CN210752734U

CN210752734U - Micro-fluidic chip

Info

Publication number: CN210752734U
Application number: CN201920826633.6U
Authority: CN
Inventors: 张歆; 王毅; 张莉
Original assignee: Leadway HK Ltd
Current assignee: Leadway HK Ltd
Priority date: 2019-06-03
Filing date: 2019-06-03
Publication date: 2020-06-16
Anticipated expiration: 2029-06-03

Abstract

The utility model relates to a micro-fluidic chip, include the base plate and be located the detection zone on the base plate, be equipped with first reservoir and second reservoir on the base plate, first reservoir, second reservoir respectively with detection zone liquid intercommunication, first reservoir and second reservoir are equipped with first opening and the second opening that supplies the liquid to flow out respectively, make first opening flow out liquid under the action of gravity earlier than the second opening through rotating micro-fluidic integrated chip to, the liquid rear end of first reservoir reachs the detection zone earlier than the liquid front end of second reservoir. Utilize the utility model discloses a micro-fluidic detection integrated chip can realize need not plus power equipment in the aspect of fluid drive, can simplify detecting instrument's structure, the energy saving. The generation of air bubbles in the fluid due to the use of an external power source is avoided.

Description

Micro-fluidic chip

Technical Field

The utility model belongs to the technical field of medical diagnosis class article, a micro-fluidic chip with stock solution function is related to.

Background

The development of the portable-of-care (point-of-care) industry has been driven by the advent of microfluidic technology in the fields of biomedical analysis, disease diagnosis. Compared with the traditional quick diagnosis technology, the microfluidic chip has the following advantages that for example, in the conventional POCT detection equipment, liquid such as calibration liquid, detection reagent and the like are externally arranged in the equipment, so that the detection equipment has the problems of large volume, complex pipeline, difficult maintenance, easy pollution and the like, and in addition, due to the detection principle characteristics of the conventional POCT product, the simultaneous detection of multiple indexes is difficult to realize in the process of quick and accurate quantitative analysis, so that the consumption and human errors of a sample to be detected are increased. On the contrary, the microfluidic detection technology has the greatest advantage that the full-automatic rapid detection of multiple indexes can be simultaneously carried out under the condition of microliter-level blood sample consumption, and accurate results can be obtained. Meanwhile, the microfluidic chip with the size of square centimeter can contain all functional units of conventional laboratories such as quantitative sample introduction, mixing, reaction, calibration, reagent storage, detection, waste liquid collection and the like, and the characteristics of full-automatic operation and the like realize the new generation of POCT products with high integration, energy conservation, convenience and small error.

Fluid control is the core of microfluidic chip design, and all functions of the microfluidic chip are realized by means of the unique design of the microchannel network. Taking the microfluidic products of several foreign trade-leading enterprises as examples, the microfluidic chip power is divided from fluid power, and can be air pump (US8986527B2), injector (US7842234B), external force extrusion (US5821399A) and centrifugal force (US20110124128A 1).

The chip using the air pump as power has the following characteristics: firstly, for more than two fluid control, the air pump requires a more complex chip micro-channel network design, and realizes sequential flow control of the fluid by relatively more valve designs. The complicated structure leads to the characteristics that the volume of the instrument is often larger, and the chip processing requirement is high in cost. Moreover, the air pump as power can increase the probability of generating air bubbles in the fluid, and the generated air bubbles can prevent the sensor from working normally.

The chip taking the injector as power firstly requires the injector to be in sealed butt joint with the sample adding port of the chip in operation, so that the operation is difficult and human errors are easily introduced; and secondly, the risk of contamination of the sample or instrument due to operational errors.

In the fluid pushing mode of external force extrusion, the force generated by extrusion deformation is small, so that the size of a chip is required to be small, and the difficulty in processing and assembling the chip can be directly caused by the change of micro-size, so that economic loss is caused.

The chip products driven by the centrifugal force are fewer, the centrifugal force driving chip can realize high-integration detection to the greatest extent in principle, the purification of samples in the chip is realized, and the advantages of equal sample division are realized.

With the rapid market demand for in vitro diagnosis, the advantages of microfluidic technology in vitro diagnostic applications are gradually highlighted, and the microfluidic technology is receiving more and more attention from the industry. In the application of the microfluidic chip, the sequential flow of various fluids and the preservation and flow control of the liquid in the test strip are the common technical difficulties at present.

SUMMERY OF THE UTILITY MODEL

The utility model provides a steerable micro-fluidic chip that flows under the action of gravity. The micro-fluidic chip can complete the automatic transmission and detection of a plurality of fluids without additional power equipment such as a micro pump, an injection pump, an extrusion device, a centrifugal force device and the like.

Particularly, the utility model provides a pair of micro-fluidic detection chip, include the base plate and be located the detection zone on the base plate, be equipped with first reservoir and second reservoir on the base plate, first reservoir, second reservoir respectively with detection zone liquid intercommunication, first reservoir and second reservoir are equipped with the first opening and the second opening that supply the liquid to flow out respectively, through rotating micro-fluidic chip makes first opening flow out liquid under the action of gravity earlier than the second opening to, the liquid rear end of first reservoir reachs the detection zone earlier in the liquid front end of second reservoir.

Specifically, the first opening reaches the downward position before the second opening by rotating the microfluidic chip, so that the liquid in the first liquid storage tank flows out from the first opening before the liquid in the second liquid storage tank flows out from the second opening under the action of self gravity; and the liquid back end of the first reservoir reaches the detection zone earlier than the liquid front end of the second reservoir.

More specifically, the microfluidic chip is rotated to enable the first opening to reach the downward position, the liquid in the first liquid storage tank flows out from the first opening under the action of gravity and reaches the detection area, then the microfluidic chip is rotated to enable the second opening to reach the downward position, and the liquid in the second liquid storage tank flows out from the second opening under the action of gravity and reaches the detection area; and the liquid front end of the second liquid storage tank does not touch the liquid rear end of the first liquid storage tank before leaving the detection area.

In some preferred embodiments, the microfluidic detection chip further comprises a waste liquid tank on the substrate, the waste liquid tank being in communication with the detection zone. When the liquid in the second liquid storage tank flows out from the second opening under the action of gravity and reaches the detection area, the liquid in the first liquid storage tank positioned in the detection area flows to the waste liquid tank under the action of gravity.

In some preferred embodiments, when the first opening discharges liquid, the first opening is higher than the detection area; when the second opening flows out of the liquid, the position of the second opening is higher than that of the detection area.

