Rapid detection device for pesticide residues

Abstract

The application discloses a pesticide residue rapid detection device, which comprises a flow control chip and a handheld host component. The flow control chip comprises a plurality of chambers, a plurality of microchannels, a plurality of diaphragm valves, a plurality of first air channels and a plurality of second air channels. The chambers comprise a sample temporary storage chamber, a magnetic bead pre-storage chamber, a quantum dot pre-storage chamber, a reaction chamber, a detection chamber, a reconstitution solution chamber, a washing liquid chamber and a waste liquid chamber. Each microchannel is used for connecting the corresponding chamber. Each diaphragm valve is arranged on the microchannel and is used for controlling the opening and closing of the microchannel. The distal end of each first air channel is connected to the control chamber of each diaphragm valve. The distal end of each second air channel is connected to each chamber. The handheld host component comprises a shell, an electromagnet assembly and a pneumatic driving system. The pneumatic driving system is configured to provide negative pressure to the diaphragm valve through the first air channel to open the microchannel corresponding to the diaphragm valve, and provide positive pressure and / or negative pressure to the corresponding chamber through the second air channel.

Description

Technical Field

[0001] This invention relates to the field of pesticide detection technology, and in particular to a rapid pesticide residue detection device. Background Technology

[0002] Food safety is a major issue concerning the national economy and people's livelihood. With the extensive use of pesticides in agricultural production, pesticide residues in vegetables and other agricultural products are increasingly attracting the attention of consumers and market regulators. Establishing an efficient safety risk prevention and control system for the agricultural and food distribution process urgently requires rapid, sensitive, low-cost, and easy-to-operate on-site testing technologies.

[0003] Currently, pesticide residue detection methods are mainly divided into two categories: one is laboratory confirmatory methods, such as gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). These methods are highly sensitive and accurate in quantification, but the equipment is expensive, the operation is complex, and the time consumption is long (usually several hours to several days), which cannot meet the needs of rapid on-site screening; the other is rapid detection methods, mainly including enzyme inhibition methods and immunochromatography.

[0004] Enzyme inhibition methods rely on the inhibitory effect of organophosphates and carbamates on acetylcholinesterase, using colorimetric reactions to determine the presence of pesticides. This method is simple and inexpensive, but suffers from poor specificity and a high false-positive rate.

[0005] Immunochromatographic assays, particularly colloidal gold immunochromatographic test strips, are the most common method. This method involves labeling pesticide antibodies onto colloidal gold particles, fixing them in a conjugation pad, and coating a nitrocellulose membrane with a pesticide-carrier protein conjugate as the detection line (T line) and goat anti-mouse IgG as the control line (C line). When a sample droplet is added to the sample pad, it migrates forward through capillary action. The free pesticide in the sample competes with the pesticide-carrier protein on the detection line for binding to the colloidal gold-labeled antibody. The pesticide concentration is determined by the color intensity of the T line. This method is simple to operate and has a short detection time (10-15 minutes), but it has the following drawbacks: (1) the sensitivity of colloidal gold is relatively low; (2) it is severely affected by impurities.

[0006] In recent years, quantum dots (QDs) have been introduced into the field of immunochromatography due to their excellent fluorescence properties (broad excitation spectrum, narrow emission spectrum, high fluorescence intensity, and good photostability), resulting in quantum dot immunochromatographic test strips. Compared with colloidal gold, quantum dot test strips offer significantly improved detection sensitivity and can achieve quantitative analysis using a fluorescence detector. However, existing quantum dot test strips still employ a traditional passive chromatography structure: the sample solution migrates spontaneously via capillary forces from the nitrocellulose membrane, making it impossible to actively control the flow rate and reaction time; pesticide concentrations in the sample are difficult to detect when they are too low; and the detection results are significantly affected by impurities. Summary of the Invention

[0007] To address the aforementioned technical problems in the prior art, embodiments of the present invention provide a rapid pesticide residue detection device.

[0008] To solve the above-mentioned technical problems, the technical solution adopted in the embodiments of the present invention is as follows:

[0009] A rapid pesticide residue detection device includes: a flow control chip and a handheld host component;

[0010] The flow control chip includes:

[0011] The system comprises multiple chambers, including: a sample storage chamber, a magnetic bead pre-storage chamber, a quantum dot pre-storage chamber, a reaction chamber, a detection chamber, a reconstitution chamber, a cleaning solution chamber, and a waste liquid chamber. The sample storage chamber receives the sample solution. The magnetic bead pre-storage chamber contains carboxyl magnetic beads with surface-coupled broad-spectrum anti-pesticide antibodies. The quantum dot pre-storage chamber contains green quantum dot-antibody conjugates. The reaction chamber is located downstream of the sample storage chamber, magnetic bead pre-storage chamber, and quantum dot pre-storage chamber, and is selectively connected to each of these chambers. The detection chamber is located downstream of the reaction chamber and is selectively connected to it. The reconstitution chamber is selectively connected to the magnetic bead pre-storage chamber and the quantum dot pre-storage chamber, and is used to provide the reconstitution solution to these chambers. The cleaning solution chamber is selectively connected to the reaction chamber, and is used to provide the cleaning solution to the reaction chamber. The waste liquid chamber is selectively connected to the reaction chamber and the detection chamber, and is used to receive waste liquid.

[0012] Multiple microchannels, each microchannel being used to connect the corresponding chambers;

[0013] Multiple diaphragm valves, each arranged on a microchannel, are used to control the opening and closing of the microchannel;

[0014] Multiple first airways and multiple second airways, the distal end of each first airway is connected to the control chamber of each diaphragm valve, and the distal end of each second airway is connected to each chamber.

