A microfluidic pesticide residue detection chip and a handheld pesticide residue detector

Abstract

This invention provides a microfluidic pesticide residue detection chip and a handheld pesticide residue detector. The microfluidic pesticide residue detection chip includes a chip body, which includes a sample inlet, a reaction chamber, a detection chamber, and an exhaust chamber. The reaction chamber is connected to the sample inlet, the detection chamber is connected to the reaction chamber via a flow channel, and the exhaust chamber is connected to the detection chamber via an exhaust channel. The exhaust chamber is sealed by a sealing unit to prevent gas from flowing out. A boss structure is provided in the flow channel to prevent the test liquid from flowing from the reaction chamber into the detection chamber when the exhaust chamber is sealed, and to allow the test liquid to flow into the detection chamber through the boss structure if the sealing unit is punctured. In this embodiment, the interaction between the boss structure and the sealing unit allows for the addition of the test sample into the microfluidic pesticide residue detection chip using pressure changes, enabling full-process detection without manual transfer and improving detection efficiency.

Description

Technical Field

[0001] This invention relates to, but is not limited to, the field of data processing technology, and particularly to a microfluidic pesticide residue detection chip and a handheld pesticide residue detector. Background Technology

[0002] Pesticide residue detection technologies include enzyme inhibition methods, which work by detecting pesticide residues based on the inhibition of enzyme activity by pesticides. Currently, there are two main technical solutions using enzyme inhibition methods: The first is a benchtop pesticide residue detector, which mainly uses a motor to provide centrifugal force to transfer the sample from the reaction area to the detection area, thereby realizing the reaction process. However, benchtop pesticide residue detection processes are complex and require highly skilled personnel, making them inconvenient for on-site testing in the fields and also unsuitable for use in ordinary households. The second is a handheld pesticide residue detector, which manually transfers the sample from the reaction area to the detection area, making automated transfer impossible and resulting in lower detection efficiency. Summary of the Invention

[0003] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of the claims.

[0004] The main objective of this invention is to provide a microfluidic pesticide residue detection chip and a handheld pesticide residue detector, which enables the sample to be tested to be automatically transferred in the microfluidic pesticide residue detection chip, achieving rapid detection and improving detection efficiency.

[0005] In a first aspect, embodiments of the present invention provide a microfluidic pesticide residue detection chip for use in a handheld pesticide residue detector. The microfluidic pesticide residue detection chip includes a chip body, which includes an inlet port, a reaction chamber, a detection chamber, and an exhaust chamber. The reaction chamber is connected to the inlet port, the detection chamber is connected to the reaction chamber via a flow channel, and the exhaust chamber is connected to the detection chamber via an exhaust channel. The exhaust chamber is sealed by a sealing unit to prevent gas from flowing out. A boss structure is provided in the flow channel. The boss structure is used to prevent the test liquid from flowing from the reaction chamber into the detection chamber when the exhaust chamber is sealed, and to allow the test liquid to flow into the detection chamber through the boss structure when the sealing unit is punctured.

[0006] In one embodiment, the flow channel includes a first flow channel region and a second flow channel region connected in sequence. The starting end of the first flow channel region is connected to the reaction chamber. The boss structure is disposed at the end of the first flow channel region and is higher than the lowest position of the first flow channel region. The starting end of the second flow channel region is connected to the end of the first flow channel region. The end of the second flow channel region is disposed near the bottom of the detection chamber. The flow channel area of ​​the first flow channel region is larger than the flow channel area of ​​the second flow channel region.

[0007] In one embodiment, the second flow channel region of the flow channel is in the shape of a straight tube, and the second flow channel region of the flow channel is perpendicular to the bottom plane of the detection chamber.

[0008] In one embodiment, the reaction chamber is a funnel-shaped structure, and the tip of the funnel-shaped structure is connected to the starting end of the first flow channel region.

[0009] In one embodiment, the projection of the reaction chamber onto a first side of the chip body is a first projection, the projection of the detection chamber onto the first side is a second projection, and the projection of the exhaust chamber onto the first side is a third projection. The first projection, the second projection, and the third projection do not overlap.

[0010] In one embodiment, a detection area is provided on the side wall of the chip body, the detection area is provided corresponding to the detection chamber, the detection area is a concave structure, the detection area includes a first detection area and a second detection area corresponding to the first detection area, the first detection area is provided on a first side of the chip body, the second detection area is provided on a second side of the chip body, the depth of the concave structure of the first detection area is less than the thickness of the first side, and the depth of the concave structure of the second detection area is less than the thickness of the second side.

[0011] In one embodiment, the projected area of ​​the first detection area on the first side is larger than the area of ​​the light spot emitted by the light-emitting element of the pesticide residue detector, and smaller than the projected area of ​​the first projection. The projected area of ​​the second detection area on the second side is smaller than the projected area of ​​the reaction chamber on the second side. The first detection area and the second detection area are arranged concentrically.