When the micro-fluidic chip is used for detection, the micro-fluidic chip is vertically placed or placed in an instrument vertically, the micro-fluidic chip is rotated to enable the first opening to gradually reach a downward position in the rotating process, the second opening cannot face downward in the rotating process, and liquid flows out of the first opening under the action of self gravity and flows to the detection area. Then the micro-fluidic chip is rotated to enable the second opening to gradually reach a downward position in the rotating process, and liquid flows out of the second opening under the action of self gravity and flows to the detection area; and the first liquid storage tank liquid in the detection area flows to the waste liquid tank under the action of self gravity. In the two rotation processes, the tail end of the liquid flowing out of the first opening reaches the detection area before the front end of the liquid flowing out of the second opening.

In some preferred embodiments, the first reservoir and the second reservoir and the waste liquid tank may or may not extend through the substrate. When the first liquid storage tank, the second liquid storage tank and the waste liquid tank do not penetrate through the substrate, the first liquid storage tank, the second liquid storage tank and the waste liquid tank are located on the same surface of the substrate or located on two surfaces of the substrate respectively.

In some preferred embodiments, the kit further comprises a first flow channel connected with the first opening, a second flow channel connected with the second opening, a third flow channel connected with the front end of the detection area, a fourth flow channel connected with the rear end of the detection area and a fifth flow channel connected with the waste liquid tank, wherein the first flow channel, the second flow channel, the third flow channel, the fourth flow channel and the fifth flow channel are arranged on the substrate; the first flow channel and the second flow channel are connected with the third flow channel; the fourth flow passage is connected with the fifth flow passage.

In some preferred embodiments, the detection area is provided with a detection flow channel and a signal acquisition channel, and the detection area comprises an electrode sensor.

In some preferred embodiments, the two ends of the detection flow channel are respectively connected with the third flow channel and the fourth flow channel.

In some preferred embodiments, the microfluidic chip comprises a cover plate for covering the substrate, the cover plate enclosing the first and second reservoirs and the waste reservoir, and the first, second, third, fourth, and fifth flow paths on the substrate.

In some preferred embodiments, in the initial state, the first reservoir, the second reservoir and the waste reservoir are sealed.

In some preferred embodiments, the cover plate corresponding to the first reservoir, the second reservoir and the waste liquid tank is provided with a first vent hole, a second vent hole and a third vent hole respectively.

In some preferred embodiments, the first, second and third venting holes are all sealed or can be opened.

In some preferred embodiments, the first, second and third vents are provided with seals.

In an initial state, the first liquid storage tank, the second liquid storage tank and the waste liquid tank are sealed; the liquid flow of the first reservoir and the second reservoir is controlled by the second and third vent holes being sealed or opened.

The utility model discloses in, still provide a micro-fluidic detection chip, the hydrophilic and hydrophobic nature difference through the runner comes the flow velocity of control liquid and makes the detection more accurate. The flow velocity and diffusion conditions of liquids such as blood and the like in different areas are controlled through the difference of hydrophilicity and hydrophobicity of the surfaces of the different areas, so that the liquids can sequentially flow into the detection areas to realize detection under the self-gravity condition. That is, when liquid is in the flowing channel, the flow velocity of the liquid is slowed down by using the hydrophobic channel, the generation of bubbles due to too fast flow velocity is avoided, and when the liquid is in the detecting channel, the liquid is diffused to the whole surface of the channel by using the hydrophilic channel, so that the full contact with a detecting instrument is ensured.

The utility model provides a micro-fluidic detection chip, includes the base plate and is located the detection zone on the base plate, is equipped with first reservoir, second reservoir and waste liquid groove on the base plate, still is equipped with the runner of connecting first reservoir and detection zone, second reservoir and detection zone on the base plate to and detection zone and waste liquid groove, the hydrophilic and hydrophobic nature on the different regional surface of runner has the difference.

In some preferred embodiments, the flow channel comprises a first flow channel connected to the first reservoir, a second flow channel connected to the second reservoir, a third flow channel connected to the front end of the detection region, a fourth flow channel connected to the rear end of the detection region, and a fifth flow channel connected to the waste liquid tank; the first flow channel and the second flow channel are connected with the third flow channel; the fourth flow passage is connected with the fifth flow passage.

In some preferred embodiments, the detection zone is provided with a detection flow channel; and two ends of the detection flow channel are respectively connected with the third flow channel and the fourth flow channel.

In some preferred embodiments, the first flow channel, the second flow channel, and the fifth flow channel are hydrophobic flow channels; the third flow channel, the fourth flow channel and the detection flow channel are hydrophilic flow channels.

In some preferred embodiments, two cover sheets are included that cover both sides of the base sheet.

In some preferred embodiments, the substrate is made of hydrophobic material or treated to be hydrophobic, one cover is made of hydrophobic material or treated to be hydrophobic, and one cover is made of hydrophilic material or treated to be hydrophilic.

In some preferred embodiments, the first, second and fifth flow channels are on one side of the substrate, and the third, fourth and detection flow channels are on the other side of the substrate.

In some preferred embodiments, the surface of the substrate provided with the first flow channel, the second flow channel and the fifth flow channel is covered with a hydrophobic cover sheet; the surface of the substrate provided with the third flow channel, the fourth flow channel and the detection flow channel is covered with a hydrophilic cover sheet.

The utility model discloses in, set up the runner respectively at the positive and negative of base plate to utilize the upper and lower cover plate water proofness of different hydrophilicity and hydrophobicity to paste the back on the positive and negative of base plate, the hydrophilicity and hydrophobicity of base plate runner will be because of the corresponding change of the hydrophilicity and hydrophobicity of cover plate. In this way, it is easy to manufacture a detection chip having different affinities and affinities in different regions.

The utility model discloses in, provide a micro-fluidic detection chip, still through the perforation connection runner that link up the base plate, can prevent the liquid backward flow through the perforation connection between the runner to guarantee liquid towards a direction unidirectional flow. In some preferred embodiments, the first flow channel and the second flow channel are connected to the third flow channel by a perforation, and the fourth flow channel and the fifth flow channel are also connected by a perforation.

In some preferred embodiments, the first flow channel and the second flow channel are connected to the third flow channel by two different perforations.

The utility model discloses in provide a micro-fluidic detection chip, the different runners in upper reaches are connected to the same runner in low reaches through solitary perforation respectively on, and the failure probability when the liquid that can avoid follow-up entering passes through detection runner (same passageway) has strengthened fluid control nature, for example the production of reducible bubble etc. this kind of design of a plurality of perforation connection.

In some preferred embodiments, the first perforation connects the first flow channel and the third flow channel, and the second perforation connects the second flow channel and the third flow channel.

