Array type electrode sampling system and application
By combining array electrodes with a microfluidic chip to create a closed electrolytic cell and siphon channel design, the problems of accuracy, stability and scalability of array electrode sample introduction systems are solved, realizing efficient and automated multi-component detection, which is applicable to fields such as biomedicine, electrochemistry and environmental monitoring.
Patent Information
- Application Number
- CN202510921144.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-04
- Publication Date
- 2025-11-07
AI Technical Summary
Existing array-type electrode sample introduction systems suffer from problems such as poor accuracy and repeatability, complex operation, high cost, large size, dependence on external power, and poor stability and consistency, making it difficult to meet the requirements of high throughput, miniaturization, and rapid detection.
An array electrode sample introduction system was designed, which combines array electrodes and microfluidic chips, and adopts a closed electrolytic cell and siphon channel to achieve automatic sample introduction without external power. The microfluidic channel enables programmable reaction, improving reaction consistency and scalability.
It enables efficient and automated sample introduction of array electrodes and simultaneous execution of multiple biochemical reactions, improving detection efficiency and reaction consistency. It is suitable for multi-component analysis and real-time dynamic monitoring, while reducing system complexity and cost.
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Figure CN120908271A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of electrode chip, and particularly relates to an array electrode sampling system, an electrochemical detection kit containing the same, and a detection system. BACKGROUND
[0002] The array electrode refers to an electrode system composed of a plurality of independent electrode units arranged according to a certain rule. The array electrode is composed of a plurality of micro electrodes arranged in a regular or customized geometric shape. Each micro electrode unit is composed of a working electrode, a counter electrode and a reference electrode. The array electrode is widely used in the fields of biomedical science, electrochemistry, neuroscience and environmental monitoring.
[0003] At present, the electrode sampling method matched with the array electrode is to realize the functionalization of the electrode and the parallel analysis and rapid detection of the sample by manual spotting or integrating a plurality of independent micro electrolytic cells. Manual spotting has the problems of poor precision and repeatability, time consumption, reagent residue, high operation complexity, sample loss and standardization difficulty. The independent micro electrolytic cell sampling system firstly integrates a plurality of independent or interconnected electrodes (such as micro discs, micro strips or interdigital arrays) on a single chip by using screen printing technology or micro processing technology, and then combines a plurality of independent micro fluidic units to form an array electrode sampling system. Each electrolytic cell is an independent reaction, including independent sampling and washing steps, so as to accurately control the sample flow rate and distribution and ensure the synchronous response of each electrode site. This technology significantly improves the detection sensitivity and spatiotemporal resolution, and is especially suitable for multi-component simultaneous analysis or real-time dynamic monitoring. The advantage of this technology is low sample consumption and strong anti-interference ability. However, the array electrode sampling system is complex in design and high in manufacturing cost, and the space occupation and scalability are limited. In addition, the design of the independent electrolytic cell usually needs an additional isolation structure or sealing device, which increases the overall volume and makes it difficult to apply in space-sensitive scenarios (such as portable devices or miniaturized systems). Meanwhile, the independent electrolytic cell sampling method may affect the stability and performance consistency of the array electrode, and the gas generated during the reaction of the electrode needs to be discharged, which further increases the integration difficulty of the system.
[0004] In addition, most of the array electrode microfluidic sampling systems for research are powered by external power sources, such as mechanical pumps (syringe pumps, peristaltic pumps, pressure pumps, etc.), electric driving (such as electroosmotic flow, electrophoresis, dielectrophoresis), etc. The system has the defects of dependence on external power equipment, large volume and slow response speed, and is difficult to meet the high-throughput or miniaturized detection requirements. Some power systems also need to rely on manual operation, which further reduces the reliability and automation level and restricts their applicability in rapid detection scenarios. In view of the above problems to be solved, there is currently no high-throughput, centralized sampling and scalable electrode array sampling system that can match the external power supply and realize automatic sampling without power. SUMMARY
[0005] The application aims at the above-mentioned problems, and proposes an injection system based on array electrode reaction, which is composed of array planar electrodes and a microfluidic chip with concentrated injection. The designed closed electrolytic cell is a reaction tank with specific size, which can realize programmable reaction by providing external power, and can also form a siphon channel to automatically enter and cover all electrode areas after sample injection at the injection port without applying external power. The array electrode injection system has the characteristics of simple design, scalability, and small difference in channel signal acquisition.
