Fluid clamp for electrode modification of intelligent biosensor

Abstract

A fluid clamp for electrode modification of an intelligent biosensor comprises a liquid path connector upper pressing plate assembly, a liquid path clamp supporting plate assembly and a multi-manifold fluid clamp. The multi-manifold fluid clamp comprises a multi-manifold fluid clamp base and a multi-manifold fluid channel plate, and a plurality of clamping grooves are formed in the upper surface of the multi-manifold fluid clamp base. The multi-manifold fluid channel plate comprises a multi-manifold flow channel cover plate and a multi-manifold flow channel base plate; a fluid inlet and a fluid outlet are distributed on the multi-branch flow channel cover plate; the multi-branch flow channel substrate is provided with a Y-shaped multi-branch flow channel and a plurality of reaction cavity grooves opposite to the sensor electrode plates; a liquid inlet and a liquid outlet are formed in two ends of the reaction cavity tank. The fluid clamp adopts a multi-manifold flow channel, so that a reagent is equally divided and shunted, eight target electrodes can be simultaneously modified in the same way, electrode modification in the batch production process of intelligent biosensor products is realized, the consistency of performance indexes of sensors in the same batch can be ensured, and the batch-to-batch difference of the performance indexes of sensors in different batches can be reduced.

Description

Technical Field

[0001] The utility model relates to the fields of biotechnology, intelligent sensors and microfluidics, in particular to the field of intelligent biosensor manufacturing, and specifically to a fluid fixture for electrode modification of intelligent biosensors (including but not limited to graphene field effect transistor biosensors or electrochemical biosensors). Background Art

[0002] With the rapid development of science and technology, smart biosensor technology has gradually penetrated into many fields including medical health, agricultural technology, environmental monitoring, industrial production, environmental monitoring and food safety, bioengineering and pharmaceuticals, agriculture and environmental protection, etc., especially in the fields of medical health and food safety, showing great potential. This technology provides people with more accurate, faster and more convenient detection and analysis methods, leading the medical and industrial fields to new heights.

[0003] One of the core technologies in the preparation process of smart biosensors is to modify the surface of smart biosensor electrodes with biological functional groups by chemical modification to form a membrane with expected specific functions to complete the functional design of the electrode. Biochemically modified electrodes are a technology that uses biological specific binding to specifically modify surface electrodes. Due to differences in electrode materials, modification reagents, and electrode functional requirements, different chemical modification methods are required. The quality of the chemical modification method directly affects the repeatability, consistency, and stability of smart biosensors, thereby affecting the value of experimental research and practical applications of smart biosensors.

[0004] At present, the modification method for electrochemical biosensor electrodes with single functional requirements is to directly drip or spray the modification reagent containing biological functional groups on a single electrode, but this method cannot be applied to the modification of graphene field effect transistor biosensor electrodes, because the size and spacing of graphene field effect transistor biosensor electrodes and graphene channels are very small, ranging from tens to hundreds of microns, and the dripped or sprayed modification reagent will overflow to the surface of other electrodes, causing contamination to other electrodes of the biosensor; in addition, the biological functional groups in the overflowed modification reagent cannot combine with the electrode to be modified, which will affect the different density of biological functional groups on the electrode to be modified and affect the consistency of the product.

[0005] With the introduction of multifunctional array graphene field-effect transistor biosensors, the closely arranged multiple groups of gates and graphene channels need to be modified separately with different biofunctional groups. At this time, the currently used modification methods are not suitable for microelectrode arrays with electrode spacing and sizes ranging from tens to hundreds of microns. It is necessary to selectively modify the electrode surface by continuously removing and adding biofunctional groups, and electrodesorb the biofunctional groups modified on the electrode or graphene channel by using a controlled potential, re-expose the unmodified gold electrode, and then modify it with different biofunctional groups, so that a variety of different biofunctional groups can be used on the closely arranged array microelectrode surface.

[0006] Among them, the China Patent Publication Announcement website disclosed two authorized invention patents whose applicant is Hefei University of Technology, namely: "A Split-Gate SGGT Sensor and Its Preparation Method and Application (CN 116482205A)" and "Multi-Gate Graphene Field Effect Transistor Sensor Array and Multiple Detection Method (CN 114624309A)". The two invention patents disclose the preparation method of the multi-gate graphene field effect transistor sensor, which includes the steps of: using waterproof glue to stick to the gate and channel area, using the hydrogel tube to connect the gate and channel area, establishing a bridge connection, and the sensor preparation is completed.

