A microfluidic detection device

Abstract

The present invention belongs to the field of microfluidic nucleic acid detection devices and biological detection, and specifically relates to a microfluidic detection device. The device includes a cover sheet and a chip board; the cover sheet has an opening for sample dripping, and a sealing plug is installed on the opening; the chip board is provided with a sample cavity at the upper part, and at least one reaction cavity is provided at the lower part, and the detection reagent is encapsulated in the reaction cavity, and the lower part of the sample cavity is provided with a liquid inlet channel and connected to the reaction cavity, and the upper end of the sample cavity is connected with the upper part of the reaction cavity to form an exhaust channel; the opening for sample dripping on the cover sheet corresponds to the sample cavity provided at the upper part of the chip board. The present invention has a simple structure, is easy to operate, and can effectively reduce sample contamination during nucleic acid detection.

Description

Technical Field

[0001] The present invention belongs to the field of microfluidic nucleic acid detection devices and biological detection, and specifically relates to a microfluidic detection device. Background Art

[0002] Based on innovative microfluidic molecular diagnostic technology, it is developed for common multiple infectious diseases in humans, and can realize self-testing of diseases such as respiratory tract, childhood infection, and reproductive tract infection, including influenza A and B, syncytial virus, rotavirus, norovirus, AIDS, syphilis, gonorrhea, and pet infection detection. Through rapid detection and diagnosis without extraction, the impact of infectious diseases on people's daily life and social economy can be reduced. Microfluidics originated from microanalysis methods, including gas chromatography (GPC), high performance liquid chromatography (HPLC) or capillary electrophoresis (CE). These technologies originated in the 1950s and 1960s, and can separate or analyze compounds or biomolecules by allowing a small amount of sample to flow into a narrow test tube or capillary, thereby achieving high sensitivity and resolution. In the early 1980s, PCRKary Mullis developed the DNA polymerase chain reaction technology, making molecular biology an important driving force for microfluidic technology research.

[0003] Microfluidics is a science and technology that precisely controls and manipulates microscale fluids, with the main feature of manipulating fluids in micro-nanoscale space. It has the ability to miniaturize basic functions of biological and chemical laboratories such as sample preparation, reaction, separation and detection to a chip of a few square centimeters. Its basic characteristics and greatest advantage are the flexible combination and large-scale integration of multiple unit technologies on an overall controllable micro-platform. Microfluidics uses pipes with a scale of tens to hundreds of microns to process or manipulate very small amounts of fluids (between cubic millimeters and cubic microns). The original microfluidics technology was used for analysis, with the advantages of high-precision and high-sensitivity separation and detection using very few samples and reagents, low cost, short analysis time, and small footprint of analytical equipment. The most obvious feature of microfluidics is its small size, and it also has the less obvious characteristics of microchannel fluids. It essentially provides the ability to centrally control molecules in space and time, and is an emerging interdisciplinary subject involving chemistry, fluid physics, microelectronics, new materials, biology and biomedical engineering. It can integrate the process of analyzing samples in biology, chemistry, medicine and other fields, including preparation, reaction, separation, detection and other basic units, into a micron-scale chip and automatically complete the entire analysis process.

[0004] Microfluidic technology can concentrate the entire process of nucleic acid sample detection on a chip of a few centimeters. Through the integration of modules such as the design of liquid flow channels, the placement of microvalves, and the design of liquid cavities, the detection operation process is comprehensively completed, and the entire detection is finally miniaturized. When DNA polymerase chain reaction technology is used, under the important development trend of increasingly miniaturized microfluidic detection devices, the bubble problem has become a major obstacle affecting the results of nucleic acid detection, such as bubbles introduced when adding media or droplets to microfluidic devices, bubbles dissolved in filling media or droplets, bubbles generated by heating during high-temperature experiments, and the expansion of bubbles, etc. If the bubbles expand or contract when moving on the microfluidic device, or get stuck at a certain position in the drive path, it will hinder the control of the droplets and destroy the stability of the drive. In severe cases, it may also damage the modified properties or coating structure of the upper and lower plates of the microfluidic chip; in addition, when nucleic acid detection is performed on droplets, the presence of bubbles will also cause great interference to the test results. Existing microfluidic detection devices exhaust bubbles that may exist in the injection hole and the flow path by providing exhaust holes and injection holes at both ends of the flow path, but this structure makes the device design complicated and increases the size of the device. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a microfluidic detection device, which can solve the problems of large size, complex product structure, inconvenient operation, and low detection accuracy of existing devices.