[0006] In order to achieve the above-mentioned purposes, the technical solutions adopted by the application are as follows:
[0007] In the first aspect of the application, an array electrode injection system is provided, which is composed of two structural forms: one form is composed of a base, array electrodes arranged on the base, and a microfluidic chip sealed on the array electrodes; the other form is composed of a base, array electrodes arranged on the base, a microfluidic chip, and an upper cover sealed on the base.
[0008] Among them, the array electrodes are sequentially arranged by multiple electrode groups, and each electrode group is composed of a working electrode, a reference electrode, and a counter electrode. The microfluidic channel on the microfluidic chip serves as a flow channel for the target detection object, and the two ends of the microfluidic channel are respectively connected with the injection port and the sample outlet.
[0009] As a preferred technical solution, in each electrode group, the working electrode, the reference electrode, and the counter electrode are also sequentially arranged. Therefore, the array electrode is composed of N groups of three-electrode systems, and 3N electrodes are arranged in parallel.
[0010] As a preferred technical solution, the base is provided with an electrode substrate, and the array electrodes are arranged on the electrode substrate. Each electrode is electrically connected with an electrode contact at the tail end portion through an electrode lead wire. The electrode contact and the base form a conductive electrode interface, and the electrode interface is exposed to the outside and connected with an electrochemical workstation.
[0011] Specifically, (1) the microfluidic chip can be directly sealed on the array electrode through plasma treatment, heat sealing or adhesive bonding, and the part between the conductive electrode interface and the microfluidic chip is sealed and packaged by an insulating layer, and the conductive electrode interface is exposed outside the insulating layer; (2) the base and the upper cover are sealed and assembled by a buckle form. The upper cover is provided with a groove for accommodating the microfluidic chip, and the base has a groove with the same three-dimensional size as the printed electrode for accommodating the printed electrode. The two grooves and the contents together form an electrolytic cell reaction tank. After the base and the upper cover are combined, the packaging of the array electrode injection system can be realized. After the upper cover and the base are sealed and assembled, the conductive electrode interface is exposed to the outside and connected with the electrochemical workstation.
[0012] As a preferred technical solution, the siphon channel width is greater than the electrode group size; the sample inlet and the sample outlet are arranged on the microfluidic chip or the upper cover, and are connected through the catheter and the electrolytic cell reaction tank respectively. The solution can enter from the sample inlet of the reaction tank, fill the entire reaction area, and infiltrate the electrode surface to form a sealed electrolytic cell.
[0013] The electrolytic cell reaction tank and the upper cover are provided with a reaction liquid inlet and outlet at the same position, and the inlet and outlet can be directly sampled, absorbed or connected with a catheter to cooperate with other power systems.
[0014] The electrolytic cell reaction tank can be adjusted in size to form a siphon channel. After sampling at one end, the sample automatically enters and covers all electrode areas without applying external power. However, external power can also be applied to realize a programmable reaction. The electrolytic cell cavity should cover the entire electrode array extension.
[0015] In the second aspect of the application, a method for detecting target substances using the above-mentioned array electrode sampling system is provided. In terms of detection principle, it is divided into two categories. One is to deposit the same electrochemically active dye on different working electrodes of the same electrode array to realize the modification of the dye polymer on the working electrode. The other is to modify specific binders (such as antibodies) on different working electrodes to realize the detection of biological substances.
[0016] The first category is mainly used for the modification of electronic mediators on the electrode array: the electrochemically active dye molecules are sampled through the sampling hole, and the amperometric and cyclic voltammetry scanning are performed using an electrochemical workstation to generate an electronic medium layer of dye polymer.
[0017] The second category is mainly used for the detection of biological information such as antigens, proteins, viruses and hormones: during chip assembly, specific binders (such as antibodies) corresponding to the target detection material are coated on the electrode array; then through sandwich reaction, manual or automatic sampling method is used to add target detection material standard solution, cleaning solution, specific binder solution labeled with marker, cleaning solution and substrate solution in turn from the sampling port, and the corresponding electrochemical tester is used to collect current signal at the same time to realize the detection of each substance.
[0018] In the third aspect of the application, a multi-substance electrochemical detection kit is provided, which includes an array electrode sampling system and buffer solution, extraction solution or standard required for detection analysis. The array electrode sampling system is the array electrode sampling system described above.
[0019] In the fourth aspect of the application, a multi-substance electrochemical detection system is provided, which includes an electrochemical detection kit and an electrochemical detection device connected thereto, and the electrochemical detection kit is as described above.
