A multi-channel microfluidic chip, ion detection system and application

Abstract

The application provides a kind of multi-channel microfluidic chip and application, belong to the technical field of device for environmental monitoring.Microfluidic chip includes flow channel layer, detection layer and electrode layer.The lower surface of flow channel layer is provided with first flow channel and second flow channel, the detection layer is provided with through detection cavity, the electrode layer is provided with detection electrode assembly, and in assembled state, first flow channel and second flow channel are both partially communicated with through detection cavity, detection electrode assembly is located in through detection cavity, and detection electrode assembly is externally connected with detection equipment.Flow channel layer is also provided with sample inlet flow channel and sample outlet flow channel, one end of sample inlet flow channel is communicated with first flow channel, the other end is externally connected with circulating buffer device, one end of sample outlet flow channel is communicated with second flow channel, the other end is externally connected with circulating buffer device.The chip of the application is low-cost modular, can detect through multi-channel parallel in chip, avoid cross contamination and response signal mutual interference, and can realize trace ion detection in trace sample with circulating buffer device.

Description

Technical Field

[0001] This invention relates to the field of environmental monitoring devices, and in particular to multi-channel microfluidic chips, ion detection systems, and their applications. Background Technology

[0002] Heavy metals refer to metals with a density greater than 4 or 5 g / cm³. 3 Heavy metals comprise approximately 45 known elements. Common heavy metal ions include lead, cadmium, chromium, mercury, nickel, zinc, copper, and the nonmetallic arsenic. Due to their toxicity and non-biodegradability in soil and water, heavy metals can enter the human body through the food chain, posing serious health risks. For example, increased lead (Pb) levels in the blood can impair children's neurological development, lead to high blood pressure, kidney damage, and anemia. Cadmium (Cd) has been proven to be a carcinogen; even small doses can induce osteomalacia and proteinuria, and in severe cases, lung cancer and even death. The various hazards and sources of heavy metal pollution have become a global concern. Heavy metals in nature are mainly distributed in the atmosphere, water bodies, and soil. Detecting heavy metals in tap water and river water is a key factor in solving the heavy metal pollution problem.

[0003] The safety limits for the concentration of many heavy metal ions in drinking water are all in the microgram per liter (ppb) range, which requires corresponding heavy metal ion detection methods to have high selectivity and detection sensitivity. Many mature technologies and detection methods have been developed for heavy metal detection, such as atomic fluorescence spectrometry, inductively coupled plasma mass spectrometry, and high-performance liquid chromatography. The advantages of these methods are high detection sensitivity and low detection limits; the disadvantages are complex sample pretreatment, large equipment size, and the need for professional operators for detection and data analysis. Electrochemical methods based on microfluidic chip technology have attracted widespread attention due to their small size, good quantitative effect, fast analysis speed, and high sensitivity. They can guide the water to be tested into microchannels through tiny channels and extremely small electrodes, and control the flow of microfluidics, promoting the miniaturization and integration of detection instruments. To date, increasing research has demonstrated that microfluidic chip electrochemical sensors based on microelectrodes can be used for online real-time analysis and detection of heavy metal ions.

[0004] Currently, after nearly 10 years of development, most microfluidic chips for heavy metal detection cannot circulate and enrich, resulting in low sensitivity for trace heavy metal detection. Furthermore, the limited size of microfluidic chips makes effective chip cleaning an essential step in trace heavy metal detection.

[0005] In summary, this application provides a multi-channel microfluidic chip for the detection of heavy metals or other ions, thereby addressing at least one of the shortcomings in the above-mentioned heavy metal detection methods. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the main objective of this invention is to provide a multi-channel microfluidic chip, an ion detection system, and an application. The chip in this application is a low-cost, modular multi-channel microfluidic chip. It can avoid cross-contamination and mutual interference of response signals by incorporating a multi-channel parallel detection structure within a single microfluidic chip, and, in conjunction with a circulating buffer device, can achieve trace ion detection in minute samples.

[0007] To achieve the above and other related objectives, the present invention is implemented through the following technical solution.