[0006] The microfluidic detection device of the present invention comprises a cover sheet and a chip board; the cover sheet is provided with an opening for sample dripping, and a sealing plug is installed on the opening; a sample cavity is arranged at the upper part of the chip board, and at least one reaction cavity is arranged at the lower part, and a detection reagent is encapsulated in the reaction cavity; a liquid inlet flow channel is arranged at the lower part of the sample cavity, a branch is arranged at the tail end of the liquid inlet flow channel and is connected to all the reaction cavities, and exhaust flow channels are arranged at the upper part of all the reaction cavities, and the top of the exhaust flow channel is connected with the upper end of the sample cavity, and the liquid inlet flow channel and the exhaust flow channel are connected with the reaction cavity through the sample cavity; the opening for sample dripping on the cover sheet corresponds to the sample cavity arranged at the upper part of the chip board; one end of the liquid inlet flow channel is obliquely cut into the connection reaction cavity from top to bottom; one end of the exhaust flow channel is connected to the top of the sample cavity, and the other end is connected to the top of the reaction cavity; the exhaust flow channel is arranged on the front side of the chip board, and the liquid inlet flow channel is arranged on the reverse side of the chip board; a blocking component is arranged at the corresponding sample cavity and the opening on the bottom sheet; a protrusion is arranged at the corresponding opening on the bottom sheet or the blocking component.

[0007] Preferably, the reaction chamber is of special-shaped design, and has a contraction portion at the top.

[0008] Preferably, a bottom plate is further provided at the bottom of the chip plate, and the cover plate, the chip plate and the bottom plate are tightly fixed.

[0009] Preferably, a filter portion is provided on the bottom film.

[0010] Preferably, the filtering portion on the bottom film is a plurality of rows of columns.

[0011] Preferably, an annular groove is provided on the sealing plug, and an annular protrusion is correspondingly provided on the opening, and the annular groove and the annular protrusion are buckled together.

[0012] Preferably, the sealing plug is integrally injection-molded with the cover plate or the chip plate via a connecting piece.

[0013] Preferably, the cover plate, the chip plate and the bottom plate are injection molded, and the bonding method is gluing, ultrasonic welding, laser welding or thermal bonding.

[0014] Preferably, the reaction chamber contains freeze-dried balls for encapsulating detection reagents.

[0015] The microfluidic detection device described in the present invention realizes the discharge of bubbles, waste gas, etc. through an opening design and the connection between the sample chamber, the liquid inlet channel, the reaction chamber and the exhaust channel, thereby avoiding sample contamination caused by opening an exhaust hole separately, and can solve the problems of complex structure, inconvenient operation, and low detection accuracy of existing nucleic acid detection products. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the liquid inlet channel of the microfluidic detection device of the present invention;

[0017] Figure 2 A schematic diagram of the exhaust flow channel of the microfluidic detection device of the present invention;

[0018] Figure 3 It is a structural exploded view of an embodiment of the present invention;

[0019] Figure 4 This is a partial enlarged view of the reaction chamber of the present invention;

[0020] Figure 5 This is a front structural exploded view of the second embodiment of the present invention;

[0021] Figure 6 This is a back structural exploded view of the second embodiment of the present invention;

[0022] Figure 7 This is a structural exploded view of the third embodiment of the present invention;

[0023] Figure 8 This is a partial enlarged view of the filter portion of the present invention;

[0024] Fig. 9 This is a schematic diagram of sample loading in the microfluidic detection device of the present invention;

[0025] Fig.10This is a stereoscopic diagram of the microfluidic detection device of the present invention.