[0007] However, the above preparation method is suitable for laboratory chemical modification, and its work efficiency is low, and it is not suitable for mass production of products. It cannot guarantee the process requirements of product electrode modification and the consistency of modified product electrodes, and it cannot ensure that the batch difference between each batch meets the technical indicators of smart biosensor products. It is necessary to introduce a method and fluid fixture for smart biosensor electrode modification based on laboratory chemical modification, transform existing scientific and technological achievements into engineering products, and realize mass production. Utility Model Content

[0008] The purpose of the utility model is to provide a fluid fixture for electrode modification of smart biosensor, aiming to solve the problem of effective control of the electrode modification process of smart biosensor during mass production of smart biosensor products, to ensure that the electrode modification area, biochemical reagent capacity and biochemical reaction flow of each batch of electrode modification process meet the process requirements of electrode modification of smart biosensor products and are completely consistent, and at the same time ensure that the batch difference of each batch meets the technical indicators of the smart biosensor products.

[0009] To this end, the utility model proposes a fluid fixture for modifying electrodes of an intelligent biosensor, comprising: a detachably connected upper pressure plate assembly of a fluid path connector and a fluid path fixture support plate assembly, and at least one multi-branch fluid fixture clamped therebetween; the multi-branch fluid fixture comprises a detachably connected multi-branch fluid fixture base and a multi-branch fluid channel plate, and the upper surface of the multi-branch fluid fixture base is provided with a plurality of slots for positioning sensor electrode sheets;

[0010] The multi-manifold fluid channel plate includes a multi-manifold flow channel cover plate and a multi-manifold flow channel substrate which are sealed and connected, and adopts a combination of bonding, gluing, film bonding and laser welding processes including but not limited to bonding; a fluid inlet and a plurality of fluid outlets are distributed on the multi-manifold flow channel cover plate; a multi-manifold flow channel with a Y-shaped multi-manifold flow is provided on the upper surface of the multi-manifold flow channel substrate, and a plurality of reaction chamber grooves are provided on the lower surface of the multi-manifold flow channel substrate, and the reaction chamber grooves are opposite to the sensor electrode sheet; a liquid inlet and a liquid outlet are provided at both ends of the reaction chamber groove; a plurality of the liquid inlets pass through the multi-manifold flow channel substrate and are respectively communicated with the multi-manifold flow channels, and then are communicated with the fluid inlet, and a plurality of the liquid outlets pass through the multi-manifold flow channel substrate and are communicated with the corresponding fluid outlets; in addition, a total fluid inlet communicated with the fluid inlet, and a total fluid outlet communicated with the fluid outlet are provided on the pressure plate assembly on the liquid path joint.

[0011] As a preferred technical solution of the present application, the multi-branched flow channel of the Y-shaped multi-branched flow is divided into three levels, and each level of the Y-shaped multi-branched flow channel divides the fluid into two parts, and finally divides it into eight parts; similarly, eight card slots are distributed in a rectangular array on the base of the multi-branched fluid fixture, and eight reaction chamber slots are also provided on the lower surface of the multi-branched flow channel substrate.

[0012] As a preferred technical solution of the present application, each of the reaction chamber grooves has a sealing ring groove around it, a sealing ring is embedded in the sealing ring groove, and the sealing ring and the sensor electrode sheet are pressed tightly to form a reaction chamber.

[0013] As a preferred technical solution of the present application, a drainage collection chamber is designed at the bottom of the reaction chamber, and the drainage collection chamber is connected to the liquid outlet.

[0014] As a preferred technical solution of the present application, the multi-manifold fluid channel plate and the multi-manifold fluid fixture base are detachably connected via positioning screws or hinge locks.

[0015] As a preferred technical solution of the present application, the upper pressure plate assembly of the liquid circuit joint includes a liquid circuit joint upper pressure plate and a diffusion chamber cover plate that are sealed and connected; the upper pressure plate of the liquid circuit joint includes a total fluid inlet, a total fluid outlet, a liquid outlet diffusion chamber and a plurality of liquid outlet diffusion ports; the plurality of liquid outlet diffusion ports penetrate the upper pressure plate of the liquid circuit joint and are respectively connected to the total fluid outlet through the liquid outlet diffusion chamber.

[0016] As a preferred technical solution of the present application, the upper pressure plate assembly of the liquid circuit joint is provided with a plurality of upper buckles, and the liquid circuit fixture support plate assembly is provided with a plurality of lower buckles matching the upper buckles, and a plurality of bottom feet.

[0017] As a preferred technical solution of the present application, the fluid path fixture support plate assembly includes a positioning groove for placing the multi-branch fluid fixture and two positioning pins for fixing the pressure plate assembly on the fluid path connector.

[0018] As a preferred technical solution of the present application, a plurality of the positioning grooves are arranged on the liquid path fixture support plate assembly, including but not limited to single column or single row arrangement, array arrangement, and a plurality of flow channel modules are correspondingly provided on the pressure plate assembly of the liquid path connector, and are respectively matched with the multi-manifold fluid fixture.

