Microfluidic chip and detection device

Abstract

The present invention discloses a microfluidic chip, comprising an electrode plate, a substrate, and a cover plate. A sample addition port and a communication port are used to add reagents to a reaction chamber. A reagent storage tank connected to the reaction chamber is provided on the substrate. The reagent storage tank can store reagents. A sliding paddle is provided in the reagent storage tank. The paddle slides and drives the reagent into the reaction chamber through pressure regulation. During the test, the paddle can be used to add reagents to the reagent storage tank, eliminating the need to add the corresponding reagents during the test. This is both convenient and time-saving, and improves the adaptability of the microfluidic chip. The present invention also provides a detection device, comprising the above-mentioned microfluidic chip. The microfluidic chip comprises a three-layer structure consisting of an electrode plate, a substrate, and a cover plate. The three-layer structure cooperates with the paddle to drive the flow of reagents, providing convenience for the detection device and facilitating improved test efficiency.

Description

Technical Field

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

[0002] The principle of a syringe is based primarily on atmospheric pressure and mechanical operation. By pushing and pulling the piston rod, atmospheric pressure is used to draw or expel the liquid medication into or out of the syringe barrel. This design allows for precise control of the amount of medication injected, making the syringe an indispensable tool in the medical field.

[0003] Microfluidics is a new interdisciplinary technology, primarily based on analytical chemistry, integrating advances in related disciplines such as biochemistry, physical chemistry, and immunology. Through the miniaturization and integration of equipment, it concentrates various analytical laboratory functions on analytical chips, achieving miniaturization of detection and analysis. It has important applications in fields such as disease diagnosis, environmental monitoring, and life sciences. The basic structure of a microfluidic chip consists of microchannels, microvalves, and micropumps, enabling precise manipulation and analysis of microfluidics. Reagent storage and flow control within a microfluidic chip are crucial components of microfluidic technology. To pre-store reagents, the reagents are added to the reagent addition reservoir. The reagents enter the feed microchannels through the feed permeation holes and, through specific manipulations (such as centrifugation), penetrate the microfluidic valves and ultimately enter the material storage chamber. Currently, pumps and valves in microfluidic chips have limitations, primarily in terms of design and manufacturing complexity, operational and control difficulties, material limitations, throughput and production, contamination and clogging risks, and standardization and interoperability. To address these limitations, technological innovation and standardization are needed to promote the further development of microfluidic technology. Summary of the Invention

[0004] The purpose of the present invention is to provide a microfluidic chip and detection device to solve the problems existing in the above-mentioned prior art. Reagents can be driven into the reaction chamber according to detection needs, eliminating the operation of adding corresponding reagents in the test link, and improving the convenience and efficiency of test operations.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a microfluidic chip, comprising:

[0007] An electrode plate, on which a working electrode, a counter electrode, and a reference electrode are provided. The working electrode and the counter electrode can be electrically connected to an external analytical instrument, and the reference electrode is used to provide a potential reference;

[0008] A substrate, the substrate having a communication port, a reagent storage tank, and a reaction tank, the communication port and the reagent storage tank being located on a side of the substrate away from the electrode plate, the reaction tank being located opposite the electrode plate and the two forming a reaction chamber, the working electrode, the counter electrode, and the reference electrode being located in the reaction chamber, the communication port and the reagent storage tank being in communication with the reaction chamber; a paddle being slidably provided in the reagent storage tank, the paddle being able to slide to drive the reagent in the reagent storage tank into the reaction chamber;

[0009] The cover plate has a sample addition port, which is connected to the communication port; the cover plate also has an operation hole adapted to the paddle, and the end of the paddle away from the reagent storage tank extends out of the operation hole and can slide back and forth along the operation hole.

[0010] Preferably, the reagent storage tank is connected to the reaction chamber via a microchannel;

[0011] The reagent storage tanks correspond to the microchannels one by one.

[0012] Preferably, the reagent storage tank is a cylindrical open structure, and the axis of the reagent storage tank is parallel to the axis of the microchannel. The paddle includes a piston plate, which is slidably disposed in the reagent storage tank, and the shape of the piston plate is consistent with the radial cross-sectional shape of the reagent storage tank.