In some preferred embodiments, the first and second perforations are at a distance.

In some preferred embodiments, the distance between the first and second perforations is greater than 2 mm.

In some preferred embodiments, the first perforations are located downstream of the second perforations in the direction of liquid flow, and the first perforations located downstream have a smaller pore size than the second perforations located upstream thereof.

In some preferred embodiments, an electrode sensor is included within the detection zone.

In some preferred embodiments, the second flow passage is provided with a segment of an elbow structure.

In some preferred embodiments, the liquid in the first reservoir is a reagent and the liquid in the second reservoir is a sample.

On the other hand, the utility model also provides a method for making the micro-fluidic detection chip for detection, specifically includes following steps:

step 1, selecting a hydrophobic material as a substrate, and forming a flow channel, a first liquid storage tank, a second liquid storage tank, a detection flow channel, a signal acquisition channel, a waste liquid tank, a perforation and other structures on the substrate through chemical etching, physical engraving, hot pressing or injection molding;

specifically, a first liquid storage tank, a second liquid storage tank, a detection flow channel, and a first through hole, a second through hole, and a third through hole are formed on a substrate; forming a third flow channel connected to the front end of the detection flow channel and a fourth flow channel connected to the rear end of the detection flow channel on one surface of the substrate; forming a first flow channel, a second flow channel, a fifth flow channel and a waste liquid tank on the other surface of the substrate, wherein the first flow channel is connected with a first liquid storage tank and a first perforation, the first perforation is connected with the first flow channel and a third flow channel, the second flow channel is connected with the second liquid storage tank and a second perforation, the second perforation is simultaneously connected with a third flow channel, the fourth flow channel is connected with the fifth flow channel through a third perforation, and the tail end of the fifth flow channel is connected with the waste liquid tank;

and 2, obtaining an electrode sensor, adhering the electrode sensor to the detection flow channel, enabling the electrode of the sensor to be positioned in the detection flow channel, and sealing the surface of the detection flow channel in a water-tight manner. Meanwhile, the electrode pin of the sensor is positioned in the signal acquisition channel of the detection area;

step 3, obtaining a cover plate made of hydrophobic materials; or treating the surface of the cover plate contacting with the substrate with hydrophobic material, i.e. providing hydrophobic coating to make the contact surface of the cover plate hydrophobic; adhering the hydrophobic surface of the cover sheet to the surface of the base plate provided with the first, second and fifth flow channels in a watertight manner;

step 4, injecting a calibration solution serving as a detection reagent into the first liquid storage tank;

step 5, obtaining a cover plate made of hydrophilic materials; or treating the surface of the cover plate contacting with the substrate with hydrophilic material to make the contact surface of the cover plate hydrophilic; attaching the hydrophilic surface of the cover sheet to the surface of the base plate provided with the third and fourth flow channels in a watertight manner;

step 6, arranging a first vent hole, a second vent hole and a third vent hole at the positions of the first liquid storage tank, the second liquid storage tank and the waste liquid tank on the cover plate;

and 7, if the step 4 is not performed, injecting the detection reagent into the first liquid storage tank through the first vent hole of the upper cover plate, and then sealing the small hole by using a sealing piece.

Finally obtaining the microfluidic detection chip for detection by the method of the steps 1-7.

The utility model also provides a method for detecting the sample by the microfluidic detection chip, which comprises a microfluidic detection chip for detection, wherein the microfluidic detection chip comprises a substrate, a cover plate, a detection area, a first liquid storage tank, a second liquid storage tank and a waste liquid tank, the detection area, the first liquid storage tank and the second liquid storage tank are respectively communicated with the detection area, and the detection area is communicated with the waste liquid tank; the first liquid storage tank and the second liquid storage tank are respectively provided with a first opening and a second opening for liquid to flow out; the first liquid storage tank comprises a detection reagent; the method comprises the following specific steps:

1. injecting the sample into a second reservoir;

2. vertically placing the microfluid detection chip or vertically placing the microfluid detection chip in an instrument;

3. communicating the first reservoir and the waste liquid tank with the atmosphere;

4. rotating the microfluid detection chip until the first opening faces downwards, so that the detection reagent in the first liquid storage tank flows out of the first opening and flows into the detection area under the action of self gravity;

5. carrying out reagent detection;

6. rotating the microfluid detection chip until the second opening faces downwards, so that the sample in the second liquid storage tank flows out of the second opening and flows into the detection area under the action of self gravity; meanwhile, the detection reagent positioned in the detection area flows into the waste liquid groove under the action of self gravity;

7. and (6) carrying out sample detection to obtain a detection result.

In a more specific embodiment, the microfluidic detection chip further comprises an electrode sensor, the detection area is provided with a detection flow channel and a signal acquisition channel, and the electrode sensor is arranged in the detection flow channel and the signal acquisition channel; the cover plate is provided with a first vent hole at the position of the first liquid storage tank, a second vent hole at the position of the second liquid storage tank and a third vent hole at the position of the waste liquid tank; the method comprises the following specific steps:

in the step 1, injecting a sample to be detected into a second liquid storage tank through a second vent hole positioned on the second liquid storage tank;

in step 2, vertically fixing the microfluid detection chip in an instrument and controlling the flow direction of fluid by driving the chip to rotate by means of components in the instrument;

in the step 3, opening the first vent hole and simultaneously opening the third vent hole;

in the step 5 and the step 7, the detection reagent and the sample staying in the detection flow channel react with the sensor, and the probe of the instrument is connected with the sensor in the signal acquisition channel and acquires a reaction signal.

In some preferred embodiments, the kit further comprises a first flow channel connected with the first opening, a second flow channel connected with the second opening, a third flow channel connected with the front end of the detection area, a fourth flow channel connected with the rear end of the detection area, and a fifth flow channel connected with the waste liquid tank; the first flow channel and the second flow channel are connected with the third flow channel; the fourth flow passage is connected with the fifth flow passage.

In step 4, the detection reagent in the first reservoir flows out from the first opening, flows to the third channel through the first channel, and reaches the detection channel.

In step 6, the sample in the second reservoir flows out from the second opening, flows to the third channel through the second channel, and reaches the detection channel.

In step 6, the detection reagent after detection reaches the waste liquid tank from the detection flow channel through the fourth flow channel and the fifth flow channel.

In some preferred embodiments, the first flow channel, the second flow channel and the fifth flow channel are located on one side of the substrate, and the third flow channel, the fourth flow channel and the detection flow channel are located on the other side of the substrate; the first flow channel is connected with the third flow channel through the first through hole, the second flow channel is connected with the third flow channel through the second through hole, and the fourth flow channel is connected with the fifth flow channel through the third through hole.