[0015] The handheld host unit components include:

[0016] The housing has a slot for attaching the flow control chip;

[0017] An electromagnet assembly includes a first electromagnet and a second electromagnet respectively arranged in regions opposite to the reaction chamber and the detection chamber;

[0018] A pneumatic drive system is configured to: provide negative pressure to a diaphragm valve through a first air passage to open the microchannel corresponding to the diaphragm valve; and provide positive pressure and / or negative pressure to the corresponding chamber through a second air passage, so that when the microchannel between the two chambers is open, fluid in one chamber flows to the other chamber;

[0019] An optical detection module is arranged in the area corresponding to the detection cavity and is used to detect the fluorescence signal in the detection cavity.

[0020] Preferably, the microchannel has a columnar cavity, a valve column is disposed in the columnar cavity, the upper end of the valve column protrudes from the columnar cavity, the upper end of the columnar cavity is covered with an elastic membrane, the elastic membrane is pressed against the valve column and adhered to the valve column, and there is a reserved space above the elastic membrane, the first air passage extends to the reserved space.

[0021] Preferably, a liquid-proof and breathable membrane is disposed between the distal end of the second airway and the chamber.

[0022] Preferably, the liquid-sealing and breathable membrane is sealed on the top of the chamber, and there is a reserved space above the liquid-sealing and breathable membrane, with the distal end of the second airway communicating with the reserved space.

[0023] Preferably, the liquid-sealing and breathable membrane is located on one side of the chamber, and there is a reserved space above the liquid-sealing and breathable membrane, with the distal end of the second airway communicating with the reserved space.

[0024] Preferably, the flow control chip includes a base layer, an upper surface layer covering the upper surface of the base layer, and a lower surface layer covering the lower surface of the base layer; wherein:

[0025] The first airway and the second airway are disposed on the upper surface layer, and the microchannel is disposed on the base layer.

[0026] Preferably, the pneumatic drive system provides negative pressure to the chamber via a second air passage.

[0027] Preferably, the proximal ends of each of the first airways and the proximal ends of each of the second airways extend to the inner side of the flow control chip and are respectively attached with rubber connectors; wherein:

[0028] The pneumatic drive system includes a diaphragm pump, a first valve group that interfaces with the proximal end of each first airway, and a second valve group that interfaces with the proximal end of each second airway.

[0029] The beneficial effects of this invention are as follows:

[0030] 1. The flow control chip of this invention employs a pneumatic drive system, achieving active, orderly, and programmable transfer of liquid between multiple chambers by independently controlling the diaphragm valves on each microchannel and the air pressure within each chamber. Compared to existing test strips that rely on passive capillary action for chromatography, this invention can precisely control the flow rate, reaction time, and number of washes of the sample solution, magnetic bead suspension, quantum dot labeled solution, reconstitution solution, and washing solution, significantly improving antigen-antibody binding efficiency and the detection capability of low-concentration pesticides.

[0031] 2. This invention pre-loads carboxyl magnetic beads with surface-coupled broad-spectrum anti-pesticide antibodies into the magnetic bead pre-storage chamber. The magnetic beads are adsorbed to the bottom of the reaction chamber by a first electromagnet, achieving efficient capture and enrichment of pesticide molecules in the sample. Combined with the cleaning solution provided in the cleaning chamber, the magnetic beads can be repeatedly cleaned 2-3 times, effectively removing non-specific adsorption interference from the sample matrix. Compared to existing test strips that cannot perform sample enrichment and cleaning, the device of this invention significantly improves detection sensitivity.

[0032] 3. This invention simultaneously configures a green quantum dot region and a red quantum dot region at the bottom of the detection chamber. The green quantum dots provide a detection signal negatively correlated with pesticide concentration, while the red quantum dots serve as a fixed internal reference for signal calibration. The optical detection module simultaneously acquires green and red fluorescence, and the main control module calculates the fluorescence ratio R. This ratio calibration method effectively eliminates systematic errors such as light source fluctuations, chip batch differences, ambient temperature variations, and differences in optical window transmittance, significantly outperforming the quantitative accuracy of existing technologies.

[0033] The overview of various implementations or examples of the technology described in this invention is not a complete disclosure of the full scope or all features of the disclosed technology. Attached Figure Description

[0034] In drawings that are not necessarily drawn to scale, the same reference numerals may describe similar parts in different views. The same reference numerals with or without letter suffixes may indicate different instances of similar parts. The drawings generally illustrate various embodiments by way of example rather than limitation and, together with the description and claims, serve to explain embodiments of the invention. Where appropriate, the same reference numerals are used in all drawings to refer to the same or similar parts. Such embodiments are illustrative and not intended to be exhaustive or exclusive embodiments of the apparatus or method.

[0035] Figure 1 A top view of the rapid pesticide residue detection device provided for an embodiment of the present invention (the housing of the handheld main unit is hidden).

[0036] Figure 2 This is a cross-sectional view of the flow control chip at the location of the diaphragm valve on the first microchannel.

[0037] Figure 3 This is a cross-sectional view of the flow control chip located at the reaction chamber.

[0038] Figure 4 This is a cross-sectional view of the flow control chip located at the detection cavity.

[0039] Figure 5A top view of the rapid pesticide residue detection device provided for an embodiment of the present invention (showing the handheld main unit and hiding the air passages).