[0020] Compared with the prior art, the present application has the beneficial effects of:
[0021] The present application realizes simultaneous sampling of array electrodes and simultaneous occurrence of multiple biochemical reactions, can greatly shorten experimental operation efficiency, and improves the consistency of biochemical reactions between electrodes. The main method is to increase a reaction groove of a microfluidic chip on the upper layer of the array screen-printed electrode, form an electrolytic cell with consistent solution amount on the electrode surface, isolate the whole electrolytic cell reaction system from the outside world, make the reaction more stable, and improve the consistency of biochemical reactions of array electrodes. BRIEF DESCRIPTION OF DRAWINGS
[0022] Figure 1 is an array electrode sampling system packaging structure schematic diagram of an embodiment of the present application.
[0023] Figure 2 is Figure 1 is a whole structure schematic diagram of the array electrode sampling system combined with the internally packaged clamping base structure.
[0024] Figure 3 is Figure 1 is a structure schematic diagram of the array electrode sampling system combined with the internally packaged base structure.
[0025] Figure 4 is an electrochemical cyclic voltammetry scan curve of the array electrode sampling system for working electrode cleaning.
[0026] Figure 5 is a time-current curve of the array electrode sampling system for electrodeposition of Prussian blue on the working electrode.
[0027] Figure 6 is a cyclic voltammetry curve of the array electrode sampling system for activation of electrodeposition of Prussian blue on the working electrode.
[0028] Figure 7 is a test result of the multi-element immunoelectrode of the array electrode sampling system for detection of four biological targets.
[0029] In the figure, 1 is a clamping buckle, 2 is an upper cover of the clamping buckle, 3 is a bottom base of the clamping buckle, 4 is a sampling port, 5 is a sample outlet, 6 is an array electrode, 7 is a microfluidic chip, 8 is an electrode base, 9 is an electrode contact, 10 is an insulating layer, 11 is a counter electrode, 12 is a working electrode, and 13 is a reference electrode. DETAILED DESCRIPTION
[0030] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the described embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without any inventive effort fall within the scope of protection of the present application.
[0031] In the present application, all the embodiments and preferred embodiments mentioned in the present application can be combined with each other to form new technical solutions if not specially stated.
[0032] I. Structure and assembly of array electrode sampling system
[0033] Specifically, Figure 1 A form of array electrode sampling system is shown, which comprises a sealed assembled card shell base 3, a card shell upper cover 2, and the two are sealed and assembled through buckles 1. The card shell upper cover 2 is provided with a sampling inlet 4 and a sample outlet 5.
[0034] Referring to Figure 2 and Figure 3 The upper cover 2 contains a microfluidic chip 7, and the microfluidic channel in it serves as a flow channel for the detection liquid to realize power-free sampling; the microfluidic chip is made of transparent material or non-transparent material combined with transparent material, and is preferably PDMS.
[0035] The array electrode 6 is sequentially arranged by a plurality of electrode groups, and each electrode group is composed of a working electrode 12, a reference electrode 13 and a counter electrode 11. The microfluidic channel on the microfluidic chip serves as a flow channel for the target detection object, and the two ends of the microfluidic channel are respectively communicated with the sampling inlet 4 and the sample outlet 5. In each electrode group, the working electrode, the reference electrode and the counter electrode are also sequentially arranged. Therefore, the array electrode is composed of N groups of three-electrode systems, and 3N electrodes are arranged in parallel.
[0036] The base is provided with an electrode substrate 8, and the array electrode 6 is arranged on the electrode substrate 8. Each electrode is electrically connected with the electrode contact 9 at the tail end part through an electrode lead; the electrode contact and the base form a conductive electrode interface, and the electrode interface is exposed to the outside and connected with an electrochemical workstation. Among them, the part between the conductive electrode interface and the microfluidic chip is sealed and packaged by an insulating layer 10.
[0037] As a specific embodiment of the present application, the electrolytic cell reaction tank for biochemical reaction is composed of array screen-printed electrodes and a PDMS microfluidic chip. The printed electrode substrate is PET material, the working electrode and the counter electrode are printed by conductive ink, and the reference electrode is silver / silver chloride paste (Ag / AgCl). The array electrode sampling system has a total of 12 independent electrodes, each group of three electrodes, working electrode, reference electrode, and counter electrode, arranged in order. Every three electrodes from left to right form a group, and there are four groups of three-electrode systems, wherein the working electrode is a circular electrode with a diameter of 3 mm, and the overall size of the electrode is 63.5*31*0.25 mm (length* width* height). The array electrode surface and the PDMS microfluidic reaction tank are chemically bonded into an array electrode sampling system after plasma treatment for 2 minutes. The left and right sides of the PDMS microfluidic reaction tank are respectively designed as liquid sampling inlet and outlet, and the size of the reaction tank is 60.5*10*3 mm, and the size of the internal liquid path reaction area of the reaction tank is 58*4*1 mm.
