Full-automatic single-chip microbiological detection system

Abstract

The invention discloses a full-automatic single-chip microbiological detection system. The system comprises a micro-fluidic chip, a cam mechanism, a pressing module for driving the cam mechanism to do reciprocating rectilinear motion, a first on-off assembly and a second on-off assembly, during working, the pressing module drives the cam mechanism, the first on-off assembly and the second on-off assembly to linearly move to approach the micro-fluidic chip, the second on-off assembly controls the micro-fluidic chip to be communicated with the atmosphere, and the cam mechanism sequentially controls the first on-off assembly to open or close a flow channel on the micro-fluidic chip. Controlling the solution to be transferred into a target chamber for a microbiological detection experiment; various solutions are quantitatively filled into the storage cavity in the micro-fluidic chip in advance, the corresponding solutions are controlled to be transferred into the target cavity for experiments in different experiment steps based on cooperation of a cam structure, the on-off puncture assembly and the like, reagent bottles and pipelines do not need to be externally connected, operation is easy and convenient, stability is good, and reliability is high.

Description

Technical Field

[0001] The present invention relates to the technical field of microbial detection, and in particular to a fully automatic single-chip microbial detection system. Background Art

[0002] Microorganisms refer to a broad group of organisms, including bacteria, viruses, fungi, and protozoa. Microorganisms are closely linked to the health of humans, animals, and plants. Many diseases in humans, animals, and plants are caused by microorganisms, known as pathogens. Pathogen detection in plant and animal samples can facilitate safety monitoring of these organisms.

[0003] Pathogen microorganism microfluidic rapid detection equipment is a new type of microbial detection system. Liquid reagents or solid reagents need to be pre-stored in the microfluidic chip, and the microfluidic chip itself is used to store and release various reagents. This method of producing microfluidic chips has high requirements on the process, and the production process is complex, resulting in high costs and is not conducive to promotion and application.

[0004] Another type of existing pathogenic microorganism microfluidic rapid detection equipment usually requires multiple external reagent bottles to be connected, and the solution in the reagent bottles is pumped into the microbial detection system for experiments. After the reagent is used up, manual rehydration is required, and the experiment requires the use of: quantitative devices such as pipettes, external pipes and reagent bottles. The system pipeline and structural design are complex, and repeated use of external pipes and reagent bottles will cause cross-contamination, which may lead to erroneous experimental results; it is not conducive to transportation and storage, and is not conducive to simplifying the process. It requires a high level of operation for the experimenters, which limits the development of full automation of microbial detection systems and is not conducive to the promotion and application of full automation of microbial detection systems. Therefore, how to complete reagent storage in the microbial detection system and how to make multiple reagents flow in sequence and direction in each experimental step of microbial detection are technical problems that need to be solved urgently.

[0005] Existing microbial detection systems require quantitative devices such as pipettes, external pipes, and reagent bottles during the experiment. Reagents need to be pumped from external reagent bottles into the detection system. The system structure is complex and repeated use of external pipes and reagent bottles will cause cross-contamination, which may lead to erroneous experimental results. It is not conducive to transportation and storage, is not conducive to simplifying the process, and requires a high level of operational skills from the experimenters. Summary of the Invention

[0006] In response to the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a fully automatic single-chip microbial detection system that is easy to operate, prevents contamination, and can detect multiple types of microorganisms through a single chip. The present invention pre-fills various solutions into the storage cavity inside the microfluidic chip in a quantitative manner, and uses a cam group and a rocker group in conjunction with a puncture on-off component to control the transfer of corresponding solutions to the target chamber for experiments in different experimental steps. No external reagent bottles and pipelines are required, and the system is easy to operate, has good stability, and high reliability.

[0007] The technical solution of the present invention is specifically described as follows.

[0008] The present invention provides a fully automatic single-chip microorganism detection system, which includes a microfluidic chip, a base plate, a chip mounting plate, a cam mechanism, a clamping module for driving the cam mechanism to reciprocate linear motion, a first on-off component for controlling the on-off of a flow channel of the microfluidic chip, and a second on-off component for controlling the connection of the microfluidic chip to the atmosphere; the microfluidic chip is vertically placed in a chip slot of the chip mounting plate, the cam mechanism is fixedly connected to the clamping module, the clamping module is slidably mounted on the base plate, the first on-off component is movably mounted on the clamping module, the cam mechanism abuts against the first on-off component, and the second on-off component is fixedly mounted on the clamping module; During operation, the clamping module drives the cam mechanism, the first on-off component, and the second on-off component to move linearly toward the microfluidic chip. The second on-off component controls the connection between the microfluidic chip and the atmosphere. The cam mechanism controls the first on-off component in turn to open or close the flow channel on the microfluidic chip, controlling the transfer of the solution to the target chamber for microbial detection experiments.

[0009] In the present invention, the clamping module includes a needle plate with a plurality of through holes, two slides and two side plates; the slide is connected to the base plate by a sliding assembly to achieve forward and backward sliding; the two side plates are respectively vertically arranged above the two slides; the needle plate is vertically installed at one end of the two side plates; a plurality of first on-off assemblies are movably connected to the needle plate through the through holes; one end of the first on-off assembly abuts against the cam mechanism, and the other end is a free end for contacting the microfluidic chip; a plurality of second on-off assemblies and positioning pins are also fixedly installed on the needle plate; the other end of the positioning pin is used to achieve positioning with the chip hole on the microfluidic chip when clamping the microfluidic chip.