[0040] Figure Labels

[0041] 11-Sample storage chamber; 12-Magnetic bead pre-storage chamber; 13-Quantum dot pre-storage chamber; 14-Reaction chamber; 15-Detection chamber; 151-Green quantum dot region; 152-Red quantum dot region; 16-Reconstitution chamber; 17-Washing solution chamber; 18-Waste liquid chamber; 21-First microchannel; 22-Second microchannel; 23-Third microchannel; 24-Fourth microchannel; 25 - 5th microchannel; 26 - 6th microchannel; 27 - 7th microchannel; 28 - 8th microchannel; 29 - 9th microchannel; 31 - 1st control airway; 32 - 2nd control airway; 33 - 3rd control airway; 34 - 4th control airway; 35 - 5th control airway; 36 - 6th control airway; 37 - 7th control airway; 38 - 8th control airway; 39 - 9th control airway; 41 - 1st power airway; 42 - 2nd power airway; 43 - 3rd power airway; 44 - 4th power airway; 45 - 5th power airway; 46 - 6th power air passage; 47-7th power air passage; 48-8th power air passage; 51-Diaphragm valve; 511-Valve column; 512-Elastic membrane; 52-Liquid-barrier and breathable membrane; 61-First valve group; 62-Second valve group; 63-Diaphragm pump; 70-Housing; 81-First electromagnet; 82-Second electromagnet; 91-Optical detection module; 92-Main control module; 93-Display module; 94-Power supply; 100-Flow control chip; 101-Base layer; 102-Upper surface layer; 103-Lower surface layer; 104-Silicone connector; 200-Handheld host component. Detailed Implementation

[0042] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0043] To keep the following description of the embodiments of the present invention clear and concise, detailed descriptions of known functions and known components are omitted.

[0044] like Figures 1 to 5 As shown, an embodiment of the present invention discloses a rapid pesticide residue detection device for detecting pesticide residues in vegetables. The device includes a flow control chip 100 and a handheld host component 200. The handheld host component 200 is a reusable component, while the flow control chip 100 is a disposable component.

[0045] The flow control chip 100 can be made of a transparent polymer material. In terms of its layered structure, the flow control chip 100 includes a base layer 101, an upper surface layer 102 covering the upper surface of the base layer 101, and a lower surface layer 103 covering the lower surface of the base layer 101. The flow control chip 100 is configured with multiple chambers, multiple microchannels, multiple air passages, and multiple diaphragm valves 51; each chamber and each microchannel is disposed on the base layer 101, and each air passage is disposed at the bottom of the upper surface layer 102.

[0046] The system comprises multiple chambers, including a sample storage chamber 11, a magnetic bead pre-storage chamber 12, a quantum dot pre-storage chamber 13, a reaction chamber 14, a detection chamber 15, a reconstitution chamber 16, a cleaning solution chamber 17, and a waste liquid chamber 18. The sample storage chamber 11, the magnetic bead pre-storage chamber 12, and the quantum dot pre-storage chamber 13 are arranged in parallel. The reaction chamber 14 is located downstream of the sample storage chamber 11, the magnetic bead pre-storage chamber 12, and the quantum dot pre-storage chamber 13, and the detection chamber 15 is located downstream of the reaction chamber 14. The sample storage chamber 11 is open at the top to receive vegetable sample solutions. A filter screen (not shown) is installed at the top of the sample storage chamber 11 to filter particulate impurities from the sample solution. The magnetic bead pre-storage chamber 12 contains lyophilized carboxyl magnetic beads with surface-coupled broad-spectrum anti-pesticide antibodies. The quantum dot pre-storage chamber 13 contains lyophilized green quantum dot-antibody conjugates. The bottom of the detection chamber 15 has a green quantum dot region 151 and a red quantum dot region 152. The reconstitution chamber 16 contains a reconstitution solution to provide to the magnetic bead pre-storage chamber 12 and the quantum dot pre-storage chamber 13, allowing the carboxyl magnetic beads and the green quantum dot-antibody conjugate to reconstitute. The washing solution chamber 17 contains washing solution to provide to the reaction chamber 14. The waste liquid chamber 18 receives waste liquid generated after washing from the reaction chamber 14 and the detection chamber 15. The bottom of the detection chamber 15 has a green quantum dot region 151 and a red quantum dot region 152.

[0047] Each microchannel includes microchannels 1 to 9. Microchannel 1 21 is used to connect sample storage chamber 11 and reaction chamber 14. Microchannel 22 is used to connect magnetic bead pre-storage chamber 12 and reaction chamber 14. Microchannel 3 23 is used to connect quantum dot pre-storage chamber 13 and reaction chamber 14. Microchannel 4 24 is used to connect detection chamber 15 and reaction chamber 14. Microchannel 5 25 is used to connect reconstitution chamber 16 and magnetic bead pre-storage chamber 12. Microchannel 6 26 is used to connect reconstitution chamber 16 and quantum dot pre-storage chamber 13. Microchannel 7 27 is used to connect cleaning fluid chamber 17 and reaction chamber 14. Microchannel 8 28 is used to connect reaction chamber 14 and waste fluid chamber 18. Microchannel 9 29 is used to connect detection chamber 15 and waste fluid chamber 18.