[0019] As a preferred technical solution of the present application, an electrode loading connector assembly is detachably installed at the left and right ends of the multi-branch fluid fixture base, and the electrode loading connector assembly is opposite to the electrode position of the sensor electrode sheet. It can be connected to a customized electrode detection device to load the required potential on the selective chemical modification electrode, and can also be connected to an electrochemical workstation to characterize the modification results.

[0020] The fluid fixture for modifying the electrode of the intelligent biosensor provided by the utility model has the following beneficial effects:

[0021] 1. The split structure design is adopted, which consists of two parts: a multi-branch fluid fixture and a liquid path joint pressure plate. The multi-branch fluid fixture can modify at least eight smart biosensor electrodes at a time, and can independently incubate the modified electrodes, thereby improving the working efficiency of the smart biosensor electrode modification fluid fixture.

[0022] 2. The fluid fixture adopts a multi-flow channel to achieve the diversion of reagents. The eight reaction chambers on the multi-flow substrate can modify eight target electrodes at the same time, realizing the electrode modification process operation in the mass production of electrochemical biosensor products.

[0023] 3. The fluid fixture can be used in combination with the reaction reagent pump valve. The instrument accurately controls the reagent advancement operation, which is more stable and accurate than manual electrode modification. And it can modify electrodes in batches at the same time, which can ensure the consistency of the performance index range of the same batch of biosensors.

[0024] In addition to the above-described purposes, features and advantages, the present application also has other purposes, features and advantages. The present application will be further described in detail with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings constituting part of the present application are used to provide a further understanding of the present application. The exemplary embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0026] Figure 1 This is a schematic structural diagram of a fluid fixture for modifying electrodes of an intelligent biosensor according to the utility model;

[0027] Figure 2 It is an exploded view of a multi-branched fluid fixture in a fluid fixture for modifying electrodes of an intelligent biosensor according to the utility model;

[0028] Figure 3 It is an exploded view of a multi-branched fluid channel plate in a fluid fixture for modifying electrodes of an intelligent biosensor according to the utility model;

[0029] Figure 4 It is a schematic structural diagram of the bottom surface of a multi-branched fluid channel plate in a fluid fixture for modifying electrodes of an intelligent biosensor according to the present utility model;

[0030] Figure 5 A partial cross-sectional view of a multi-branched fluid channel plate in a fluid fixture for modifying electrodes of an intelligent biosensor according to the present invention Figure 1 ;

[0031] Figure 6 A partial cross-sectional view of a multi-branched fluid channel plate in a fluid fixture for modifying electrodes of an intelligent biosensor according to the present invention Figure 2 ;

[0032] Figure 7 This is a schematic structural diagram of a pressure plate assembly on a fluid path joint in a fluid fixture for modifying electrodes of an intelligent biosensor according to the utility model;

[0033] Figure 8 This is a structural schematic diagram of a liquid path fixture support plate assembly in a fluid fixture for modifying electrodes of an intelligent biosensor according to the utility model;

[0034] Fig. 9 It is a top cross-sectional view of a multi-branched fluid fixture in the fluid fixture for modifying electrodes of an intelligent biosensor of the present utility model;

[0035] Fig.10 A side cross-sectional view of a multi-branched fluid fixture in a fluid fixture for modifying electrodes of a smart biosensor according to another embodiment of the utility model;

[0036] Description of Reference Numerals

[0037] 100, multi-branch fluid fixture; 110, multi-branch fluid fixture base; 111, card slot; 120, sensor electrode sheet; 130, multi-branch fluid channel plate; 140, electrode loading connector assembly; 131, multi-branch flow channel cover plate; 1311, fluid inlet; 1312, fluid outlet; 132, multi-branch flow channel substrate; 1321, multi-branch flow channel; 1322, reaction chamber groove; 1323, liquid inlet; 1324, liquid outlet; 1325, sealing ring groove; 1326, drainage collection chamber; 133, sealing ring;

[0038] 200, liquid circuit connector pressure plate assembly; 210, liquid circuit connector upper pressure plate assembly; 211, liquid circuit connector upper pressure plate; 2111, total fluid inlet; 2112, total fluid outlet; 2113, liquid outlet diffusion chamber; 2114, liquid outlet diffusion port; 212, diffusion chamber cover; 213, O-ring; 214, upper buckle; 220, liquid circuit fixture support plate assembly; 221, positioning groove; 222, positioning pin; 224, lower buckle; 225, base. DETAILED DESCRIPTION

[0039] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0040] Embodiment 1

[0041] like Figure 1 to Figure 9 As shown, the fluid fixture for modifying the electrodes of the intelligent biosensor of the present invention comprises two parts: a multi-manifold fluid fixture 100 and a liquid path connector pressure plate assembly 200; and the liquid path connector pressure plate assembly 200 comprises a liquid path connector upper pressure plate assembly 210 and a liquid path fixture support plate assembly 220, and the multi-manifold fluid fixture 100 is assembled between the two.

