CN217733113U

CN217733113U - Closed PCR micro-fluidic chip for multi-sample detection

Info

Publication number: CN217733113U
Application number: CN202221450501.6U
Authority: CN
Inventors: 刘博�; 徐佳君; 豆传国
Original assignee: Shanghai Sige Biotechnology Co ltd
Current assignee: Shanghai Sige Biotechnology Co ltd
Priority date: 2022-06-10
Filing date: 2022-06-10
Publication date: 2022-11-04
Anticipated expiration: 2032-06-10

Abstract

The utility model relates to the field of biological medical treatment, in particular to a closed PCR micro-fluidic chip for multi-sample detection, which comprises at least two sample inlets and gas outlets, at least two sample inlet guide pipes and at least two gas outlet pipes, wherein at least two amplification units are integrated on the same silicon chip, and the same heat conducting sheet is utilized to uniformly transfer heat to the at least two amplification units, so that the temperature rise and fall of all amplification cavities can be synchronous with the temperature rise and fall of an external heat source, and the uniform heat transfer of all amplification cavities is realized, thereby realizing rapid temperature rise and fall and greatly shortening the time consumption of nucleic acid detection; in the present disclosure, no gap exists between the heat conducting fin and the silicon-based chip, and the heat transfer efficiency is further improved.

Description

Closed PCR micro-fluidic chip for multi-sample detection

Technical Field

The utility model relates to a biomedical field, concretely relates to closed PCR micro-fluidic chip for many sample detection.

Background

As one of the main detection modes in the field of in vitro diagnosis, nucleic acid detection is the most direct, reliable and sensitive method for realizing early, rapid and specific detection of pathogens, can rapidly detect pathogen nucleic acid in a detection sample, and provides scientific detection basis for accurate diagnosis of infectious cases. The nucleic acid amplification detection is to amplify a nucleic acid sequence to be detected through the action of enzyme, wherein the PCR (polymerase chain reaction) technology is most widely applied due to the advantages of good specificity, low cost and the like. PCR consists of three basic reaction steps of denaturation, annealing and extension, the reaction time is always the limiting factor of the application of the PCR technology, and an instrument improved aiming at the PCR reaction time is presented at present, for example, patent document CN 111269825A discloses a rapid nucleic acid instant detector with a rapid temperature raising and lowering module, but the current PCR reaction container has lower heat conduction efficiency, and for the PCR reaction needing circulating temperature raising and lowering, the heat conduction efficiency of the PCR reaction container is lower, so that the temperature raising and lowering speed is slow, and the whole process takes longer.

The micro-fluidic chip technology integrates the traditional biochemical analysis on a chip with the size of a few square centimeters or even smaller, and completes detection and analysis in a micro-nano scale channel and a micro-chamber in the chip. However, the microfluidic chip requires a suitable heat-conducting material in nucleic acid detection, so that the manufacturing difficulty and cost are greatly increased, and the totally-enclosed PCR amplification environment is difficult to realize, thereby limiting the further clinical application of the microfluidic chip.

In addition, a closed microfluidic chip for PCR reaction is disclosed in patent 2021221063932, but in this technique, when a plurality of samples are detected, a plurality of closed microfluidic chips are independently distributed on the pressure cover, and at this time, the same heat transfer component is commonly used by the plurality of closed microfluidic chips, and there is a possibility that the detection effect is affected by non-uniform temperature rise among the plurality of closed microfluidic chips; meanwhile, the patent adopts a buckle structure to realize sealing between the closed microfluidic chip and the gland, so that a gap exists between the closed microfluidic chip and the heat conducting component when the integral structure is heated, and the heat conducting efficiency is not high.

Therefore, a micro-fluidic chip with uniform temperature rise and high heat conduction efficiency is urgently needed, and the heat conduction efficiency of the micro-fluidic chip is improved while the full-closed PCR amplification environment is realized.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned prior art is whole or some deficiency, the utility model provides a closed PCR micro-fluidic chip for many sample detections, make the temperature rise and fall of all amplification chambeies can with the temperature rise and fall of external heat source synchronous, realize fast, evenly rise and fall the temperature, greatly shorten nucleic acid detection's consuming time; meanwhile, no gap exists between the heat conducting fins and the silicon-based chip, and the heat transfer efficiency is further improved.