[0048] Each diaphragm valve 51 is correspondingly arranged on each microchannel to control the opening and closing of each microchannel. Each diaphragm valve 51 controls the passage of each microchannel via a first airway among multiple airways. Each first airway includes a first to a ninth control airway corresponding to each microchannel. The distal ends of the first to the ninth control airways are respectively connected to the diaphragm valves 51 on the first to the ninth microchannels (i.e., the distal end of the first control airway 31 is connected to the diaphragm valve 51 on the first microchannel 21; the distal end of the second control airway 32 is connected to the diaphragm valve 51 on the second microchannel 22; the distal end of the third control airway 33 is connected to the diaphragm valve 51 on the third microchannel 23; and the distal end of the fourth control airway 34 is connected to the fourth microchannel 23). The diaphragm valve 51 on the 4th microchannel; the distal end of the 5th control airway 35 is connected to the diaphragm valve 51 on the 5th microchannel 25; the distal end of the 6th control airway 36 is connected to the diaphragm valve 51 on the 6th microchannel 26; the distal end of the 7th control airway 37 is connected to the diaphragm valve 51 on the 7th microchannel 27; the distal end of the 8th control airway 38 is connected to the diaphragm valve 51 on the 8th microchannel 28; the distal end of the 9th control airway 39 is connected to the diaphragm valve 51 on the 9th microchannel 29; the proximal ends of the 1st to 9th control airways extend to the inner side of the flow control chip 100 and a silicone connector 104 is installed at the proximal port.

[0049] like Figure 2As shown, columnar cavities are fabricated on each microchannel, with the diameter of the columnar cavity significantly larger than the width of the microchannel. A groove is fabricated at the bottom of the upper surface layer 102 of the flow control chip 100, opposite to the columnar cavity. The tops of the microchannels on both sides of the columnar cavity are encapsulated. A valve post 511 is arranged in the columnar cavity, with its top protruding from the upper surface of the base layer 101 and capable of vertical movement. An elastic membrane 512 covers the columnar cavity and its surrounding area, pressing against the valve post 511, and the top of the valve post 511 is bonded and fixed to the elastic membrane 512. The distal end of the corresponding control air passage extends to the wall of the groove, thus communicating with the groove, i.e., communicating with the reserved space formed by the groove that allows the elastic membrane 512 to deform upwards. It should be noted that the elastic membrane 512 is a membrane that does not allow either liquid or gas to pass through. By drawing gas into the reserved space formed by the submerged groove connected to the distal end of the control airway, a negative pressure is created within the reserved space. This causes the elastic diaphragm 512 to move the valve column 511 upward, opening the microchannel. When the drawing of gas into the reserved space is stopped and it is opened to the outside atmosphere, allowing the elastic diaphragm 512 to reset, the reset of the elastic diaphragm 512 forces the valve column 511 downward, closing the microchannel. In this way, gas can be drawn into the control airway to control the closure of the corresponding microchannel.

[0050] like Figure 1 As shown, the multiple air channels also include multiple second air channels. The number of second air channels is the same as the number of chambers, and each second air channel corresponds one-to-one with each chamber. By drawing gas into the second air channels, the transfer of liquid in the chambers is powered. Since each second air channel is used to provide power for the transfer of liquid, it can be referred to as a power air channel. Specifically, each power air channel includes: a first power air channel 41 with its distal end connected to the sample storage chamber 11; a second power air channel 42 with its distal end connected to the magnetic bead pre-storage chamber 12; a third power air channel 43 with its distal end connected to the quantum dot pre-storage chamber 13; a fourth power air channel 44 with its distal end connected to the reaction chamber 14; a fifth power air channel 45 with its distal end connected to the detection chamber 15; a sixth power air channel 46 with its distal end connected to the reconstitution chamber 16; a seventh power air channel 47 with its distal end connected to the cleaning liquid chamber 17; and an eighth power air channel 48 with its distal end connected to the waste liquid chamber 18. Each power airway extends proximal to the inner side of the flow control chip 100 and has a silicone connector 104 installed at its proximal port. By using the aforementioned power airways to draw gas into the corresponding chambers, a pressure difference is created between the two chambers involved in the transfer, thereby driving the fluid to transfer from one chamber to another.

[0051] like Figure 3 and Figure 4As shown, a liquid-proof and breathable membrane 52 is arranged between the distal end of each power air channel and its corresponding chamber. This ensures that the fluid within the chamber is not drawn away when gas is drawn into the chamber through the power air channel. Except for the liquid-proof and breathable membrane 52 corresponding to the detection chamber 15, the liquid-proof and breathable membranes 52 corresponding to the other chambers cover the top of the chamber, with reserved space provided in each membrane. The distal end of the corresponding power air channel connects to the side wall of the liquid-proof and breathable membrane 52. The liquid-proof and breathable membrane 52 corresponding to the detection chamber 15 is arranged on one side of the top of the detection chamber 15. The area above the top of the detection chamber 15 is used to arrange the optical detection module 91, which will be described below. Arranging the liquid-proof and breathable membrane 52 on one side of the top of the detection chamber 15 avoids obstructing the optical detection module 91.

[0052] The following describes how to control fluid transfer using the control airway, diaphragm valve 51, and power airway.

[0053] For example, if it is necessary to provide a reconstituted solution to the magnetic bead pre-storage chamber 12, firstly, the fifth control airway 35 is used to draw gas into the diaphragm valve 51 on the fifth microchannel 25, causing the valve stem 511 of the diaphragm valve 51 to move upward, thereby opening the fifth microchannel 25. This allows the second control airway 32 to be in a state of communication with the atmosphere, so that the valve stem 511 of the diaphragm valve 51 remains in the lower position, thereby keeping the second microchannel 22 in a closed state. At this time, the magnetic bead pre-storage chamber 12 is only connected to the reconstituted solution chamber 16 through the fifth microchannel 25. Then, the sixth power airway 46 is made to be in a state of communication with the atmosphere, thereby making the reconstituted solution chamber 16 connected to the atmosphere. The second power airway 42 is used to draw gas into the magnetic bead pre-storage chamber 12, creating a negative pressure in the magnetic bead pre-storage chamber 12. Under the action of the negative pressure, the reconstituted solution in the reconstituted solution chamber 16 enters the magnetic bead pre-storage chamber 12 through the fifth microchannel 25.