[0026] Among them: 1-cover plate; 2-chip plate; 3-opening; 31-annular protrusion; 4-sealing plug; 41-annular groove; 42-connector; 5-sample chamber; 6-reaction chamber; 7-liquid inlet channel; 8-exhaust channel; 9-lysis liquid tube; 10-lyophilized ball; 11-base film; 111 blocking component; 112 protrusion; 12 filtering part. DETAILED DESCRIPTION

[0027] The preferred technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0028] like Figure 1-3 As shown, the present invention provides a microfluidic detection device, including a cover sheet 1 and a chip board 2, wherein the cover sheet 1 has an opening 3 for sample dripping, and a sealing plug 4 is installed on the opening 3 for sealing; the chip board 2 is provided with a sample chamber 5 at the top and at least one reaction chamber 6 at the bottom, wherein the reaction chamber encapsulates the detection reagent, and a liquid inlet channel 7 is provided at the bottom of the sample chamber and connected to the reaction chamber 6, and an exhaust channel 8 is provided at the sample chamber and connected to the top of the reaction chamber 6. Figure 2 When two reaction chambers 6 are arranged on the chip board 2, the tail end of the liquid inlet flow channel arranged at the lower part of the sample chamber 5 is provided with a branch and connected to the two reaction chambers respectively, and the exhaust flow channels 8 are arranged at the upper part of the two reaction chambers, and the tops of the two exhaust flow channels are connected to the upper end of the sample chamber, and the liquid inlet flow channel and the exhaust flow channel are connected to the reaction chamber through the sample chamber. At this time, the sample drips into the sample chamber 5 through the opening 3, and under the action of capillary and gravity, it flows into the reaction chamber through the liquid inlet flow channel 7 by itself, and because the sample position and the reaction chamber form a large height difference when the device is placed vertically, the sample can fill the reaction chamber in a relatively fast time. At this time, if there are bubbles or reaction gases in the liquid inlet flow channel and the reaction chamber, they can float upward and enter the space at the upper part of the sample chamber 5 through the exhaust flow channel 8 connected to the upper part of the reaction chamber. The microfluidic detection device described in the present invention realizes sample dripping only through one opening 3, and at the same time realizes the discharge of bubbles, exhaust gas, etc. through the connection of the sample chamber, the liquid inlet flow channel and the exhaust flow channel, avoiding sample contamination caused by opening an exhaust hole separately, and can also effectively reduce the volume of the device.

[0029] One end of the liquid inlet channel is obliquely cut from top to bottom into the connected reaction chamber; one end of the exhaust channel is connected to the top of the sample chamber, and the other end is connected to the top of the reaction chamber. One end of the liquid inlet channel is obliquely cut from top to bottom into the connected reaction chamber, which not only facilitates the sample liquid to flow into the reaction chamber, but also prevents the liquid in the reaction chamber from flowing back into the liquid inlet channel. The exhaust channel is respectively connected to the sample chamber and the top of the reaction chamber to allow gas or bubbles to float up and move from the reaction chamber to the top of the sample chamber, thereby reducing the contamination of nucleic acid test samples in the reaction chamber and the test results. At the same time, the gas or bubbles are discharged into the top of the sample chamber, which will not affect the flow of the sample at the bottom of the sample chamber into the liquid inlet channel. Furthermore, if Figure 4 As shown, the reaction chamber is of special-shaped design, with a contraction portion at the top, which reserves space for accommodating bubbles. Even if trace bubbles are generated, it will not affect the detection.

[0030] Referring to this embodiment Figure 3 As shown, a bottom film 11 is arranged at the bottom of the chip board 2, and the cover sheet 1, the chip board 2 and the bottom film 11 are tightly fixed, so that the sample liquid, exhaust gas, etc. can only pass through the sample cavity, the reaction cavity, the liquid inlet channel and the exhaust channel. The cover sheet 1, the chip board 2 and the bottom film 11 are injection molded, and the bonding method is adhesive bonding, ultrasonic welding, laser welding, thermal bonding, etc., so that the cover sheet 1, the chip board 2 and the bottom film 11 are tightly fitted. The liquid inlet channel 7 and the exhaust channel 8 of the chip board are respectively arranged on both sides of the chip board 2 to ensure smooth liquid inlet and exhaust; the exhaust channel is on the front side of the chip board, facing upward, which not only ensures that the sample liquid will not block the exhaust channel at the beginning, but also ensures that the distance between the liquid inlet and the exhaust port is the farthest to the greatest extent, and minimizes the possibility of forming large bubbles in the reaction chamber.