[0013] Preferably, the paddle also includes a sealing plate, which is connected to the piston plate and is located on the top of the reagent storage tank. The piston plate, the sealing plate and the reagent storage tank form a storage chamber, and the piston plate slides back and forth to change the volume of the storage chamber to drive the reagent.

[0014] Preferably, the cover plate has a sliding groove matched with the blocking plate on a side facing the base plate, and the blocking plate is slidably disposed in the sliding groove.

[0015] Preferably, the paddle further includes a paddle rod, which is disposed on the top of the blocking plate and extends out from the operating hole.

[0016] Preferably, the sample addition port is coaxially arranged with the communication port, the working electrode is arranged facing the communication port, and the counter electrode and the reference electrode are arranged around the working electrode;

[0017] The electrode plate is provided with positioning grooves adapted to the working electrode, the counter electrode and the reference electrode.

[0018] Preferably, there are a plurality of reagent storage tanks, and the reagent storage tanks are arranged around the reaction chamber.

[0019] Preferably, the electrode plate, the substrate and the cover plate are all prepared by 3D printing technology;

[0020] The electrode plate is made of a transparent material, the working electrode is made of conductive glass or gold, the counter electrode is made of carbon, and the reference electrode is a silver / silver chloride electrode;

[0021] The substrate and the cover are made of polydimethylsiloxane or acrylic photosensitive resin.

[0022] The present invention also provides a detection device comprising the above-mentioned microfluidic chip.

[0023] Compared with the prior art, the present invention has achieved the following technical effects: the microfluidic chip of the present invention includes an electrode plate, a substrate and a cover plate, and a working electrode, a counter electrode and a reference electrode are arranged on the electrode plate, the working electrode and the counter electrode can be electrically connected to an external analytical instrument, and the reference electrode is used to provide a potential reference; the substrate has a connecting port, a reagent storage tank and a reaction tank, the connecting port and the reagent storage tank are both located on the side of the substrate away from the electrode plate, the reaction tank is arranged opposite to the electrode plate and the two form a reaction chamber, the working electrode, the counter electrode and the reference electrode are all located in the reaction chamber, and the connecting port and the reagent storage tank are both connected to the reaction chamber; a paddle is slidingly arranged in the reagent storage tank, and the sliding of the paddle can drive the reagent in the reagent storage tank into the reaction chamber; the cover plate has a sample loading port, and the sample loading port is connected to the connecting port; the cover plate also has an operating hole adapted to the paddle, and the end of the paddle away from the reagent storage tank extends from the operating hole and can slide back and forth along the operating hole.

[0024] The microfluidic chip of the present invention includes a cover plate, a base plate and an electrode plate stacked from top to bottom. The base plate and the electrode plate form a reaction chamber. Reagents can be added to the reaction chamber using a sample addition port and a connecting port. At the same time, a reagent storage tank connected to the reaction chamber is provided on the base plate. The reagent storage tank can store reagents. A sliding paddle is provided in the reagent storage tank. The paddle slides and drives the reagent into the reaction chamber through pressure regulation. During the test, the paddle can be used to add reagents to the reagent storage tank, eliminating the operation of adding corresponding reagents in the test link. This is convenient and time-saving, and improves the adaptability of the microfluidic chip.

[0025] The present invention also provides a detection device, including the above-mentioned microfluidic chip. The microfluidic chip consists of a three-layer structure consisting of an electrode plate, a substrate and a cover plate. The three-layer structure cooperates with the paddle to drive the flow of reagents, which provides convenience for the detection device and is conducive to improving test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 A schematic structural diagram of a microfluidic chip disclosed in an embodiment of the present invention;

[0028] Figure 2 A schematic structural diagram of a cover plate of a microfluidic chip disclosed in an embodiment of the present invention;

[0029] Figure 3 Schematic diagram of the structure of the cover plate of the microfluidic chip disclosed in an embodiment of the present invention from other perspectives;

[0030] Figure 4 A schematic structural diagram of a substrate of a microfluidic chip disclosed in an embodiment of the present invention;

[0031] Figure 5 Schematic diagram of the structure of the substrate of the microfluidic chip disclosed in the embodiment of the present invention from other perspectives;

[0032] Figure 6 A schematic structural diagram of an electrode plate of a microfluidic chip disclosed in an embodiment of the present invention;

[0033] Figure 7 A schematic structural diagram of a paddle of a microfluidic chip disclosed in an embodiment of the present invention;

[0034] Figure 8 This is a diagram showing the results of electrochemiluminescence detection of o-diphenol using the microfluidic chip disclosed in an embodiment of the invention.