[0010] In the present invention, the cam mechanism includes a cam group and a rocker group. Different cams in the cam group have different angular radius layout designs. The cam group and the rocker group are respectively installed on the two side plates of the clamping module through the cam shaft and the rocker shaft. Each cam is abutted against the corresponding bearing. The bearing is rotatably arranged at the first end of the rocker. The second end of the rocker is a free end, which is connected to one end of the first on-off component. The third end of the rocker is hinged to the rocker shaft.

[0011] In the present invention, a pressure plate module is arranged between the clamping module and the chip mounting plate; the pressure plate module includes a chip pressure plate and a guide column, one end of the guide column passes through the through hole on the needle plate to achieve a movable connection with the needle plate, and the other end is fixedly connected to the chip pressure plate and passes through the through hole on the chip pressure plate to achieve guidance. A second spring is sleeved on the guide column, and the chip pressure plate and the second spring cooperate to compress the microfluidic chip so that the microfluidic chip is fixed in the chip slot without shaking.

[0012] In the present invention, in order to enable the chip pressing plate and the guide column to move smoothly back and forth linearly relative to the needle plate, the diameter of the guide column matches the diameter of the through hole on the chip pressing plate; one end of the guide column is fixedly connected to the chip pressing plate by a screw, and the other end of the guide column is provided with a limit plate. When the chip pressing plate and the guide column move linearly back and forth in the through hole on the needle plate, the limit plate limits the chip pressing plate and the guide column to prevent the chip pressing plate and the guide column from falling off the needle plate.

[0013] In the present invention, a positioning plate is provided between the clamping module and the cam mechanism, the positioning plate and the needle plate are connected by a support column, the first on-off assembly passes through the through hole on the positioning plate, and the first on-off assembly between the positioning plate and the needle plate is sleeved with a first spring.

[0014] In the present invention, the microfluidic chip body is provided with several solution storage chambers and flow channels separated by sealing spacers and / or on-off valves, as well as a negative pressure extraction port. The sealing spacers are arranged on the flow channels running through the microfluidic chip body, the channel valves are arranged through the microfluidic chip body, and the back of the microfluidic chip is sealed by backing glue.

[0015] In the present invention, the first on-off component includes a solid needle with two structures. The solid needle with a sharp portion includes a sharp portion and a convex edge portion. The sharp portion is used to pierce the sealing spacer, and the convex edge portion is used to press the back glue to close the corresponding flow channel; the solid needle without a sharp portion presses the back glue, and based on the deformation of the back glue, it blocks and closes the channel valve; the second on-off component is a hollow needle with a sharp portion, which is used to pierce the solution storage cavity and connect it to the atmosphere.

[0016] The present invention further includes a heating detection module, which is arranged on the needle plate and / or the chip mounting plate at a position corresponding to the reaction chamber of the microfluidic chip to heat and detect the reaction system.

[0017] In the present invention, the sliding assembly includes a guide rail, a slider and a mounting plate; the guide rail is arranged on the base plate, the slider and the guide rail are slidably connected, and the slider is connected to the bottom of the slide; the two ends of the mounting plate are fixedly arranged on the two side plates, and the mounting plate is driven by a screw stepper motor to drive the clamping module to move forward and backward linearly relative to the base plate.

[0018] The present invention also includes correspondingly arranged sensing sheets and photoelectric sensors. When the sensing sheets enter the groove of the photoelectric sensor and block the optical axis, the pressing module returns to the starting point.

[0019] In the present invention, the cam group is installed on a camshaft, and shaft sleeves are arranged between different cams on the camshaft; several rocker arms in the rocker arm group are hinged to a rocker arm shaft; the stepping reduction motor drives the gear to rotate and drives the camshaft and the cam group to rotate to a preset angle.

[0020] In the present invention, a guide sleeve is provided on the through hole of the needle plate, and the first on-off assembly passes through the guide sleeve for guidance and positioning.

[0021] Compared with the prior art, the present invention has the following beneficial effects: The present invention pre-fills various different solutions into the storage cavity inside the microfluidic chip in a quantitative manner. The reagent storage cavity is independently provided with various reagents that do not cross-contaminate each other in the microfluidic chip. The equipment adopts a cam group and a rocker group in conjunction with a puncture component. In different experimental steps, the cam group controls the directional flow of the corresponding solution and transfers it to the target chamber for experiment. No external reagent bottles and pipelines are required, and no aerosol pollution is generated during the operation of the equipment. The operation is simple and the experimental process is fully automated. It has good stability, no cross contamination, and high reliability. It is suitable for use in various scenarios, has high detection efficiency, has low requirements on the operator's level, and does not require a professional PCR laboratory and PCR instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the microorganism detection system provided by the present invention.

[0023] Figure 2 This is a schematic diagram of the structure of a microbial detection system with one side panel omitted.

[0024] Figure 3 It is a schematic diagram of the needle plate structure.