[0012] In one embodiment, the exhaust chamber includes an exhaust unit, which includes an exhaust pipe and an exhaust port communicating with the exhaust pipe. The exhaust port is disposed on the first side, and the exhaust pipe is disposed in the exhaust chamber and perpendicular to the first side. The length of the exhaust pipe is less than the distance between the first side and the second side. The sealing unit is used to seal the exhaust port to prevent the gas in the detection chamber and the exhaust chamber from communicating with the atmosphere outside the chip body.

[0013] In one embodiment, the exhaust channel includes a first channel region, a second channel region, and a third channel region connected in sequence. The inlet end of the first channel region is located at the top of the detection chamber and communicates with the detection chamber. The vertical distance between the connecting end of the first channel region and the second channel region relative to the bottom of the detection chamber is greater than the vertical distance between the inlet end of the first channel region and the bottom of the detection chamber. The vertical distance between the connecting end of the second channel region and the third channel region relative to the bottom of the detection chamber is greater than the vertical distance between the connecting end of the first channel region and the second channel region relative to the bottom of the detection chamber. The outlet end of the third channel region is located at the top of the exhaust chamber and communicates with the exhaust chamber. The vertical distance between the outlet end of the third channel region and the bottom of the detection chamber is smaller than the vertical distance between the connecting end of the second channel region and the third channel region relative to the bottom of the detection chamber.

[0014] In one embodiment, the chip body includes a foolproof structure disposed on the first side, the foolproof structure being a groove structure.

[0015] In one embodiment, the error prevention structure includes a first error prevention unit and a second error prevention unit, wherein the projection of the first error prevention unit on the first side surface overlaps with the projection of the flow channel on the first side surface, and the projection of the second error prevention unit on the first side surface overlaps with the projection of the gas channel on the first side surface.

[0016] In one embodiment, the reaction chamber is filled with an enzyme reagent, and the detection chamber is filled with a colorimetric reagent.

[0017] In one embodiment, the chip body further includes a third side, a fourth side, a fifth side, and a sixth side. The first side and the second side have the same shape and are arranged parallel to each other. The third side and the fourth side have the same shape and are arranged perpendicular to the first side. The fifth side and the sixth side have the same shape, are arranged perpendicular to the first side, and are also perpendicular to the fifth side. The side length of the bounding rectangle of the first side is the length and width of the chip body. The side length of the bounding rectangle of the third side is the length and height of the chip body. The side length of the bounding rectangle of the fifth side is the width and height of the chip body.

[0018] In one embodiment, the length of the chip body is less than or equal to 50 mm, the width of the chip body is less than or equal to 45 mm, and the height of the chip body is less than or equal to 10 mm.

[0019] Secondly, embodiments of the present invention provide a handheld pesticide residue detector, including the microfluidic pesticide residue detection chip described in the first aspect.

[0020] The beneficial effects of this invention include: the microfluidic pesticide residue detection chip applied to a handheld pesticide residue detector includes a chip body, which includes an inlet port, a reaction chamber, a detection chamber, and an exhaust chamber. The reaction chamber is connected to the inlet port, the detection chamber is connected to the reaction chamber through a flow channel, and the exhaust chamber is connected to the detection chamber through an exhaust channel. The exhaust chamber is sealed by a sealing unit to prevent gas from flowing out. A boss structure is provided in the flow channel. The boss structure is used to prevent the test liquid from flowing from the reaction chamber into the detection chamber when the exhaust chamber is sealed. In the event that the sealing unit is punctured, the test liquid flows into the detection chamber through the boss structure. In this embodiment, the liquid to be tested enters the reaction chamber through the inlet. As the amount of liquid flowing into the reaction chamber increases, the gas in the reaction chamber enters the detection chamber through the flow channel between the reaction chamber and the detection chamber. Since the detection chamber and the exhaust chamber are sealed, the pressure difference between the detection chamber and the exhaust chamber is higher than the pressure in the reaction chamber. This pressure difference exerts a force on the liquid to be tested in the reaction chamber. Furthermore, due to the presence of a boss structure in the flow channel, the combined effect of the pressure difference and the boss structure causes... With the exhaust chamber sealed, the liquid being tested can be prevented from flowing from the reaction chamber into the detection chamber, allowing the liquid to react fully in the reaction chamber. After the liquid has reacted in the reaction chamber, the sealing unit in the exhaust chamber can be punctured by the needle unit in the handheld pesticide residue detector, reducing the pressure difference between the detection chamber and the exhaust chamber. Without the pressure exerted on the liquid, it flows into the detection chamber through the protrusion structure. The sample can be automatically transferred in the microfluidic pesticide residue detection chip, enabling rapid detection and improving detection efficiency.

[0021] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a microfluidic pesticide residue detection chip provided in one embodiment of the present invention;

[0023] Figure 2 This is an internal plan view of a microfluidic pesticide residue detection chip provided in one embodiment of the present invention;

[0024] Figure 3 This is an internal schematic diagram of a microfluidic pesticide residue detection chip provided in one embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram showing the size settings of a microfluidic pesticide residue detection chip provided in one embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the first side view of a microfluidic pesticide residue detection chip provided in an embodiment of the present invention;

[0027] Figure 6 This is a cross-sectional schematic diagram of a microfluidic pesticide residue detection chip provided in one embodiment of the present invention.