[0035] Figure 9 This is a diagram showing the results of electrochemiluminescence immunoassay of brain natriuretic peptide using a microfluidic chip disclosed in an embodiment of the invention.

[0036] In the figure: 1, electrode plate; 101, working electrode; 102, counter electrode; 103, reference electrode;

[0037] 2. Substrate; 201. Communication port; 202. Reagent storage tank; 203. Reaction tank; 204. Microchannel;

[0038] 3. Cover plate; 301. Sample loading port; 302. Operation hole; 303. Slide slot;

[0039] 4. Paddle; 401. Piston plate; 402. Sealing plate; 403. Paddle rod. DETAILED DESCRIPTION

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0041] The purpose of the present invention is to provide a microfluidic chip and detection device to solve the problems existing in the above-mentioned prior art. Reagents can be driven into the reaction chamber according to detection needs, eliminating the operation of adding corresponding reagents in the test link, and improving the convenience and efficiency of test operations.

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] Example 1

[0044] This embodiment provides a microfluidic chip, including an electrode plate 1, a substrate 2 and a cover plate 3 arranged in sequence from bottom to top. Figure 1-Figure 7 The electrode plate 1 is provided with a working electrode 101, a counter electrode 102 and a reference electrode 103. The working electrode 101 and the counter electrode 102 can be electrically connected to an external analytical instrument, and the reference electrode 103 is used to provide a potential reference; the substrate 2 has a connecting port 201, a reagent storage tank 202 and a reaction tank 203. The connecting port 201 and the reagent storage tank 202 are both located on the side of the substrate 2 away from the electrode plate 1. The reaction tank 203 is arranged opposite to the electrode plate 1 and the two form a reaction chamber. The working electrode 101, the counter electrode 102 and the reference electrode 103 are arranged on the substrate 2. The electrodes 103 are both located in the reaction chamber, and the connecting port 201 and the reagent storage tank 202 are both connected to the reaction chamber; a paddle 4 is slidably provided in the reagent storage tank 202, and the sliding of the paddle 4 can drive the reagent in the reagent storage tank 202 into the reaction chamber; the cover plate 3 has a sample injection port 301, and the sample injection port 301 is connected to the connecting port 201; the cover plate 3 also has an operating hole 302 adapted for the paddle 4, and the end of the paddle 4 away from the reagent storage tank 202 extends from the operating hole 302 and can slide back and forth along the operating hole 302.

[0045] The microfluidic chip of the present invention includes a cover plate 3, a substrate 2 and an electrode plate 1 stacked from top to bottom. The substrate 2 and the electrode plate 1 form a reaction chamber. Reagents can be added to the reaction chamber using a sample addition port 301 and a connecting port 201. At the same time, a reagent storage tank 202 connected to the reaction chamber is provided on the substrate 2. The reagent storage tank 202 can store reagents. A sliding paddle 4 is provided in the reagent storage tank 202. The paddle 4 slides and drives the reagent into the reaction chamber through pressure regulation. During the test, the paddle 4 can be used to add reagents to the reagent storage tank 202, eliminating the operation of adding corresponding reagents in the test link, which is convenient and saves time, and improves the adaptability of the microfluidic chip.

[0046] Among them, the reagent storage tank 202 is connected to the reaction chamber via the microchannel 204. The reagent storage tank 202, the paddle 4 and the microchannel 204 form a structure similar to a syringe. The sliding paddle 4 drives the reagent from the microchannel 204 into the reaction chamber under the action of pressure, thereby achieving the purpose of detecting the reaction.

[0047] In practical applications, multiple reagent storage tanks 202 can be provided, with each microchannel 204 and paddle 4 corresponding to each reagent storage tank 202. During use, according to the reaction steps of the experiment, the paddle 4 in the corresponding reagent storage tank 202 is slid to allow the reagents to enter the reaction chamber along the microchannel 204 in sequence for reaction, or the paddles 4 are slid simultaneously to drive the mixed solution into the reaction chamber for reaction. When there are multiple reagent storage tanks 202, the reagent storage tanks 202 are arranged around the reaction chamber to improve the uniformity of force applied to the microfluidic chip. A reasonable layout also helps to shorten the length of each microchannel 204, ensuring that the reagents in each reagent storage tank 202 can flow smoothly into the reaction chamber.

