Integrated microsensor for detecting various heavy metals

Abstract

The invention provides an integrated multi-heavy metal detection microsensor which can be applied to the technical field of water quality detection sensors. The sensor comprises a substrate, a thin-layer detection cavity structure, N functionalized electrode pairs, a common counter electrode and a common reference electrode, and any one functionalized electrode pair, the common counter electrode and the common reference electrode form a four-electrode system; the thin-layer detection cavity structure comprises a groove, a sample inlet and a sample outlet; a cavity is formed between the groove and the substrate; a sample to be detected flows into the cavity from the sample inlet and flows out from the sample outlet; one end of the four-electrode system is located in the cavity. A plurality of four-electrode systems with micro-area pH regulation and control capability are prepared at different positions of the detection pool, so that the effect of presenting different pH solution environments in different micro-areas in the same detection pool is realized, and the simultaneous detection of the concentrations of various heavy metal pollutants in the same detection pool is realized.

Description

Technical Field

[0001] The present disclosure relates to the technical field of water quality detection sensors, and in particular to an integrated multi-heavy metal detection microsensor. Background Art

[0002] Heavy metals are those with high atomic weight and density exceeding 4.5 g / cm 3 Heavy metal elements, common heavy metal elements in natural water bodies mainly include zinc (Zn), lead (Pb), cadmium (Cd), mercury (Hg), copper (Cu), chromium (Cr) and nickel (Ni). In addition, some metalloid elements, such as arsenic (As), are usually classified as heavy metals due to their toxicity in the environment and negative impact on the ecosystem. Heavy metals are highly toxic in trace amounts in water bodies, and multiple heavy metal pollutants usually exist at the same time. Once environmental water bodies are contaminated by heavy metals, they are often sudden, urgent and persistent. If not handled in time, they will cause long-term and difficult-to-eliminate damage to the natural environment and ecosystem. Therefore, on-site rapid and accurate detection of the concentration of heavy metal ions in the water environment is of great significance for environmental protection and pollution prevention and control.

[0003] At present, there are many methods for detecting the content of heavy metals in water. Conventional methods include atomic absorption spectroscopy, atomic emission spectroscopy, atomic fluorescence spectroscopy and inductively coupled plasma mass spectrometry. Although these methods have high detection accuracy, they often rely on expensive and sophisticated large-scale experimental instruments, and the operation process is cumbersome and requires professional personnel to carry out. They can only be carried out in a laboratory environment, and it is difficult to achieve rapid and simultaneous detection of multiple heavy metal ions. With the development of materials science and the advancement of analytical detection technology, researchers have explored new methods based on principles such as fluorescence analysis, colorimetry and electrochemical analysis, which can also achieve more efficient and practical heavy metal detection applications. Among them, electrochemical analysis has the advantages of low cost, simple operation, high sensitivity and short time consumption. It has become an important development direction for heavy metal ion detection in recent years and is considered to be a rapid detection method for heavy metals suitable for field applications. At present, electrochemical methods are used to detect heavy metal ions in water, usually using electrochemical stripping voltammetry, that is, a certain amount of target in the solution is deposited on the surface of the sensor sensitive electrode by electrochemical reduction / oxidation at a certain potential, and then the deposited target is oxidized / reduced by voltammetry. The type and concentration of heavy metals can be detected based on the dissolution peak potential and peak current intensity of the sediment. The heavy metal detection sensor based on this principle is the electrochemical heavy metal detection sensor.