[0038] The array electrode sampling system disclosed in the present application can also realize non-powered sampling by designing the channel size of the PDMS microfluidic chip to form a siphon channel. The height of the reaction tank of the PDMS microfluidic electrolytic cell is between 0.1-0.5 mm, and the width is less than 10 mm.
[0039] The electrode array microfluidic channel in the present embodiment can not only perform electrochemical luminescence detection of different substances, but also perform multi-element immunological analysis. Specifically as follows:
[0040] Application Example 1
[0041] The array electrode sampling system is used for Prussian blue electrodeposition reaction on the electrode surface: the self-made screen-printed array carbon electrode is selected, the working electrode and the counter electrode are screen-printed carbon, and the reference electrode is a silver / silver chloride electrode, and the process is as follows:
[0042] 1) Electrode cleaning: use 100 mM phosphate buffer solution (PB solution) to clean the electrode, add 1 mL of PB buffer solution in the array electrode sampling system, and use the self-developed matching 16-channel electrochemical tester to perform cyclic voltammetry scanning. The specific parameters are: potential range -0.3 V ~ 0.6 V, scanning speed -0.5 V / s, scanning 50 times, and the test curve is shown in the accompanying Figure 4 After removing the impurities on the surface of the array electrode, the PB buffer solution in the sampling system is removed, and the ultrapure water is cleaned for 3 times.
[0043] 2) Electrodeposition of Prussian Blue PB: 1.5 mL of electrodeposition solution was prepared (150 μL of 20 mM FeCl3.6H2O, 150 μL of 20 mM K3[Fe(CN)6], 750 μL of 0.1 M HCl, 250 μL of 0.3 M KCl, and 100 μL of ultrapure water). 500 μL of the electrodeposition solution was added to the above-mentioned array electrode sample system, and time-current curve scanning was performed using the self-developed electrochemical tester. The constant potential was set to 0.4 V, and scanning was continuously performed for 60 s, as shown in FIG. 2. A layer of blue Prussian blue film was formed on the surface of the working electrode, and the electrodeposition solution was removed. 1.5 mL of activation solution was prepared (0.1 M KCl solution and 10 mM HCl solution were mixed in equal proportions), 1 mL of the activation solution was added to the array electrode sample system, and cyclic voltammetry curve scanning was performed using the self-developed 16-channel electrochemical tester, as shown in FIG. 3. The specific parameters were as follows: initial potential: -0.1 V, maximum potential: 0.35 V, minimum potential: -0.1 V, and scanning rate: 0.05 V / s. The array electrode was activated, and forward scanning was performed for 12 cycles to complete the electrodeposition of Prussian blue on the array electrode. Figure 5 Figure 6 Application Example 2
[0044] Application Example 2
[0045] The above-mentioned array electrode sample system was used for multi-element immunoassay, and a self-made screen-printed array carbon electrode was selected. The working electrode and the counter electrode were screen-printed carbon, and the reference electrode was a silver / silver chloride electrode. The process was as follows:
[0046] 1) Coating of different antibodies on the array electrode: A multi-element immunoelectrode was prepared using the above-mentioned array electrode, and antibodies for detecting different targets were modified on the four working electrodes. The array electrode was washed with ultrapure water to clean the electrode surface, and nitrogen was blown dry. The above four antibodies were diluted with phosphate buffer to a concentration of 50 μg / mL, and 10 μL was added to the electrode surface. The array electrode was placed in a sealed humid box at 4°C overnight to prevent evaporation of the sample solution. After overnight, the array electrode was washed with PBA, dried with nitrogen, then blocked with 2% bovine serum albumin (BSA) at 37°C for 2 h, and finally washed with PBS buffer and dried with nitrogen.
[0047] 2) Cover the array electrode coated with influenza virus H1N1 antibody, S protein antibody of new coronavirus SARS-CoV-2, C-reactive protein (CRP) antibody, interleukin 6 (IL-6) antibody with a layer of PDMS mask on the surface, and the PDMS reaction tank is plasma treated for 2 minutes. After the surface of the array electrode and the surface of the PDMS reaction tank are modified, the two are tightly combined together to form a completely sealed array electrode sampling system, which is packaged in a card shell.