[0028] Explanation of reference numerals in the attached figures:

[0029] Sample inlet 100, reaction chamber 200, detection chamber 300, exhaust chamber 400, sealing unit 500, boss structure 600;

[0030] Flow channel 2300, first flow channel region 2310, second flow channel region 2320;

[0031] Exhaust passage 3400, first passage area 3410, second passage area 3420, third passage area 3430;

[0032] Exhaust pipe 411, exhaust port 412, air inlet 413;

[0033] First foolproof unit 710, second foolproof unit 720;

[0034] First side 810, second side 820, third side 830, fourth side 840, fifth side 850, sixth side 860;

[0035] Testing area 900, first testing area 910, second testing area 920. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0037] It should be noted that although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, or the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0038] Among related technologies, pesticide residue detection technologies include enzyme inhibition methods. The principle is based on the inhibition of enzyme activity by pesticides to detect pesticide residues. Currently, there are two main technical solutions using enzyme inhibition methods: The first is a benchtop pesticide residue detector, which mainly uses a motor to provide centrifugal force to transfer the sample from the reaction area to the detection area, thereby realizing the reaction process. However, the benchtop pesticide residue detection process is complex and requires highly skilled personnel, making it inconvenient for on-site testing in the fields and also not suitable for use in ordinary people's homes. The second is a handheld pesticide residue detector, which manually transfers the sample from the reaction area to the detection area, making automated transfer impossible and resulting in lower detection efficiency.

[0039] To address the aforementioned problems, this invention provides a microfluidic pesticide residue detection chip. The microfluidic pesticide residue detection chip for use in a handheld pesticide residue detector includes a chip body. The chip body includes an inlet port, a reaction chamber, a detection chamber, and an exhaust chamber. The reaction chamber is connected to the inlet port. The detection chamber is connected to the reaction chamber via a flow channel. The exhaust chamber is connected to the detection chamber via an exhaust channel. The exhaust chamber is sealed by a sealing unit to prevent gas from flowing out. A boss structure is provided in the flow channel. The boss structure prevents the tested liquid from flowing from the reaction chamber into the detection chamber when the exhaust chamber is sealed. In the event of a puncture of the sealing unit, the tested liquid flows into the detection chamber through the boss structure.

[0040] In this embodiment, the liquid to be tested enters the reaction chamber through the inlet. As the amount of liquid flowing into the reaction chamber increases, the gas in the reaction chamber enters the detection chamber through the flow channel between the reaction chamber and the detection chamber. Since the detection chamber and the exhaust chamber are sealed, the pressure difference between the detection chamber and the exhaust chamber is higher than the pressure in the reaction chamber. This pressure difference exerts a force on the liquid to be tested in the reaction chamber. Furthermore, due to the presence of a boss structure in the flow channel, the combined effect of the pressure difference and the boss structure causes... With the exhaust chamber sealed, the liquid being tested can be prevented from flowing from the reaction chamber into the detection chamber, allowing the liquid to react fully in the reaction chamber. After the liquid has reacted in the reaction chamber, the sealing unit in the exhaust chamber can be punctured by the needle unit in the handheld pesticide residue detector, reducing the pressure difference between the detection chamber and the exhaust chamber. Without the pressure exerted on the liquid, it flows into the detection chamber through the protrusion structure. The sample can be automatically transferred in the microfluidic pesticide residue detection chip, enabling rapid detection and improving detection efficiency.

[0041] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0042] like Figure 1-5 As shown, where Figure 1 This is a schematic diagram of the internal structure of a microfluidic pesticide residue detection chip provided in one embodiment of this application. The microfluidic pesticide residue detection chip is applied to a handheld pesticide residue detector. The microfluidic pesticide residue detection chip includes a chip body, which includes an inlet port 100, a reaction chamber 200, a detection chamber 300, and an exhaust chamber 400. The reaction chamber 200 is connected to the inlet port 100. The detection chamber 300 is connected to the reaction chamber 200 through a flow channel 2300. The exhaust chamber 400 is connected to the detection chamber 300 through an exhaust channel 3400. The exhaust chamber 400 is sealed by a sealing unit 500 to prevent gas from flowing out. A boss structure 600 is provided in the flow channel 2300. The boss structure 600 is used to prevent the test liquid from flowing from the reaction chamber 200 into the detection chamber 300 when the exhaust chamber 400 is sealed. When the sealing unit 500 is punctured, the test liquid flows into the detection chamber 300 through the boss structure 600.