[0004] Based on the limitation of the detection principle, under the existing technical conditions, when using electrochemical stripping voltammetry to detect heavy metals in water, for different heavy metal elements, it is usually necessary to construct a specific solution environment during testing. For example, for water samples containing heavy metals such as mercury, arsenic, and chromium, when using stripping voltammetry for detection, it is necessary to acidify the water sample to be tested and the sample solution serving as the standard. The required degree of acidification varies depending on the type of heavy metal ions and the detection electrode used. When using a gold electrode to detect chromium, it is necessary to use acetic acid to acidify the pH value of the test solution to pH=5 in order to obtain a well-shaped stripping voltammetry curve, thereby achieving more accurate and sensitive chromium detection; similar situations exist for mercury and arsenic detection solutions. When using a gold electrode to detect mercury, it is necessary to use high-concentration hydrochloric acid to acidify the pH value of the test solution to pH=1 in order to obtain better electrochemical detection results; and when using a gold electrode to detect arsenic, it is necessary to acidify the pH value of the test solution to a high-strength acid state of pH=0. Based on this constraint, existing commercial electrochemical heavy metal detectors usually need to prepare a variety of different types of acidified test solutions to meet the detection needs of various types of heavy metal pollutants that may exist. This complex and hazardous test solution acidification requirement not only increases the operation steps and increases the detection cost, but also brings additional detection operation processes, and naturally increases the possibility of errors and processing errors. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In order to solve the problems existing in the prior art when detecting multiple heavy metal ions in water at the same time, the embodiments of the present invention provide an integrated multiple heavy metal detection microsensor. By configuring multiple four-electrode systems with micro-area pH control capabilities at different positions in the detection pool, the effect of presenting different pH solution environments in different microscopic areas in the same detection pool is achieved. There is no need to replace the test solution or add additional acidifying reagents, thereby achieving simultaneous detection of the concentrations of multiple heavy metal pollutants in the same detection pool.

[0007] (II) Technical solution

[0008] In view of the above problems, an embodiment of the present disclosure provides an integrated multi-heavy metal detection microsensor.

[0009] According to the first aspect of the present disclosure, an integrated multi-heavy metal detection microsensor is provided, comprising: a substrate, a thin-layer detection cavity structure, N functionalized electrode pairs, a common counter electrode, and a common reference electrode, wherein N is an integer greater than or equal to 2; any one of the functionalized electrode pairs and the common counter electrode and the common reference electrode form a four-electrode system; the thin-layer detection cavity structure comprises a groove, an injection port, and an outlet; a cavity is formed between the groove of the thin-layer detection cavity structure and the substrate; the sample to be detected flows into the cavity from the injection port and flows out from the outlet; one end of the functionalized electrode pair, the common reference electrode, and the common counter electrode is located inside the cavity.

[0010] In some exemplary embodiments, at least one functionalized electrode pair includes a pH controlling electrode and a detection working electrode, wherein the pH controlling electrode and the detection working electrode form a circular concentric array and are distributed in a double helix structure; the pH controlling electrode is used to control the pH value of the solution in the vicinity of the electrode, and the pH value of the solution is related to the potential or current applied to the pH controlling electrode; and the distance between the detection working electrode and the pH controlling electrode does not exceed the range in which the pH controlling electrode can control the pH value of the solution.

[0011] In some exemplary embodiments, each functionalized electrode pair forms a pH control micro-zone within its pH control range, and the intensity of the hydrolysis reaction in the pH control micro-zone is controlled by configuring scanning voltages or currents of different sizes on the pH control electrodes, so as to obtain pH control micro-zones with different pH values ​​in the same detection pool, thereby constructing different solution pH microenvironments for the detection of different heavy metal ions.

[0012] In some exemplary embodiments, at least one of the following features is included: the height of the cavity is 50μm-400µm; the electrode width of the detection working electrode is 2μm-20µm; the electrode width of the pH control electrode is 2μm-20µm; the spacing between the pH control electrode and the detection working electrode is 1 to 5 times the width of the pH control electrode.

[0013] In some exemplary embodiments, the structure of the common counter electrode is a ring structure; the electrode width of the common counter electrode is 1mm-5mm; the distance between the inner ring of the common counter electrode and the functionalized electrode pair is 5mm-25mm; the area of ​​the common counter electrode is greater than 1000 times the area of ​​the detection working electrode.

[0014] In some exemplary embodiments, the common reference electrode includes an on-chip integrated Ag / AgCl solid-state reference electrode, wherein the preparation method of Ag / AgCl includes: preparing it by chlorinating a metal silver film in an acidic solution environment; or preparing it by coating Ag / AgCl slurry on a gold base electrode.

[0015] In some exemplary embodiments, the detection working electrode, the common counter electrode and the common reference electrode form a micro-electrochemical three-electrode system, which can perform stripping voltammetric scanning to achieve the identification and detection of heavy metal ions; and the pH control electrode, the common counter electrode and the common reference electrode form an electrochemical pH control system, which performs electrochemical constant current and / or constant voltage scanning to maintain the hydrolysis reaction in the thin layer detection cavity, so as to achieve the regulation of the pH value of the solution in the detection area of ​​the detection working electrode in the functionalized electrode pair where the pH control electrode is located.