[0048] Specifically, the reagent storage tank 202 has an open cylindrical structure. In this embodiment, the reagent storage tank 202 has a semi-cylindrical structure to avoid dead angles in the reagent storage tank 202 that could affect the flow of reagents. The axis of the reagent storage tank 202 is parallel to the axis of the microchannel 204, allowing the reagent storage tank 202 and the microchannel 204 to be coaxially arranged, thereby improving the reliability of reagent circulation. The paddle 4 includes a piston plate 401, which is slidably disposed within the reagent storage tank 202. The shape of the piston plate 401 is consistent with the radial cross-section of the reagent storage tank 202. The piston plate 401 slides along the reagent storage tank 202 to drive the reagent through the microchannel 204 and into the reaction chamber.

[0049] More specifically, the paddle 4 also includes a sealing plate 402, which is connected to the piston plate 401 and is located on the top of the reagent storage tank 202. The piston plate 401, the sealing plate 402 and the reagent storage tank 202 form a storage chamber to prevent leakage of the reagent in the reagent storage tank 202 and ensure the smooth progress of the experiment. The piston plate 401 slides back and forth to change the volume of the storage chamber to drive the reagent. Under the action of pressure, the reagent is driven into the microchannel 204 and then flows into the reaction chamber.

[0050] To ensure the sliding accuracy of the paddle 4, the side of the cover plate 3 facing the base plate 2 has a groove 303 that mates with the blocking plate 402. The blocking plate 402 is slidably disposed within the groove 303. The piston plate 401 slides along the reagent storage tank 202, guiding the movement of the paddle 4. However, to further enhance operational accuracy, the blocking plate 402 cooperates with the groove 303 to provide an additional sliding guide, improving the movement accuracy of the paddle 4. In practice, by adjusting the speed and force of the paddle 4, the state of reagent entry into the reaction chamber can be controlled, meeting different reagent addition requirements and ensuring smooth testing.

[0051] For ease of operation, the paddle 4 further includes a lever 403 , which is disposed on the top of the blocking plate 402 and extends from the operating hole 302 . The operator uses the lever 403 to slide the paddle 4 to complete the addition of the reagent.

[0052] It should also be noted that the sample addition port 301 is coaxially arranged with the communication port 201, the working electrode 101 is arranged directly opposite the communication port 201 to ensure the smooth progress of the reaction, and the counter electrode 102 and the reference electrode 103 are arranged around the working electrode 101. In addition, the electrode plate 1 has positioning grooves adapted to the working electrode 101, the counter electrode 102 and the reference electrode 103, which facilitates the preparation of the working electrode 101, the counter electrode 102 and the reference electrode 103. The working electrode 101, the counter electrode 102 and the reference electrode 103 can be prepared using magnetron sputtering and laser induction technology to ensure the preparation accuracy of each electrode and provide strong support for the detection test.

[0053] In this specific embodiment, the electrode plate 1, substrate 2, and cover plate 3 are all manufactured using 3D printing technology, resulting in high molding precision. The electrode plate 1 is made of a transparent material to facilitate observation of test results. Flexible or rigid transparent materials can be used. The working electrode 101 is made of conductive glass or gold, the counter electrode 102 is made of carbon, and the reference electrode 103 is a silver / silver chloride electrode. The substrate 2 and cover plate 3 are made of polydimethylsiloxane or acrylic photosensitive resin. In actual application, the appropriate material can be selected based on the specific detection conditions.

[0054] Example 2

[0055] This embodiment provides a detection device, including the microfluidic chip of embodiment 1. The microfluidic chip consists of a three-layer structure consisting of an electrode plate 1, a substrate 2 and a cover plate 3. The three-layer structure cooperates with the paddle 4 to drive the flow of reagents, which provides convenience for the detection device and is conducive to improving test efficiency.

[0056] Example 3

[0057] This embodiment discloses Experimental Example 1, electrochemiluminescence detection of o-diphenol, using the microfluidic chip of Example 1.