In order to realize the purpose of the utility model, the utility model provides a following technical scheme: a closed PCR micro-fluidic chip for multi-sample detection comprises a gland, a first surface sample inlet, a gas outlet and a sealing film, wherein the first surface sample inlet is arranged on the gland; the sealing membrane covers the sample inlet and the gas outlet, the second surface is provided with mounting grooves, at least two sample inlets are arranged, at least two gas outlets are arranged, the first surface of the gland is also provided with at least two sample introduction guide pipes and at least two gas outlet pipes, the sample introduction guide pipes are communicated with the sample inlet, and the gas outlet pipes are communicated with the gas outlets; the device comprises a silicon-based chip, wherein at least two amplification units which are independently arranged are arranged on the silicon-based chip; the silicon-based chip is arranged in the mounting groove through a sealing element containing a micro-cavity hole. The technical scheme has the advantages that through the arrangement of the sealing element with the micro-cavity hole, on one hand, elastic buffering between the silicon-based chip and the pressing cover can be realized, so that the silicon-based chip can effectively contact with an external heat transfer seat without generating an air cavity, and meanwhile, the silicon-based chip is fixedly connected onto the pressing cover by the sealing element with the micro-cavity hole, so that no gap exists between the heat conducting fins and the silicon-based chip, and the heat transfer efficiency is further improved; on the other hand, the simultaneous detection of a plurality of samples is realized by arranging at least two amplification units on the same silicon-based chip; in addition, the pollution caused by aerosol diffusion generated in the reaction process is further reduced by arranging the sample introduction guide pipe and the gas outlet pipe, and the sealing effect of the whole product is further improved.

The silicon-based chip comprises a glass layer and a silicon-based layer, the amplification unit is arranged in the silicon-based layer and comprises a liquid inlet micro-channel, a liquid outlet micro-channel and an amplification cavity, and the liquid inlet micro-channel and the liquid outlet micro-channel penetrate through the glass layer and are communicated with the amplification cavity. The glass layer is arranged on the silicon-based chip to seal the silicon-based layer amplification cavity, and meanwhile, the glass layer is arranged on the silicon-based layer to directly perform fluorescence detection on a sample after the amplification is finished; the micro-circulation of sample introduction, reaction and exhaust is realized by arranging a liquid inlet micro-channel, a liquid outlet micro-channel and an amplification cavity in a silicon substrate.

The silicon-based layer is also provided with a heat insulation groove for insulating the amplification cavity. The technical scheme has the advantages that the heat insulation groove is arranged around the amplification cavity of the silicon substrate, so that the amplification cavity is separated from the external area around the silicon substrate, the heat load is effectively reduced, the heating heat of external heat transfer equipment is concentrated in the amplification cavity, the heating speed of the amplification cavity is effectively increased, and the time required by amplification reaction is shortened.

The sealing element containing the microcavity hole is double-sided sealing glue, and the silicon-based chip is fixedly arranged in the mounting groove through the double-sided sealing glue; the micro-cavity holes are a liquid inlet micro-cavity hole and a gas outlet micro-cavity hole. The technical scheme has the beneficial effects that the silicon-based chip is fixedly connected to the gland by using the double-sided sealant containing the micro-cavity hole, so that no gap exists between the heat conducting fins and the silicon-based chip, and the heat transfer efficiency is further improved.

Furthermore, one side of the double-sided sealant is connected with the gland, and the other side of the double-sided sealant is connected with the glass layer.

The sample introduction guide pipe and the gas outlet pipe are communicated with the liquid inlet micro-channel and the liquid outlet micro-channel respectively through the liquid inlet micro-cavity hole and the gas outlet micro-cavity hole. The technical scheme has the beneficial effects that the sample introduction guide pipe and the gas outlet pipe penetrate through the micro-cavity hole of the double-sided sealant to be communicated with the liquid inlet micro-channel and the liquid outlet micro-channel, so that on one hand, the sample introduction guide pipe can guide a sample during sample introduction, and the sample introduction efficiency is improved; on the other hand, the diffusion of aerosol generated in the reaction process is further reduced, the generated aerosol can be directly discharged out of the amplification unit through the air outlet pipe, the pollution is reduced, and meanwhile, the sealing performance is improved.

Furthermore, the sample introduction flow guide pipe and the gas outlet pipe penetrate through the liquid inlet micro-cavity hole and the gas outlet micro-cavity hole and are directly communicated with the liquid inlet micro-channel and the liquid outlet micro-channel respectively.