[0043] In this embodiment, the liquid to be tested enters the reaction chamber 200 through the inlet port 100. As the amount of liquid flowing into the reaction chamber 200 increases, the gas in the reaction chamber 200 enters the detection chamber 300 through the flow channel 2300 between the reaction chamber 200 and the detection chamber 300. Since the detection chamber 300 and the exhaust chamber 400 are in a sealed state, the pressure difference between the detection chamber 300 and the exhaust chamber 400 is higher than the pressure in the reaction chamber 200. At this time, the pressure difference between the detection chamber 300 and the exhaust chamber 400 exerts a force on the liquid to be tested in the reaction chamber 200. Moreover, since the flow channel 2300 is provided with a boss structure 600, the pressure difference and the boss structure exert a force on the liquid to be tested. The combined effect of 600 prevents the test liquid from flowing from the reaction chamber 200 into the detection chamber 300 when the exhaust chamber 400 is sealed, thus allowing the test liquid to react fully in the reaction chamber 200. After the test liquid completes its reaction in the reaction chamber 200, the sealing unit 500 in the exhaust chamber 400 can be punctured by the piercing unit in the handheld pesticide residue detector, reducing the pressure difference between the detection chamber 300 and the exhaust chamber 400. In the absence of pressure exerted on the test liquid, the test liquid flows into the detection chamber 300 through the boss structure 600. The sample to be tested can be automatically transferred in the microfluidic pesticide residue detection chip, enabling rapid detection and improving detection efficiency.

[0044] It should be noted that the sealing unit 500 can be a sealing membrane or an elastic plug; this embodiment does not specifically limit it. The sealing unit 500 can be a part of the exhaust chamber 400, which is already pasted onto the exhaust chamber during the production process, or it can be independent and pasted onto the exhaust chamber only when the user uses the microfluidic pesticide residue detection chip to achieve the purpose of sealing; this embodiment does not specifically limit it.

[0045] It should be noted that the height of the boss structure 600 is set such that the pressure of the liquid being tested cannot exceed the pressure of the air in the detection chamber 300 acting on the liquid being tested, so that when the exhaust chamber 400 is sealed, the boss structure 600 can prevent the liquid being tested from flowing from the reaction chamber 200 into the detection chamber 300.

[0046] In some alternative embodiments, from Figure 2 , Figure 3As can be seen, the flow channel 2300 between the reaction chamber 200 and the detection chamber 300 forms a U-shaped channel through the provided boss structure 600. Specifically, the flow channel 2300 includes a first flow channel region 2310 and a second flow channel region 2320 connected in sequence. The starting end of the first flow channel region 2310 is connected to the reaction chamber 200, and the boss structure 600 is disposed on the end of the first flow channel region 2310. The boss structure 600 is higher than the lowest position of the first flow channel region 2310. The starting end of the second flow channel region 2320 is connected to the end of the first flow channel region 2310, and the end of the second flow channel region 2320 is disposed near the bottom of the detection chamber 300. When the liquid to be tested flows into the reaction chamber 200 through the inlet 100, the gas in the reaction chamber 200 flows into the detection chamber 300 through the flow channel 2300. Since the exhaust chamber 400, which is connected to the detection chamber 300, is in a sealed state, as the amount of liquid to be tested increases, the gas density in the detection chamber 300 and the exhaust chamber 400 continuously increases, thereby increasing the gas pressure in the detection chamber 300 and the exhaust chamber 400, which is higher than the gas pressure in the reaction chamber 200. The pressure difference between the detection chamber 300 and the reaction chamber 200 will exert a reaction force on the liquid being tested. Furthermore, due to the presence of the boss structure 600, which increases the resistance of the flow channel 2300, the pressure on the liquid being tested in the reaction chamber 200 is the same as the pressure in the flow channel 2300, thus allowing the liquid being tested to remain in the reaction chamber 200. That is, with the exhaust chamber 400 sealed, the liquid being tested can fully react with the enzyme reagent filled in the reaction chamber 200.

[0047] In some alternative embodiments, refer to Figure 3 The second flow channel region 2320 of the flow channel 2300 is in the shape of a straight pipe. The second flow channel region 2320 of the flow channel 2300 is perpendicular to the bottom plane of the detection chamber 300. Through the design of the second flow channel region 2320 of the flow channel 2300, the liquid to be tested can flow into the detection chamber 300 quickly, and through the flood discharge effect, the liquid to be tested in the first flow channel region 2310 can also be brought into the second flow channel region 2320.

[0048] In some optional embodiments, the flow area of ​​the first flow channel region 2310 is larger than that of the second flow channel region 2320, that is, the flow channel 2300 is set as a variable diameter microchannel. The design of the boss structure 600 combined with the variable diameter microchannel has the effect of increasing the local resistance of the flow channel 2300, which makes the pressure of the test liquid on the reaction chamber 200 side the same as the pressure in the flow channel 2300, so that the test liquid can stay in the reaction chamber 200; so that when the exhaust chamber 400 is sealed, the test liquid can fully react with the enzyme reagent filled in the reaction chamber 200. Furthermore, the flow area of ​​the first flow channel region 2310 of the variable diameter microchannel is larger than that of the second flow channel region 2320. The flow velocity of the liquid in the second flow channel region 2320 is greater than that of the liquid in the first flow channel region 2310. This allows the liquid being measured in the first flow channel region 2310 to be carried into the second flow channel region 2320 more effectively through the flood discharge effect.