[0016] In some exemplary embodiments, the material of the substrate includes one of silicon or glass. When the material of the substrate is silicon, an insulating film is grown on the silicon surface, and the material of the insulating film includes silicon oxide and silicon nitride; the material of the pH controlling electrode includes gold; the material of the common counter electrode includes gold; the material of the detection working electrode includes gold; and the surfaces of the pH controlling electrode, the common counter electrode, the detection working electrode and the common reference electrode are covered with an insulating layer, and the material of the insulating layer includes one of silicon oxide, silicon nitride, a composite film composed of silicon oxide and silicon nitride, or a photoresist.

[0017] In some exemplary embodiments, whether the surface of the detecting working electrode needs to be modified by a material is related to the type of target heavy metal to be detected, wherein when the surface of the detecting working electrode needs to be modified by a material, the type of the modifying material is related to the type of target heavy metal to be detected.

[0018] In some exemplary embodiments, at least one of the following features is included: a thin-layer detection cavity structure is prepared by using a PDMS material using a demolding process; the thin-layer detection cavity structure and the substrate are packaged and formed by an oxygen plasma bonding process; and the preparation method of the detection working electrode, the pH regulating electrode, the common counter electrode and the common reference electrode includes one of a magnetron sputtering method or an electron beam evaporation method.

[0019] (III) Beneficial effects

[0020] It can be seen from the above technical solutions that the integrated multiple heavy metal detection microsensor provided by the embodiments of the present disclosure has at least one of the following beneficial effects:

[0021] (1) By configuring multiple four-electrode systems with micro-area pH control capabilities at different locations in the detection pool, the effect of presenting different pH solution environments in different microscopic areas in the same detection pool can be achieved. There is no need to replace the test solution or add additional acidifying reagents, and the concentrations of multiple heavy metal pollutants can be detected simultaneously in the same detection pool.

[0022] (2) By adjusting the potential or current applied to the pH control electrode, the pH value of the micro-area solution in the thin layer detection cell is controlled, thereby avoiding the acidification operation step required for the conventional electrochemical stripping voltammetry detection of heavy metals.

[0023] (3) For different heavy metal ions, different pH values ​​can be adjusted in different micro-areas by changing the configuration potential or current parameters, and the detection working electrodes of different materials in different pH-controlled micro-areas can be combined to achieve the simultaneous detection of multiple heavy metal ions in the same detection cell.

[0024] (4) The process of using electrochemical methods to detect heavy metals has been greatly simplified, which is of great significance for the detection of heavy metal concentrations in water. It also has application value in the use of electrochemical sensors to realize on-site in-situ analysis of heavy metals in water and the simultaneous detection of multiple heavy metals. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above contents and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0026] Figure 1 The overall structure of an integrated multi-heavy metal detection microsensor according to an embodiment of the present disclosure is schematically shown;

[0027] Figure 2 Schematically shows an exploded structural diagram of an integrated multi-heavy metal detection microsensor according to an embodiment of the present disclosure; and

[0028] Figure 3 The plan distribution diagram of an integrated multi-heavy metal detection microsensor according to an embodiment of the present disclosure is schematically shown.

[0029] Reference numerals:

[0030] 1-thin layer detection cavity structure; 11-inlet; 12-outlet; 13-groove; 2-substrate; 3-cavity; 4-functionalized electrode pair; 41-pH control electrode; 42-detection working electrode; 5-common counter electrode; 6-common reference electrode. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present disclosure.

[0032] Figure 1 The overall structure of an integrated multi-heavy metal detection microsensor according to an embodiment of the present disclosure is schematically shown; Figure 2Schematically shows an exploded structural diagram of an integrated multi-heavy metal detection microsensor according to an embodiment of the present disclosure; and Figure 3 The plan distribution diagram of an integrated multi-heavy metal detection microsensor according to an embodiment of the present disclosure is schematically shown.