In step 4, the detection reagent in the first reservoir flows out from the first opening, flows to the third channel on the other side of the substrate through the first through hole via the first channel, and reaches the detection channel.

In step 6, the sample in the second reservoir flows out of the second opening, passes through the second through hole via the second flow channel, flows to the third flow channel on the other side of the substrate, and reaches the detection flow channel.

In step 6, the detection reagent after detection flows from the detection flow channel to the fifth flow channel on the other side of the substrate through the third through hole via the fourth flow channel and reaches the waste liquid tank.

Advantageous effects

(1) Utilize micro-fluidic detection chip can realize need not to add power equipment in the aspect of fluid drive like micropump, the syringe pump, the extrusion device, centrifugal force device etc. accomplishes a plurality of fluidic automatic conveyances. The structure of the detection instrument can be simplified, and energy is saved. The generation of air bubbles in the fluid due to the use of an external power source is avoided.

(2) The flow speed and diffusion condition of liquid such as blood in different areas can be controlled by the difference of the hydrophilicity and hydrophobicity of the surfaces of the different areas. For example, when the flow rate of the blood sample flowing out of the second reservoir in the hydrophobic second flow channel is slower than that of the blood sample in the hydrophilic detection flow channel, and the hydrophilic treatment of the detection flow channel can assist the diffusion of the fluid at the plurality of detection sites, thereby avoiding the generation of air bubbles.

(3) The flow channels are respectively arranged on the front and back surfaces of the base plate, and after the upper and lower cover plates with different hydrophilicity and hydrophobicity are pasted on the front and back surfaces of the base plate in a watertight manner, the hydrophilicity and hydrophobicity of the flow channels of the base plate can be changed correspondingly due to the hydrophilicity and hydrophobicity of the cover plates. In this way, it is easy to manufacture a detection chip having different affinities and affinities in different regions.

(4) The design of the plurality of through holes in the same channel can avoid the failure probability of the subsequently entering liquid passing through the detection flow channel (the same channel), enhance the fluid controllability, for example, reduce the generation of bubbles and the like.

Drawings

FIG. 1 is a perspective view of a first microfluidic test chip.

Fig. 2 is a front view of fig. 1, with solid lines indicating the structures on the front side of the substrate and dashed lines indicating the structures on the back side of the substrate.

Fig. 2-1 is another angular schematic view of fig. 2 after rotation.

Fig. 3 is an exploded view of fig. 1, showing the front side of the substrate.

Fig. 4 is an exploded view of fig. 1, showing the opposite side of the substrate.

Fig. 5 is a schematic view of the front side of the substrate of fig. 1.

Fig. 6 is a schematic view of the reverse side of the substrate of fig. 1.

Fig. 7-1 to 7-4 are schematic views illustrating the process of fluid flow in the microfluidic detection chip.

FIGS. 8-1 to 8-6 are schematic views illustrating the flow of fluids in another microfluidic chip.

FIG. 9 is a schematic of a microfluidic detection chip with four reservoirs.

Fig. 10 is a schematic view of a base plate provided with two fluid control systems.

FIG. 11-A is a schematic view of the first flow channel and the second flow channel being in the same plane as the third flow channel and the liquid in the first flow channel being gradually flowing into the third flow channel.

Fig. 11-B is a schematic view of the liquid in the first flow channel flowing into the third flow channel.

Fig. 11-C is a schematic view of the liquid in the second flow channel flowing.

Detailed Description

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. We do not exclude that the invention can also be implemented with other embodiments and that the structure of the invention can be changed without violating the scope of the invention.

The microfluidic detection chip 1000 shown in fig. 1 to 6 includes a substrate 100, an upper cover sheet 200, a lower cover sheet 300, and an electrode sensor 400. The substrate 100 is provided with a first reservoir 11, a second reservoir 12, a detection area 2 and a waste liquid tank 3, and the electrode sensor 400 is arranged in the detection area 2. In some embodiments, the microfluidic detection chip is made of a transparent material, and specifically, only the upper cover plate and the lower cover plate may be made of a transparent material.

The liquid storage tank, the detection zone and the waste liquid tank are communicated through a flow channel, so that a complete flow path is formed, wherein the reagent and the sample to be detected sequentially flow out of the liquid storage tank, flow through the detection zone and are stored in the waste liquid tank. The upper and

lower sheets

200 and 300 are adhered to the front and rear surfaces of the substrate in a watertight manner, respectively, so that the liquid storage tank, the waste liquid tank, and the flow path are sealed in the substrate.

The utility model discloses in, the opening that the liquid through first reservoir 11 and second reservoir 12 flows out is the difference of position and direction on the chip and flow under through liquid self gravity, and the liquid that realizes first reservoir 11 and second reservoir 12 is successively and flow in proper order and detect the detection function that realizes this chip to detection zone 2. Specifically, the opening direction of the first reservoir is made to face downwards, so that the liquid in the first reservoir flows out of the first reservoir under the self gravity and continuously flows to the detection area under the action of the gravity. And then the opening direction of the second liquid storage tank faces downwards, so that the liquid in the second liquid storage tank flows out of the second liquid storage tank under the self gravity and continuously flows to the detection area under the action of the gravity.

In some embodiments, the opening direction of the first opening 51 of the first reservoir 11 connected with the first flow channel 41 and the opening direction of the second opening 52 of the second reservoir 12 connected with the second flow channel 42 are opposite, and the first reservoir and the second reservoir are in a generally parallel position; for example, the opening direction of the first opening is leftward, and the opening direction of the second opening is rightward. As shown in FIG. 2, when the chip is in the upright position, the first opening 51 is open downward, the liquid in the first reservoir 11 can flow out through the first opening, the second opening 52 is open upward, and the liquid in the second reservoir 12 cannot flow out through the second opening. When the chip is rotated to the position shown in fig. 2-1, the opening of the second opening 52 is facing downward and the liquid in the second reservoir 12 flows out of the second opening. The liquid stored in the first liquid storage tank and the second liquid storage tank of the chip sequentially flows out along with the rotation of the chip, sequentially enters the detection flow channel through the flow channel to be contacted with the electrode sensor, and an analysis signal is obtained by using the electrode sensor.