[0025] Figure 4 It is a schematic diagram of the cam mechanism and needle plate structure.

[0026] Figure 5 is with Figure 4 Schematic diagram of the cam mechanism and needle plate structure at different angles.

[0027] Figure 6 This is a schematic diagram of the structure of a microbial detection system with the side panels and chip mounting plate omitted.

[0028] Figure 7 Schematic diagram of the microfluidic chip structure Figure 1 .

[0029] Figure 8 Schematic diagram of the microfluidic chip structure Figure 2 .

[0030] Figure 9 This is a block diagram of the microfluidic chip structure.

[0031] Figure 10 This is a schematic diagram of the first on-off component controlling the opening or closing of the solution storage chamber and the corresponding flow channel.

[0032] Figure numerals: 1-needle plate, 2-guide column, 3-locating pin, 4-chip pressure plate, 5-second spring, 6-solenoid valve, 7-camshaft, 8-screw stepper motor, 9-stepping reduction motor, 10-cam, 11-rocker, 12-side plate, 13-positioning plate, 14-guide rail, 15-slider, 16-rocker shaft, 17-chip mounting plate, 18-chip slot, 19-bottom plate, 20-mounting plate, 21-slide plate, 22-bearing, 23-heating detection module, 24-motor fixing plate, 25-sensor plate, 26-photoelectric sensor, 27 - support column, 28- first spring; 29- first solution storage chamber, 30- second solution storage chamber, 31- third solution storage chamber, 32- fourth solution storage chamber, 33- fifth solution storage chamber, 34- premixing chamber, 35- reaction chamber, 36- first sealing spacer, 37- second sealing spacer, 38- third sealing spacer, 39- fourth sealing spacer, 40- fifth sealing spacer, 41- first negative pressure pumping port, 42- second negative pressure pumping port, 43- third negative pressure pumping port, 44- first on-off valve, 45- second on-off valve, 46- nucleic acid adsorbent; 101-first hollow needle, 102-second hollow needle, 103-third hollow needle, 104-fourth hollow needle, 105-fifth hollow needle, 106-sixth hollow needle; 201-first solid needle, 202-second solid needle, 203-third solid needle, 204-fourth solid needle, 205-fifth solid needle, 206-sixth solid needle, 207-seventh solid needle; 301-first joint, 302-second joint, 303-third joint, 304-fourth joint; 401-first cam, 402 second cam, 403-third cam, 404-fourth cam, 405-fifth cam, 406-sixth cam, 407-seventh cam. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0034] Example 1

[0035] The present invention provides a fully automatic single-chip microbial detection system. Except for the sample solution obtained after lysis, the remaining various solutions are pre-quantified and filled into the storage cavity inside the microfluidic chip. A cam group and a rocker group are used in conjunction with a puncture on-off component to control the transfer of corresponding solutions to the target chamber for experiment in different experimental steps.

[0036] like Figure 1-Figure 7As shown, the system of the present invention includes a microfluidic chip, a cam mechanism, a first on-off component for controlling the on-off of the flow channel of the microfluidic chip, a second on-off component for controlling the connection between the microfluidic chip and the atmosphere, a clamping module, a pressure plate module and a heating detection module 23 and a chip mounting plate 17. The chip mounting plate 17 is fixedly set on the base plate 19. The chip mounting plate 17 is provided with a chip slot 18, and the microfluidic chip is placed in the chip slot 18; the chip mounting plate 17 and the microfluidic chip reaction chamber are provided with a heating detection module 23 at the corresponding positions. When the reaction is completed, the experimental results are detected based on the optical detection module.