[0042] Specifically, the multi-manifold fluid fixture 100 includes a multi-manifold fluid fixture base 110 and a multi-manifold fluid channel plate 130; a plurality of sensor electrode sheets 120 are placed on the multi-manifold fluid fixture base 110; the multi-manifold fluid channel plate 130 and the multi-manifold fluid fixture base 110 are assembled by positioning screws or hinge locks.

[0043] The upper surface of the multi-branch fluid fixture base 110 is provided with eight slots 111 for positioning the sensor electrode sheets 120 , which are distributed in a rectangular array.

[0044] The multi-channel fluid plate 130 includes a multi-channel cover plate 131, a multi-channel substrate 132 and eight reaction chamber groove sealing rings 133; the multi-channel cover plate 131 and the multi-channel substrate 132 are combined into a whole, and the combination method includes but is not limited to bonding, laser welding, adhesive bonding and double-sided adhesive bonding.

[0045] A fluid inlet 1311 and eight fluid outlets 1312 are distributed on the multi-branched flow channel cover plate 131. The bonding surface of the multi-branched flow channel substrate 132 has a multi-branched flow channel 1321, and the multi-branched flow channel 1321 adopts a three-level Y-shaped multi-branched flow, and the inner surface of the flow channel is subjected to hydrophilic denaturation treatment. The other surface of the multi-branched flow channel substrate 132 has eight reaction chamber grooves 1322, and the two ends of the reaction chamber groove 1322 are respectively provided with a reaction chamber groove liquid inlet 1323 and a liquid outlet 1324 that penetrate the upper surface. Each reaction chamber groove liquid inlet 1323 is respectively communicated with the multi-branched flow channel 1321, and each reaction chamber groove liquid outlet 1324 is respectively communicated with the fluid outlet 1312 of the multi-branched flow channel cover plate.

[0046] Each reaction chamber 1322 has a sealing ring groove 1325 around it, and a sealing ring 133 is embedded in the sealing ring groove 1325, which is pressed tightly with the sensor electrode sheet 120 to form a reaction chamber. The shape and volume of the reaction chamber are determined according to the position of the electrode to be modified, the volume of the electrode modification reagent and the modification process.

[0047] In order to ensure that all waste liquid in the reaction chamber groove 1322 can be discharged, a drainage collection chamber 1326 is specially designed at the bottom of the reaction chamber groove 1322 and is connected to the liquid outlet 1324. When the driving gas for discharging the waste liquid enters the reaction chamber groove 1322 from the liquid inlet 1323, the driving gas will remain above the liquid reagent, and the drainage collection chamber 1326 connected to the liquid outlet 1324 will always store the liquid reagent, so the liquid outlet 1324 will always discharge the waste liquid.

[0048] The reagents or gases in the electrode modification process enter the multi-branched flow channel 1321 from the fluid inlet 1311 of the multi-branched flow channel cover plate 131, and are evenly divided into three levels when flowing through the Y-shaped multi-branched flow channel 1321. Each level of the Y-shaped multi-branched flow channel divides the fluid into 2 parts, and finally it is evenly divided into 8 parts, and enters the reaction chamber groove 1322 respectively through the reaction chamber groove liquid inlet 1323 connected to the multi-branched flow channel 1321; the multi-branched fluid channel plate 130 and the multi-branched fluid fixture base 110 are combined by positioning screws or hinge locks. After the combination, the reaction chamber groove 1322 of the multi-branched fluid channel plate 130 is respectively combined with the surface of the sensor electrode sheet 120 through the reaction chamber sealing ring 133 to form a sealed reaction chamber.

[0049] like Fig. 9As shown, in this embodiment, the reaction chamber groove 1322 is in the shape of a cam with one end larger than the other end, and the end of the reaction chamber groove 1322 close to the reaction chamber groove liquid inlet 1323 is larger and only covers the graphene field effect transistor sensor gate or electrochemical electrode working electrode (WE) to be modified; it is smaller near the liquid outlet 1324; by designing the reaction chamber groove 1322 into a cam shape, the size of the chamber at the liquid outlet of the reaction chamber groove 1322 is reduced while ensuring the modification area of ​​the electrode to be modified of the sensor electrode sheet 120, ensuring that all the waste liquid in the reaction chamber groove 1322 can be discharged from the liquid outlet 1324, when the driving gas for discharging the waste liquid enters the reaction chamber groove 1322 from the liquid inlet 1323, the size of the reaction chamber groove 1322 connected to the liquid outlet 1324 is reduced and the waste liquid automatically gathers, so the liquid outlet 1324 will always discharge the waste liquid.