[0033] like Figure 1 and Figure 2 As shown, according to an embodiment of the present disclosure, an integrated multi-heavy metal detection microsensor includes: a substrate 2, a thin layer detection cavity structure 1, N functionalized electrode pairs 4, a common counter electrode 5, and a common reference electrode 6, wherein N is an integer greater than or equal to 2; any one of the functionalized electrode pairs 4 and the common counter electrode 5 and the common reference electrode 6 form a four-electrode system; the thin layer detection cavity structure 1 includes a groove 13, an injection port 11, and an outlet port 12; a cavity 3 is formed between the groove 13 of the thin layer detection cavity structure 1 and the substrate 2; the sample to be detected flows into the cavity 3 from the injection port 11 and flows out from the outlet port 12; one end of the N functionalized electrode pairs 4, the common reference electrode 6, and the common counter electrode 5 is located inside the cavity 3. Figure 1 and Figure 2 In the figure, N is 4. It is understandable that N may also be other integers greater than 2.

[0034] By configuring multiple identical four-electrode systems with micro-area pH control capabilities at different positions in the detection pool, the effect of presenting different pH solution environments in different microscopic areas in the same detection pool can be achieved. There is no need to replace the test solution or add additional acidifying reagents, and the concentrations of multiple heavy metal pollutants can be detected simultaneously in the same detection pool.

[0035] In some exemplary embodiments, at least one functionalized electrode pair 4 includes a pH control electrode 41 and a detection working electrode 42, wherein the pH control electrode 41 and the detection working electrode 42 form a circular concentric array and are distributed in a double helix structure, see Figure 3 ; The pH control electrode 41 is used to control the pH value of the solution, and the pH value of the solution is related to the potential or current applied to the pH control electrode 41; and the distance between the detection working electrode 42 and the pH control electrode 41 does not exceed the range in which the pH control electrode 41 can control the pH value of the solution.

[0036] In some exemplary embodiments, each functionalized electrode pair 4 forms a pH control micro-region within its pH control range, and by configuring scanning voltages or currents of different sizes on the pH control electrode 41, the intensity of the hydrolysis reaction in the pH control micro-region is controlled, so that pH control micro-regions with different pH values ​​are obtained in the same detection pool, and different solution pH microenvironments are constructed for the detection of different heavy metal ions. The area where the pH control electrode 41 and the detection working electrode 42 are located is the pH control micro-region. By adjusting the potential or current applied to the pH control electrode 41, the pH value of the micro-region solution in the thin layer detection pool is controlled, thereby avoiding the acidification operation steps required for the detection of heavy metals by conventional electrochemical stripping voltammetry. For different heavy metal ions, different micro-regions can be regulated to present different pH values ​​by changing the configuration potential or current parameters, and the detection working electrodes 42 of different materials in different pH control micro-regions can be combined to achieve simultaneous detection of multiple heavy metal ions in the same detection pool.

[0037] In some exemplary embodiments, the detection working electrode 42, the common counter electrode 5 and the common reference electrode 6 form a micro-electrochemical three-electrode system, which can perform stripping voltammetric scanning to achieve the identification and detection of heavy metal ions; and the pH control electrode 41, the common counter electrode 5 and the common reference electrode 6 form an electrochemical pH control system, which performs electrochemical constant current and / or constant voltage scanning to maintain the hydrolysis reaction in the thin layer detection cavity, so as to achieve the control of the pH value of the solution in the detection area of ​​the detection working electrode 42 in the functionalized electrode pair 4 where the pH control electrode 41 is located.

[0038] For example, a microsensor is prepared by using micromachining (MEMS) technology, and two or more four-electrode systems with micro-area pH control capabilities are integrated in a thin-layer detection cavity to form two or more pH control micro-areas that can work independently. Each four-electrode system includes two functionalized electrodes, which include a pH control electrode 41 and a detection working electrode 42, as well as a common counter electrode 5 and a common reference electrode 6 shared with other four-electrode systems. Among them, the pH control electrode 41 and the detection working electrode 42 are adjacent to each other and distributed in a double helix structure; the area where the pH control electrode 41 and the detection working electrode 42 are located is the pH control micro-area. The pH control electrode 41, the common counter electrode 5 and the common solid reference electrode constitute an electrochemical pH control system, and perform electrochemical constant current / constant voltage scanning to maintain the hydrolysis reaction in the thin-layer detection cavity, so as to achieve the control of the solution pH value in the detection working electrode 42 area adjacent to the pH control electrode 41. By configuring scanning voltages or currents of different sizes on the pH control electrode 41, the intensity of the hydrolysis reaction in the pH control micro-area is controlled, thereby realizing and maintaining the difference in pH values ​​in different micro-area solution environments in the same detection pool, and constructing different solution pH microenvironments for the detection of different heavy metal ions. The detection working electrode 42, the common counter electrode 5 and the common reference electrode 6 form a micro-electrochemical three-electrode system to perform electrochemical stripping voltammetric scanning to achieve the identification and detection of heavy metal ions. The multiple four-electrode systems integrated in the thin-layer detection cavity each independently perform measurements on a specific category of heavy metal ions, ultimately achieving simultaneous detection of multiple heavy metal ions.

