Micro-fluidic chip and use method thereof

Abstract

The invention discloses a micro-fluidic chip and a use method thereof, the chip comprises an extraction assembly and an amplification assembly, the extraction assembly comprises a cracking cavity, a first valve chamber, a cleaning cavity and a second valve chamber which are communicated in sequence; the amplification assembly comprises a chip substrate, a barrier layer and a conductive cover plate; the blocking layer is located between the chip substrate and the conductive cover plate, a storage cavity, an elution cavity, a liquid path cavity and an amplification cavity which are sequentially communicated are defined by the blocking layer, the chip substrate and the conductive cover plate, and the elution cavity is communicated with the second valve chamber through a first channel; a cavity with an opening in the bottom is formed in one side, adjacent to the chip substrate, of the conductive cover plate, and the elution cavity comprises a cavity; an electrode array located under the elution cavity, the liquid path cavity and the amplification cavity is arranged on the chip substrate; the storage cavity is communicated with the elution cavity through a second channel; the liquid path cavity comprises a liquid storage area adjacent to the elution cavity. The chip disclosed by the invention is compact in structure, eluent is convenient to store and move, and the detection efficiency is effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of microfluidic technology, and in particular to a microfluidic chip and a method of using the same. Background Art

[0002] Polymerase chain reaction (PCR) is a core technology in modern molecular biology and diagnostics. This temperature-dependent technology amplifies DNA exponentially through repeated cycles of heating and cooling. Traditional thermal cyclers are bulky and a typical PCR reaction usually takes 12 hours. In clinical point-of-care diagnosis, especially for infectious diseases, reaction time, reaction specificity, and instrument portability are crucial for rapid clinical decision-making at the point of care. Many rapid PCR methods have been developed and applied to point-of-care diagnosis using the miniaturized features of microfluidics or capillary reactors.

[0003] Digital microfluidics (DMF) is a branch technology in the field of microfluidics that can control single droplets of microliter to nanoliter size. Digital microfluidics based on electrowetting-ondielectric (EWOD) can process single droplets on electrode arrays through electrowetting forces. Its electrical drive function and small footprint make it a promising technology for point-of-care diagnosis.

[0004] The existing integrated microfluidic chip includes a lysis chamber, a cleaning chamber, an elution chamber, a liquid path chamber and an amplification chamber which are connected in sequence. The lysis chamber is pre-stored with a lysis solution, the cleaning chamber is pre-stored with a washing solution, and the elution chamber is pre-stored with an elution solution. The elution chamber and the liquid path chamber are usually separated by an insulating material such as a paraffin valve, and an electrode array is usually not provided on the substrate directly below the elution chamber. However, the storage method of the eluent of the microfluidic chip is relatively cumbersome, because it takes time to heat and melt the paraffin valve in sequence, resulting in a slow detection efficiency, and the substrate located directly below the elution chamber is usually not provided with an electrode array, and it is impossible to move all the eluted sample droplets to the liquid path chamber, resulting in inaccurate sample detection.

[0005] In order to move all the eluted sample droplets into the liquid path cavity, some existing microfluidic chips usually use air pumps or gravity to move the sample droplets into the liquid path cavity. Both operations are cumbersome and complicated, and the latter cannot perform more sophisticated operations, such as liquid separation. Summary of the invention

[0006] In order to solve the problems existing in the above-mentioned prior art, the first purpose of the present invention is to provide a microfluidic chip which is convenient for storing and moving eluent, can accelerate detection efficiency, and can fully move sample droplets in the elution chamber to the liquid path chamber.

[0007] The second object of the present invention is to provide a method for using the above-mentioned microfluidic chip.

[0008] In order to achieve the above-mentioned first purpose, the microfluidic chip provided by the present invention includes an extraction component and an amplification component, the extraction component includes a lysis chamber, a first valve chamber, a cleaning chamber and a second valve chamber connected in sequence; the amplification component includes a chip substrate, a barrier layer and a conductive cover plate; the barrier layer is located between the chip substrate and the conductive cover plate, and the barrier layer, the chip substrate and the conductive cover plate surround an elution chamber, a liquid path chamber and an amplification chamber connected in sequence, and the elution chamber and the second valve chamber are connected through a first channel; an electrode array is arranged on the chip substrate; a cavity with a bottom opening is arranged on one side of the cover plate adjacent to the chip substrate, and the elution chamber contains the cavity; the electrode array is located in the elution chamber; The amplification component also includes a storage chamber for storing a surfactant, and the storage chamber is connected to the elution chamber through a second channel; the liquid path chamber includes a liquid storage area, and the liquid storage area is adjacent to the elution chamber; the distance between the top wall of the first channel and the upper surface of the chip substrate is less than 7mm and greater than or equal to 4mm; along the thickness direction of the microfluidic chip, the thickness of the cavity is 0.6mm to 2mm; the distance between the top wall of the second channel and the upper surface of the chip substrate is less than 7mm and greater than or equal to 4mm; the distance between the top wall of the liquid storage area and the upper surface of the chip substrate is less than 7mm and greater than or equal to 4mm.