[0050] like Figure 1 As shown, the liquid circuit connector pressure plate assembly 200 includes a liquid circuit connector upper pressure plate assembly 210 and a liquid circuit fixture support plate assembly 220; the two are fixed together by four pairs of buckles, and the multi-branch fluid fixture 100 is clamped between the liquid circuit connector upper pressure plate assembly 210 and the liquid circuit fixture support plate assembly 220.

[0051] like Figure 7 As shown, the upper pressure plate assembly 210 of the liquid path joint includes an upper pressure plate 211 of the liquid path joint, a diffusion chamber cover plate 212, a plurality of O-rings 213 and a plurality of upper buckles 214; wherein the upper pressure plate 211 of the liquid path joint includes a total fluid inlet 2111, a total fluid outlet 2112, a liquid outlet diffusion chamber 2113 and a plurality of liquid outlet diffusion ports 2114 penetrating the upper pressure plate 211 of the liquid path joint. The plurality of liquid outlet diffusion ports 2114 penetrate the upper pressure plate 211 of the liquid path joint and are respectively connected to the total fluid outlet 2112 through the liquid outlet diffusion chamber 2113.

[0052] like Figure 8 As shown, the fluid path fixture support plate assembly 220 includes at least one positioning groove 221 for placing the multi-manifold fluid fixture 100, two positioning pins 222 for fixing the fluid path connector upper pressure plate assembly 210, four lower buckles 224 for fixing and pressing the fluid path connector upper pressure plate assembly 210, and four base feet 225.

[0053] Furthermore, the liquid path fixture support plate assembly 220 may include a positioning groove 221 for placing the multi-branch fluid fixture 100, or a plurality of the positioning grooves 221 may be arranged, including but not limited to a single column or single row arrangement, an array arrangement, and a 2*3 or 3*4 array arrangement is recommended; when the liquid path fixture support plate assembly 220 adopts an arrangement of a plurality of the positioning grooves 221, the corresponding liquid path connector upper pressure plate 211 of the liquid path connector upper pressure plate assembly 210 also adopts the same arrangement of a plurality of diffusion chamber cover plates 212, O-rings 213, a total fluid inlet 2111, a total fluid outlet 2112, a liquid outlet diffusion chamber 2113 and a liquid outlet diffusion port 2114, and a plurality of liquid outlet diffusion ports 2114 are respectively connected to the total fluid outlet 2112 through the liquid outlet diffusion chamber 2113. At this time, each corresponding unit of the liquid path connector upper pressing plate assembly 210 and the liquid path fixture supporting plate assembly 220 cooperates with a multi-branch fluid fixture 100, so that more smart biosensor electrodes can be modified at one time.

[0054] The following is a brief description of the assembly of the electrode modification fluid fixture for the smart biosensor product in conjunction with the attached drawings:

[0055] When in use, the multi-manifold fluid fixture 100 should be assembled first; then the assembled multi-manifold fluid fixture 100 is placed in the positioning groove 221 of the fluid path fixture support assembly 220, ensuring that the side positioning notches of the multi-manifold fluid fixture 100 and the protruding parts of the positioning groove 221 are aligned and in good contact.

[0056] The assembly of the multi-branch fluid fixture 100 includes the following steps: the first step is to place the sensor electrode sheets 120 in the slots 111 of the multi-branch fluid fixture base 110 respectively; the second step is to carefully check the reaction chamber sealing ring 133 at the bottom of the multi-branch fluid channel plate 130. If there is any abnormal condition such as missing, damaged, deformed, or warped, the reaction chamber sealing ring 133 should be replaced or repaired immediately. Then, the multi-branch fluid channel plate 130 is placed above the sensor electrode sheet 120, ensuring that the bottom of the multi-branch fluid channel plate 130 is aligned and in good contact with the multi-branch fluid fixture base 110, and tighten the positioning screws or locks.

[0057] The installation of the pressure plate assembly 210 on the liquid circuit connector includes the following steps: the first step is to carefully check the O-ring 213 at the bottom of the pressure plate assembly 210 on the liquid circuit connector. If any abnormal conditions such as missing, damaged, deformed, or warped occur, the O-ring 213 should be replaced or repaired immediately; the second step is to align the positioning pin hole at the bottom of the pressure plate assembly 210 on the liquid circuit connector with the positioning pin 222 on the liquid circuit fixture support plate assembly 220, and ensure that the positioning pin hole is inserted into the positioning pin 222 and is in good contact; the third step is to respectively insert the rings of the four lower buckles 224 on the side of the liquid circuit fixture support plate assembly 220 into the grooves of the buckles 214 on the side of the pressure plate assembly 210 of the liquid circuit connector at the corresponding positions, and then reset and tighten the buckles in turn.