[0037] In a specific embodiment, the microfluidic chip body is provided with independent first to fifth solution storage chambers 29, 30, 31, 32, and 33 (respectively, a lysate storage chamber, a washing liquid storage chamber, an eluate storage chamber, a waste liquid chamber, and a reaction liquid storage chamber). The top surfaces of the above solution storage chambers are all sealed by plugs, and the flow channels connecting the above solution storage chambers are all provided on the front of the microfluidic chip. The front of the microfluidic chip is sealed by a sealing film, and a sealing spacer is provided at the connection between the solution storage chamber and the corresponding flow channel to isolate several solution storage chambers from the corresponding flow channel; the first solution storage chamber 29 storing the lysate is isolated from the flow channel where the nucleic acid adsorbent 46 is located by a first sealing spacer 36, the second solution storage chamber 30 storing the washing liquid is isolated from the flow channel where the nucleic acid adsorbent 46 is located by a second sealing spacer 37, the third solution storage chamber 31 storing the eluate is isolated from the flow channel where the nucleic acid adsorbent 46 is located by a third sealing spacer 38, and the flow channel where the nucleic acid adsorbent 46 is located is isolated from the third solution storage chamber 31 storing the waste liquid. A first on-off valve 44 is provided between the four solution storage chambers 32, the flow channel where the nucleic acid adsorbent 46 is located is provided on the front side of the microfluidic chip, and a second on-off valve 45 is provided in the flow channel between the rear end of the nucleic acid adsorbent 46 and the rear end of the first on-off valve 44. A fourth sealing spacer 39 is provided between the fifth solution storage chamber 33 storing the reaction solution and the premixing chamber 34, and the fifth solution storage chamber 33 is isolated from the premixing chamber 34 by the fourth sealing spacer 39. A fifth sealing spacer 40 is provided between the premixing chamber 34 and the reaction chamber 35. The above sealing spacers are all integrally formed with the microfluidic chip and are provided on the flow channel running through the microfluidic chip body. The first on-off component is used to control the connection or closing of the solution storage chamber and the corresponding flow channel. When the solution storage chamber and the corresponding flow channel need to be connected, the first access component pierces the sealing spacer and retreats, at which time the solution storage chamber is connected to the corresponding flow channel. When the solution storage chamber and the corresponding flow channel need to be closed, the first on-off component presses the corresponding adhesive, at which time the solution storage chamber and the corresponding flow channel are closed. The first on-off assembly controls the opening or closing of the solution storage chamber and the corresponding flow channel in sequence, so as to realize the sequential and directional release of the solutions in the plurality of solution storage chambers.The first on-off valve 44 and the second on-off valve 45 are formed by the flow channel and the adhesive backing at a specific position on the microfluidic chip. The first on-off valve and the second on-off valve intersect and connect to the nucleic acid adsorbent. The first on-off valve is arranged between the nucleic acid adsorbent and the waste liquid chamber, and the second on-off valve is arranged between the nucleic acid adsorbent and the fourth sealing spacer. The back side of the microfluidic chip is sealed by the adhesive backing. The first on-off valve 44 and the second on-off valve 45 are initially open. In subsequent experimental steps, the first on-off component is controlled to press the adhesive backing to achieve the closing of the first and second on-off valves 44 and 45. Specifically, in the initial state, the first and second on-off valves are open, and the first on-off component is used to control the opening or closing of the first and second on-off valves. When the lysate and the cleaning solution pass through the nucleic acid adsorbent, the first on-off valve is controlled to open and the second on-off valve is closed, and the lysate and the cleaning solution ultimately enter the fourth solution storage chamber (waste liquid chamber). When the eluate passes through the nucleic acid adsorbent, the first on-off valve is controlled to close and the second on-off valve is controlled to open, and the eluate ultimately enters the premixing chamber. In order to simplify the structure of the cam group, the first to fourth sealing spacers 3, 37, 38, 39 and the first and second on-off valves 44, 45 can be arranged on the same straight line.

[0038] The cam mechanism comprises a cam assembly and a rocker assembly. The cam assembly comprises seven cams 10, which are keyed to the camshaft 7 to form a module. (To prevent the cams 10 from rotating relative to the camshaft 7, the cams 10 and camshaft 7 are connected by a flat key.) To prevent the cams 10 from swinging, sleeves are placed between the cams 10 on the camshaft 7. A stepper motor 9 drives the gears, rotating the camshaft 7 and the cam assembly to a preset angle. Each rotation of the camshaft 7 rotates all seven cams 10. Each cam 10 abuts against a corresponding bearing 22. Throughout the experiment, the rims of the cams 10 and the bearings maintain contact. The bearing 22 is rotatably mounted on the first end of the rocker 11. The second (free) end of the rocker 11 abuts against the first on / off assembly. The third end of the rocker 11 is hinged to the rocker shaft 16. Each cam 10 controls the linear motion of a first on / off assembly.

[0039] In the embodiment, Figure 10As shown, a first on-off component is used to control the on-off of the flow channel of the microfluidic chip. The first on-off component adopts a solid needle, including a solid needle with a sharp part and a solid needle without a sharp part. The solid needle with a sharp part includes a sharp part and a convex edge part. The convex edge part is used to press the back glue to close the corresponding flow channel, and the sharp part is used to pierce the different solution storage chambers in the microfluidic chip, as well as the sealing partitions between the solution storage chamber and the flow channel. The solid needle without a sharp part acts like a pressure rod, which is used to press the back glue to block the channel valve; the second on-off component is used to control the connection between the microfluidic chip and the atmosphere, and the second channel component is a hollow needle with a sharp part; the solid needle and the hollow needle are both installed on the needle plate 1, wherein the hollow needle is fixedly installed on the needle plate 1 , the solid needle is movably connected to the through hole of the needle plate 1; a guide sleeve is fixedly arranged on the through hole of the needle plate 1, and the first on-off component (solid needle) passes through the guide sleeve for guiding and positioning, corresponding to the position corresponding to the microfluidic chip; the first row of the needle plate 1 is provided with the first to fourth hollow needles 101~104, and the first to fourth hollow needles 101~104 are arranged on the same horizontal line; the middle row of the needle plate 1 is provided with the first to sixth solid needles 201~206, and the first to sixth solid needles 201~206 are arranged on the same horizontal straight line; the third row of the needle plate 1 is provided with the fifth hollow needle 105, the sixth hollow needle 106 and the seventh solid needle 207, the fifth and sixth hollow needles 105, 106, and the seventh solid needle 207 are arranged on the same horizontal straight line, and the ends of the third hollow needle 103 and the fourth hollow needle 104 away from the spike portion are respectively provided with a first connector 301 and a second connector 302. The first connector 301 is connected to the waste liquid peristaltic pump, and the second connector 302 is connected to the normally closed solenoid valve 6 (normally closed, the fifth solution storage chamber 33 is controlled to open when it needs to be vented to the atmosphere, and is closed after the reaction liquid and the nucleic acid premix enter the reaction chamber 35. This prevents the nucleic acid aerosol from overflowing from the chip when the reaction liquid and the nucleic acid premix are heated, prevents aerosol contamination, and ensures the accuracy of the experimental results); the ends of the fifth hollow needle 105 and the sixth hollow needle 106 away from the spike portion are respectively provided with a third connector 303 and the fourth joint 304, the third joint 303 is connected to the peristaltic pump for extracting the premixing chamber, and the fourth joint 304 is connected to the peristaltic pump for extracting the reaction chamber; the first to seventh solid needles 201~207 are driven and controlled by the cam group, the solid needles 201-203, 206-207 have a sharp part for piercing the sealing spacer, the fourth and fifth solid needles 204, 205 have no sharp part, the fourth solid needle 204 is used to block the first on-off valve 44 of the microfluidic chip, and the fifth solid needle 205 is used to block the second on-off valve 45 of the microfluidic chip; the fourth solid needle 204 and the fifth solid needle 205 close the first on-off valve 44 or the second on-off valve 45 by pressing the back glue to deform the back glue.