[0039] In some exemplary embodiments, the electrode width of the detection working electrode 42 is 2μm-20µm; the electrode width of the pH control electrode 41 is 2μm-20µm; and the spacing between the pH control electrode 41 and the detection working electrode 42 is 1 to 5 times the width of the pH control electrode 41.

[0040] In some exemplary embodiments, the structure of the common counter electrode 5 is a ring structure; the electrode width of the common counter electrode 5 is 1mm-5mm; the distance between the inner ring of the common counter electrode 5 and the functionalized electrode pair 4 is 5mm-25mm; and the area of ​​the common counter electrode is greater than 1000 times the area of ​​the detection working electrode.

[0041] In some exemplary embodiments, the material of the substrate 2 includes one of silicon or glass. When the material of the substrate 2 is silicon, an insulating film is grown on the silicon surface, and the material of the insulating film includes silicon oxide and silicon nitride; the material of the pH control electrode 41 includes gold; the material of the common counter electrode 5 includes gold; the material of the detection working electrode 42 includes gold; and the surfaces of the pH control electrode 41, the common counter electrode 5, the detection working electrode 42, and the common reference electrode 6 are covered with an insulating layer, and the material of the insulating layer includes one of silicon oxide, silicon nitride, a composite film composed of silicon oxide and silicon nitride, or a photoresist. Optionally, the preparation method of the detection working electrode 42, the pH control electrode 41, the common reference electrode 6, and the common counter electrode 5 includes one of a magnetron sputtering method or an electron beam evaporation method.

[0042] In some exemplary embodiments, whether the surface of the detection working electrode 42 needs to be modified with a material is related to the type of target heavy metal to be detected, wherein when the surface of the detection working electrode 42 needs to be modified with a material, the type of the modified material is related to the type of target heavy metal to be detected. For example, depending on the type of target heavy metal to be detected, the surface of the detection working electrode 42 of different pH-controlled micro-regions does not need to be modified or is modified with different sensitive materials. These sensitive materials include but are not limited to nano-gold, nano-bismuth, etc., as well as carbon materials such as glassy carbon, graphene, and carbon nanotubes.

[0043] In some exemplary embodiments, the common reference electrode 6 includes an on-chip integrated Ag / AgCl solid-state reference electrode, wherein the preparation method of Ag / AgCl includes: preparing it by chlorinating a metal silver film in an acidic solution environment; or preparing it by coating Ag / AgCl slurry on a gold substrate 22 electrode.

[0044] In some exemplary embodiments, the thin layer detection cavity structure 1 is made of PDMS material (polydimethylsiloxane, a silicone polymer material composed of alternating silicon and oxygen atoms and carrying methyl groups. These methyl groups give PDMS good plasticity and elasticity, and its physical and chemical properties can be changed by adjusting the molecular weight and cross-linking degree) using a demolding process, and the thin layer detection cavity structure 1 and the substrate 2 are encapsulated and formed by an oxygen plasma bonding process. Optionally, the height of the cavity 3 is 50μm-400µm.

[0045] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. An integrated multi-heavy metal detection microsensor, characterized in that: include: Substrate, thin layer detection cavity structure, N functionalized electrode pairs, common counter electrode, common reference electrode, Wherein, N is an integer greater than or equal to 2; Any one of the functionalized electrode pairs, the common counter electrode and the common reference electrode form a four-electrode system; The thin layer detection cavity structure includes a groove, an injection port and an output port; A cavity is formed between the groove of the thin layer detection cavity structure and the substrate; The sample to be detected flows into the cavity from the sample inlet and flows out from the sample outlet; The functionalized electrode pair, the common reference electrode and one end of the common counter electrode are located inside the cavity.