[0058] The multi-branch fluid fixture 100 is the core device of the electrode modification fluid fixture device of the intelligent biosensor product of the utility model. After the specific biological functional group reagent of the modified electrode is injected into the reaction chamber groove 1322 according to the modification process flow, it needs to be incubated for 4 to 12 hours. At this time, the multi-branch fluid fixture 100 can be taken out from the intelligent biosensor electrode modification fluid fixture for independent incubation and real-time detection of electrochemical characterization.

[0059] This embodiment is an example of the engineering application of the invention patent "A separated gate SGGT sensor, its preparation method and application CN116482205 A", which is used for covalent chemical modification of the gate of a graphene field effect transistor biosensor with a diameter of 2 mm, and can also be used for covalent chemical modification of a screen-printed three-electrode electrochemical working electrode WE with a diameter of 2 mm.

[0060] In this embodiment, the reaction cavity slot 1322 of the multi-branched flow channel substrate 132 only covers the screen-printed electrochemical working electrode that needs to be modified, the modification reagent only contacts the surface of the working electrode, and the electrochemical counter electrode and the reference electrode are not in contact with the modification reagent; similarly, for the graphene field effect transistor sensor, the reaction cavity slot 1322 of the multi-branched flow channel substrate 132 only covers the gate of the graphene field effect transistor sensor that needs to be modified, the modification reagent only contacts the surface of the gate, and the source, drain and graphene channel are not in contact with the modification reagent.

[0061] The following briefly describes the workflow and working principle of the fluidic fixture for modifying electrodes of smart biosensors in this embodiment.

[0062] First, the multi-manifold fluid fixture 100 should be assembled, and the screen-printed electrochemical biosensor electrode sheet or the field effect transistor biosensor electrode sheet 120 should be placed in the card slot 111 of the multi-manifold fluid fixture base 110 respectively; then the multi-manifold fluid channel plate 130 should be placed above the screen-printed electrochemical biosensor electrode sheet or the field effect transistor biosensor electrode sheet 120, ensuring that the bottom of the multi-manifold fluid channel plate 130 is positioned and aligned with the multi-manifold fluid fixture base 110 and in good contact, and tighten the positioning screws or locks.

[0063] At this time, the reaction chamber groove 1322 of the assembled multi-branch fluid channel plate 130 is respectively combined with the surface of the screen-printed electrochemical biosensor electrode sheet or the field effect transistor biosensor electrode sheet 120 through the reaction chamber sealing ring 133 to form a sealed reaction chamber.

[0064] Place the assembled multi-branch fluid fixture 100 in the positioning groove 221 of the fluid path fixture support plate assembly 220, ensuring that the positioning notch on the side of the multi-branch fluid fixture 100 and the protruding part of the positioning groove 221 are aligned and in good contact;

[0065] Align the positioning pin hole at the bottom of the pressure plate assembly 210 on the liquid circuit joint with the positioning pin 222 on the liquid circuit fixture support plate assembly 220, and ensure that the positioning pin hole is inserted into the positioning pin 222 and is in good contact.

[0066] Finally, the rings of the four lower buckles 224 on the side of the liquid circuit fixture support plate assembly 220 are respectively inserted into the grooves of the buckles 214 on the side of the liquid circuit joint upper pressure plate assembly 210 at the corresponding positions, and then the buckles are reset and fastened in turn.

[0067] When the modification reagent is loaded according to the process, the liquid path connector pressure plate assembly 200 can be opened, the multi-branch fluid fixture 100 can be taken out, and the fluid inlet 1311 and the fluid outlet 1312 can be sealed with a sealing film to prevent the modification reagent from overflowing and evaporating, and incubated for 4 to 12 hours according to the modification process. After the incubation is completed, the electrode loading connector assembly 140 is installed and connected to the electrochemical workstation or a customized electrode detection device to characterize the modification results and determine whether the modification has achieved the expected effect.

[0068] Embodiment 2

[0069] This embodiment has a similar structure to the first embodiment, except that the multi-manifold fluid fixture 100 in this embodiment includes not only a multi-manifold fluid fixture base 110 and a multi-manifold fluid channel plate 130, but also two electrode loading connector assemblies 140; the electrode loading connector assemblies 140 are correspondingly arranged at the left and right ends of the multi-manifold fluid fixture base 110, and the positioning holes at both ends of the electrode loading connector assemblies 140 are aligned with the positioning holes on one side of the multi-manifold fluid fixture base 110, and are tightened and fixed with screws or steel ball locking pins.

[0070] By installing the electrode loading connector assembly 140 on the multi-branch fluid fixture base 110, and the electrode loading connector assembly 140 is opposite to the position of the biosensor electrode sheet 120, the electrode loading connector assembly 140 is connected to an electrochemical workstation or a customized electrode detection device to characterize the modification results and determine whether the modification achieves the expected effect.