[0048] 3) Take 500 μL of the target solution mixed with influenza virus H1N1 (10 ng / mL), S protein of new coronavirus SARS-CoV-2 (10 ng / mL), C-reactive protein (10 ng / mL), and interleukin 6 (10 ng / mL), and drop it into the sampling port. Use a syringe pump (or a pipette) to diffuse it to the electrode area in the sampling system, and cover the entire array electrode area. After 1 hour of reaction, the specific recognition of the four different antibody electrodes and target molecules is completed, and the mixed target solution is removed.
[0049] 4) Drop 500 μL of PBS buffer solution from the sampling port, so that it diffuses through the sampling system to the entire electrode area, and washes the electrode surface. Remove the washing liquid from the outlet, and repeat the washing for 3 times.
[0050] 5) Add the mixed solution of horseradish peroxidase (HRP) labeled H1N1 antibody, S protein antibody of new coronavirus SARS-CoV-2, C-reactive protein (CRP) antibody, and interleukin 6 (IL-6) antibody from the sampling port to the sampling system, so that it covers the entire area of the array electrode, and reacts in the sampling system for 1 hour. Then remove the unbound mixed antibody from the outlet.
[0051] 6) Drop 500 μL of PBS buffer solution from the sampling port, so that it diffuses through the sampling system to the entire electrode area, and washes the electrode surface. Remove the washing liquid from the outlet with a pipette, and repeat the washing for 3 times.
[0052] 7) Drop 500 μL of substrate TMB solution into the sampling port, so that it diffuses through the sampling system to the entire electrode area. Use the self-developed 16-channel electrochemical tester to collect the electrical signal, and the test result is shown in FIG. 2. Figure 7
[0053] The preferred embodiments of the application have been specifically described above, but the application is not limited to the described embodiments. Those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the application. These equivalent modifications or replacements are all included in the scope defined by the claims of the present application.
Claims
1. An array electrode sampling system, comprising: The array electrode sampling system comprises a base, an array electrode arranged on the base, and a microfluidic chip arranged on the array electrode, The array electrode is sequentially arranged by a plurality of electrode groups, and each electrode group comprises a working electrode, a reference electrode, and a counter electrode, The microfluidic channel on the microfluidic chip serves as a flow channel for the target detection object, and the two ends of the microfluidic channel are respectively connected to the sample inlet and the sample outlet.
2. The array electrode sampling system according to claim 1, wherein: wherein In each electrode group, the working electrode, the reference electrode, and the counter electrode are sequentially arranged.
3. The array electrode sampling system according to claim 1, wherein: wherein The base is provided with an electrode substrate, and the array electrode is arranged on the electrode substrate, and each electrode is connected to the electrode contact at the tail end through an electrode lead wire; The electrode contact and the base form a conductive electrode interface, and the electrode interface is exposed to the outside and connected to an electrochemical workstation.
4. The array electrode sampling system according to claim 1, wherein: wherein The microfluidic chip is sealed on the array electrode by plasma treatment, heat sealing, or adhesive bonding.
5. The array electrode sampling system according to claim 4, wherein: wherein The part between the conductive electrode interface and the microfluidic chip is sealed and packaged by an insulating layer.
6. The array electrode sampling system according to claim 2, wherein: wherein The base and the upper cover are sealed and assembled by a buckle form; The upper cover is provided with a groove for accommodating the microfluidic chip, and the base is provided with a groove for accommodating the array electrode, and the conductive electrode interface is exposed to the outside and connected to the electrochemical workstation after the upper cover and the base are sealed and assembled.
7. The array electrode sampling system according to claim 1, wherein: wherein The flow channel has a width greater than the size of the electrode group, The sample inlet and the sample outlet are arranged on the microfluidic chip or simultaneously penetrate the upper cover and are connected through a conduit and a flow channel, respectively.
8. Use of the array electrode sampling system according to any one of claims 1-7 in the preparation of a multi-component substance analysis product.
9. A multi-element electrochemical test kit, characterized by It comprises: An array electrode sampling system and buffer solution, extraction solution, or standard required for detection analysis, The array electrode sampling system is the array electrode sampling system according to any one of claims 1-8.
10. A multi-analyte electrochemical detection system, comprising: It comprises: An electrochemical detection kit and an electrochemical detection device connected thereto, and the electrochemical detection kit is as claimed in claim 9.