[0009] As can be seen from the above, the thickness of the peripheral wall of the cavity of the microfluidic chip of the present invention is 0.6mm to 2mm, the distance between the top wall of the liquid storage area and the chip substrate is less than 7mm and greater than or equal to 4mm, and the distance between the top wall of the first channel and the second channel and the chip substrate is less than 7mm and greater than or equal to 4mm. Since the surface tension of the eluent without the addition of surfactant is relatively high, it is blocked by the side wall of the cavity, and the surfactant cannot enter the liquid storage area and the storage area. There is no need to separate the liquid storage area from the elution cavity through barriers such as paraffin valves, which is convenient for operation and production. An electrode array is arranged under the elution cavity. Through the effect of electrowetting, the liquid in the elution cavity can all enter the liquid storage area. The operation is convenient, and a variety of refined operations can be completed.

[0010] A further solution is that the electrode array includes an elution area electrode portion and a liquid storage area electrode portion adjacent to each other, the elution area electrode portion includes at least one elution electrode, and the projection on the chip substrate is that the elution electrode is located in the elution cavity; the liquid storage area electrode portion includes a transition electrode and a liquid storage electrode group adjacent to each other, and the projection on the chip substrate is that the transition electrode spans the elution cavity and the liquid storage area, and the transition electrode is located between the elution area electrode portion and the liquid storage electrode group, and the liquid storage electrode group is located in the liquid storage area.

[0011] It can be seen from the above that the transition electrode can make the sample droplets move more conveniently and smoothly from the elution chamber to the liquid storage area, preventing the sample droplets from being unable to move or unable to move completely to the liquid storage area due to the dual effects of the obstruction of the elution chamber wall and the gap between the electrodes.

[0012] A further solution is that the liquid storage electrode group includes at least two liquid storage electrodes, and the multiple liquid storage electrodes are arranged in sequence along the direction from the elution chamber to the liquid path chamber, the area of ​​the next liquid storage electrode is larger than the area of ​​the previous liquid storage electrode, and the previous liquid storage electrode is close to the transition electrode relative to the next liquid storage electrode.

[0013] As can be seen from the above, the area of ​​the next liquid storage electrode is larger than that of the previous liquid storage electrode, so that the liquid storage area can fully temporarily store the sample droplets to be tested, which can meet the needs of testing a large number of samples.

[0014] A further solution is that each liquid storage electrode includes a first side and a second side extending in the direction from the elution chamber to the liquid path chamber, the first side and the second side are opposite, and the width between the first side and the second side of the next liquid storage electrode is greater than the width between the first side and the second side of the previous liquid storage electrode.

[0015] As can be seen from the above, the width between the first side and the second side of the next liquid storage electrode is greater than that of the previous liquid storage electrode, which can effectively reduce the volume of the chip and make the structure more compact.

[0016] A further solution is that the first sides of all the liquid storage electrodes are arranged in a collinear manner, and the second sides of all the liquid storage electrodes are arranged in a collinear manner.

[0017] As can be seen from the above, the first sides of all the liquid storage electrodes are collinearly arranged, and the second sides of all the liquid storage electrodes are collinearly arranged, so that the sample droplets move faster.

[0018] A further solution is that the transition electrode and the liquid storage electrode adjacent to the transition electrode have mutually interlocking first arc portions, the opening of the first arc portion faces the transition electrode; and the two adjacent liquid storage electrodes have mutually interlocking second arc portions, the opening of the second arc portion faces the transition electrode.

[0019] A further solution is that at least one first arc segment is arranged in the first arc portion, and the opening of the first arc segment faces away from the transition electrode; at least one second arc segment is arranged in the second arc portion, and the opening of the second arc segment faces away from the transition electrode.