[0054] For example, if it is necessary to transfer the fluid in the reaction chamber 14 to the detection chamber 15, firstly, the control air channels corresponding to the diaphragm valves 51 on the first microchannel 21, the second microchannel 22, the third microchannel 23, the seventh microchannel 27, and the eighth microchannel 28 are connected to the atmosphere, thereby closing these five microchannels. Then, the fourth control air channel 34 is used to draw gas into the diaphragm valve 51 on the fourth microchannel 24, causing the valve stem 511 of the diaphragm valve 51 to move upward, thereby opening the fourth microchannel 24. At this time, the detection chamber 15 and the reaction chamber 14 are only connected through the fourth microchannel 24, and are not connected to other chambers. Then, the fourth power air channel 44 is connected to the atmosphere, thereby connecting the reaction chamber 14 to the atmosphere. The fifth power air channel 45 is used to draw gas into the detection chamber 15, creating a negative pressure in the detection chamber 15. Under the action of negative pressure, the fluid in the reaction chamber 14 enters the detection chamber 15 through the fourth microchannel 24.

[0055] It should be noted that the negative pressure provided to the diaphragm valve 51 via the control airway should be much greater than the negative pressure provided to the chamber via the power airway, in order to avoid the diaphragm valve 51 on the microchannel being unable to obtain sufficient pressure difference and thus unable to be opened due to the negative pressure state of the target chamber being transferred.

[0056] like Figure 5 and combined Figure 1 As shown, the handheld host component 200 includes: a housing 70, a pneumatic drive system, an optical detection module 91, an electromagnet module, a main control module 92, a display module 93, and a power supply 94.

[0057] The housing 70 is configured with a card slot, and the aforementioned flow control chip 100 is detachably inserted into the card slot through the slot opening. After the flow control chip 100 is inserted into the card slot, at least the sample storage chamber 11, the magnetic bead pre-storage chamber 12, and the quantum dot pre-storage chamber 13 are exposed outside the housing 70, while at least the reaction chamber 14 and the detection chamber 15 are located inside the housing 70.

[0058] The pneumatic drive system is arranged in the housing 70 and adjacent to the proximal ports of each air passage of the flow control chip 100; the optical detection module 91 is arranged on the housing 70 and opposite to the top of the detection cavity 15. A lens with good light transmission is installed between the detection cavity 15 and the optical detection module 91 to avoid obstructing the optical detection module 91; the electromagnet module includes a first electromagnet 81 module and a second electromagnet 82 module. The first electromagnet 81 module is arranged on the housing 70 and corresponds to the bottom of the reaction cavity 14. The second electromagnet 82 module is arranged on the housing 70 and corresponds to the bottom of the detection cavity 15; the display module 93 is arranged in the housing 70, and the main control module 92 is arranged in the housing 70 and is used to control the pneumatic drive system, the optical detection module 91, and the electromagnets, process the detection data of the optical detection module 91, and display the detection results on the display module 93; the power supply 94 provides power to each electrical component.

[0059] The pneumatic drive system includes a diaphragm pump 63 for providing suction power, a first valve group 61 connected between the diaphragm pump 63 and each control airway to control the on / off connection between the diaphragm pump 63 and each control airway, and a second valve group 62 connected between the diaphragm pump 63 and each power airway to control the on / off connection between the diaphragm pump 63 and each power airway. The diaphragm pump 63 draws gas into the corresponding airway or connects the airway to the atmosphere through the valves in the corresponding valve groups. Therefore, the valves in the valve groups have interfaces for connecting to the atmosphere. After the flow control chip 100 is inserted into the slot of the housing 70, each valve in each valve group mates with the rubber joint at the proximal port of each airway, thereby sealing the connection with each airway.

[0060] The first electromagnet 81 and the second electromagnet 82 are controlled by the main control module 92. By energizing the electromagnets, the electromagnets can attract carboxyl magnetic beads that have entered the reaction chamber 14 or the detection chamber 15. By intermittently switching the power on and off, the carboxyl magnetic beads can switch between being adsorbed and being released.

[0061] The following describes the process of using the aforementioned detection device to detect pesticide residues in vegetables.

[0062] The following describes the workflow of the detection device of the present invention in detail, taking the detection of organophosphorus or carbamate pesticides in vegetable samples as an example. The entire process is automatically controlled by the main control module 92 of the handheld host component 200, and the user only needs to complete the sample pretreatment and chip insertion operations.

[0063] I. Preliminary preparations.

[0064] 1. Sample pretreatment: Take 5g of vegetable leaves to be tested, cut them into small pieces, add 10mL of extraction solution, shake to extract for 2 minutes, let stand or filter, and take the supernatant as the sample to be tested.

[0065] 2. Chip Installation: Insert the flow control chip 100 into the slot of the housing 70 of the handheld host component 200 until the chip is fully in place. The silicone connectors 104 of each airway proximal port on the flow control chip 100 are sealed and connected to the corresponding valve group of the pneumatic drive system; the sample storage chamber 11, the magnetic bead pre-storage chamber 12, and the quantum dot pre-storage chamber 13 are exposed outside the housing 70 for sample loading, while the reaction chamber 14, the detection chamber 15, etc. are located inside the housing 70.

[0066] 3. Sample addition: Use a pipette or dropper to draw a certain amount of the sample solution to be tested and add it from the open end of the sample storage chamber 11. The filter screen at the top of the sample storage chamber 11 can filter out large particulate impurities.