[0058] The cover plate 3 and substrate 2 of the microfluidic chip are made of polydimethylsiloxane (PDMS) and are processed by a high-precision 3D printer. The electrode plate 1 of the microfluidic chip is made of transparent glass. The working electrode 101, counter electrode 102 and reference electrode 103 on the surface of the electrode plate 1 are processed by magnetron sputtering and laser induction.

[0059] The electrode plate 1 adopts a three-electrode system, including a working electrode 101 (WE), a counter electrode 102 (CE) and a reference electrode 103 (RE). In order to collect the luminous intensity of electrochemiluminescence detection in blood, the working electrode 101 is set as a gold electrode, which has good conductivity; the counter electrode 102 adopts a carbon electrode, which is relatively cheap and has good stability; the reference electrode 103 is a silver / silver chloride electrode, which provides a stable potential as a reference, so that the working electrode 101 can be accurately measured. The working parts of the three electrodes correspond to the reaction chamber, so that the conductive area of ​​the three electrodes is exactly located inside the reaction chamber to form a detection area. The lead-out part of the electrode is connected to the detection instrument of the electrochemical workstation during detection to ensure that the circuit is conductive. In some specific embodiments, the width of the working part of each electrode is in the range of 1.5mm-2mm, and the side length of the square formed by the counter electrode 102 and the reference electrode 103 is 10mm.

[0060] During the test, slide the pick 4 from left to right to drive 6 μL of Cd S QDs solution to the treated working electrode 101 surface, dry it at room temperature, repeat 4 times, and then slide another pick 4 from left to right to drive 10 μL of MWCNTs-AuNPS-Ru(bpy)3 2+ The mixed solution was driven to the electrode surface and dried at room temperature to obtain Cd S / Ru(bpy)3 2+ The ECL sensor is used for subsequent analysis and detection. The electrode system is inserted into a liquid containing 0.1 mol·L -1 KCl phosphate buffer solution (PBS) (0.1 mol·L -1 , pH = 8) solution, in the range of -1.5 to 1.5 V at 200 mV·s -1Scan at a scan rate (starting potential is 0V, scanning direction is positive) and record the ECL signal. When detecting catechol, different concentrations of catechol are added to the detection base solution, and the catechol is quantitatively detected based on the change in the ECL signal before and after the addition of catechol.

[0061] Under the optimized experimental conditions, the ECL response of the sensor to catechol was investigated. Different molar concentrations of catechol were added to the detection base solution (containing 0.1 mol·L -1 KCl in PBS (0.1 mol·L -1 , pH = 8.0)) Figure 8 a to g represent 0nmo1·L -1 , 5.0nmo1·L -1 , 50nmo1·L -1 , 100nmo1·L -1 , 500nmo1·L -1 , 1000nmo1·L -1 , 10000nmo1·L -1 ), and measure the corresponding ECL signal. Figure 8 As shown in the figure, as the concentration of catechol increases, the corresponding ECL signal gradually weakens. The inset shows that at 5 nmol·L -1 ~10000nmo1·L -1 The change in ECL value ΔL (ΔL = L0-L, L0 represents the ECL intensity without catechol, L represents the ECL intensity with catechol) within the range showed a good linear relationship with the logarithm of the molar concentration of catechol, and the detection limit was 1.36 nmol·L -1 , the results are as follows Figure 8 shown.

[0062] Example 4

[0063] This embodiment discloses Experimental Example 2, electrochemiluminescence immunoassay of a heart failure marker, brain natriuretic peptide (BNP), using the microfluidic chip of Example 1.

[0064] The cover plate 3 and substrate 2 in the microfluidic chip are made of polydimethylsiloxane (PDMS) and are processed by a high-precision 3D printer. The electrode plate 1 of the microfluidic chip is made of transparent glass. The working electrode 101, counter electrode 102 and reference electrode 103 on the surface of the electrode plate 1 are processed by magnetron sputtering and laser induction.