Furthermore, the sample introduction flow guide pipe and the gas outlet pipe are indirectly communicated with the liquid inlet micro-channel and the liquid outlet micro-channel through the liquid inlet micro-cavity hole and the gas outlet micro-cavity hole respectively. The sample introduction guide pipe and the gas outlet pipe are indirectly communicated with the liquid inlet micro-channel and the liquid outlet micro-channel through the micro-cavity holes of the double-sided sealant, so that the sample addition efficiency is improved, and meanwhile, the sealing performance is ensured.

The silicon-based chip is connected with external heat transfer equipment through the heat conducting fins; the heat conducting fin is fixedly connected to the center of the silicon-based chip. The beneficial effects of this technical scheme lie in, through being fixed in silicon substrate chip central authorities with the conducting strip and realizing the even heat conduction of a plurality of amplification units on the silicon substrate chip, realize that silicon substrate chip rises and falls the temperature and synchronous with outside infectious equipment.

Preferably, 16 amplification units are arranged on the silicon-based chip, and the 16 amplification units are arranged on the silicon-based chip in parallel. By arranging 16 amplification units on the silicon-based chip, 16 samples can be detected simultaneously, and the detection efficiency is improved.

The silicon-based chip is provided with a plurality of amplification units, the gland is provided with at least two mounting grooves, and one silicon-based chip is mounted in each mounting groove.

Preferably, the silicon-based chip is provided with 5 amplification units, the gland is provided with 5 mounting grooves, and one silicon-based chip is mounted in each mounting groove. Through set up 5 mounting grooves on the gland, set up a slice silicon-based chip on every mounting groove, set up 5 amplification unit on every silicon-based chip, realize detecting when 25 samples.

The sampling guide pipe, the air outlet pipe and the gland are integrally formed. The injection guide pipe, the air outlet pipe and the gland are integrally formed through an injection molding process, so that the manufacturing cost of the product is reduced.

One end of the sample introduction flow guide pipe close to the sample introduction port is of a conical structure, and the other end of the sample introduction flow guide pipe is of a hollow cylinder; the air outlet pipe is a hollow cylinder; the inner diameter of the sample injection guide pipe is larger than that of the air outlet pipe. One end of the sample introduction guide pipe close to the sample introduction port is arranged to be of a conical structure, so that the sample introduction guide pipe is conveniently connected with a suction head of a liquid transfer gun, and the sample introduction efficiency is improved; the internal diameter of advance kind honeycomb duct is greater than the internal diameter of outlet duct, and the sample of being convenient for flows in, sets up the internal diameter of outlet duct little and reduces the cost of manufacture when satisfying the exhaust demand.

The heat conducting sheet is a graphite sheet. The heat conduction coefficient of graphite flake is higher, adopts the graphite flake as the conducting strip, and the material can further improve the heat transfer efficiency of whole chip.

The utility model discloses technical scheme beneficial effect mainly embodies: the plurality of amplification cavities are integrated on the silicon-based chip, and the heat conducting sheet is fixed in the center of the silicon-based chip, so that the temperature rise and fall of all the amplification cavities can be synchronous with the temperature rise and fall of an external heat source, the rapid and uniform temperature rise and fall are realized, and the time consumption of nucleic acid detection is greatly shortened; the silicon-based chip is fixedly connected to the pressure cover by using the double-sided sealant containing the micro-cavity hole, so that no gap exists between the heat conducting fins and the silicon-based chip, and the heat transfer efficiency is further improved; meanwhile, by arranging the sample introduction guide pipe and the gas outlet pipe, the pollution caused by aerosol generated in the reaction process is further reduced, and the sealing effect is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic bottom perspective view of a closed PCR microfluidic chip for multi-sample detection according to a first embodiment of the present invention;

FIG. 2 is a schematic top view of FIG. 1;

FIG. 3 is a schematic perspective view of FIG. 1;

FIG. 4 is a schematic front perspective view of FIG. 1;

FIG. 5 is a schematic front view of the silicon-based chip of FIG. 1;

FIG. 6 is a schematic top view of the amplification unit in the silicon-based layer of FIG. 5;

fig. 7 is a front perspective view of a closed PCR microfluidic chip for multi-sample detection according to the second embodiment of the present invention.