[0040] A positioning plate 13 with several through-holes is also provided between the cam mechanism and needle plate 1. Positioning plate 13 and needle plate 1 are connected via support columns 27. A first on-off assembly, connected to the free end of rocker arm 11, passes through the through-holes in positioning plate 13 and needle plate 1, respectively. A first spring 28 is sleeved around the first on-off assembly between positioning plate 13 and needle plate 1. The provision of positioning plate 13 prevents the solid needle from tilting or deflecting as it makes linear motion toward the microfluidic chip. This ensures that the solid needle precisely controls the on-off switching of each flow path in the microfluidic chip, preventing errors and making the detection process more stable and reliable, ultimately guaranteeing accurate detection results. Furthermore, the principle behind using the first on-off assembly (a solid needle with a spiked portion) to puncture the sealed spacer in the chip is as follows: the motor drives camshaft 7 to rotate, driving the cam assembly to rotate. Camshaft 7 passes through the cam hole, causing the distance between the cam hole and the rim of cam 10 to change. When the distance between the cam hole and the cam rim increases, cam 10 pushes rocker 11, which further pushes the end of the solid needle forward, causing the solid needle to move forward and puncture the corresponding spacer. The principle behind the solid needle leaving the microfluidic chip is that the motor drives camshaft 7 to rotate, driving the cam assembly 7 in reverse, causing the distance between the cam hole and the rim of cam 10 to slowly and uniformly decrease. The compressed first spring 28 then recovers its elastic deformation, pushing the solid needle out of the microfluidic chip.

[0041] In the embodiment, the clamping module drives the cam mechanism, the first on-off component, and the second on-off component to move linearly toward the microfluidic chip. The second on-off component controls the connection between the microfluidic chip and the atmosphere. The cam mechanism sequentially controls the first on-off component to open or close the flow channel on the microfluidic chip, thereby controlling the transfer of the solution to the target chamber for microbial detection experiments.

[0042] The camshaft 7 and the rocker shaft 16 in the cam structure are fixedly arranged on the side plate 12, the side plate 12 is fixedly arranged on the slide 21, the bottom of the slide 21 is fixedly provided with a slider 15, the slider 15 is slidably arranged on the guide rail 14, the guide rail 14 is fixedly arranged on the bottom plate 19, the needle plate 1, the side plate 12 and the slide 21 are fixed to form a clamping module; the clamping module is driven by the screw stepping motor 8 to rotate the screw and drive it to slide back and forth on the guide rail 14; the on-off component is driven to approach or enter the microfluidic chip; the screw passes through the screw nut, The lead screw nut is fixed on the mounting plate 20, both ends of the mounting plate 20 are fixed on the side plate 12, the fixed end of the lead screw stepper motor 8 is fixed on the motor fixing plate 24, and the motor fixing plate 24 is fixed on the base plate 19; a sensing sheet 25 is fixed on the mounting plate 20, and a photoelectric sensor 26 corresponding to the sensing sheet 25 is provided on the motor fixing plate 24. When the sensing sheet 25 enters the groove of the photoelectric sensor 26 and blocks the optical axis, the clamping module returns to the starting point and the lead screw stepper motor 8 stops rotating.