[0065] The electrode plate 1 uses a three-electrode system, including a working electrode 101 (WE), a counter electrode 102 (CE), and a reference electrode 103 (RE). To collect the luminous intensity of electrochemiluminescence detection in blood, the working electrode 101 is set as an ITO electrode, which has good conductivity and high transparency; the counter electrode 102 is a carbon electrode, which is relatively cheap and has good stability; the reference electrode 103 is a silver / silver chloride electrode, which provides a stable potential as a reference, allowing the working electrode 101 to be accurately measured. The working parts of the three electrodes correspond to the reaction chamber, so that the conductive areas of the three electrodes are exactly located inside the reaction chamber, forming a detection area. The lead-out part of the electrode is connected to the detection instrument of the electrochemical workstation during detection to ensure circuit conductivity. In some specific embodiments, the width of the working part of each electrode is in the range of 1.5mm-2mm, and the side length of the square formed by the counter electrode 102 and the reference electrode 103 is 10mm.

[0066] During detection, paddle 4 was first slid from left to right to apply 6 μL of a 0.2 mg / mL CdS NWs-CS solution to the reaction cell to modify the working electrode 101, which was then dried at 60°C. Another paddle 4 was then slid from left to right to apply 6 μL of 5% GLD to the electrode, which was then incubated at room temperature for 30 minutes. After 30 minutes, paddle 43 was applied to modify the electrode with 6 μL of a 40 μg / mL Ab, which was then incubated at 37°C for 1 hour. Next, 6 μL of 1% BSA was added to block nonspecific binding sites. The solution was incubated at 37°C for 1 hour, followed by washing with 0.01 mol / L PBS to remove excess BSA. Paddle 43 was then applied to modify the electrode with 6 μL of BNP at varying concentrations, which was then incubated at 37°C for 1 hour. Finally, paddle 44 was applied to modify the electrode with 6 μL of AuNPs-Ab, which was then incubated at 37°C for 1 hour. The modified electrode (working electrode 101), auxiliary electrode (counter electrode 102), and reference electrode 103 were placed in a 0.1 mol / L PBS solution containing 0.1 mol / L K₂S₂O₂ for detection. Electrochemical excitation was performed in a cyclic scanning voltage mode with a potential scan range of -1.3 to 0 V, a scan rate of 0.1 V / s, and a photomultiplier tube high voltage of -500 V.

[0067] Under the optimized conditions, the ECL response of the sensor was tested at different BNP concentrations. The results are shown in Figure 2. Figure 9 As shown in Figure 2, due to the RET effect and protein steric hindrance, with the increase of BNP concentration, at 1.0×10 -12 ~1.0×10 -7 In the concentration range of g / mL, the ECL signal intensity gradually decreased. Figure 9 The linear relationship between the ECL response of different concentrations of BNP and the logarithm of the corresponding concentration was obtained. The detection limit of BNP was 7.6×10 -13 g / mL.

[0068] It should also be noted that the reagents in Examples 3 and 4 are as follows:

[0069] 3-Mercaptopropionic acid (MPA), CHIT, and L-cysteine ​​(L-cys) were purchased from Sigma-Aldrich Chemical Company, USA; 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl) and N-hydroxysuccinimide (NHS) were purchased from Aladdin (Shanghai) Co., Ltd.; Ru(bpy)3 2+ Cadmium chloride (CdCl2·2.5H2O), and catechol were purchased from Sinopharm Chemical Reagent Co., Ltd.; sodium sulfide (Na2S·9H2O) was purchased from Tianjin Chemical Reagent Research Institute; MWCNTs (mass fraction ≥95%, outer diameter 20–40 nm) were purchased from Shenzhen Nanoport Co., Ltd.; sodium hydroxide (NaOH) was purchased from Tianjin Guangcheng Chemical Reagent Co., Ltd.; concentrated sulfuric acid (H2SO4) and concentrated nitric acid (HNO3) were purchased from Shanghai Chemical Reagent Company. All chemicals were of analytical grade, and solutions were prepared with ultrapure water.

[0070] Brain natriuretic peptide (BNP), BNP polyclonal antibody (Ab, L3C00303), and human immunoglobulin (hIgG) were purchased from Shanghai Lingchao Biotechnology Co., Ltd. Cadmium nitrate tetrahydrate (Cd(NO3)2, 4H2O) was purchased from Tianjin Guangfu Chemical Reagent Co., Ltd. Thiourea (CH4N2S) and sodium citrate (C6H5Na3O7) were purchased from Tianjin Yongda Chemical Reagent Co., Ltd. Ethylenediamine (C2H8N2), chloroauric acid tetrahydrate (HAuCl4·4H2O), chitosan (CS), and glutaraldehyde (GLD) were purchased from Sinopharm Chemical Co., Ltd. Bovine serum albumin (BSA), Tween 20, and human serum albumin (HSA) were purchased from Shanghai Xibao Biotechnology Co., Ltd.