Reference numerals: 1-a gland, 101-a sample inlet, 102-a gas outlet, 103-a sample introduction guide pipe, 104-a gas outlet pipe, 2-an iron sheet, a 3-silicon-based chip and 31-a glass layer; a 32-si base layer; 301-snake-shaped amplification cavity, 302-liquid inlet microchannel, 303-liquid outlet microchannel, 304-heat insulation groove, 4-graphite sheet, 5-positioning hole, 6-hand-held buckle groove, 7-serial number mark, 8-sealing film, 9-double-sided sealant, 901-liquid inlet microcavity, 902-gas outlet microcavity, 10-fluorescence detection area and 11-mounting groove.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely below, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts all belong to the protection scope of the present invention.

Example one

As shown in fig. 1 to 6, it should be noted that the steps described in this embodiment are not strictly corresponding to the steps described in the content of the present invention.

The closed PCR microfluidic chip for multi-sample detection in the embodiment comprises a gland 1, a double-sided sealant 9 and a silicon-based chip 3 which are arranged from top to bottom, wherein the gland 1 is made of a high polymer material through an injection molding process. Four positioning holes 5 are arranged on the gland 1, and the four positioning holes 5 are symmetrically arranged on two sides of the silicon-based chip 3 in pairs. The left side and the right side of the back of the gland 1 are respectively provided with a magnetic iron sheet 2 in an embedding mode in the injection molding process, and the left side and the right side of the gland 1 are provided with two symmetrical handheld buckle grooves 6.

Be provided with 16 introduction port 101 and gas outlet 102 on gland 1's the front, wherein every 8 introduction port 101 and gas outlet 102 are listed as, and two are listed as introduction port 101 and gas outlet 102 symmetry and set up in the left and right sides of silicon-based chip 3, and there is serial number sign 7 on every introduction port 101 one side to the record of application of sample and testing result. In this embodiment, the gland 1 is further provided with 16 sampling guide tubes 103 and an air outlet tube 104, which are integrally formed with the gland 1 through an injection molding process. Furthermore, each sample introduction guide pipe 103 is communicated with the sample introduction port 101 in a one-to-one correspondence manner, and each gas outlet pipe 104 is communicated with the gas outlet 102 in a one-to-one correspondence manner. During sample adding, the sample enters from the sample inlet 101 and flows to the silicon-based chip 3 through the sample introduction flow guide pipe 103. Of course, in other embodiments, the number of the sample inlets 101 and the gas outlets 102 may vary with the number of the amplification units in the silicon-based chip 3, and is not limited herein.

Further, in this embodiment, the end of the sample introduction guide tube 103 close to the sample inlet 101 is a hollow conical structure, the lower end of the hollow conical structure is a hollow cylinder, the upper end of the sample introduction guide tube 103 is designed to be a conical structure so as to be connected with the suction head of the liquid transfer gun, the sample introduction efficiency is improved, and the sample overflow during sample introduction is avoided. In addition, in this embodiment, in order to improve the sample-adding efficiency and reduce the manufacturing cost of the product, the inner diameter of the sample-feeding guide pipe 103 is larger than the inner diameter of the gas outlet pipe 104.

The back of the gland 1 is provided with a square mounting groove 11, the silicon-based chip 3 is fixedly mounted in the mounting groove 11 through double-sided sealant 9, and the gland 1 and the silicon-based chip 3 are sealed through the double-sided sealant 9. Wherein, the double-sided sealing glue 9 is provided with micro-cavity holes, and the number and the position distribution of the micro-cavity holes are consistent with the number and the position distribution of the sample introduction guide pipe 103 and the air outlet pipe 104. Specifically, the microcavity holes are divided into an inlet microcavity hole 901 and an outlet microcavity hole 902.

In the embodiment, the silicon-based chip 3 includes a glass layer 31 and a silicon-based layer 32, specifically, one side of the double-sided sealant 9 is fixedly connected to the mounting groove 11, and the other side is fixedly connected to the glass layer 31, so that the fluorescence detection can be directly performed by using the product after amplification is completed by disposing the glass layer 31 in the silicon-based chip 3, as shown in fig. 3, the fluorescence detection area is 10. The silicon substrate 32 has 16 amplification units, and the 16 amplification units are arranged in a 4 × 4 array on the silicon substrate 3. Of course, in other embodiments, the number of independent amplification units on each silicon-based chip 3 can be set according to the requirement, and is not limited herein. Wherein, each amplification unit comprises a liquid inlet micro-channel 302, an amplification cavity and a liquid outlet micro-channel 303, the liquid inlet micro-channel 302, the amplification cavity and the liquid outlet micro-channel 303 are communicated in sequence to form 16 amplification units which are not communicated with each other, and the amplification cavity is a snake-shaped amplification cavity 301.