[0008] The first aspect of the present invention provides a multi-channel microfluidic chip, wherein the microfluidic chip comprises, from top to bottom, a flow channel layer, a detection layer and an electrode layer;

[0009] The lower surface of the flow channel layer is provided with a first flow channel and a second flow channel that do not intersect each other;

[0010] The detection layer is provided with at least one through detection cavity, and in the assembled state, both the first flow channel and the second flow channel are partially connected to the through detection cavity;

[0011] The electrode layer is provided with a detection electrode assembly, and in the assembled state, the detection electrode assembly is located inside the through detection cavity, and the detection electrode assembly is externally connected to a detection device;

[0012] The flow channel layer is further provided with an inlet flow channel and an outlet flow channel. One end of the inlet flow channel is connected to the first flow channel, and the other end is connected to a circulation buffer device. One end of the outlet flow channel is connected to the second flow channel, and the other end is connected to a circulation buffer device.

[0013] In some preferred embodiments, the detection layer is provided with a first through-hole detection cavity and a second through-hole detection cavity;

[0014] The first flow channel includes a first main flow channel and a branch flow channel and a second branch flow channel connected to the first main flow channel. The branch flow channel and the second branch flow channel are respectively connected to the first penetration detection cavity and the second penetration detection cavity.

[0015] The second flow channel includes a second main flow channel and a three-branch flow channel and a four-branch flow channel connected to the second main flow channel. The three-branch flow channel and the four-branch flow channel are respectively connected to the first penetration detection cavity and the second penetration detection cavity.

[0016] In some preferred embodiments, the first main flow channel and the second main flow channel are arranged in parallel;

[0017] The first, second, third, and fourth branch channels are all arranged in parallel.

[0018] In some preferred embodiments, the flow channel layer is further provided with a first connecting channel and a second connecting channel; the two ends of the first connecting channel are respectively connected to the head end of the sample inlet flow channel and the first flow channel, and the two ends of the second connecting channel are respectively connected to the head end of the sample outlet flow channel and the second flow channel.

[0019] In some preferred embodiments, the inlet channel and the outlet channel are arranged in parallel and are parallel to the upper surface of the channel layer; the first connecting channel and the second connecting channel are arranged in parallel and are perpendicular to the upper surface of the channel layer.

[0020] In some preferred embodiments, the lower surface of the flow channel layer is provided with an embedding groove for accommodating the detection layer; the first flow channel and the second flow channel are located at the bottom of the embedding groove.

[0021] In some preferred embodiments, the flow channel layer, detection layer, and electrode layer are detachably connected.

[0022] In some preferred embodiments, the microfluidic chip further includes several connectors; the flow channel layer, the detection layer and the electrode layer are each provided with several corresponding fixing holes, and each connector is detachably connected to each fixing hole.

[0023] In some preferred embodiments, the detection electrode assembly includes a working electrode, a counter electrode, and a reference electrode.

[0024] In some preferred embodiments, the materials of the flow channel layer and the detection layer are selected from polydimethylsiloxane, polymethyl methacrylate, or polycarbonate.

[0025] In some preferred embodiments, the connection method between the flow channel layer and the detection layer is selected from photocurable UV adhesive bonding, epoxy adhesive bonding, or plasma bonding.

[0026] In some preferred embodiments, the depth of the first and second flow channels is 1 to 5 mm.

[0027] In some preferred embodiments, the penetration detection cavity is elliptical.

[0028] In some preferred embodiments, the substrate of the electrode layer may be a printed circuit board, PET, or ceramic.

[0029] A second aspect of the present invention provides an ion detection system, including at least one of the aforementioned microfluidic chips, and further including a circulation buffer device; the circulation buffer device includes a circulation pump and a first circulation pipeline and a second circulation pipeline connected to the circulation pump, the first circulation pipeline being connected to the sample inlet channel and the second circulation pipeline being connected to the sample outlet channel.

[0030] In some preferred embodiments, the chip further includes an injection tube and a control valve; the injection tube is connected to the first circulation line, and the control valve is located in the injection tube.

[0031] The third aspect of the present invention provides the use of the aforementioned multichannel microfluidic chip in ion detection, particularly in the detection of heavy metal ions.

[0032] As described above, the multi-channel microfluidic chip and ion detection system of the present invention mainly have the following beneficial effects:

[0033] 1) This invention provides a low-cost, modular multi-channel microfluidic chip, which can achieve parallel detection of multiple parameters by integrating multiple channels in a single microfluidic chip or by combining multiple microfluidic chips with different detection composite electrodes; by replacing the detection composite electrode assembly, flexible, fast and low-cost multi-parameter detection can be achieved.