[0020] It can be seen from the above that the sample droplet can move more smoothly between two adjacent electrodes by providing the first arc-shaped portion, the second arc-shaped portion, the third arc-shaped portion and the fourth arc-shaped portion.

[0021] A further solution is that the conductive cover plate includes a plate body and a cover body; the top of the cavity is open, and the cover body covers the top opening of the cavity.

[0022] In order to achieve the above-mentioned second purpose, the present invention provides a method of using the above-mentioned microfluidic chip, wherein a magnetic suction device controls the sample droplets to be tested with magnetic beads to pass through the lysis chamber and the cleaning chamber in sequence and then move to the elution chamber, and the magnetic suction device controls the magnetic beads so that the magnetic beads move back and forth between the storage chamber and the elution chamber, and the electrode array is energized so that the sample droplets in the elution chamber enter the liquid storage area.

[0023] As can be seen from the above, the reciprocating motion of the magnetic beads allows the surfactant in the storage chamber to be fully mixed with the sample droplets, thereby reducing the surface tension of the sample droplets and facilitating the movement of the sample droplets.

[0024] In summary, the microfluidic chip provided by the present invention has a simple and compact structure, is convenient for storing eluent, has a larger capacity, can accelerate detection efficiency, and allows sample droplets in the elution chamber to fully move to the microfluidic chip in the liquid path chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a structural diagram of a microfluidic chip embodiment of the present invention from a first perspective.

[0026] Figure 2 This is a structural diagram of the microfluidic chip embodiment of the present invention from a second viewing angle.

[0027] Figure 3 The microfluidic chip embodiment of the present invention includes a partial cross-sectional view of an elution chamber, a first channel and a liquid path chamber.

[0028] Figure 4 A partial cross-sectional view of an embodiment of a microfluidic chip of the present invention including an elution chamber and a storage chamber.

[0029] Figure 5 It is a plan view of the electrode portion of the elution area and the electrode portion of the liquid storage area of ​​the microfluidic chip embodiment of the present invention. DETAILED DESCRIPTION

[0030] See also Figures 1 to 5The microfluidic chip of this embodiment includes an extraction cover plate 3, a conductive cover plate 2, a barrier layer 12 and a chip substrate 1. The extraction cover plate 3 is adjacent to the conductive cover plate 2. The extraction cover plate 3 and the chip substrate 1 are combined to form an extraction component. The extraction component includes a lysis chamber 4, a first valve chamber 100, a first cleaning chamber 5, a second cleaning chamber 6 and a second valve chamber 101 that are connected in sequence. The first valve chamber 100 and the second valve chamber 101 are filled with paraffin. The barrier layer 12, the chip substrate 1 and the conductive cover plate 2 are combined to form an amplification component. The barrier layer 12 is located between the conductive cover plate 2 and the chip substrate 1. The barrier layer 12, the chip substrate 1 and the conductive cover plate 1 are surrounded by a storage chamber 10, an elution chamber 7, a liquid path chamber 8 and an amplification chamber 9 that are connected in sequence. The elution chamber 7 and the second valve chamber 101 are connected through a first channel 1010. The barrier layer 12 includes a gasket (not shown in the figure) and glue (not shown in the figure). Optionally, the number of cleaning chambers is at least one. The conductive cover plate 2 comprises a plate body 21 and a cover body 20, the plate body 21 is provided with a cavity 72 with both bottom and top openings, the bottom opening of the cavity 72 is located on the side of the plate body 21 adjacent to the chip substrate 1, the top opening of the cavity 72 is located on the side of the plate body 21 away from the chip substrate 1, the cover body 20 covers the top opening of the cavity 72, and the elution chamber 7 includes the cavity 72. Optionally, the cover body 20 and the plate body 2 are integrally formed.

[0031] The extraction cover plate 3 is provided with a first loading hole 40, a second loading hole 50 and a third loading hole 60. The first loading hole 40 is connected to the lysis chamber 4, the second loading hole 50 is connected to the first cleaning chamber 5, and the third loading hole 60 is connected to the second cleaning chamber 6. The cover body 20 is provided with a fourth loading hole 70, which is connected to the elution chamber 7. The lysis chamber 4 is pre-stored with a lysis solution, the first cleaning chamber 5 and the second cleaning chamber 6 are pre-stored with a washing solution, and the elution chamber 7 is pre-stored with an elution solution. The positions corresponding to the first valve chamber 100 and the second valve chamber 101 on the chip substrate 1 are provided with heating wires (not shown in the figure) for melting the paraffin in the first valve chamber 100 and the second valve chamber 101. The chip substrate 1 is provided with an electrode array, which is located directly below the elution chamber 7, the liquid path chamber 8 and the amplification chamber 9.