[0071] This embodiment is an engineering application example of the invention patent "Multi-gate graphene field effect transistor sensor array and multiple detection method CN114624309 A", which is used for selective chemical modification of graphene field effect transistor biosensor electrodes, and is also suitable for modification of graphene field effect transistor sensor arrays with multiple graphene channels. The graphene field effect transistor biosensor only exposes closely arranged gates and two graphene channels, and graphene channels 1 and 2 are respectively modified with different biological functional groups 1 and biological functional groups 2. Each gate size is 0.5mm*0.8mm, and the size of the graphene channel is 0.1~0.2mm. In addition, two different modification reagents are used to modify the graphene channel respectively. The graphene channel cannot be modified directly by covalent bond chemical modification, and a selective chemical modification method must be used for modification. Therefore, the modification process requires the electrode to be modified to be powered on, and it is also necessary to install the electrode loading connector assembly 140.

[0072] In this embodiment, the reaction chamber groove 1322 of the multi-branched flow channel substrate 132 covers the gate and graphene channel of the graphene field effect transistor sensor to be modified, and the modification reagents 1 and 2 are used to modify the graphene channel 1 and the graphene channel 2 respectively. The two modification reagents each carry a different biological functional group and are in contact with not only the graphene channel surface of the graphene field effect transistor sensor, but also the gate surface of the graphene field effect transistor sensor at the same time;

[0073] The following briefly describes the workflow and working principle of the fluidic fixture for modifying electrodes of smart biosensors in this embodiment.

[0074] First, the multi-manifold fluid fixture 100 should be assembled, and the graphene field effect transistor sensor electrode sheet should be placed in the slot 111 of the multi-manifold fluid fixture base 110; then the multi-manifold fluid channel plate 130 should be placed above the graphene field effect transistor biosensor electrode sheet 120, ensuring that the bottom of the multi-manifold fluid channel plate 130 is positioned and aligned with the multi-manifold fluid fixture base 110 and in good contact, and the positioning screws or locks should be tightened; then the electrode loading connector assembly 140 should be installed.

[0075] After assembly, the reaction chamber grooves 1322 of the multi-branched fluid channel plate 130 are respectively combined with the surface of the graphene field effect transistor biosensor electrode sheet 120 through the reaction chamber sealing ring 133 to form a sealed reaction chamber.

[0076] Place the assembled multi-manifold fluid fixture 100 in the positioning groove 221 of the fluid path fixture support assembly 220, ensuring that the side positioning notches of the multi-manifold fluid fixture 100 and the protruding parts of the positioning groove 221 are aligned and in good contact; insert the FPC wire rows of the customized electrode detection device into the FPC socket ports of the electrode loading connector assembly 140 respectively.

[0077] Align the positioning pin hole at the bottom of the pressure plate assembly 210 on the liquid circuit joint with the positioning pin 222 on the liquid circuit fixture support plate assembly 220, and ensure that the positioning pin hole is inserted into the positioning pin 222 and is in good contact.

[0078] Finally, the rings of the four lower buckles 224 on the side of the liquid circuit fixture support plate assembly 220 are respectively inserted into the grooves of the buckles 214 on the side of the liquid circuit joint upper pressure plate assembly 210 at the corresponding positions, and then the buckles are reset and fastened in turn.

[0079] In this embodiment, the graphene channel 1 and the graphene channel 2 of the graphene field effect transistor sensor are selectively chemically modified. First, the modification reagent is loaded through the pump valve according to the modification process containing the biological functional group 1, and the graphene channel 1 and the graphene channel 2 are chemically modified. Then, the graphene channel 2 is loaded with a suitable potential through the electrode loading connector assembly 140, so that the graphene channel 2 electrodesorbs the biological functional group 1, and the unmodified graphene channel 2 is re-exposed, while the graphene channel 1 is still modified by the biological functional group 1; then, the modification reagent is loaded through the pump valve according to the modification process containing the biological functional group 2, and the graphene channel 2 is chemically modified. At this time, since the graphene channel 1 is still modified by the biological functional group 1, the biological functional group 2 will only chemically modify the graphene channel 2.