[0034] 2) The microfluidic chip of the present invention has low material and process costs, highly integrated structure, simple assembly, easy disassembly and replacement, and easy mass production. It can be used as a disposable consumable. The detection process and detection time are simplified by pre-modifying electrodes, pre-calibrating, and pre-filling the detection cell with standard products.

[0035] 3) The invented microfluidic chip can be customized with different composite electrode components according to different ions to be measured, and different working electrode materials, electrode modifiers and modification methods can be selected to achieve modular ion detection.

[0036] 4) The microfluidic chip of the present invention can avoid cross-contamination and mutual interference of response signals through multi-channel parallel detection.

[0037] 5) The microfluidic chip of this invention has a simple structure and a small detection cell formed throughout the detection chamber, enabling detection of trace samples. When used in conjunction with a circulating buffer device as an ion detection system, it can improve detection efficiency and sensitivity, achieving trace ion detection in minute samples. Attached Figure Description

[0038] Figure 1 The diagram shown is a structural schematic of the ion detection system of the present invention.

[0039] Figure 2 The image shown is a cross-sectional view of the microfluidic chip of the present invention.

[0040] Figure 3 The image shown is a cross-sectional view of the flow channel layer of the microfluidic chip of the present invention.

[0041] Figure 4 The diagram shows the overall structure of the microfluidic chip of the present invention, wherein the flow channel layer is made transparent.

[0042] Figure 5 The diagram shows the lower surface of the flow channel layer of the microfluidic chip of the present invention.

[0043] Figure 6 The diagram shown is an exploded view of the microfluidic chip of the present invention, wherein each layer is made transparent.

[0044] Figure 7 The graph shown is a curve of the lead ion concentration in lead nitrate standard tested according to the anodic stripping voltammetry method of this invention.

[0045] Figure 8 The graph shown is a curve of chloride ion concentration in potassium chloride standard tested by potentiometric analysis according to the present invention.

[0046] Figures 1-8 The labels in the attached figures are as follows:

[0047] 11 First Stream 111 First main channel 112 One branch channel 113 Two-branch flow channels 12 Second flow channel 121 Second main channel 122 Three-branch flow channel 123 Four-branch flow channel 13 Sample inlet channel 14 Sample outlet channel 15 First connection channel 16 Second connection channel 17 Inlay groove 18 Fixing hole 2 Detection layer 21 First penetrating detection cavity 22 Second penetrating detection cavity 3 Electrode layer 31 Working electrode mounting hole 32 Electrode mounting holes 33 Reference electrode mounting hole 100 microfluidic chip 201 Circulating pump 202 First circulation pipeline 203 Second circulation pipeline 301 Sample inlet tube 302 control valve Detailed Implementation

[0048] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content described in this specification.

[0049] Please see Figures 1 to 8 The structures, proportions, and sizes illustrated in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, terms such as "upper," "lower," "inner," "outer," "head," "tail," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0050] Example 1

[0051] This example provides a multi-channel microfluidic chip; see reference... Figures 1-3The microfluidic chip 100 comprises, from top to bottom, a channel layer 1, a detection layer 2, and an electrode layer 3. The lower surface of the channel layer 1 has a first channel 11 and a second channel 12 that do not intersect. The detection layer 2 has at least one through-detection cavity, and in the assembled state, both the first channel 11 and the second channel 12 are partially connected to the through-detection cavity. The electrode layer 3 has a detection electrode assembly, and in the assembled state, the detection electrode assembly is located within the through-detection cavity and is externally connected to a detection device. The channel layer 1 also has an inlet channel 13 and an outlet channel 14. One end of the inlet channel 13 is connected to the first channel 11, and the other end is externally connected to a circulation buffer device. One end of the outlet channel 14 is connected to the second channel 12, and the other end is externally connected to a circulation buffer device.