[0031] Wherein, a blocking component 111 is arranged on the negative film 11 corresponding to the sample cavity 5 and the opening 3, and the blocking component 111 is arranged to be a semi-circular portion corresponding to the upper part of the opening 3. When the sample drips into the sample cavity, due to the blocking of the blocking component 111, the sample liquid flows from the blocking component 111 to the lower end of the chip board, and the liquid can be prevented from flowing to the top of the sample cavity as much as possible, providing a space for collecting waste gas or bubbles in the upper part of the sample cavity. Further, a protrusion 112 is arranged on the negative film 11 or the blocking component 111 corresponding to the opening 3, and the protrusion 112 is higher than the plane of the negative film 11. When the lysing liquid tube 9 is inserted into the opening to drip the sample, the plane of the lysing liquid tube opening is prevented from being flush with the plane of the negative film, and the sample liquid cannot flow out.

[0032] like Figure 5-6 As shown, it is an embodiment of the present invention when there are 6 reaction chambers, and 6 liquid inlet channels 7 and exhaust channels 8 are provided accordingly. In order to save the chip board space to the maximum extent and facilitate the flow of channels, the liquid inlet channels 7 and exhaust channels 8 are provided on both sides of the chip board respectively. At the same time, the channels will not cross each other, which can ensure the flow of channels to the maximum extent.

[0033] like Figure 7-8 As shown, it is an embodiment that the bottom film 11 includes a filter part 12. The filter part 12 is placed at the lower end of the blocking component 111 and is composed of multiple rows of columns with a certain gap. The column can be a cylinder, a cone or a truncated cone. The front and rear rows of columns are staggered and arranged to filter larger foreign matter in the liquid sample, such as swab lint.

[0034] Optionally, the sealing plug 4 is integrally injection molded with the cover sheet 1 or the chip board 2 through the connecting piece 42, so that the sealing plug 4 is connected to the device of the present invention to avoid loss and inconvenience in use. Figure 9-10As shown, an annular groove 41 is provided on the sealing plug 4, and an annular protrusion 31 is correspondingly provided on the opening 3 (or an annular protrusion is provided on the sealing plug 4, and an annular groove is correspondingly provided on the opening 3). After the sample in the lysis liquid tube 9 is dripped into the sample cavity, the annular groove and the annular protrusion are buckled together, so that the sealing plug cannot be opened after being buckled with the opening, thereby avoiding sample contamination and ensuring the accuracy of the detection result.

[0035] Preferably, the detection reagent encapsulated in the reaction chamber is a freeze-dried ball 10. Figure 1 What is displayed is a dual-reaction chamber device, with three ball placement schemes: a. One reaction chamber is placed with a reagent ball for detecting a certain viral nucleic acid, and the other reaction chamber is placed with an internal reference reagent ball to check the validity of the sample; b. Both reaction chambers are placed with reagent balls for detecting a certain viral nucleic acid, which can greatly improve the detection accuracy; c. Two reaction chambers are respectively placed with two reagent balls for detecting different viral nucleic acids, which can greatly increase the screening range.