2. The integrated multi-heavy metal detection microsensor according to claim 1, characterized in that: At least one of the functionalized electrode pairs includes a pH control electrode and a detection working electrode, Wherein, the pH regulating electrode and the detection working electrode form a circular concentric array and are distributed in a double helix structure; The pH regulating electrode is used to regulate the pH value of a solution in an area adjacent to the electrode, and the pH value of the solution is related to the potential or current applied to the pH regulating electrode; and The distance between the detection working electrode and the pH regulating electrode does not exceed the range in which the pH regulating electrode can regulate the pH value of the solution.

3. The integrated multi-heavy metal detection microsensor according to claim 2, characterized in that: Each of the functionalized electrode pairs forms a pH control micro-region within its pH control range. By configuring scanning voltages or currents of different sizes on the pH control electrodes, the intensity of the hydrolysis reaction in the pH control micro-region is controlled, so that pH control micro-regions with different pH values ​​are obtained in the same detection pool, thereby constructing different solution pH microenvironments for the detection of different heavy metal ions.

4. The integrated multi-heavy metal detection microsensor according to claim 2, characterized in that: Include at least one of the following features: The height of the cavity is 50μm-400µm; The electrode width of the detection working electrode is 2μm-20µm; The electrode width of the pH control electrode is 2μm-20μm; The distance between the pH regulating electrode and the detection working electrode is 1 to 5 times the width of the pH regulating electrode.

5. The integrated multi-heavy metal detection microsensor according to claim 3 is characterized in that: The structure of the common counter electrode is a ring structure; The electrode width of the common counter electrode is 1 mm-5 mm; The distance between the inner ring of the common electrode pair and the functionalized electrode pair is 5 mm to 25 mm; The area of ​​the common counter electrode is 1000 times greater than the area of ​​the detection working electrode.

6. The integrated multi-heavy metal detection microsensor according to claim 2, characterized in that: The common reference electrode comprises an on-chip integrated Ag / AgCl solid-state reference electrode, wherein the preparation method of the Ag / AgCl comprises: Prepared by chlorinating the metallic silver film in an acidic solution environment; or The Ag / AgCl slurry is coated on the base electrode to prepare it.

7. The integrated multi-heavy metal detection microsensor according to claim 2, characterized in that: The detection working electrode, the common counter electrode and the common reference electrode form a micro electrochemical three-electrode system, which can perform electrochemical stripping voltammetric scanning to achieve recognition and detection of heavy metal ions; and The pH control electrode, the common counter electrode and the common reference electrode form an electrochemical pH control system, and perform electrochemical constant current and / or constant voltage scanning to maintain the hydrolysis reaction in a specific area of ​​the thin layer detection cavity, so as to achieve the control of the solution pH value in the detection area of ​​the detection working electrode in the functional electrode pair where the pH control electrode is located.

8. The integrated multi-heavy metal detection microsensor according to any one of claims 2 to 7, characterized in that: The material of the substrate includes one of silicon or glass. When the material of the substrate is silicon, an insulating film is grown on the surface of the silicon. The material of the insulating film includes silicon oxide and silicon nitride. The material of the pH regulating electrode includes gold; The material of the common counter electrode includes gold; The material of the detection working electrode includes gold; and The surfaces of the pH regulating electrode, the common counter electrode, the detection working electrode and the common reference electrode are covered with an insulating layer, and the material of the insulating layer includes one of silicon oxide, silicon nitride, a composite film composed of silicon oxide and silicon nitride, or a photoresist.

9. The integrated multi-heavy metal detection microsensor according to any one of claims 2 to 7, characterized in that: Whether the surface of the detection working electrode needs to be modified by a material is related to the type of target heavy metal to be detected. When the surface of the detection working electrode needs to be modified by a material, the type of the modification material is related to the type of target heavy metal to be detected.

10. The integrated multi-heavy metal detection microsensor according to any one of claims 2 to 7, characterized in that: Include at least one of the following features: The thin layer detection cavity structure is prepared by using PDMS material and a demoulding process; The thin layer detection cavity structure and the substrate are packaged and formed by an oxygen plasma bonding process; and The preparation method of the detection working electrode, the pH regulating electrode, the common counter electrode and the common reference electrode comprises a magnetron sputtering method or an electron beam evaporation method.

Images