[0043] In the embodiment, a pressure plate module consisting of a chip pressure plate 4 and a guide column 2 is further arranged between the clamping module and the microfluidic chip. The chip pressure plate 4 and the needle plate 1 are arranged in parallel. One end of the guide column 2 is movably connected to the needle plate 1, and the other end is fixedly connected to the chip pressure plate 4. It passes through the through hole on the chip pressure plate 4 to achieve guidance, and a second spring 5 is sleeved on the guide column; the pressure plate module makes a forward and backward linear motion relative to the needle plate 1 through the guide column 2; the chip pressure plate 4 and the second spring 5 cooperate to compress the microfluidic chip so that the microfluidic chip is fixed in the chip slot 18 without shaking; at the same time, when the second spring 5 is in a free state, the chip pressure plate 4 hides all needle tips in the chip pressure plate 4 to prevent the sharp thorns from being exposed to the chip pressure plate 4, thereby avoiding injuries to the hands when taking and placing the chip. Furthermore, in order to make the chip pressing plate 4 and the guide column 2 move smoothly back and forth linearly relative to the needle plate 1, the diameter of the guide column 2 matches the diameter of the through hole on the chip pressing plate 4; one end of the guide column 2 is fixedly connected to the chip pressing plate 4 by a screw, and the other end of the guide column 2 is provided with a limit plate. When the chip pressing plate 4 and the guide column 2 move linearly back and forth in the through hole on the needle plate 1, the limit plate limits the chip pressing plate 4 and the guide column 2 to prevent the chip pressing plate 4 and the guide column 2 from falling off from the needle plate 1.

[0044] In the embodiment, a heating detection module 23 may be further provided at positions corresponding to the microfluidic chip reaction chambers on the needle plate 1 and the chip mounting plate 17 to heat the reaction system to improve reaction efficiency and perform detection.

[0045] In the embodiment, each chamber in the microfluidic chip is vented to the atmosphere in the following manner: the second and third solution storage chambers 30 and 31 are punctured with a second on-off assembly (hollow needle) to vent to the atmosphere; the first solution storage chamber 29 is connected to a sampling tube or the plug on the first solution storage chamber 29 is opened to vent to the atmosphere; the fourth solution storage chamber 32 does not need to be vented to the atmosphere and is connected to a peristaltic pump to pump negative pressure therein; the fifth solution storage chamber 33 is opened by a normally closed solenoid valve 6 to communicate with the outside atmosphere; the premixing chamber 34 and the reaction chamber 35 are connected to a peristaltic pump to pump negative pressure therein.