[0049] Specifically, refer to Figure 4 The height h2 of the 600-degree boss structure can be calculated based on the following relationships, as follows:

[0050] Formula (1):

[0051] in, —Local atmospheric pressure, —The volume of the reaction chamber is 200. —The total volume of the detection chamber 300, the exhaust chamber 400, and the exhaust passage 3400;

[0052] —The local resistance loss of the test liquid through section 1 is related to the length L1 of the reaction chamber 200, the area S1 of the flow channel 2300 at the beginning of the first flow channel region 2310, the local flow velocity, the density of the test liquid, and the surface roughness of the material.

[0053] —The local resistance loss of the test liquid through section 2 is related to the length L2 of the detection chamber 300, the distance h1 between the starting end and the lowest point of the first flow channel region 2310, the local flow velocity, and the surface roughness of the material.

[0054] —The local resistance loss of the measured liquid through section 3 is related to the flow area S2 at the end of the first flow channel region 2310, the area S1 of the flow channel 2300 at the beginning of the first flow channel region 2310, the height h2 of the boss structure 600, the local flow velocity, and the surface roughness of the material.

[0055] —The local resistance loss of the test liquid through section 4 is related to the flow area S3 of the second flow channel region 2320, the length L2 of the detection chamber 300, the local flow velocity, and the surface roughness of the material;

[0056] —The local resistance loss of the test liquid through section 5 is related to the airway area S4 of the second channel region 3420, the length L2 of the detection chamber 300, the local flow velocity, and the surface roughness of the material;

[0057] —The local resistance loss of the test liquid through section 6 is related to the air passage area S4 of the second channel region 3420, the length L4 of the exhaust chamber 400, the local flow velocity, and the surface roughness of the material.

[0058] —The friction loss of the test liquid through channel 1 is related to the length h3 of the second flow channel region 2320, the flow area S3 of the second flow channel region 2320, the local flow velocity, and the viscosity coefficient of the test liquid.

[0059] —The friction loss of the test liquid through channel 2 is related to the length L3 of the first channel region 3410, the air passage area S4 of the second channel region 3420, the length h4 of the second channel region 3420, the local flow velocity, and the viscosity coefficient of the test liquid.

[0060] Formula (2):

[0061] Where H is the liquid level, ρ is the density of the liquid being tested, and g is the local gravity proportionality constant.

[0062] By substituting the parameters of formulas (1) and (2) into the calculation, the height h2 can be obtained.

[0063] In some alternative embodiments, refer to Figure 2 , Figure 3 The microfluidic detection chip is made of PC plastic injection molding, and its volume can be set to 30mm×26mm×5mm. It mainly includes two chambers: the upper chamber is the reaction chamber and the lower chamber is the detection chamber. Each chamber is pre-embedded with lyophilized reagents. The volume of the reaction chamber 200 on the microfluidic detection chip is about 750 microliters. A sample inlet 100 is opened at the top of the reaction chamber 200. This inlet is used to fill lyophilized reagent beads (the particle size of the lyophilized reagent beads is about 2.0-3.5mm). This embodiment does not specify the specific size of the beads.

[0064] In some alternative embodiments, refer to Figure 2 , Figure 3The reaction chamber 200 has a funnel-shaped structure, and its tip 210 is connected to the flow channel 2300. The liquid to be tested can flow more effectively into the flow channel 2300 between the reaction chamber 200 and the detection chamber 300 through the converging effect of the tip 210. The funnel-shaped design of the reaction chamber 200 facilitates the complete flow of the liquid to be tested and its smooth transfer to the detection chamber 300 through the tip 210, avoiding any residual droplets in the reaction chamber 200.

[0065] In some optional embodiments, the projection of the reaction chamber 200 onto the first side 810 of the chip body is the first projection, the projection of the detection chamber 300 onto the first side 810 is the second projection, and the projection of the exhaust chamber 400 onto the first side 810 is the third projection. The first, second, and third projections do not overlap. By setting three non-overlapping chambers on the first side 810, the chip body can be designed to be thinner and is not affected by the stacking of internal chamber structures.

[0066] In some alternative embodiments, refer to Figure 6 A detection area 900 is provided on the side wall of the chip body, corresponding to the detection chamber 300. The detection area 900 has a concave structure. Specifically, the detection area 900 includes a first detection area 910 and a second detection area 920 corresponding to the first detection area 910. The first detection area 910 is located on the first side 810 of the chip body, and the second detection area 920 is located on the second side 820 of the chip body. The depth of the concave structure of the first detection area 910 is less than the thickness of the first side 810, and the depth of the concave structure of the second detection area 920 is less than the thickness of the second side 820. This portion is thinner to improve light transmittance. Furthermore, the projected area of ​​the first detection area 910 on the first side 810 is larger than the area of ​​the light spot emitted by the light-emitting element of the pesticide residue detector, but smaller than the projected area of ​​the first projection. The projected area of ​​the second detection area 920 on the second side 820 is smaller than the projected area of ​​the reaction chamber 200 on the second side 820. The first detection area 910 and the second detection area 920 are arranged concentrically, and both the first detection area 910 and the second detection area 920 are circular with the same diameter. Since the areas of the first detection area 910 and the second detection area 920 are larger than the size of the light spot emitted by the light-emitting element, the concave structure design is to reduce the chip thickness of the detection area 9001, which can effectively allow the light spot emitted by the light-emitting element to pass smoothly through the detection cavity, improve the light spot transmittance, and thus improve the detection accuracy.