[0067] II. Reconstitution Steps.

[0068] The main control module 92 controls the pneumatic drive system to inject the reconstituted solution into the magnetic bead pre-storage chamber 12 and the quantum dot pre-storage chamber 13 in the following sequence to reconstitute the lyophilized powder.

[0069] 1. Reconstituted magnetic beads:

[0070] The main control module 92 instructs the valve corresponding to the fifth control air passage 35 in the first valve group 61 to activate, connecting the air intake port of the diaphragm pump 63 with the fifth control air passage 35, drawing gas into the diaphragm valve 51 on the fifth microchannel 25, causing the valve stem 511 of the diaphragm valve 51 to move upward, and the fifth microchannel 25 to open.

[0071] At the same time, the valve corresponding to the second control airway 32 is switched to the state of being connected to the atmosphere, so that the diaphragm valve 51 on the second microchannel 22 remains closed (valve column 511 is in the lower position).

[0072] The main control module 92 instructs the valve corresponding to the sixth power air channel 46 in the second valve group 62 to switch to atmospheric connection, making the reconstitution chamber 16 open to the atmosphere; simultaneously, it instructs the valve corresponding to the second power air channel 42 to connect the diaphragm pump 63's suction port to the second power air channel 42, drawing gas into the magnetic bead pre-storage chamber 12. Under negative pressure, the reconstitution solution in the reconstitution chamber 16 is drawn into the magnetic bead pre-storage chamber 12 through the fifth microchannel 25, and the freeze-dried carboxyl magnetic beads are reconstituted to form a magnetic bead suspension. After reconstitution is completed, the fifth control air channel 35 is closed (releasing negative pressure, the fifth microchannel 25 is closed), and the evacuation of gas from the magnetic bead pre-storage chamber 12 is stopped.

[0073] 2. Reconstituted quantum dots:

[0074] Similarly, the main control module 92 instructs the 6th control airway 36 to open the 6th microchannel 26 while keeping the 3rd microchannel 23 closed.

[0075] The reconstitution chamber 16 is connected to the atmosphere through the sixth power air channel 46, and gas is drawn into the quantum dot pre-storage chamber 13 through the third power air channel 43. The reconstitution solution is drawn from the reconstitution chamber 16 into the quantum dot pre-storage chamber 13 through the sixth microchannel 26, so that the freeze-dried green quantum dot-antibody conjugate is reconstituted to form a quantum dot labeled solution.

[0076] Close microchannel 26 after completion.

[0077] 3. Mix the sample with the magnetic beads and incubate.

[0078] 1. Transfer the sample to reaction chamber 14:

[0079] The main control module 92 instructs the first control airway 31 to open the first microchannel 21 (diaphragm valve 51 opens), while ensuring that the second, third, fourth, seventh, and eighth microchannels are all closed.

[0080] Switch the first power gas channel 41 to be connected to the atmosphere (connect the sample storage chamber 11 to the atmosphere), and instruct the fourth power gas channel 44 to draw gas into the reaction chamber 14.

[0081] The sample solution is drawn from the sample storage chamber 11 into the reaction chamber 14 through the first microchannel 21. After the transfer is complete, the first microchannel 21 is closed.

[0082] 2. The magnetic bead suspension is transferred to reaction chamber 14:

[0083] Open microchannel 22, and keep other related channels closed.

[0084] Connect the second power air channel 42 to the atmosphere (the magnetic bead pre-storage chamber 12 is also connected to the atmosphere). Continue to draw gas into the reaction chamber 14 through the fourth power air channel 44, and draw the magnetic bead suspension into the reaction chamber 14 through the second microchannel 22. After the transfer is complete, close the second microchannel 22.

[0085] 3. Mixing and incubation:

[0086] All microchannels are shut down. The main control module 92 controls the power supply 94 to intermittently energize the first electromagnet 81 at a certain frequency (e.g., 1Hz), causing the carboxyl magnetic beads in the reaction chamber 14 to reciprocate in the solution and come into full contact with the pesticide molecules in the sample.

[0087] During incubation, the broad-spectrum anti-pesticide antibodies on the surface of the carboxyl magnetic beads capture free pesticide molecules in the sample, forming an "antibody-pesticide" complex on the surface of the carboxyl magnetic beads.

[0088] IV. First magnetic separation and discharge of supernatant.

[0089] 1. Magnetic separation: The main control module 92 instructs the first electromagnet 81 to be continuously energized, adsorbing the carboxyl magnetic beads onto the bottom of the reaction chamber 14.

[0090] 2. Drain the supernatant:

[0091] Open the 8th microchannel 28 (from reaction chamber 14 to waste liquid chamber 18).

[0092] Connect the fourth power air passage 44 to the atmosphere (connect the reaction chamber 14 to the atmosphere), and instruct the eighth power air passage 48 to draw gas from the waste liquid chamber 18.

[0093] The supernatant (unbound sample solution and impurities) in reaction chamber 14 is drawn into waste chamber 18 through microchannel 8 28. After drainage, microchannel 8 28 is closed.

[0094] 5. Clean the magnetic beads (to remove non-specific adsorption).

[0095] 1. Inject cleaning solution:

[0096] Open the 7th microchannel 27.

[0097] The seventh power air passage 47 is connected to the atmosphere (the cleaning liquid chamber 17 is connected to the atmosphere), and the gas is drawn into the reaction chamber 14 through the fourth power air passage 44, so that a certain amount of cleaning liquid is drawn into the reaction chamber 14.

[0098] Close the 7th microchannel 27.