[0052] Specifically, see Figure 2 This application modularizes the multi-channel microfluidic chip, mainly comprising three modules: flow channel layer 1, detection layer 2, and electrode layer 3. For details, please refer to [link to relevant documentation]. Figure 2 and Figure 3 By creating grooves on the lower surface of the flow channel layer 1 to form non-intersecting first and second flow channels 11 and 12, a through-hole detection cavity is provided in the detection layer 2. The number of detection cavities is the same as the number of flow channels, with each flow channel corresponding to one through-hole detection cavity. The electrode layer 3 is used to mount detection electrode assemblies; specifically, multiple sets of electrode mounting holes are formed on the electrode layer 3. After stacking the flow channel layer 1, detection layer 2, and electrode layer 3, each flow channel is fluidly connected to its corresponding through-hole detection cavity, and each through-hole detection cavity corresponds to a set of electrode mounting holes on the electrode layer 3. That is, the three modules are stacked to form a microfluidic chip and form a reaction pool in the through-hole detection cavity. This modular microfluidic chip, through the setting of multiple flow channels and the use of different targeted detection composite electrodes, can achieve multi-parameter parallel detection. By replacing the detection composite electrode assembly, flexible, fast, and low-cost multi-parameter detection can be achieved. Moreover, multi-channel parallel detection can avoid cross-contamination and mutual interference of response signals. In addition, this example also includes an inlet channel 13 connected to the first channel 11 and an outlet channel 14 connected to the second channel 12. The inlet channel 13 and the outlet channel 14 are also connected to an external circulation buffer device. That is, by using a circulation buffer device as an ion detection system, this example can improve detection efficiency and detection sensitivity, and realize the detection of trace ions in trace samples.

[0053] More specifically, the preferred dimensions of the flow channel layer 1, the detection layer 2, and the electrode layer 3 are: a length of 20-60 mm, a width of 20-50 mm, and a height of 6-15 mm. That is, the reaction cell formed in this example has a small volume, which can be used to detect trace samples. When used with a circulating buffer device as an ion detection system, it can improve detection efficiency and detection sensitivity, and realize the detection of trace ions in trace samples.

[0054] More specifically, as in the example above, parallel detection is achieved through the configuration of multiple flow channels. That is, the number of flow channels in the chip in this example is not limited to two; the first flow channel 11 can include multiple non-intersecting first flow channels, and the second flow channel 12 can also include multiple non-intersecting second flow channels to achieve more parallel detection. More specifically, the depth of the first flow channel 11 and the second flow channel 12 is 1~5mm, which can be set according to actual needs.

[0055] In a specific example, see Figure 4 The penetration detection cavity is elliptical. Specifically, the detection layer 2 is provided with a first penetration detection cavity 21 and a second penetration detection cavity 22. The first flow channel 11 includes a first main flow channel 111 and a branch flow channel 112 and a second branch flow channel 113 connected to the first main flow channel 111. The branch flow channel 112 and the second branch flow channel 113 are respectively connected to the first penetration detection cavity 21 and the second penetration detection cavity 22. The second flow channel 12 includes a second main flow channel 121 and a third branch flow channel 122 and a fourth branch flow channel 123 connected to the second main flow channel 121. The third branch flow channel 122 and the fourth branch flow channel 123 are respectively connected to the first penetration detection cavity 21 and the second penetration detection cavity 22. Specifically, the first flow channel 11 is "F" shaped and the second flow channel 12 is "E" shaped. By connecting the same flow channel with two detection through-cavities, it is possible to simultaneously test two types of ions in the same sample or to perform two electrode testing methods (such as anodic stripping voltammetry and potentiometric analysis) on the same sample, thus improving detection efficiency.

[0056] In a specific example, see Figure 4 The first main flow channel 111 and the second main flow channel 121 are arranged in parallel, and the first branch flow channel 112, the second branch flow channel 113, the third branch flow channel 122 and the fourth branch flow channel 123 are also arranged in parallel. This flow channel arrangement is reasonable in structure, facilitates increasing the number of flow channels and is also easy to manufacture.

[0057] In a specific example, see Figure 4 The flow channel layer 1 also includes a first connecting channel 15 and a second connecting channel 16. The two ends of the first connecting channel 15 are connected to the head ends of the sample inlet channel 13 and the first flow channel 11, respectively. The two ends of the second connecting channel 16 are connected to the head ends of the sample outlet channel 14 and the second flow channel 12, respectively. More specifically, the sample inlet channel 13 and the sample outlet channel 14 are arranged in parallel and parallel to the upper surface of the flow channel layer 11, while the first connecting channel and the second connecting channel are arranged in parallel and perpendicular to the upper surface of the flow channel layer 11. This design makes efficient use of the spatial structure of the flow channel layer 1 to avoid interference between the channels.