[0080] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A fluid fixture for modifying electrodes of smart biosensors, characterized in that: include: A detachably connected upper pressure plate assembly (210) of a fluid path joint and a fluid path fixture support plate assembly (220), and at least one multi-branch fluid fixture (100) clamped therebetween; The multi-branch fluid fixture (100) comprises a multi-branch fluid fixture base (110) and a multi-branch fluid channel plate (130) that are detachably connected, and a plurality of slots (111) for positioning sensor electrode sheets (120) are provided on the upper surface of the multi-branch fluid fixture base (110); The multi-branched fluid channel plate (130) comprises a multi-branched flow channel cover plate (131) and a multi-branched flow channel substrate (132), and is formed by a combination of processes including but not limited to bonding, gluing, film bonding and laser welding; a fluid inlet (1311) and a plurality of fluid outlets (1312) are distributed on the multi-branched flow channel cover plate (131); a multi-branched flow channel (1321) with a Y-shaped multi-branched flow is provided on the upper surface of the multi-branched flow channel substrate (132); a plurality of reaction chamber grooves (1322) are provided on the other side of the multi-branched flow channel substrate (132), and the reaction chamber grooves (1322) are opposite to the sensor electrode sheet (120); The reaction chamber groove (1322) is provided with a liquid inlet (1323) and a liquid outlet (1324) at both ends; a plurality of the liquid inlets (1323) penetrate the multi-branched flow channel substrate (132) and are respectively communicated with the multi-branched flow channel (1321), and are then communicated with the fluid inlet (1311); a plurality of the liquid outlets (1324) penetrate the multi-branched flow channel substrate (132) and are communicated with the corresponding fluid outlets (1312); In addition, the fluid path joint upper pressure plate assembly (210) is provided with a fluid main inlet (2111) connected to the fluid inlet (1311), and a fluid main outlet (2112) connected to the fluid outlet (1312).

2. The fluid fixture for modifying electrodes of a smart biosensor according to claim 1, characterized in that: The multi-branched flow channel (1321) of the Y-shaped multi-branched flow is divided into three levels, and each level of the Y-shaped multi-branched flow channel divides the fluid into two parts, and finally the fluid is divided into eight parts; similarly, eight card slots (111) are arranged in a rectangular array on the multi-branched fluid clamp base (110), and eight reaction chamber slots (1322) are also arranged on the lower surface of the multi-branched flow channel substrate (132).

3. The fluid fixture for modifying electrodes of a smart biosensor according to claim 1, characterized in that: Each reaction chamber groove (1322) has a sealing ring groove (1325) around it, a sealing ring (133) is embedded in the sealing ring groove (1325), and the reaction chamber groove (1322) and the sealing ring (133) are pressed tightly with the sensor electrode sheet (120) to form a reaction chamber.

4. The fluid fixture for modifying electrodes of a smart biosensor according to claim 3, characterized in that: A drainage collection chamber (1326) is designed at the bottom of the reaction chamber groove (1322), and the drainage collection chamber (1326) is connected to the liquid outlet (1324).

5. The fluid fixture for modifying electrodes of a smart biosensor according to claim 1, characterized in that: The multi-branch fluid channel plate (130) and the multi-branch fluid fixture base (110) are detachably connected via positioning screws or hinge locks.

6. The fluid fixture for modifying electrodes of a smart biosensor according to claim 1, characterized in that: The liquid path joint upper pressure plate assembly (210) comprises a liquid path joint upper pressure plate (211) and a diffusion chamber cover plate (212) which are sealed and connected; the liquid path joint upper pressure plate (211) comprises a total fluid inlet (2111), a total fluid outlet (2112), a liquid outlet diffusion chamber (2113) and a plurality of liquid outlet diffusion ports (2114); the plurality of liquid outlet diffusion ports (2114) penetrate the liquid path joint upper pressure plate (211) and are respectively connected to the total fluid outlet (2112) through the liquid outlet diffusion chamber (2113).

7. The fluid fixture for modifying electrodes of a smart biosensor according to claim 1, characterized in that: The liquid circuit joint upper pressure plate assembly (210) is provided with a plurality of upper buckles (214), and the liquid circuit fixture support plate assembly (220) is provided with a plurality of lower buckles (224) matching the upper buckles (214), and a plurality of bottom feet (225).

8. The fluid fixture for modifying electrodes of a smart biosensor according to claim 1, characterized in that: The fluid path fixture support plate assembly (220) comprises a positioning groove (221) for placing the multi-branch fluid fixture (100) and two positioning pins (222) for fixing the pressure plate assembly (210) on the fluid path connector.

9. The fluid fixture for modifying electrodes of a smart biosensor according to claim 8, characterized in that: A plurality of the positioning grooves (221) are arranged on the liquid path fixture support plate assembly (220), including but not limited to a single row or single column arrangement or an array arrangement, and a plurality of flow channel modules are correspondingly provided on the liquid path connector upper pressure plate assembly (210), and are respectively matched with the multi-branch fluid fixture (100).

10. The fluid fixture for modifying electrodes of a smart biosensor according to claim 1, characterized in that: An electrode loading connector assembly (140) is detachably mounted on the left and right ends of the multi-branch fluid clamp base (110), respectively, and the electrode loading connector assembly (140) is located opposite to the electrode position of the sensor electrode sheet (120).

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