As shown in fig. 1 to 6, the substrate 100 is made of a hydrophobic material, or the surface of the substrate is subjected to hydrophobic treatment, or the surface of the substrate in contact with a liquid is subjected to hydrophobic treatment. The surface of the upper cover sheet 200 contacting the substrate 100 is a hydrophilic material or the surface is treated with a hydrophilic material. The surface of the lower cover sheet 300 contacting the substrate 100 is a hydrophobic material or a surface thereof is hydrophobic-treated. The hydrophobic material can be made of any one or two mixed materials of the following materials, such as silicon, ceramics, glass, plastics and the like, wherein the plastics are selected from the following materials: acrylonitrile-butadiene-styrene copolymer (ABS), cycloolefin polymer (COP), Polyamide (PA), polybutylene terephthalate (PBT), Polycarbonate (PC), Polydimethylsiloxane (PDMS), Polyethylene (PE), Polyetheretherketone (PEEK), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), Polyoxymethylene (POM), polypropylene (PP), polystyrene diethyl ether (PPE), Polystyrene (PS), Polysulfone (PSU), Polytetrafluoroethylene (PTFE), and the like. The hydrophilic material may be a material in which the surface of a hydrophobic material is treated to have hydrophilic groups, eventually exhibiting hydrophilic properties, such as plasma treatment or a hydrophilic coating. The material with hydrophilicity can also be directly selected, for example, hydrophilic substances are added into the raw materials during injection molding.

The detection zone 2 is equipped with and detects runner 21 and signal acquisition passageway 22, detects runner 21 and signal acquisition passageway 22 and passes the base plate positive and negative, and whole piece electrode sensor adhesion is in base plate reverse side detection zone to airtight live base plate reverse side detection zone exposes electrode sensor's check site in detecting runner 21, and the electrode pin of sensor exposes in signal acquisition passageway 22. The third flow channel 44 and the fourth flow channel 45 are connected to the front and rear ends of the detection flow channel, respectively, and are located together on the front surface of the substrate. The first flow passage 41, the second flow passage 42, the fifth flow passage 43 and the waste liquid tank 3 are arranged on the reverse surface of the substrate, when the hydrophobic lower cover sheet is adhered to the reverse surface of the substrate in a watertight manner, the first flow passage, the second flow passage, the fifth flow passage and the waste liquid tank form a closed pipeline or cavity, and the surfaces of the formed pipeline and cavity are hydrophobic surfaces. When the upper cover plate with the hydrophilic surface is adhered to the front surface of the base plate in a watertight manner, the third flow channel, the fourth flow channel and the detection flow channel form a closed pipeline, and the hydrophobicity of the pipeline of the detection flow channel is weaker than that of the pipeline formed by the first flow channel, the second flow channel and the fifth flow channel which are adhered with the lower cover plate. Therefore, the flow velocity of liquid such as blood and the like in different areas can be controlled and the diffusion performance of the fluid can be adjusted through the difference of the hydrophilicity and the hydrophobicity of the surfaces of the different areas. For example, when the flow rate of the blood sample from the second reservoir in the hydrophobic second flow channel is slower than the flow rate of the blood sample in the detection flow channel. In this way, the residence time of the sample in the detection flow channel can be ensured to ensure sufficient detection time.

When the upper cover sheet with the hydrophilic surface is adhered to the front surface of the base plate in a watertight manner, the blood sample is contacted with the hydrophilic surface in the flowing process of the detection flow channel, so that the diffusion performance of the fluid in the area is effectively adjusted, for example, under the hydrophilic action, the blood sample is more beneficial to completely covering the electrode area of the sensor in the flow channel in the flowing process of the fluid, even if a plurality of detection sites with different surface tensions are arranged in the channel, the blood can be diffused more fully, the generation of bubbles is avoided, and the detection accuracy is ensured. If the detection flow channel is completely hydrophobic, when the blood sample flows in the flow channel, the surface tension of some areas of the electrodes of the sensor may be different and the blood may bypass the detection flow channel, so that air bubbles are formed, and the detection accuracy is affected.

The first flow channel, the second flow channel and the fifth flow channel have strong hydrophobicity (relative to the hydrophobicity of the detection flow channel), and the diffusion performance of the fluid in the areas of the first flow channel, the second flow channel and the third flow channel is adjusted through the hydrophobicity treatment, for example, the diffusion speed of the fluid in the areas becomes slow, so that the generation of bubbles in the flowing process is prevented.

The first flow channel 41 and the second flow channel 42 of the microfluidic detection chip on the reverse side of the substrate 100 are respectively connected with the third flow channel 44 on the front side of the substrate through a through hole.

In one aspect, the first and second flow passages share a common aperture that communicates with the third flow passage 44. Because the aperture of the flow channel is small, if only one perforation is provided, the liquid flowing through the first reservoir of the perforation forms a liquid film on the wall of the perforation, which can affect the controllability of the subsequent liquid (such as the liquid in the second reservoir) flowing through the perforation to a great extent, for example, the hole generates a hydrophilic effect after the first liquid is soaked, the flow rate control capability of the liquid is lost, and thus bubbles are easily generated. It is also possible that liquid flowing first through the perforated first reservoir forms a liquid film at the perforation that blocks the perforation and prevents liquid in the second reservoir from flowing through the perforation to the detection zone.

In the modification shown in fig. 1 to 6, the first flow channel and the second flow channel communicate with the detection flow channel without sharing a single through hole. Specifically, one end of the first channel 41 disposed on the back surface of the substrate 100 is communicated with the first reservoir 11, and the other end is communicated with the third channel 44 of the front surface detection area of the substrate through the first through hole 61 on the substrate. The second channel 42 disposed on the reverse side of the substrate has one end communicating with the second reservoir 12 and the other end communicating with the third channel 44 of the detection region on the front side of the substrate through the second through hole 62 on the substrate. The fourth flow channel 45 communicates with the waste liquid tank 3 through the third perforation 63 and the third flow channel 43.

The first flow channel and the second flow channel are located on the same plane, the first flow channel and the second flow channel are not located on the same plane as the third flow channel 44 and the detection flow channel, and the first flow channel and the third flow channel 44 are connected together through respective through holes, and the second flow channel and the third flow channel 44 are connected together. Such a design has at least the following effects compared to the first, second and third flow channels 44 being disposed in the same plane (as shown in fig. 11-a to 11-C): the failure probability of the subsequently entering liquid passing through the detection flow channel can be avoided, the fluid controllability is enhanced, and the generation of bubbles can be reduced. For another example, even if the liquid in the first reservoir forms a liquid film at the first perforation to block the first perforation, the flow of the liquid in the second reservoir into the detection flow path through the second perforation is not affected.