[0099] 2. Resuspension and cleaning: The main control module 92 controls the power supply 94 to intermittently energize the first electromagnet 81 at a certain frequency (e.g., 1Hz), so that the carboxyl magnetic beads in the reaction chamber 14 reciprocate in the solution to wash away the non-specific adsorbed substances on the surface of the carboxyl magnetic beads.

[0100] Secondary magnetic separation and waste discharge: The first electromagnet 81 is energized to attract carboxyl magnetic beads, opening the 8th microchannel 28, and drawing gas through the 8th power air passage 48 to discharge the cleaning waste liquid into the waste liquid chamber 18.

[0101] 3. Repeat cleaning: Repeat the above steps of injecting cleaning solution, resuspending, magnetic separation, and waste discharge 2-3 times to ensure that the surface of the carboxyl magnetic beads is clean.

[0102] VI. Quantum Dot Labeling

[0103] 1. Inject quantum dot labeling solution:

[0104] Open the third microchannel 23 (from quantum dot pre-storage chamber 13 to reaction chamber 14).

[0105] The third power airway 43 is connected to the atmosphere, and gas is drawn into the reaction chamber 14 through the fourth power airway 44 to draw in the green quantum dot-antibody conjugate suspension (mixed with carboxyl magnetic beads).

[0106] Close the third microchannel 23.

[0107] 2. Incubation and Combination: The control module controls the power supply 94 to intermittently energize the first electromagnet 81 at a certain frequency (e.g., 1Hz), so that the carboxyl magnetic beads and quantum dot labeling solution are fully mixed. The incubation time is preset to 1-3 minutes. During this process, the quantum dot label binds to the pesticide molecules already captured on the carboxyl magnetic beads through antibody recognition, forming an "antibody-pesticide-antibody-quantum dot" complex.

[0108] 3. Cleaning unbound quantum dots:

[0109] The first electromagnet 81 is energized to attract carboxyl magnetic beads.

[0110] Open the 7th microchannel 27, inject the cleaning fluid (from the cleaning fluid chamber 17) into the reaction chamber 14, resuspend, magnetically separate, and discharge waste. Repeat 2-3 times to remove unbound quantum dot markers.

[0111] VII. Transfer to detection chamber 15

[0112] The first electromagnet 81 is continuously energized to keep the carboxyl magnetic beads adsorbed at the bottom of the reaction chamber 14.

[0113] Open the fourth microchannel 24 (from detection chamber 15 to reaction chamber 14).

[0114] The fourth power airway 44 is opened to the atmosphere (the reaction chamber 14 is opened to the atmosphere), and the fifth power airway 45 is instructed to draw gas into the detection chamber 15.

[0115] The magnetic bead suspension (containing carboxyl magnetic beads with quantum dots) in the reaction chamber 14 is drawn into the detection chamber 15 through the fourth microchannel 24.

[0116] Close the 4th microchannel 24.

[0117] VIII. Magnetic Adsorption and Optical Detection in Detection Chamber 15

[0118] 1. Magnetic bead adsorption: The main control module 92 instructs the second electromagnet 82 to be energized, adsorbing the carboxyl magnetic beads in the detection cavity 15 to the bottom of the detection cavity 15.

[0119] 2. Optical inspection:

[0120] The main control module 92 starts the optical detection module 91. The excitation light emitted by the ultraviolet LED is focused by the lens, passes through the optical window at the top of the detection cavity 15, and vertically illuminates the bottom of the detection cavity 15.

[0121] The green quantum dot region 151 and the red quantum dot region 152 at the bottom of the detection chamber 15, as well as the green quantum dots bound to the carboxyl magnetic beads, are simultaneously excited, emitting 550nm (green) and 620nm (red) fluorescence, respectively.

[0122] The fluorescence signal is received by the detector of the optical detection module 91, and after photoelectric conversion, it is transmitted to the main control module 92. The main control module 92 collects the green fluorescence intensity and the red fluorescence intensity respectively.

[0123] 3. Calculate the ratio: The main control module 92 calculates the fluorescence ratio R. Red fluorescence is used as an internal parameter to eliminate light source fluctuations, chip batch differences, and environmental interference.

[0124] 4. Concentration conversion: The main control module 92 converts the ratio R into the pesticide concentration in the sample based on the pre-stored standard curve.

[0125] 5. Result Output: The main control module 92 displays the concentration value and the "pass / fail" judgment result on the display module 93, and automatically stores the test record (including time, chip batch number, and concentration value). If wireless communication is enabled, the data can be uploaded to the cloud platform.

[0126] IX. Waste Liquid Treatment and Chip Disposal

[0127] 1. Emptying the detection chamber 15: After the optical detection is completed, open the 9th microchannel 29 (from the detection chamber 15 to the waste liquid chamber 18), and draw gas into the waste liquid chamber 18 through the 8th power air channel 48 to draw the residual waste liquid in the detection chamber 15 into the waste liquid chamber 18.

[0128] 2. Chip Removal: The user removes the disposable flow control chip 100 from the card slot and disposes of it as biological waste. The handheld host unit 200 requires no additional cleaning and can be used to insert a new chip for the next test.

[0129] 10. Optional Step: Chip Reuse (if designed to be reusable)

[0130] If the chip is designed to be reused 2-3 times, it should not be discarded immediately after testing, but instead undergo an automatic cleaning process:

[0131] Cleaning solution is injected into reaction chamber 14 and detection chamber 15 through cleaning liquid chamber 17 and corresponding microchannels, respectively, to resuspend residual carboxyl magnetic beads and discharge them into waste liquid chamber 18. This process is repeated 2-3 times.