[0036] The microfluidic detection device described in the present invention is easy to operate. When in use, the sample is first dripped in through the cover opening, and then the sealing plug is buckled. The sealing plug is buckled with the opening to prevent manpower from opening the sealing plug, so that the sample is kept in a non-contamination state once added. Secondly, the device described in the present invention is erected on the nucleic acid detection device. Because the blocking component is set at the corresponding sample cavity and the opening on the base film, the sample will be in the lower end of the blocking component of the sample cavity and flow downward, that is, the sample is prevented from being dispersed in the entire sample cavity, and the gas storage space is reserved for the upper part of the sample cavity, and it also plays a role in draining the sample to the lower liquid inlet flow channel; a protrusion is set at the corresponding opening on the base film or the blocking component, so that when the lysis liquid tube is extended into the sample cavity to add the sample, the tube mouth will not directly contact the base film directly with the plane, effectively increasing the fluency and speed when the sample is added; a plurality of rows of columnar filtering parts are set at the lower end of the base film to filter larger foreign matter in the liquid sample. Afterwards, the device described in the present invention is erected on the detection equipment, the sample enters the reaction chamber through the liquid inlet channel and reacts with the nucleic acid detection reagent, and the bubbles or gas in the liquid inlet channel and the reaction chamber enter the top of the sample chamber through the exhaust channel at the top of the reaction chamber, so that the upper part of the sample chamber is gas and the lower part is the sample flowing to the liquid inlet channel.

[0037] The device of the present invention has a good user experience, only one sample needs to be added, and when adding the sample, all of it can be squeezed into the mouth, without the need to accurately control the number of sample drops; after the sample is added, the sealing plug can be covered without waiting for the sample to fill the reaction chamber; the device covered with the sealing plug can be placed in the instrument for incubation and detection, and there is no need to wait for the sample to fill the reaction chamber. The structure is simple, the operation is convenient, and the sample is not easily contaminated during detection, which improves the accuracy of the nucleic acid detection results.

[0038] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. As long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A microfluidic detection device, characterized in that: The invention comprises a cover sheet and a chip board; the cover sheet is provided with an opening for sample dripping, and a sealing plug is installed on the opening; the chip board is provided with a sample cavity at the upper part, and at least one reaction cavity is provided at the lower part, and the detection reagent is encapsulated in the reaction cavity; the lower part of the sample cavity is provided with a liquid inlet channel, the tail end of the liquid inlet channel is provided with a branch and connected to all the reaction cavities, and the upper part of all the reaction cavities is provided with an exhaust channel, the top of the exhaust channel is connected with the upper end of the sample cavity, and the liquid inlet channel and the exhaust channel are connected with the reaction cavity through the sample cavity; the opening for sample dripping on the cover sheet corresponds to the sample cavity provided on the upper part of the chip board; one end of the liquid inlet channel is obliquely cut into the connection reaction cavity from top to bottom; one end of the exhaust channel is connected to the top of the sample cavity, and the other end is connected to the top of the reaction cavity; the exhaust channel is provided on the front side of the chip board, and the liquid inlet channel is provided on the reverse side of the chip board; the bottom of the chip board is also provided with a bottom sheet, and the cover sheet, the chip board and the bottom sheet are tightly fixed; a blocking component is provided on the bottom sheet corresponding to the sample cavity and the opening; a protrusion is provided on the bottom sheet or the blocking component corresponding to the opening.

2. The microfluidic detection device according to claim 1, characterized in that: The reaction chamber is of special-shaped design, and has a contraction portion at the top.

3. The microfluidic detection device according to claim 1, characterized in that: A filter portion is arranged on the bottom sheet.

4. The microfluidic detection device according to claim 3, characterized in that: The filtering part on the bottom sheet is a plurality of rows of columns.

5. The microfluidic detection device according to claim 1, characterized in that: An annular groove is arranged on the sealing plug, and an annular protrusion is correspondingly arranged on the opening, and the annular groove and the annular protrusion are buckled together.

6. The microfluidic detection device according to claim 1, characterized in that: The sealing plug is integrally injection-molded with the cover plate or the chip plate through a connecting piece.

7. The microfluidic detection device according to claim 1, characterized in that: The cover sheet, the chip plate and the bottom sheet are injection molded, and the bonding method is gluing, ultrasonic welding, laser welding or thermal bonding.

8. The microfluidic detection device according to claim 1 or 2, characterized in that: The reaction chamber is encapsulated with freeze-dried balls for detection reagents.

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