[0032] See also Figure 3 and Figure 4, a surfactant (not shown in the figure) is pre-stored in the storage chamber 10, and the solidified surfactant can be pre-stored in the storage chamber 10 by freeze-drying or drying. The storage chamber 10 is connected to the elution chamber 7 through the second channel 1000, and the liquid path chamber 8 includes a liquid storage area 81 and a liquid separation area 82 arranged in sequence along the direction from the liquid path chamber 8 to the amplification chamber 9, the liquid storage area 81 is adjacent to the elution chamber 7, and the liquid separation area 82 is adjacent to the amplification chamber 9. Along the thickness direction of the microfluidic chip, the thickness c of the cavity 72 is 0.6mm to 2mm, the distance b between the top wall of the first channel 1010 and the upper surface of the chip substrate 1 is less than 7mm and greater than or equal to 4mm, the distance d between the top wall of the second channel 1000 and the upper surface of the chip substrate 1 is less than 7mm and greater than or equal to 4mm, and the distance a between the top wall of the liquid storage area 81 and the upper surface of the chip substrate 1 is less than 7mm and greater than or equal to 4mm.

[0033] See also Figure 5 The electrode array includes an elution region electrode portion 71 and a liquid storage region electrode portion 11 adjacent to each other, the elution region electrode portion 71 includes an elution electrode 710, and the projection on the chip substrate 1, the elution electrode 710 is located in the elution cavity 7. The liquid storage region electrode portion 11 includes a transition electrode 110 and a liquid storage electrode group adjacent to each other, and the projection on the chip substrate 1, the transition electrode 110 spans the elution cavity 7 and the liquid storage region 81, the transition electrode 110 is located between the elution region electrode portion 71 and the liquid storage electrode group, and the liquid storage electrode group is located in the liquid storage region 81. Optionally, the elution region electrode portion 71 includes more than two elution electrodes 710, and the multiple elution electrodes 710 are arranged in sequence along the direction from the elution cavity 7 to the liquid path cavity 8.

[0034] The liquid storage electrode group includes three liquid storage electrodes 111, and the three liquid storage electrodes 111 are arranged in sequence along the direction from the elution chamber 7 to the liquid path chamber 8. The area of ​​the next liquid storage electrode 111 is larger than the area of ​​the previous liquid storage electrode 111, and the previous liquid storage electrode 111 is closer to the transition electrode 110 relative to the next liquid storage electrode 111. Each liquid storage electrode 111 includes a first side and a second side extending along the direction from the elution chamber 7 to the liquid path chamber 8, the first side and the second side are opposite, and the width between the first side and the second side of the next liquid storage electrode 111 is larger than the width of the first side and the second side of the previous liquid storage electrode 111. The first sides of all liquid storage electrodes 111 are collinearly arranged, and the second sides of all liquid storage electrodes 111 are collinearly arranged. Optionally, the number of liquid storage electrodes 111 includes more than two.

[0035] The transition electrode 110 and the liquid storage electrode 111 adjacent to the transition electrode 110 have mutually interlocking first arc portions 1100, the opening of the first arc portion 1100 faces the transition electrode 110; the two adjacent liquid storage electrodes 111 have mutually interlocking second arc portions 1110, the opening of the second arc portion 1110 faces the transition electrode 110. Three first arc segments 1101 are arranged at intervals in the first arc portion 1100, the opening of the first arc segment 1101 faces away from the transition electrode 110; three second arc segments 1111 are arranged in the second arc portion 1110, the opening of the second arc segment 1111 faces away from the transition electrode 110. Optionally, the number of the first arc segment 1101 is at least one, and the number of the second arc segment 1111 is at least one.

[0036] The present embodiment also provides a method for using the above-mentioned microfluidic chip, wherein a magnetic suction device (not shown in the figure) controls a sample to be tested (not shown in the figure) with magnetic beads to pass through the lysis chamber 4 and the cleaning chamber in sequence and then move to the elution chamber 7, and then the magnetic suction device controls the magnetic beads to make the magnetic beads reciprocate between the storage chamber 10 and the elution chamber 7, so that the surfactant and the sample droplets to be tested are fully mixed, and then the electrode array is energized to allow the sample droplets to enter the liquid storage area 81 from the elution chamber 7.