[0132] Finally, the detection chamber 15 is evacuated and dried, and it can be used for the next test (sample needs to be added again).

[0133] Furthermore, although exemplary embodiments have been described in this invention, their scope includes any and all embodiments based on the invention that have equivalent elements, modifications, omissions, combinations (e.g., schemes involving intersections of various embodiments), adaptations, or alterations. Elements in the claims will be interpreted broadly based on the language used in the claims and are not limited to the examples described in this specification or during the implementation of this application, and such examples will be interpreted as non-exclusive. Therefore, this specification and examples are intended to be considered illustrative only, and the true scope and spirit are indicated by the full scope of the following claims and their equivalents.

[0134] The above description is intended to be illustrative and not restrictive. For example, the above examples (or one or more of them) can be used in combination with each other. Other embodiments may be used by those skilled in the art upon reading the above description. Furthermore, in the above detailed description, various features may be grouped together to simplify the invention. This should not be construed as an intention that a disclosed feature, which is not claimed, is necessary for any claim. Rather, the subject matter of the invention may be less than all the features of the particular disclosed embodiment. Thus, the following claims are incorporated herein by reference as examples or embodiments, wherein each claim is independently considered as a separate embodiment, and these embodiments are contemplated as being possible in various combinations or arrangements. The scope of the invention should be determined by reference to the appended claims and the full scope of their equivalents.

[0135] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within its spirit and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of the present invention.

Claims

1. A rapid pesticide residue detection device, characterized in that, include: Flow control chips and handheld host components; The flow control chip includes: The system comprises multiple chambers, including: a sample storage chamber, a magnetic bead pre-storage chamber, a quantum dot pre-storage chamber, a reaction chamber, a detection chamber, a reconstitution chamber, a cleaning solution chamber, and a waste liquid chamber. The sample storage chamber receives the sample solution. The magnetic bead pre-storage chamber contains carboxyl magnetic beads with surface-coupled broad-spectrum anti-pesticide antibodies. The quantum dot pre-storage chamber contains green quantum dot-antibody conjugates. The reaction chamber is located downstream of the sample storage chamber, magnetic bead pre-storage chamber, and quantum dot pre-storage chamber, and is selectively connected to each of these chambers. The detection chamber is located downstream of the reaction chamber and is selectively connected to it. The reconstitution chamber is selectively connected to the magnetic bead pre-storage chamber and the quantum dot pre-storage chamber, and is used to provide the reconstitution solution to these chambers. The cleaning solution chamber is selectively connected to the reaction chamber, and is used to provide the cleaning solution to the reaction chamber. The waste liquid chamber is selectively connected to the reaction chamber and the detection chamber, and is used to receive waste liquid. Multiple microchannels, each microchannel being used to connect the corresponding chambers; Multiple diaphragm valves, each arranged on a microchannel, are used to control the opening and closing of the microchannel; Multiple first airways and multiple second airways, the distal end of each first airway is connected to the control chamber of each diaphragm valve, and the distal end of each second airway is connected to each chamber. The handheld host unit components include: The housing has a slot for attaching the flow control chip; An electromagnet assembly includes a first electromagnet and a second electromagnet respectively arranged in regions opposite to the reaction chamber and the detection chamber; A pneumatic drive system is configured to: provide negative pressure to a diaphragm valve through a first air passage to open the microchannel corresponding to the diaphragm valve; and provide positive pressure and / or negative pressure to the corresponding chamber through a second air passage, so that when the microchannel between the two chambers is open, fluid in one chamber flows to the other chamber; An optical detection module is arranged in the area corresponding to the detection cavity and is used to detect the fluorescence signal in the detection cavity.

2. The rapid pesticide residue detection device according to claim 1, characterized in that, The microchannel has a columnar cavity, and a valve column is disposed in the columnar cavity. The upper end of the valve column protrudes from the columnar cavity. An elastic membrane covers the outer periphery of the upper end of the columnar cavity. The elastic membrane is pressed against the valve column and adheres to it. There is a reserved space above the elastic membrane, and the first air passage extends into the reserved space.

3. The rapid pesticide residue detection device according to claim 1, characterized in that, A liquid-barrier and breathable membrane is disposed between the distal end of the second airway and the chamber.

4. The rapid pesticide residue detection device according to claim 3, characterized in that, The liquid-sealing and breathable membrane is sealed on the top of the chamber, and there is a reserved space above the liquid-sealing and breathable membrane. The distal end of the second airway is connected to the reserved space.

5. The rapid pesticide residue detection device according to claim 3, characterized in that, The liquid-sealing and breathable membrane is located on one side of the chamber, and there is a reserved space above the liquid-sealing and breathable membrane. The distal end of the second airway is connected to the reserved space.

6. The rapid pesticide residue detection device according to claim 1, characterized in that, The flow control chip includes a base layer, an upper surface layer covering the upper surface of the base layer, and a lower surface layer covering the lower surface of the base layer; wherein: The first airway and the second airway are disposed on the upper surface layer, and the microchannel is disposed on the base layer.

7. The rapid pesticide residue detection device according to claim 1, characterized in that, The pneumatic drive system provides negative pressure to the chamber via a second air passage.

8. The rapid pesticide residue detection device according to claim 2, characterized in that, The proximal ends of each of the first airways and the proximal ends of each of the second airways extend to the inner side of the flow control chip and are respectively attached with rubber connectors; wherein: The pneumatic drive system includes a diaphragm pump, a first valve group that interfaces with the proximal end of each first airway, and a second valve group that interfaces with the proximal end of each second airway.

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