The silicon substrate layer 32 is also provided with a plurality of heat insulation grooves 304 which are distributed around the snake-shaped amplification cavity 301 to isolate the snake-shaped amplification cavity 301 from other parts of the silicon substrate layer, so that heat is concentrated in the snake-shaped amplification cavity 301 to effectively improve the heating efficiency, thereby shortening the time required by amplification reaction and finally achieving the purpose of improving the detection efficiency. Specifically, in the present embodiment, 22 thermal insulation grooves 304 are disposed in the silicon substrate 32, wherein two strip thermal insulation grooves 304 are disposed on the upper and lower sides of the 16 serpentine amplification chambers 301, a shorter strip thermal insulation groove 304 is disposed between each serpentine amplification chamber 301 and the liquid outlet micro-channel 302, and a strip thermal insulation groove 304 is also disposed between the liquid outlet micro-channel 302 and the liquid inlet micro-channel, so as to realize that the 22 thermal insulation grooves 304 separate the serpentine amplification chambers 301 from other parts of the silicon substrate 32, prevent heat from diffusing to the areas except the serpentine amplification chambers 301, concentrate the heat in the serpentine amplification chambers 301, improve the temperature rise efficiency, and shorten the reaction time. Of course, in other embodiments, the arrangement position and number of the heat insulation slots 304 may be adjusted according to the requirement, and only the heat insulation effect and the heat load reduction effect need to be satisfied, which is not limited herein.

In this embodiment, the sample introduction flow guide tube 103 and the gas outlet tube 104 respectively penetrate through the liquid inlet micro-cavity hole 901 and the gas outlet micro-cavity hole 902 and are directly communicated with the liquid inlet micro-channel 302 and the liquid outlet micro-channel 303, so as to further improve the sealing effect. During sample adding, a sample enters the coiled tube amplification cavity 301 through the sample inlet 101 via the sample introduction guide tube 103 and flows into the liquid inlet microchannel 302 for amplification reaction, and redundant gas generated in the reaction process is finally discharged from the gas outlet 102 via the liquid outlet microchannel 303 via the gas guide tube 104.

Furthermore, after the sample is added, sealing films 8 are manually attached to the sample inlet 101 and the gas outlet 102 on the left side and the right side of the front surface of the gland 1, so that the sample inlet 101 and the gas outlet 102 are sealed, and a closed PCR reaction environment is formed; in the present example, a biocompatible rubber film was used as the sealing film 8, and the plastic film was resistant to a temperature of 100 ℃ for 1 hour. Of course, in other embodiments, the sealing film is made of biocompatible TPE, and the plastic film can resist the temperature of 100 ℃ for 1.5 hours.

Manually pasting a graphite flake 4 at the central position of a silicon-based chip 3 on the back surface of a gland 1 after sealing is finished, accurately connecting an assembled product with an external TEC heating seat through a positioning hole 5, realizing that external heat is transferred to the graphite flake 4 through the TEC heating seat, and then uniformly transferring the heat to each amplification unit in a silicon-based layer 32, thereby effectively realizing uniform temperature rise and fall of a plurality of coiled pipe amplification cavities 301, wherein the average temperature rise and fall can be realized to be more than 15 ℃/s, and the time consumed by 4 PCR amplification cycles in the past market can be reduced to 5min; the area of the central position of the front surface of the gland 1 is an optical detection area 9, and the product can be used for directly carrying out fluorescence detection on a sample after amplification reaction is completed.

Certainly, in other embodiments, 5 mounting grooves 11 are formed in the back surface of the gland 1, one silicon-based chip 3 is arranged in each mounting

groove

11, 5 independent amplification units are arranged in each silicon-based chip 3, and one graphite sheet 4 is attached to the center of each silicon-based chip 3, so that simultaneous detection of 25 samples is realized. In some embodiments, the number of the mounting grooves 11 and the number of the independent amplification units on each silicon-based chip 3 can be set according to the requirement, and is not limited herein.