[0046] In the embodiment, the solution is controlled to release and flow in a directional manner in steps as follows: 1. Open the stopper on the first solution storage chamber 29, add the lysed sample solution into the first solution storage chamber 29, and place the microfluidic chip into the chip slot 18; 2. The screw stepper motor 8 drives the side plate 12, the needle plate 1 and the slide plate 21 to form a pressing module that slides on the guide rail 14 and approaches the microfluidic chip steadily. The positioning pin 3 is aligned with the chip hole to adjust the position of the microfluidic chip. The pressing module continues to approach the microfluidic chip. At the same time, the chip pressing plate 4 in the pressing plate module cooperates with the second spring 5 to press the microfluidic chip so that the microfluidic chip is fixed and does not shake. At this time, the first, second and fourth hollow needles 101, 102, 104 on the needle plate 1 pierce the second, third and fifth solution storage chambers 30, 31, 33, so that the second and third solution storage chambers Chambers 30 and 31 are vented to the atmosphere. When the fifth solution storage chamber 33 is punctured, it is cut off from the outside atmosphere by the normally closed solenoid valve 6 (to ensure the activity of the reaction solution). At the same time, the third hollow needle 103 punctures the fourth solution storage chamber 32. The end of the third hollow needle 103 away from the needle tip is the first negative pressure withdrawal port 41. The fifth hollow needle 105 punctures the second negative pressure withdrawal port 42. The sixth hollow needle 106 punctures the third negative pressure withdrawal port 43. The seventh solid needle 207 punctures the fifth sealing spacer 40 between the premixing chamber 34 and the reaction chamber 35 (puncturing and blocking the passage, i.e., the seventh solid needle does not retreat). 3. Add lysate, start the stepping reduction motor 9, drive the cam group to rotate, the first cam 401 drives the first solid needle 201 to enter the microfluidic chip and puncture the first sealing spacer 36. At the same time, the fifth cam 405 drives the fifth solid needle 205 to block the adhesive and close the second on-off valve 45. The first cam 401 is controlled to rotate to drive the first solid needle 201 out of the microfluidic chip. At this time, the first solution storage chamber 29 and the fourth solution storage chamber 32 are connected; negative pressure is drawn at the first negative pressure pumping port 41, and the lysate flows into the fourth solution storage chamber 32, and the nucleic acid is adsorbed on the nucleic acid adsorbent 46; 4. Add washing solution, drive the cam assembly to rotate, control the first cam 401 to rotate and drive the first solid needle 201 into the microfluidic chip. At this time, the first solution storage chamber 29 and the fourth solution storage chamber 32 are disconnected, and the first solution storage chamber 29 is isolated from the remaining passages. (This design ensures that the solution in the second solution storage chamber can be smoothly driven by negative pressure. If the first solution storage chamber is not isolated from the remaining passages in this step, since the lysate has been completely pumped out and only air is left inside, the liquid flow resistance is greater than the gas flow resistance, and the solution in the second solution storage chamber cannot be driven to flow in a directional manner.) At the same time, the second cam 402 drives the second solid needle 202 into the microfluidic chip to puncture the second sealing spacer 37. The second cam 402 is controlled to rotate to drive the second solid needle 202 out of the microfluidic chip. At this time, the second solution storage chamber 30 and the fourth solution storage chamber 32 are connected. Negative pressure is applied to the first negative pressure port 41, and the washing solution flows into the fourth solution storage chamber 32 to clean impurities on the nucleic acid adsorbent 46. 5. Add eluent, drive the cam assembly to rotate, control the second cam 402 to rotate and drive the second solid needle 202 to enter the microfluidic chip. At this time, the second solution storage chamber 30 and the fourth solution storage chamber 32 are disconnected (the first solution storage chamber 29 is isolated from the other passages, the purpose is the same as above), and the second solution storage chamber 30 is isolated from the other passages; at the same time, the third cam 403 drives the third solid needle 203 to enter the microfluidic chip and pierce the third sealing spacer 38, and at the same time drives the fourth cam 404 to cooperate with the fourth solid needle 204 to block the first on-off valve 44. The fifth cam 405 is driven to cooperate with the fifth solid needle 205 to open the second on-off valve 45. The third cam 403 is controlled to rotate to drive the third solid needle 203 away from the microfluidic chip. At this time, the third solution storage chamber 31 is connected to the premixing chamber 34, and the nucleic acid adsorbent 46 is heated (heating improves the elution efficiency of the nucleic acid, thereby improving the detection sensitivity of the device). After the temperature reaches the set temperature, negative pressure is applied to the second negative pressure port 42, and the eluent elutes the nucleic acid from the nucleic acid adsorbent 46. The eluent and nucleic acid enter the premixing chamber 34 together. The corresponding heating module is turned off. 6. Add the reaction solution, drive the cam group to rotate, control the third cam 403 to rotate and drive the third solid needle 203 to enter the microfluidic chip. At this time, the third solution storage chamber 31 is isolated from the other passages. At the same time, control the fifth cam 405 to cooperate with the fifth solid needle 205 to close the second on-off valve 45. At this time, the front end of the second on-off valve 45 is isolated from the rear end premixing chamber 34 and is not connected to each other; the sixth cam 406 drives the sixth solid needle 206 to enter the microfluidic chip and puncture the fourth sealing spacer 39. Control the sixth cam 406 to rotate and drive the sixth solid needle 206 to leave the microfluidic chip. At this time, the fifth solution storage chamber 33 is connected to the premixing chamber 34; The normally closed solenoid valve 6 of the fifth solution storage chamber 33 is opened, and the fifth solution storage chamber 33 is connected to the atmosphere (connection to the atmosphere allows the solution in the chamber to be driven by negative pressure). Negative pressure is drawn through the second negative pressure extraction port 42, and the reaction solution enters the premixing chamber 34 under the action of the negative pressure. 7. Drive the cam assembly to rotate, control the seventh cam 407 to rotate, and drive the seventh solid needle 207 to leave the microfluidic chip. At this time, the premixing chamber 34 is connected to the reaction chamber 35. (In this last step, the reaction chamber 35 is controlled to be connected to the premixing chamber 34 to prevent the substance in the reaction chamber 35 from contacting other chambers prematurely, thereby ensuring the activity of the substance in the reaction chamber 35 and the accuracy and sensitivity of the experiment.) The third negative pressure pumping port 43 is used to pump negative pressure to drive the nucleic acid and reaction solution in the premixing chamber 34 into the reaction chamber 35 . 8. Drive the cam assembly to rotate, which drives the first, second, third, fourth, fifth, and sixth solid needles 201, 202, 203, 204, 205, and 206 to leave the microfluidic chip and drives the seventh solid needle 207 to enter the microfluidic chip, thereby isolating the premixing chamber 34 from the reaction chamber 35 (before the reaction chamber 35 is heated and the substances in the reaction chamber 35 react, the reaction chamber 35 is isolated from other flow paths to prevent aerosols generated during the reaction from overflowing, thereby protecting the device from aerosol contamination and ensuring the stability and accuracy of the device operation. Without this isolation step, aerosol contamination of the device may result in false positives, making the sample results unanalyzable). Control the normally closed solenoid valve 6 of the fifth solution storage chamber 33 to close, thereby isolating the fifth solution storage chamber 33 from the atmosphere (ensuring that the reaction solution is not directly connected to the outside atmosphere during the next experiment, thereby ensuring the activity of the reaction solution during each experiment and further ensuring the accuracy of the experiment). 9. Heat the reaction chamber 35 and monitor the reaction process; 10. Drive needle plate 1 back to its initial position and discard the chip.

[0047] The above steps implement the process of initial state, binding, washing, elution, reaction solution loading, and sample loading; it is automatically controlled according to the cam timing table shown in Table 1, combined with the angle radius layout design of the cam structure, so that in steps 3-8, the cam on the cam group rotates 360 degrees in six steps, completing the entire detection process of microorganisms based on the directional release flow of the solution.

[0048] Table 1 Cam timing table

[0049] Note: The first to third cams are used to control the opening or closing of the first to third solution storage chambers and flow channels respectively; The fourth to fifth cams are used to control the opening or closing of the first and second on-off valves respectively; The sixth cam is used to control the opening or closing of the fifth solution storage chamber and the flow channel; The seventh cam is used to control the connection or closing between the premixing chamber and the reaction chamber; The cam radius becomes larger, and the corresponding solid needle approaches the chip, puncturing the sealing spacer or closing the flow channel; The cam radius becomes smaller, and the corresponding solid needle moves away from the chip, opening the flow channel or opening the on-off valve.