[0037] Finally, it should be emphasized that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A microfluidic chip, comprising an extraction component and an amplification component, wherein the extraction component comprises a lysis chamber, a first valve chamber, a cleaning chamber and a second valve chamber connected in sequence; The amplification component includes a chip substrate, a barrier layer and a conductive cover plate; The barrier layer is located between the chip substrate and the conductive cover plate, the barrier layer, the chip substrate and the conductive cover plate enclose an elution chamber, a liquid path chamber and an amplification chamber that are connected in sequence, and the elution chamber and the second valve chamber are connected through a first channel; An electrode array is arranged on the chip substrate; Features: A cavity with a bottom opening is provided on one side of the conductive cover plate adjacent to the chip substrate, and the elution cavity includes the cavity; The electrode array is located directly below the elution chamber, the liquid path chamber, and the amplification chamber; The amplification component further comprises a storage chamber for storing a surfactant, and the storage chamber is connected to the elution chamber via a second channel; The liquid path cavity includes a liquid storage area, and the liquid storage area is adjacent to the elution cavity; The distance between the top wall of the first channel and the upper surface of the chip substrate is less than 7 mm and greater than or equal to 4 mm; Along the thickness direction of the microfluidic chip, the thickness of the cavity is 0.6 mm to 2 mm; The distance between the top wall of the second channel and the upper surface of the chip substrate is less than 7 mm and greater than or equal to 4 mm; The distance between the top wall of the liquid storage area and the upper surface of the chip substrate is less than 7 mm and greater than or equal to 4 mm.

2. The microfluidic chip according to claim 1, characterized in that: The electrode array comprises an elution region electrode portion and a liquid storage region electrode portion adjacent to each other, the elution region electrode portion comprises at least one elution electrode, the projection of which on the chip substrate, the elution electrode being located in the elution cavity; The liquid storage area electrode portion includes a transition electrode and a liquid storage electrode group adjacent to each other. In the projection on the chip substrate, the transition electrode spans the elution chamber and the liquid storage area, and the transition electrode is located between the elution area electrode portion and the liquid storage electrode group. The liquid storage electrode group is located in the liquid storage area.

3. The microfluidic chip according to claim 2, characterized in that: The liquid storage electrode group includes at least two liquid storage electrodes, and the multiple liquid storage electrodes are arranged in sequence along the direction from the elution chamber to the liquid path chamber. The area of ​​the next liquid storage electrode is larger than the area of ​​the previous liquid storage electrode, and the previous liquid storage electrode is close to the transition electrode relative to the next liquid storage electrode.

4. The microfluidic chip according to claim 3, characterized in that: Each of the liquid storage electrodes includes a first side and a second side extending in the direction from the elution chamber to the liquid path chamber, the first side and the second side are opposite, and the width between the first side and the second side of the next liquid storage electrode is greater than the width between the first side and the second side of the previous liquid storage electrode.

5. The microfluidic chip according to claim 4, characterized in that: The first side edges of all the liquid storage electrodes are collinearly arranged, and the second side edges of all the liquid storage electrodes are collinearly arranged.

6. The microfluidic chip according to any one of claims 3 to 5, characterized in that: The transition electrode and the liquid storage electrode adjacent to the transition electrode have first arc-shaped portions that fit into each other, and the opening of the first arc-shaped portion faces the transition electrode; Two adjacent liquid storage electrodes have second arc-shaped portions that fit in with each other, and the openings of the second arc-shaped portions face the transition electrode.

7. The microfluidic chip according to claim 6, characterized in that: At least one first arc segment is disposed in the first arc portion, and an opening of the first arc segment faces away from the transition electrode; At least one second arc segment is disposed in the second arc portion, and an opening of the second arc segment faces away from the transition electrode.

8. The microfluidic chip according to any one of claims 1 to 5, characterized in that: The conductive cover plate comprises a plate body and a cover body; The top of the cavity is open, and the cover body covers the top opening of the cavity.

9. A method for using a microfluidic chip, characterized in that: The method is applied to the microfluidic chip described in any one of 1 to 8 above, and the method comprises: The magnetic suction device controls the sample droplets to be tested with magnetic beads to pass through the lysis chamber and the cleaning chamber in sequence and then move to the elution chamber. The magnetic suction device controls the magnetic beads to make the magnetic beads reciprocate between the storage chamber and the elution chamber, and energizes the electrode array so that the sample droplets in the elution chamber enter the liquid storage area.

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