[0058] In a specific example, see Figure 5The lower surface of the flow channel layer 1 is provided with an inlay groove 17 for accommodating the detection layer 2. The first flow channel 11 and the second flow channel 12 are located at the bottom of the inlay groove 17, which facilitates the high integration of the chip structure.

[0059] In a specific example, see Figure 4 The flow channel layer 1, detection layer 2, and electrode layer 3 are detachably connected. Specifically, the microfluidic chip also includes several connectors. Each of the flow channel layer 1, detection layer 2, and electrode layer 3 has several corresponding fixing holes 18, and each connector is detachably connected to each fixing hole 18. The connectors are, for example, bolts, which are easy to assemble and disassemble / replace.

[0060] In a specific example, see Figure 6 The substrate of electrode layer 3 can be a printed circuit board, PET, or ceramic. The detection electrode assembly includes a working electrode, a counter electrode, and a reference electrode. Electrode layer 3 has a working electrode mounting hole 31, a counter electrode mounting hole 32, and a reference electrode mounting hole 33. Specifically, depending on the sample being tested, the working electrode can be prepared from a specific material, such as gold, platinum, glassy carbon, or boron-doped diamond. The surface of the working electrode can be specifically modified to obtain higher detection sensitivity and selectivity. The counter electrode 15 can be a gold electrode, a platinum electrode, or a carbon / graphite electrode, and the reference electrode is a silver / silver chloride electrode. All three electrodes are connected to an electrochemical workstation or a dedicated detection device.

[0061] In some specific examples, the materials for the flow channel layer 1 and the detection layer 2 are selected from polydimethylsiloxane, polymethyl methacrylate, or polycarbonate. The connection method between the flow channel layer 1 and the detection layer 2 is selected from photocurable UV adhesive bonding, epoxy adhesive bonding, or plasma bonding. That is, the microfluidic chip for ion detection in this example features low material and process costs, highly integrated structure, simple assembly, easy disassembly and replacement, and easy mass production. It can be used as a disposable consumable, and the detection process and detection time are simplified by pre-modifying electrodes, pre-calibrating, and pre-filling the detection cell with standards.

[0062] Example 2

[0063] See Figure 1 This example provides an ion detection system, including a microfluidic chip 100 and a circulation buffer device. The circulation buffer device includes a circulation pump 201 and a first circulation line 202 and a second circulation line 203 connected to the circulation pump 201. The first circulation line 202 is connected to the sample inlet channel 13, and the second circulation line 203 is connected to the sample outlet channel 14. Using a small-volume reaction cell in conjunction with a circulation buffer device as an ion detection system can improve detection efficiency and sensitivity, enabling the detection of trace ions in minute samples.

[0064] Specifically, the ion detection system also includes a sample inlet tube 301 and a control valve 302. The sample inlet tube 301 is connected to the first circulation line 201, and the control valve 302 is located in the sample inlet tube 301. The control valve 302 can be a common check valve to prevent the sample to be tested from flowing back into the first circulation line 201 through the sample inlet tube 301.

[0065] Application Example 1

[0066] Using the ion detection system described in Example 2, and following the requirements of anodic stripping voltammetry, the standard (lead nitrate solution) was sequentially injected into the multichannel microfluidic chip via injection tube 301, and the circulation buffer was activated to purge air from the circulation system. During the enrichment and dissolution steps in the anodic stripping voltammetry detection process, the circulation pump can also be activated to improve enrichment and detection efficiency and suppress concentration polarization. Finally, the lead ion concentration was obtained using an electrochemical workstation, and the test results are as follows: Figure 7 .

[0067] Application Example 2

[0068] Using the ion detection system described in Example 2, and following the requirements of potentiometric analysis, the standard (potassium chloride solution) was sequentially injected into the multichannel microfluidic chip via injection tube 301, and the circulation buffer device was activated to remove air from the circulation system. Finally, the chloride ion concentration was detected and obtained using an electrochemical workstation, and the test results are as follows: Figure 8 As shown.

[0069] As described in Application Examples 1 and 2, the microfluidic chip and ion detection system of this application are suitable for testing ions in samples by anodic stripping voltammetry and potentiometric analysis.

