these processes can be performed synchronously or asynchronously, for example, in multiple modules.

[0099] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and examples are to be considered as exemplary only, and the true scope and spirit of the present disclosure are indicated by the claims.

[0100] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. An immunoassay system based on a digital microfluidic chip, characterized in that: The invention comprises a microfluidic chip, a heating unit, a magnetic field loading unit, a fluorescence detection unit and a control unit, wherein the microfluidic chip comprises a liquid injection area, a magnetic mixing area, a magnetic separation area, a detection area, a waste liquid area and an electrode array; the heating unit is arranged in the magnetic mixing area, the magnetic field loading unit is arranged in the magnetic separation area, and the fluorescence detection unit is arranged in the detection area; the electrode array covers each area and drives the movement of droplets in the area; the control unit is used for controlling the movement sequence and position of the droplets driven by the electrode array in each area according to the immunoassay process; wherein the heating unit is used for regulating the immune reaction temperature of the droplets in the magnetic mixing area, and driving the droplets to continuously move in the magnetic mixing area through the electrode array covered by the magnetic mixing area, so that the samples, magnetic beads and fluorescent microspheres in the droplets are fully mixed and reacted.

2. The immunoassay system according to claim 1, characterized in that: A plurality of electrodes in the electrode array covering the magnetic mixing zone are arranged in a closed manner around the outer peripheral edge of the magnetic mixing zone, so that the droplets in the magnetic mixing zone can continue to move in the magnetic mixing zone under the drive of the plurality of electrodes.

3. The immunoassay system according to claim 2, characterized in that: Multiple electrodes in the electrode array covering the magnetic mixing zone are arranged in a "mouth" shape.

4. The immunoassay system according to claim 1, characterized in that: The microfluidic chip comprises a plurality of liquid injection areas, a plurality of magnetic mixing areas and a plurality of magnetic separation areas, and the plurality of liquid injection areas, a plurality of magnetic mixing areas and a plurality of magnetic separation areas are connected to the same detection area and the same waste liquid area.

5. The immunoassay system according to claim 1, characterized in that: The electrode array covering the magnetic separation zone can drive the droplets to move bidirectionally toward the magnetic mixing zone or the detection zone under the control of the control unit.

6. An immunoassay method based on a digital microfluidic chip, characterized in that: Utilizing the immunoassay system according to any one of claims 1 to 7, the method comprises the following steps: 1) Injecting samples, immune capture magnetic beads and fluorescent microsphere solution into the microfluidic chip; 2) driving the mixed solution to move to the magnetic mixing area for immune response operation; 3) After the immune reaction is completed, the reaction mixture is driven to move to the magnetic separation area for magnetic bead enrichment operation; 4) After the magnetic beads are enriched, a cleaning solution is injected into the microfluidic chip to perform a magnetic bead re-dissolution and cleaning operation; 5) After the magnetic beads are re-dissolved and cleaned, a buffer solution is injected into the microfluidic chip to re-dissolve the magnetic beads and the magnetic bead mixture is driven to move to the detection area for fluorescent immunoassay.

7. The immunoassay method according to claim 6, characterized in that: Step 2) includes: The temperature of the magnetic mixing zone is adjusted to the immune response temperature; driving the mixed solution to move to the magnetic mixing zone; The mixed liquid is driven to continuously move in the magnetic mixing zone during the immune response time; After the immune response time is reached, the mixed solution is driven to move to the magnetic separation area.

8. The immunoassay method according to claim 6, characterized in that: Step 3) includes: Loading a magnetic field in the magnetic separation area to adsorb and position the magnetic beads in the mixed solution after the immune reaction in the magnetic separation area; After driving the supernatant in the mixed solution to move to the waste liquid area, the magnetic field loaded in the magnetic separation area is removed.

9. The immunoassay method according to claim 6, characterized in that: Step 4) includes: After the enrichment is completed, a cleaning solution is injected into the microfluidic chip and moved to the magnetic separation area to re-dissolve the magnetic beads, and the re-dissolved magnetic bead mixture is driven to move to the magnetic mixing area to mix the magnetic beads; After mixing the magnetic beads, the magnetic bead supernatant mixture is driven to move to the magnetic separation area for magnetic bead enrichment; Repeat the above cleaning operation 2-3 times and then proceed to step 5).

10. An electronic device, characterized in that: include: processor; as well as A memory having computer-readable instructions stored thereon, wherein the computer-readable instructions, when executed by the processor, implement the method according to any one of claims 6 to 9.

11. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed by a processor, the method according to any one of claims 6 to 9 is implemented.

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