As shown in FIG. 11-A and FIG. 11-B, the first flow channel, the second flow channel and the detection flow channel are arranged on the same plane. As shown in fig. 11-a, first letting the first liquid 501 of the first flow channel flow into the third flow channel 44 causes a little first liquid to enter the second flow channel 42. As shown in fig. 11-B, after the first liquid completely flows into the third flow channel 44, the first liquid 501 that has previously entered the second flow channel remains in the second flow channel. As shown in fig. 11-C, when the second liquid 502 enters the second flow channel, there will be a portion of the air column 600 between the second liquid and the first liquid residing in the second flow channel. Since the liquid in the chip does not depend on an external power source, the presence of the air column prevents the second liquid from continuing to flow into the third flow channel 44, and finally the second liquid cannot reach the detection flow channel through the third flow channel 44 to complete the detection.

In a preferred embodiment, the first and second perforations are at a distance, for example greater than 2 mm. This ensures that the liquid in the first reservoir does not flow in the opposite direction to the second perforation when the liquid flows through the detection flow path.

Based on the design that the first flow channel and the second flow channel are located on the same plane, the first flow channel and the second flow channel are not located on the same plane with the third flow channel 44 and the detection flow channel, the first flow channel and the second flow channel are respectively connected with the third flow channel 44 through the first perforation and the second perforation, and the liquid in the first flow channel firstly flows into the third flow channel 44 and the detection flow channel through the first perforation. In a further preferred design, the first perforations are located downstream (in the direction of flow of the liquid) of the second perforations, and the apertures of the first perforations located downstream are smaller than the apertures of the second perforations located upstream thereof, and when the second liquid flows through the first perforations, a liquid film is formed at the perforations due to the small first apertures. This design prevents on the one hand the second liquid from flowing further out of the third flow channel 44 from the first through-hole into the first through-hole. On the other hand, the second through hole has a large opening, which can accelerate the flow of the second liquid into the third flow channel 44 and accelerate the detection process.

In some embodiments, the first flow channel and the second flow channel have an opening in the substrate of 0.2 to 0.8mm in width, 0.2 to 0.6mm in depth, and the waste liquid tank has an opening of 0.2 to 3mm in width. Specifically, for example, the thickness of the substrate is 0.4 to 5mm, the opening width of the first flow channel and the second flow channel on the substrate is 0.4mm, the depth is 0.3mm, and the opening width of the waste liquid tank is 1.5 mm.

Utilize micro-fluidic detection chip can realize need not plus power equipment in the aspect of fluid drive, accomplishes the automatic conveying of a plurality of fluids.

The microfluidic detection chip as shown in fig. 7-1 to 7-4 includes a substrate, an upper cover sheet, a lower cover sheet, and an electrode sensor 400. The substrate 100 is provided with a first liquid storage tank 11, a second liquid storage tank 12, a detection area 2 and a waste liquid tank 3, and the electrode sensor is arranged in the detection area 2. The liquid storage tank, the detection area and the waste liquid tank are communicated through a flow channel, and the upper cover plate and the lower cover plate are respectively adhered to the front side and the back side of the substrate in a watertight manner, so that the liquid storage tank, the waste liquid tank, the flow channel and the like are sealed in the substrate. The base plate is made of hydrophobic materials, one surface of the upper cover plate, which is attached to the base plate, is made of hydrophilic materials, and one surface of the lower cover plate, which is attached to the base plate, is made of hydrophobic materials. The opening direction of the first opening 51 where the first reservoir 11 is connected to the first channel 41 and the opening direction of the second opening 52 where the second reservoir 12 is connected to the second channel 42 are substantially opposite to each other. Specifically, when the first opening is downward, the second opening is upward or obliquely upward. More specifically, when the first opening is downward, the second opening is inclined upward at an angle of between about 30 degrees and vertically upward.

In this embodiment, the upper cover plate is provided with a first vent hole 110 at the position of the first reservoir, a second vent hole 120 at the position of the second reservoir, and a third vent hole 310 at the position of the waste reservoir. And the vent hole is sealed with a sealing member. After the sealing element is removed, the detection reagent in the first liquid storage tank is injected into the first liquid storage tank through the first vent hole, and the detection sample is injected into the second liquid storage tank through the second vent hole. During detection operation, gas in the pipeline is exhausted out of the chip through the third vent hole.

The specific operation is shown in fig. 7-1 to 7-4. The first reservoir 11 is used for storing a detection reagent 501, such as a calibration solution, and the second reservoir 12 is used for storing a sample 502 to be detected, such as a blood sample. The chip in operation is vertically fixed in the instrument and drives the chip to rotate by means of parts in the instrument so as to control the flow direction of the fluid, thereby realizing the purpose of sequentially conveying the detection reagent and the sample to be detected to the detection flow channel. When the chip is in the position of FIG. 7-1, the opening direction of the first opening 51 of the first reservoir 11 connected to the first flow channel 41 is downward, so that the detection reagent 501 in the first reservoir flows into the first flow channel 41 under the action of its own weight and the capillary force provided by the first flow channel 41. Meanwhile, the opening direction of the second opening 52 where the second reservoir 12 is connected to the second channel 42 is inclined upward, and the liquid 502 in the second reservoir cannot flow out from the second opening 52. When the chip is rotated from the position shown in fig. 7-1 to the position shown in fig. 7-2, the detection reagent in the first channel 41 flows from the back surface of the substrate to the third channel 44 and the detection channel 21 on the front surface of the substrate through the first through hole 61, the detection reagent staying in the detection channel 21 reacts with the sensor, and the probe of the instrument is connected with the pin of the sensor in the signal collection channel 22 and collects the reaction signal. In the position of fig. 7-2, the liquid in the first reservoir flows out into the detection flow channel before the liquid in the second reservoir, so that an air column is formed between the sample to be detected in the second reservoir 12 and the detection reagent in the detection flow channel, and the sample to be detected stored in the second reservoir is subjected to unequal air pressure, and therefore, the sample to be detected is retained in the second reservoir 12. When the detection of the detection reagent is finished, the chip rotates to the position shown in fig. 7-3, and the detection reagent in the detection flow channel 21 flows into the fifth flow channel 43 on the reverse side of the substrate through the fourth flow channel 45 and the third through hole 63 until the detection reagent flows into the waste liquid tank 13. During this rotation, the second opening of the second reservoir reaches a downward position, and the sample in the second reservoir flows out of the opening into the second flow channel 42. In a preferred embodiment, since the second flow path 42 comprises a bend, a portion of the liquid flowing from the second reservoir will remain in the bend when the chip is in the position of fig. 7-3. The chip continues to rotate to the position of 7-4, the detection reagent flows out of the detection flow channel and enters the waste liquid tank, the volume of the waste liquid tank is large, the detection reagent 501 can completely enter the waste liquid tank (a third vent hole is formed between the detection reagent and the outside), the fluid in the second liquid storage tank flows out of the liquid storage tank under the action of self gravity, flows into the third flow channel 44 and the detection flow channel 21 on the front surface of the substrate through the second flow channel 42 and the second through hole 62 on the back surface of the substrate, the sample staying in the detection flow channel reacts with the sensor 400, and at the moment, the instrument collects the signal of the sample to be detected through the pins of.