Claims

1. A fully automatic single-chip microbial detection system, characterized in that: The microfluidic chip comprises a microfluidic chip, a base plate, a chip mounting plate, a cam mechanism, a pressing module for driving the cam mechanism to reciprocate linear motion, a first on-off component for controlling the on-off of a flow channel of the microfluidic chip, and a second on-off component for controlling the connection between the microfluidic chip and the atmosphere; the microfluidic chip is vertically placed in a chip slot of the chip mounting plate, the cam mechanism is fixedly connected to the pressing module, the pressing module is slidably arranged on the base plate, the first on-off component is movably arranged on the pressing module, the cam mechanism abuts against the first on-off component, and the second on-off component is fixedly arranged on the pressing module; During operation, the clamping module drives the cam mechanism, the first on-off component, and the second on-off component to move linearly toward the microfluidic chip. The second on-off component controls the connection between the microfluidic chip and the atmosphere. The cam mechanism controls the first on-off component in turn to open or close the flow channel on the microfluidic chip, controlling the transfer of the solution to the target chamber for microbial detection experiments.

2. The fully automatic single-chip microbial detection system according to claim 1, characterized in that: The clamping module includes a needle plate with several through holes, two slides and two side plates; the slide is connected to the base plate by a sliding assembly to achieve forward and backward sliding connection, the two side plates are vertically arranged above the two slides, and the needle plate is vertically installed at one end of the two side plates. Several first on-off components are movably connected to the needle plate through the through holes, one end of the first on-off component is in contact with the cam mechanism, and the other end is a free end for contacting the microfluidic chip. Several second on-off components and positioning pins are also fixedly installed on the needle plate, and the other end of the positioning pin is used to achieve positioning with the chip hole on the microfluidic chip when compressing the microfluidic chip.

3. The fully automatic single-chip microorganism detection system according to claim 2, characterized in that: The cam mechanism includes a cam group and a rocker group. Different cams in the cam group have different angular radius layout designs. The cam group and the rocker group are respectively installed on the two side plates of the clamping module through the cam shaft and the rocker shaft. Each cam is abutted against the corresponding bearing. The bearing is rotatably set at the first end of the rocker. The second end of the rocker is a free end, which is connected to one end of the first on-off component. The third end of the rocker is hinged to the rocker shaft.

4. The fully automatic single-chip microorganism detection system according to claim 2, characterized in that: A pressure plate module is arranged between the clamping module and the chip mounting plate; the pressure plate module includes a chip pressure plate and a guide column, one end of the guide column passes through the through hole on the needle plate to achieve a movable connection with the needle plate, and the other end is fixedly connected to the chip pressure plate and passes through the through hole on the chip pressure plate to achieve guidance. A second spring is sleeved on the guide column, and the chip pressure plate and the second spring cooperate to compress the microfluidic chip so that the microfluidic chip is fixed in the chip slot without shaking.

5. The fully automatic single-chip microorganism detection system according to claim 2, characterized in that: A positioning plate is provided between the pressing module and the cam mechanism. The positioning plate and the needle plate are connected via a support column. The first on-off assembly passes through a through hole on the positioning plate. A first spring is sleeved on the first on-off assembly between the positioning plate and the needle plate.

6. The fully automatic single-chip microorganism detection system according to claim 2, characterized in that: The microfluidic chip body is provided with several solution storage chambers and flow channels separated by sealing spacers and / or on-off valves, as well as a negative pressure extraction port. The sealing spacers are set on the flow channels that run through the microfluidic chip body. The on-off valves are formed by the flow channels and backing adhesive on the microfluidic chip. The back of the microfluidic chip is sealed by the backing adhesive.

7. The fully automatic single-chip microorganism detection system according to claim 6, characterized in that: The first on-off component includes a solid needle with two structures. The solid needle with a sharp part includes a sharp part and a convex edge part. The sharp part is used to pierce the sealing spacer, and the convex edge part is used to press the back glue to close the corresponding flow channel. The solid needle without a sharp part presses the back glue, and based on the deformation of the back glue, it blocks the closing channel valve; the second on-off component is a hollow needle with a sharp part, which is used to pierce the solution storage cavity and connect it to the atmosphere.

8. The fully automatic single-chip microorganism detection system according to claim 2, characterized in that: It also includes a heating detection module, which is arranged on the needle plate and / or the chip mounting plate at the reaction chamber position corresponding to the microfluidic chip to heat and detect the reaction system.

9. The fully automatic single-chip microorganism detection system according to claim 2, characterized in that: The sliding assembly includes a guide rail, a slider and a mounting plate; the guide rail is set on the base plate, the slider and the guide rail are slidingly connected, and the slider is connected to the bottom of the slide; the two ends of the mounting plate are fixedly set on the two side plates, and the mounting plate is driven by a screw stepper motor to drive the clamping module to move forward and backward linearly relative to the base plate.

10. The fully automatic single-chip microorganism detection system according to claim 1, characterized in that: It also includes a correspondingly arranged sensing sheet and a photoelectric sensor. When the sensing sheet enters the groove of the photoelectric sensor and blocks the optical axis, the pressing module returns to the starting point.

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