[0067] It should be noted that the detection area 9001 can be a concave structure with a diameter of 9 mm and a depth of 1 mm, or it can be a concave structure with a diameter of 10 mm and a depth of 1.2 mm. This embodiment does not make specific limitations on it.

[0068] In some alternative embodiments, refer to Figure 3 The exhaust passage 3400 includes a first passage region 3410, a second passage region 3420, and a third passage region 3430 connected in sequence. The air inlet end of the first passage region 3410 is located at the top of the detection chamber 300 and communicates with it. The vertical distance between the connecting ends of the first passage region 3410 and the second passage region 3420 and the bottom of the detection chamber 300 is greater than the vertical distance between the air inlet end of the first passage region 3410 and the bottom of the detection chamber 300. The vertical distance between the connecting ends of the second passage region 3420 and the third passage region 3430 is greater than the vertical distance between the connecting ends of the second passage region 3410 and the bottom of the detection chamber 300. The vertical distance between the connecting end of the third channel region 3410 and the bottom of the detection chamber 300 is greater than the vertical distance between the connecting end of the first channel region 3410 and the second channel region 3420 and the bottom of the detection chamber 300. The outlet end of the third channel region 3430 is located at the top of the exhaust chamber 400 and communicates with the exhaust chamber 400. The vertical distance between the outlet end of the third channel region 3430 and the bottom of the detection chamber 300 is smaller than the vertical distance between the connecting end of the second channel region 3420 and the third channel region 3430 and the bottom of the detection chamber 300. Because the vertical distance between the connecting end of the first channel region 3410 and the second channel region 3420 and the bottom of the detection chamber 300 is greater than the vertical distance between the air inlet end of the first channel region 3410 and the bottom of the detection chamber 300, even if the liquid being tested quickly passes through the second flow channel region 2320 and flows into the detection chamber 300, the collision between the liquid being tested and the bottom of the detection chamber 300 will generate a large rebound force, causing some of the liquid being tested to enter the first channel region 3410. Due to the sloping design of the first channel region 3410, this portion of the liquid being tested will be re-entered into the first channel region 3410. The liquid flows back to the detection chamber 300. Furthermore, since the vertical distance between the connecting end of the second channel region 3420 and the third channel region 3430 and the bottom of the detection chamber 300 is greater than the vertical distance between the connecting end of the first channel region 3410 and the second channel region 3420 and the bottom of the detection chamber 300, the first channel region 3410 and the second channel region 3420 can form a double resistance in the gas channel, making it difficult for the liquid being tested in the detection chamber 300 to flow to the exhaust chamber 400, effectively reducing the risk of the liquid being tested flowing out of the chip body, thereby effectively protecting the handheld pesticide residue detector.

[0069] In some alternative embodiments, refer to Figure 6The exhaust chamber 400 includes an exhaust unit 410, which includes an exhaust pipe 411, an exhaust port 412 communicating with the exhaust pipe 411, and an air inlet 413 communicating with the exhaust pipe 411. The exhaust port 412 is located on the first side 810. The exhaust pipe 411 is located inside the exhaust chamber 400 and perpendicular to the first side 810. The length of the exhaust pipe 411 is less than the distance between the first side 810 and the second side 820. The gas in the exhaust chamber 400 enters the exhaust pipe 411 through the air inlet 413 and then exits through the exhaust port 412. The sealing unit 500 is a sealing membrane used to seal the exhaust port 412 to prevent the gas in the detection chamber 300 and the exhaust chamber 400 from communicating with the atmosphere outside the chip body. Because the exhaust pipe 411 is designed to be perpendicular to the first side 810 and has a certain length, even if the liquid being tested flows into the exhaust chamber when the chip body is tilted or vibrated during use, it will not flow through the exhaust pipe 411 to the exhaust hole 412 and out of the chip body, thus effectively protecting the handheld pesticide residue detector.

[0070] It should be noted that when the sealing unit 500 is a sealing film, the sealing unit 500 can be a thin aluminum film with a thickness of 0.05 mm or a thin adhesive film with a thickness of 0.03 mm. This embodiment does not make specific limitations on it.