In another embodiment, the microfluidic detection chip and the specific operation steps are shown in FIGS. 8-1 to 8-6. The microfluidic detection chip comprises a substrate, an upper cover plate, a lower cover plate and an electrode sensor. The substrate 100 is provided with a first liquid storage tank 11, a second liquid storage tank 12, a detection area 2 and a waste liquid tank 3, and the electrode sensor is arranged in the detection area 2. The liquid storage tank, the detection area and the waste liquid tank are communicated through a flow channel, and the upper cover plate and the lower cover plate are respectively adhered to the front side and the back side of the substrate in a watertight manner, so that the liquid storage tank, the waste liquid tank, the flow channel and the like are sealed in the substrate. The reservoir opening of the microfluidic detection chip is arranged in a state that when the liquid in the first reservoir flows out of the first opening, the liquid level in the second reservoir is lower than the second opening, so that the liquid cannot flow out of the second opening. The second reservoir 12 is for storing a sample 502 to be tested, such as a blood sample. The first reservoir 11 is used for storing a detection reagent 501, such as a calibration solution, a quality control solution, or a reaction reagent such as an enzyme.

The specific operation is shown in fig. 8-1 to 8-6. When the chip is at the position shown in fig. 8-1 to 8-3, the liquid level in the second reservoir is lower than the opening of the second opening 52, the first opening 51 is directed downward so that the liquid in the first reservoir flows into the first channel 41 under the action of its own gravity, and flows from the reverse side of the substrate to the third channel 44 on the substantially front side through the first through hole 61 to finally reach the detection channel 21, and the detection reagent in the detection channel reacts with the sensor within a reserved time. The instrumentation probes connect to the pins of the sensor and collect the response signals within the signal collection channels 22. When the detecting chip is rotated to the position shown in FIGS. 8 to 4, the detecting reagent in the detecting flow path 21 enters the fifth flow path 43 through the fourth flow path and the third through hole and then enters the waste liquid tank 3. At this point the liquid in the second reservoir continues to remain within the second reservoir. When the detection chip is further rotated to the position shown in fig. 8-5, the second opening of the second reservoir faces downward, and is in the liquid outflow position, and the liquid in the second reservoir flows into the second flow channel 42 under the action of its own weight, and flows into the third flow channel 44 and the detection flow channel 21 on the front surface of the substrate through the second through hole 62. The chip continues to rotate to the position shown in fig. 8-6, so that the liquid in the second liquid storage tank completely enters the detection flow channel 21, the sample staying in the detection flow channel 21 reacts with the sensor, and the instrument collects the signal of the sample to be detected through the pin of the sensor.

As shown in fig. 9, the microfluidic detection chip includes a first reservoir 11, a second reservoir 12, a third reservoir 13 and a fourth reservoir 14 disposed on a substrate and correspondingly connected to a first channel to a fourth channel (410-. The first waste liquid tank 31 communicates with the sixth flow path 460 and the first detection flow path 21 through the ninth flow path 490 and the perforation 65, and the second waste liquid tank 32 communicates with the eighth flow path 480 and the second detection flow path 23 through the tenth flow path 491 and the perforation 66. The first reservoir, the first channel, the first through hole, the fifth channel, the first detection channel, the sixth channel, the through hole 65, the ninth channel, and the first waste liquid channel form a flow path. The second reservoir, the second channel, the second through hole, the fifth channel, the first detection channel, the sixth channel, the through hole 65, the ninth channel, and the first waste liquid channel form a flow path. The third reservoir, the third channel, the third through hole, the seventh channel, the second detection channel, the eighth channel, the through hole 66, the tenth channel 491 and the second waste liquid channel form a flow path. The fourth reservoir, the fourth channel, the fourth hole, the seventh channel, the second detection channel, the eighth channel, the hole 66, the tenth channel 491 and the second waste liquid channel form a flow path. By rotating the chip, the liquid in the liquid storage tank flows out in sequence under the action of self gravity and flows in the flow path.

As shown in fig. 10, the microfluidic test chip has two fluid control systems on one substrate. The first fluid control system comprises a first reservoir 11, a second reservoir 12, a first flow channel 41, a second flow channel 42, a detection flow channel 21 arranged in the reaction area 2 and a first waste liquid tank 31. The second fluid control system comprises a third reservoir 13, a fourth reservoir 14, a third flow channel 43, a fourth flow channel 44, a detection flow channel 23 arranged in the reaction area 2, and a first waste liquid tank 32.

In the other substrate of the microfluidic detection chip, the first liquid storage tank, the second liquid storage tank, the first flow channel, the second flow channel detection flow channel, the third flow channel and the waste liquid tank are all arranged on the front surface of the substrate, and the first flow channel and the second flow channel are all the same as the detection flow channel. By rotating the chip, the liquid in the liquid storage tank flows out in sequence under the action of self gravity and flows in the flow path.

The method of manufacturing the chip will be described with reference to the chip of FIG. 7-1 as an example.

Step 1, selecting a hydrophobic material as a substrate, and forming a flow channel, a liquid storage tank, a detection flow channel, a signal acquisition channel, a waste liquid tank, a perforation and other structures on the substrate through chemical etching, physical engraving, hot pressing or injection molding.

And 2, obtaining an electrode sensor, and sticking the electrode sensor to the detection flow channel on the lower surface of the substrate so as to enable the electrode of the sensor to be positioned in the detection flow channel and seal the lower surface of the detection flow channel in a water-tight manner. And meanwhile, the electrode pins of the sensor are positioned in the signal acquisition channel of the detection area.

And 3, obtaining a hydrophobic lower cover plate (or treating the surface of the lower cover plate, which is contacted with the reverse surface of the substrate, with a hydrophobic material, wherein the contact surface of the lower cover plate is hydrophobic), and adhering the lower cover plate to the reverse surface of the substrate in a watertight manner.