[0071] The instruments are as follows:

[0072] A Leici pHS-25 precision pH meter was purchased from Shanghai Precision Scientific Instrument Co., Ltd.; a KQ-100DE CNC ultrasonic cleaner was purchased from Kunshan Ultrasonic Instrument Co., Ltd.; a three-electrode system was used: a glassy carbon electrode (GCE) as the working electrode 101, a platinum (Pt) wire as the counter electrode 102, and an Ag / Ag Cl electrode (saturated KCl solution) as the reference electrode 103; an MPI-A / B electrochemiluminescence test system was purchased from Xi'an Ruimai Analytical Instrument Co., Ltd.; a CHI660E electrochemical workstation was purchased from Shanghai Chenhua Instrument Co., Ltd.; an S-4800 field emission scanning electron microscope (FE-SEM) was purchased from Shanghai Hitachi; and a 3D printer, model microArch S350, was purchased from Mofang Precision Co., Ltd.

[0073] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A microfluidic chip, characterized in that: Including the following settings from bottom to top: An electrode plate, on which a working electrode, a counter electrode, and a reference electrode are provided. The working electrode and the counter electrode can be electrically connected to an external analytical instrument, and the reference electrode is used to provide a potential reference; A substrate, the substrate having a communication port, a reagent storage tank, and a reaction tank, the communication port and the reagent storage tank being located on a side of the substrate away from the electrode plate, the reaction tank being located opposite the electrode plate and the two forming a reaction chamber, the working electrode, the counter electrode, and the reference electrode being located in the reaction chamber, the communication port and the reagent storage tank being in communication with the reaction chamber; a paddle being slidably provided in the reagent storage tank, the paddle being able to slide to drive the reagent in the reagent storage tank into the reaction chamber; A cover plate, the cover plate having a sample addition port, the sample addition port being connected to the communication port; the cover plate also having an operation hole adapted for the paddle, the end of the paddle away from the reagent storage tank extending from the operation hole and being capable of reciprocatingly sliding along the operation hole; The reagent storage tank is connected to the reaction chamber via a microchannel; The reagent storage tanks correspond one to one with the microchannels; The reagent storage tank is a cylindrical open structure, and the axis of the reagent storage tank is parallel to the axis of the microchannel. The paddle includes a piston plate, which is slidably disposed in the reagent storage tank, and the shape of the piston plate is consistent with the radial cross-sectional shape of the reagent storage tank; The paddle also includes a sealing plate, which is connected to the piston plate and is located on the top of the reagent storage tank. The piston plate, the sealing plate and the reagent storage tank form a storage chamber. The piston plate slides back and forth to change the volume of the storage chamber to drive the reagent.

2. The microfluidic chip according to claim 1, wherein: The cover plate has a sliding groove on one side facing the base plate, which is matched with the blocking plate. The blocking plate is slidably arranged in the sliding groove.

3. The microfluidic chip according to claim 1, wherein: The paddle further includes a paddle rod, which is arranged on the top of the blocking plate and extends out from the operating hole.

4. The microfluidic chip according to claim 1, wherein: The sample addition port is coaxially arranged with the communication port, the working electrode is arranged facing the communication port, and the counter electrode and the reference electrode are arranged around the working electrode; The electrode plate is provided with positioning grooves adapted to the working electrode, the counter electrode and the reference electrode.

5. The microfluidic chip according to claim 1, wherein: There are multiple reagent storage tanks, and the reagent storage tanks are arranged around the reaction chamber.

6. The microfluidic chip according to claim 1, characterized in that: The electrode plate, the substrate and the cover plate are all prepared by 3D printing technology; The electrode plate is made of a transparent material, the working electrode is made of conductive glass or gold, the counter electrode is made of carbon, and the reference electrode is a silver / silver chloride electrode; The substrate and the cover are made of polydimethylsiloxane or acrylic photosensitive resin.

7. A detection device, characterized in that: The microfluidic chip comprises the microfluidic chip according to any one of claims 1 to 6.

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