[0071] In some alternative embodiments, refer to Figure 5 The chip body includes a foolproof structure disposed on the first side 810, which is a groove structure. Specifically, the foolproof structure includes a first foolproof unit 710 and a second foolproof unit 720. The projection of the first foolproof unit 710 on the first side 810 overlaps with the projection of the flow channel 2300 on the first side 810, and the projection of the second foolproof unit 720 on the first side 810 overlaps with the projection of the gas channel on the first side 810. That is, the foolproof structure does not need to increase the area of ​​the first side 810 of the chip body. It can maximize the volume of the reaction chamber 200, the detection chamber 300, and the exhaust chamber 400 with a fixed area of ​​the first side 810. This is beneficial for controlling the size of the microfluidic pesticide residue detection chip and allows the microfluidic pesticide residue detection chip to be designed as a microstructure.

[0072] It should be noted that the shape of the error-proof structure is "L" shaped, or it can be other irregular shapes. This embodiment does not specifically limit it, as long as it can effectively prevent the chip body from shifting during the detection process.

[0073] In some alternative embodiments, refer to Figure 1 , Figure 3 , Figure 5 , Figure 6The chip body includes a first side 810, a second side 820, a third side 830, a fourth side 840, a fifth side 850, and a sixth side 860. The first side 810 and the second side 820 have the same shape and are arranged parallel to each other. The third side 830 and the fourth side 840 have the same shape and are arranged perpendicular to the first side 810. The fifth side 850 and the sixth side 860 have the same shape, are arranged perpendicular to the first side 810, and are also perpendicular to the fifth side 850. The side length of the bounding rectangle of the first side 810 is the length and width of the chip body. The side length of the bounding rectangle of the third side 830 is the length and height of the chip body. The side length of the bounding rectangle of the fifth side 850 is the width and height of the chip body.

[0074] It should be noted that the length of the chip body is less than or equal to 50mm, the width is less than or equal to 45mm, and the height is less than or equal to 10mm. For example, the size can be set to 30mm×26mm×5mm; another example is 40mm×23mm×7mm. Of course, other dimensions can be set according to actual needs to meet the requirements of small instrument size, low manufacturing cost, and easy portability.

[0075] Working principle of the microfluidic detection chip: Before adding the reaction liquid to the microfluidic pesticide residue detection chip, a sealing unit 500 is attached to the exhaust chamber 400, so that the end of the microfluidic pesticide residue detection chip is in a sealed state (the detection chamber 300 and the exhaust chamber 400 are in a sealed state). During the detection process, the liquid to be tested enters the reaction chamber 200 through the inlet 100. As the amount of liquid to be tested flowing into the reaction chamber 200 increases, the amount of gas in the reaction chamber 200 entering the detection chamber 300 through the flow channel 2300 between the reaction chamber 200 and the detection chamber 300 also increases. Since the detection chamber 300 and the exhaust chamber 400 are in a sealed state, the gas pressure in the detection chamber 300 and the exhaust chamber 400 continuously increases and becomes higher than the gas pressure in the reaction chamber 200. At this time, the gas pressure in the detection chamber 300 and the exhaust chamber 400 relative to the reaction chamber 200... The liquid being tested in chamber 200 exerts a force, and because the flow channel 2300 has a boss structure 600, which increases the resistance of the flow channel 2300, the liquid being tested remains in the reaction chamber 200 under the combined action of the pressure difference and the boss structure 600, and does not flow into the detection chamber 300. Thus, the liquid being tested can react fully in the reaction chamber 200. After the liquid being tested has completed the reaction in the reaction chamber 200, the sealing unit 500 in the exhaust chamber 400 can be punctured by the needle unit in the handheld pesticide residue detector, which reduces the air pressure in the detection chamber 300 and the exhaust chamber 400. In the absence of air pressure exerting a force on the liquid being tested, the liquid being tested flows into the detection chamber 300 through the boss structure 600. The sample to be tested can be automatically transferred in the microfluidic pesticide residue detection chip, which can realize rapid detection and improve detection efficiency.

[0076] It should be noted that the sample inlet 100 can be filled with lyophilized reagent beads, the reaction chamber 200 can be filled with enzyme reagents, and the detection chamber 300 can be filled with colorimetric reagents. Specifically, the working principle of the optical detection module used in the detection process of the test liquid in the microfluidic pesticide residue detection chip is as follows: Organophosphorus and carbamate pesticides have an inhibitory effect on the normal function of cholinesterase, and the inhibition rate is positively correlated with the pesticide concentration. During detection, the enzyme catalyzes the hydrolysis of the neurotransmitter metabolite (acetylcholine), and the hydrolysis product reacts with the colorimetric reagent to produce a yellow substance. The light spot emitted by the LED light-emitting element of the handheld pesticide residue detector passes through the detection chamber 300, and the light-collecting element of the handheld pesticide residue detector measures the change of its absorbance over time. The data transmission value is used by the control system to calculate the inhibition rate. If the inhibition rate is greater than 50%, the test sample can be determined to be positive; otherwise, it is negative.