And 4, obtaining a hydrophilic upper cover plate (or treating the surface of the upper cover plate, which is contacted with the front surface of the substrate, with a hydrophilic material, wherein the contact surface of the upper cover plate is hydrophilic). The upper cover sheet is attached to the front surface of the base sheet in a watertight manner. The detection reagent is injected into the first liquid storage groove through the first vent hole of the upper cover plate, and then the sealing member is used for sealing the small hole. Obtaining the microfluid detection chip for detection.

In another embodiment, if the upper cover sheet does not have the first vent hole, the step 4 above injects a calibration solution as a detection reagent into the first reservoir, and then the hydrophilic upper cover sheet or the hydrophilic upper cover sheet whose surface contacting with the front surface of the substrate is subjected to hydrophilic treatment is attached to the front surface of the substrate in a watertight manner, thereby sealing the detection reagent in the first reservoir. In the detection procedure, when liquid in the first liquid storage tank needs to flow out of the first liquid storage tank, a small hole is broken in the upper cover plate above the first liquid storage tank, air can enter the first liquid storage tank, but the liquid cannot flow out of the first liquid storage tank through the small hole, and the flow channel detects the outside of the chip.

Utilize the utility model discloses a method that micro-fluidic chip carried out sample detection, its step is as follows:

step 1, obtain the utility model discloses in micro-fluidic detection chip.

And 2, injecting the blood sample to be detected into the second liquid storage tank through a second vent hole formed in the second liquid storage tank through the upper cover plate.

And 3, vertically fixing the detection chip in the instrument and controlling the flow direction of the fluid by driving the chip to rotate by means of parts in the instrument. When the chip is in the position of fig. 7-1, the first vent hole on the first reservoir of the upper cover plate is opened, and the third vent hole is opened at the same time. The calibration liquid in the first reservoir 11 flows into the first flow path 41. Meanwhile, the opening direction of the second opening 52 where the second reservoir 12 is connected with the second flow channel 42 is inclined upward, and the liquid 502 in the second reservoir cannot flow out from the second port.

And 4, rotating the chip from the position shown in the figure 7-1 to the position shown in the figure 7-2, allowing the detection reagent in the first flow channel 41 to flow from the reverse side of the substrate to the detection flow channel positioned on the front side of the substrate through the first through hole 61, staying in the detection flow channel, allowing the detection reagent to react with the sensor, and allowing the contact pins of the instrument to be connected with the pins of the sensor in the contact pin contact openings 22 and acquiring reaction signals.

Step 5, the chip is rotated from the position shown in FIG. 7-2 to the position shown in FIG. 7-3, and the detection reagent in the detection flow channel 21 flows into the third flow channel 43 on the reverse side of the substrate through the third through hole 63 until it flows into the waste liquid tank 13.

And 6, continuously rotating the chip to the position 7-4, enabling the detection reagent to flow out of the detection flow channel and enter the waste liquid tank, enabling the blood sample to be detected in the second liquid storage tank to flow out of the liquid storage tank, enabling the blood sample to flow into the detection flow channel 21 on the front surface of the substrate through the second flow channel 42 and the second through hole 62 on the aspect of the substrate, enabling the sample staying in the detection flow channel to react with the sensor, and enabling the instrument to acquire a signal of the sample to be detected through the connecting pin of the sensor. Thereby obtaining a detection result.

The detection method in the detection area can be a biosensor for treating the electrode, and can also be an optical detection method such as a turbidity method, a fluorescence method, a chemiluminescence method, a scattering method and the like.

The micro-fluidic detection chip can carry out quantitative, semi-quantitative or qualitative detection. For example, one or more test strips (either blank or pre-loaded) are fixed in the detection area, and after the detection reagent or the sample flows through the detection flow channel and contacts with the test strips, the reagent reacts with the sample to generate a color change, and then the detection result is obtained through instrument or human observation.

Claims

1. The micro-fluidic chip is characterized by comprising a substrate and a detection area positioned on the substrate, wherein a first liquid storage tank and a second liquid storage tank are arranged on the substrate, the first liquid storage tank and the second liquid storage tank are respectively communicated with liquid in the detection area, a first opening and a second opening are respectively arranged for liquid to flow out, the micro-fluidic chip enables the first opening to flow out of liquid under the action of gravity before the second opening, and the rear end of the liquid in the first liquid storage tank reaches the detection area earlier than the front end of the liquid in the second liquid storage tank.

2. The microfluidic chip of claim 1, wherein the first opening reaches a downward position before the second opening by rotating the microfluidic chip, such that the liquid in the first reservoir flows out of the first opening under the action of gravity before the liquid in the second reservoir flows out of the second opening under the action of gravity.

3. The microfluidic chip according to claim 1, wherein the first opening is rotated to a downward position, and the liquid in the first reservoir flows out of the first opening to the detection region under the action of gravity; and then the microfluidic chip is rotated to enable the second opening to reach a downward position, and the liquid in the second liquid storage tank flows out of the second opening under the action of gravity and reaches the detection area.

4. The microfluidic chip according to claim 3, further comprising a waste tank on the substrate, the waste tank communicating with the detection zone; when the liquid in the second liquid storage tank flows out from the second opening under the action of gravity and reaches the detection area, the liquid in the first liquid storage tank positioned in the detection area flows to the waste liquid tank under the action of gravity.

5. The microfluidic chip according to claim 1, wherein when the first opening discharges liquid, the first opening is higher than the detection area; when the second opening flows out of the liquid, the position of the second opening is higher than that of the detection area.

6. The microfluidic chip according to claim 4, further comprising a first channel disposed on the substrate and connected to the first opening, a second channel connected to the second opening, a third channel connected to a front end of the detection region, a fourth channel connected to a rear end of the detection region, and a fifth channel connected to a waste liquid tank; the first flow channel and the second flow channel are connected with the third flow channel; the fourth flow passage is connected with the fifth flow passage.

7. The microfluidic chip according to claim 6, wherein the detection area is provided with a detection flow channel and a signal acquisition channel, and the detection area comprises an electrode sensor; the two ends of the detection flow channel are respectively connected with the third flow channel and the fourth flow channel.

8. The microfluidic chip according to claim 6, wherein the microfluidic detection integrated chip comprises a cover plate for covering the substrate, the cover plate enclosing the first and second reservoirs and the waste reservoir, and the first, second, third, fourth and fifth channels.

9. The microfluidic chip according to claim 8, wherein the cover plate corresponding to the first reservoir, the second reservoir and the waste liquid reservoir is provided with a first vent hole, a second vent hole and a third vent hole, respectively.

10. The microfluidic chip according to claim 9, wherein the first, second and third venting holes are provided with a sealing member.