[0070] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. An ion detection system, characterized in that, Includes a microfluidic chip (100) and a circulating buffer device; The microfluidic chip (100) comprises, from top to bottom, a channel layer (1), a detection layer (2) and an electrode layer (3); The lower surface of the flow channel layer (1) is provided with a first flow channel (11) and a second flow channel (12) that do not intersect each other. The detection layer (2) is provided with at least one through detection cavity, and in the assembled state, the first flow channel (11) and the second flow channel (12) are both partially connected to the through detection cavity; The electrode layer (3) is provided with a detection electrode assembly, and in the assembled state, the detection electrode assembly is located inside the through detection cavity, and the detection electrode assembly is connected to an external detection device; The flow channel layer (1) is further provided with an inlet flow channel (13) and an outlet flow channel (14). One end of the inlet flow channel (13) is connected to the first flow channel (11), and the other end is connected to a circulation buffer device. One end of the outlet flow channel (14) is connected to the second flow channel (12), and the other end is connected to a circulation buffer device. The circulating buffer device includes a circulating pump (201) and a first circulating pipeline (202) and a second circulating pipeline (203) connected to the circulating pump (201). The first circulating pipeline (202) is connected to the sample inlet channel (13), and the second circulating pipeline (203) is connected to the sample outlet channel (14). The lower surface of the flow channel layer (1) is provided with an inlay groove (17) for accommodating the detection layer (2); the first flow channel (11) and the second flow channel (12) are located at the bottom of the inlay groove (17).

2. The ion detection system according to claim 1, characterized in that, The detection layer (2) is provided with a first through detection cavity (21) and a second through detection cavity (22); The first flow channel (11) includes a first main flow channel (111) and a branch flow channel (112) and a second branch flow channel (113) connected to the first main flow channel (111). The branch flow channel (112) and the second branch flow channel (113) are respectively connected to the first penetration detection cavity (21) and the second penetration detection cavity (22). The second flow channel (12) includes a second main flow channel (121) and a three-branch flow channel (122) and a four-branch flow channel (123) connected to the second main flow channel (121). The three-branch flow channel (122) and the four-branch flow channel (123) are respectively connected to the first penetration detection cavity (21) and the second penetration detection cavity (22).

3. The ion detection system according to claim 2, characterized in that, The first main flow channel (111) and the second main flow channel (121) are arranged in parallel; The first branch flow channel (112), the second branch flow channel (113), the third branch flow channel (122), and the fourth branch flow channel (123) are all arranged in parallel.

4. The ion detection system according to claim 1, characterized in that, The flow channel layer (1) is further provided with a first connecting channel (15) and a second connecting channel (16); the two ends of the first connecting channel (15) are respectively connected to the head end of the sample inlet flow channel (13) and the first flow channel (11), and the two ends of the second connecting channel (16) are respectively connected to the head end of the sample outlet flow channel (14) and the second flow channel (12).

5. The ion detection system according to claim 4, characterized in that, The inlet and outlet channels are arranged in parallel and are parallel to the upper surface of the channel layer (1); the first connecting channel and the second connecting channel are arranged in parallel and are perpendicular to the upper surface of the channel layer (1).

6. The ion detection system according to claim 1, characterized in that, It also includes at least one of the following technical features: a1) The flow channel layer (1), detection layer (2) and electrode layer (3) are detachably connected; a2) The detection electrode assembly includes a working electrode, a counter electrode and a reference electrode, and the electrode layer (3) is provided with a working electrode mounting hole (31), a counter electrode mounting hole (32) and a reference electrode mounting hole (33). a3) The materials of the flow channel layer (1) and the detection layer (2) are selected from one of polydimethylsiloxane, polymethyl methacrylate or polycarbonate; a4) The connection method between the flow channel layer (1) and the detection layer (2) is selected from photocurable UV adhesive bonding, epoxy adhesive bonding or plasma bonding; a5) The depth of the first flow channel (11) and the second flow channel (12) is 1~5mm; a6) The penetration detection cavity is elliptical; a7) The substrate of the electrode layer (3) can be a printed circuit board, PET or ceramic.

7. The ion detection system according to claim 6, characterized in that, In technical feature a1), the microfluidic chip also includes several connectors; the flow channel layer (1), the detection layer (2) and the electrode layer (3) are each provided with several corresponding fixing holes (18), and each connector is detachably connected to each fixing hole (18).

8. The ion detection system according to claim 1, characterized in that, It also includes an injection tube (301) and a control valve (302); the injection tube (301) is connected to the first circulation pipeline (202), and the control valve (302) is located in the injection tube (301).

9. The use of the ion detection system as described in any one of claims 1 to 8 in ion detection.

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