Example two

Different from the first embodiment, in the present embodiment, the sample introduction flow guide tube 103 and the gas outlet tube 104 do not penetrate through the liquid inlet micro-cavity 901 and the gas outlet micro-cavity 902, but are indirectly communicated with the liquid inlet micro-channel 302 and the liquid outlet micro-channel 303 through the liquid inlet micro-cavity 901 and the gas outlet micro-cavity 902. Specifically, as shown in fig. 7, in this embodiment, during sample addition, a sample enters the sample introduction guide tube 103 through the sample introduction port 101, then enters the liquid inlet micro-cavity hole 901, and finally flows into the coiled tube amplification cavity 301 for amplification reaction, and excess gas generated during the reaction process flows from the liquid outlet micro-channel 304, passes through the gas outlet micro-cavity hole 902, and then passes through the gas guide tube 104, and finally is discharged from the gas outlet 102.

The above description of the embodiments is only intended to facilitate the understanding of the method and the core idea of the present invention. It should be noted that, for those skilled in the art, without departing from the principle of the present invention, the present invention can be further modified and modified, and such modifications and modifications also fall within the scope of the appended claims.

Claims

1. A closed PCR microfluidic chip for multi-sample detection comprises a gland (1), wherein a first surface of the gland (1) is provided with a sample inlet (101), a gas outlet (102) and a sealing film (8); seal membrane (8) cover in inlet (101) with on gas outlet (102), the second face is provided with mounting groove (11), its characterized in that: the number of the sample inlets (101) is at least two, the number of the gas outlets (102) is at least two, the first surface of the gland (1) is also provided with at least two sample introduction guide pipes (103) and at least two gas outlet pipes (104), the sample introduction guide pipes (103) are communicated with the sample inlets (101), and the gas outlet pipes (104) are communicated with the gas outlets (102);

the device comprises a silicon-based chip (3), wherein at least two amplification units which are independently arranged are arranged on the silicon-based chip (3); the silicon-based chip (3) is arranged in the mounting groove (11) through a sealing element with a micro-cavity hole.

2. The closed PCR microfluidic chip for multiple sample detection according to claim 1, wherein the silicon-based chip (3) comprises a glass layer (31) and a silicon-based layer (32), the amplification unit is disposed in the silicon-based layer (32), the amplification unit comprises an inlet microchannel (302), an outlet microchannel (303) and an amplification chamber, and the inlet microchannel (302) and the outlet microchannel (303) penetrate through the glass layer (31) and communicate with the amplification chamber.

3. The closed PCR microfluidic chip for multi-sample detection according to claim 2, wherein the silicon substrate (32) is further provided with a heat insulation groove (304) for heat insulation of the amplification chamber.

4. The closed PCR microfluidic chip for multi-sample detection according to claim 3, wherein the sealing member containing the micro-cavity hole is a double-sided sealant (9), and the silicon-based chip (3) is fixedly mounted in the mounting groove (11) through the double-sided sealant (9); the micro-cavity holes are a liquid inlet micro-cavity hole (901) and a gas outlet micro-cavity hole (902).

5. The closed PCR microfluidic chip for multi-sample detection according to claim 4, wherein the sample introduction flow guide tube (103) and the gas outlet tube (104) are respectively communicated with the liquid inlet micro-channel (302) and the liquid outlet micro-channel (303) through the liquid inlet micro-cavity hole (901) and the gas outlet micro-cavity hole (902).

6. The closed PCR microfluidic chip for multi-sample detection according to any one of claims 1 to 5, wherein the silicon-based chip (3) is connected with an external heat transfer device through a heat conducting sheet.

7. The enclosed PCR microfluidic chip for multi-sample detection according to claim 6, wherein the heat conducting sheet is fixedly connected to the center of the silicon-based chip (3).

8. The closed PCR microfluidic chip for multi-sample detection according to claim 7, wherein the silicon-based chip (3) is provided with a plurality of amplification units, the pressing cover is provided with at least two mounting grooves (11), and one silicon-based chip (3) is mounted in each mounting groove (11).

9. The closed PCR microfluidic chip for multi-sample detection according to claim 1, wherein the sample introduction guide tube (103), the gas outlet tube (104) and the gland (1) are integrally formed.

10. The closed PCR microfluidic chip for multi-sample detection according to claim 9, wherein one end of the sample introduction flow guide tube (103) near the sample inlet (101) is a conical structure, and the other end is a hollow cylinder; the air outlet pipe (104) is a hollow cylinder.

11. The closed PCR microfluidic chip for multi-sample detection according to claim 10, wherein the inner diameter of the sample introduction guide tube (103) is larger than the inner diameter of the gas outlet tube (104).

12. The closed PCR microfluidic chip for multi-sample detection according to claim 6, wherein the heat conducting sheet is a graphite sheet (4).