[0077] In addition, a handheld pesticide residue detector includes the microfluidic pesticide residue detection chip in the above embodiments. The structure of the handheld pesticide residue detector is designed to match the structure of the microfluidic pesticide residue detection chip. The technical means in the above embodiments can solve the technical problems in the above embodiments and achieve the technical effects in the above embodiments, which will not be elaborated here.

[0078] The above provides a detailed description of the preferred embodiments of this application. However, this application is not limited to the above-described embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A microfluidic pesticide residue detection chip, characterized in that, This microfluidic pesticide residue detection chip, applied to a handheld pesticide residue detector, includes a chip body comprising an inlet port, a reaction chamber, a detection chamber, and an exhaust chamber. The reaction chamber is connected to the inlet port, the detection chamber is connected to the reaction chamber via a flow channel, and the exhaust chamber is connected to the detection chamber via an exhaust channel. The exhaust chamber is sealed by a sealing unit to prevent gas from flowing out. A boss structure is provided in the flow channel. This boss structure prevents the test liquid from flowing from the reaction chamber into the detection chamber when the exhaust chamber is sealed, and allows the test liquid to flow into the detection chamber through the boss structure if the sealing unit is punctured. The flow channel includes a first flow channel region and a second flow channel region connected in sequence. The starting end of the first flow channel region is connected to the reaction chamber. The boss structure is disposed at the end of the first flow channel region and is higher than the lowest position of the first flow channel region. The starting end of the second flow channel region is connected to the end of the first flow channel region. The end of the second flow channel region is disposed near the bottom of the detection chamber. The flow channel area of ​​the first flow channel region is larger than the flow channel area of ​​the second flow channel region.

2. The microfluidic pesticide residue detection chip according to claim 1, characterized in that, The second flow channel region of the flow channel is in the shape of a straight tube, and the second flow channel region of the flow channel is perpendicular to the bottom plane of the detection chamber.

3. The microfluidic pesticide residue detection chip according to claim 1, characterized in that, The reaction chamber has a funnel-shaped structure, and the tip of the funnel-shaped structure is connected to the starting end of the first flow channel region.

4. The microfluidic pesticide residue detection chip according to claim 1, characterized in that, The projection of the reaction chamber onto the first side of the chip body is the first projection, the projection of the detection chamber onto the first side is the second projection, and the projection of the exhaust chamber onto the first side is the third projection. The first projection, the second projection, and the third projection do not overlap.

5. The microfluidic pesticide residue detection chip according to claim 4, characterized in that, A detection area is provided on the side wall of the chip body, the detection area is provided corresponding to the detection chamber, the detection area is a concave structure, the detection area includes a first detection area and a second detection area corresponding to the first detection area, the first detection area is provided on the first side of the chip body, the second detection area is provided on the second side of the chip body, the depth of the concave structure of the first detection area is less than the thickness of the first side, and the depth of the concave structure of the second detection area is less than the thickness of the second side.

6. The microfluidic pesticide residue detection chip according to claim 5, characterized in that, The projected area of ​​the first detection area on the first side is larger than the area of ​​the light spot emitted by the light-emitting element of the pesticide residue detector, but smaller than the projected area of ​​the first projection. The projected area of ​​the second detection area on the second side is smaller than the projected area of ​​the reaction chamber on the second side. The first detection area and the second detection area are arranged concentrically.

7. The microfluidic pesticide residue detection chip according to claim 5, characterized in that, The exhaust chamber includes an exhaust unit, which includes an exhaust pipe and an exhaust port communicating with the exhaust pipe. The exhaust port is located on the first side. The exhaust pipe is located inside the exhaust chamber and is perpendicular to the first side. The length of the exhaust pipe is less than the distance between the first side and the second side. The sealing unit is a sealing membrane, which is used to seal the exhaust port to prevent the gas in the detection chamber and the exhaust chamber from communicating with the atmosphere outside the chip body.

8. The microfluidic pesticide residue detection chip according to claim 1, characterized in that, The exhaust channel includes a first channel region, a second channel region, and a third channel region connected in sequence. The air inlet of the first channel region is located at the top of the detection chamber and communicates with the detection chamber. The vertical distance between the connecting end of the first channel region and the second channel region and the bottom of the detection chamber is greater than the vertical distance between the air inlet of the first channel region and the bottom of the detection chamber. The vertical distance between the connecting end of the second channel region and the third channel region and the bottom of the detection chamber is greater than the vertical distance between the connecting end of the first channel region and the second channel region and the bottom of the detection chamber. The air outlet of the third channel region is located at the top of the exhaust chamber and communicates with the exhaust chamber. The vertical distance between the air outlet of the third channel region and the bottom of the detection chamber is smaller than the vertical distance between the connecting end of the second channel region and the third channel region and the bottom of the detection chamber.

9. The microfluidic pesticide residue detection chip according to claim 1, characterized in that, The reaction chamber is filled with enzyme reagents, and the detection chamber is filled with colorimetric reagents.

10. A handheld pesticide residue detector, comprising the microfluidic pesticide residue detection chip as described in any one of claims 1-9.

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