Microelectrode structure and sensor

Abstract

The microelectrode structure comprises a flexible substrate and a microelectrode system arranged on the surface of the flexible substrate, the microelectrode system comprises a counter electrode, a working electrode and a reference electrode, and electrode units are horizontally laid on the upper surface and the lower surface of the flexible substrate. The electrode units on the upper surface and the lower surface of the flexible substrate respectively comprise at least one of a counter electrode, a working electrode and a reference electrode, the electrode units on the upper surface of the flexible substrate form a first microelectrode system, and the electrode units on the lower surface of the flexible substrate form a second microelectrode system; or the electrode units on the upper surface and the lower surface of the flexible substrate jointly form a third microelectrode system. The electrodes are manufactured on the front side and the back side of the flexible substrate to form one or two microelectrode systems, maximization of the area of the microelectrode systems is achieved on the limited substrate surface, and the detection precision is improved; double-channel double-substance monitoring, double-channel single-substance monitoring or single-channel single-substance monitoring can be achieved, and functional diversity is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to sensor technical field, more specifically, the utility model relates to a kind of microelectrode structure and sensor. BACKGROUND

[0002] Electrochemical sensor has become the most common means for people to detect body fluid analyte, especially miniature implantable electrochemical biosensor, such as dynamic blood glucose sensor, lactic acid sensor, uric acid sensor, etc., can realize the dynamic monitoring of human body fluid analyte concentration, provide reliable body fluid analyte concentration change data, assist in the prevention and external diagnosis of related diseases.

[0003] Microelectrode is an important structure of electrochemical sensor, which plays a role in signal conversion and transmission. The working principle of electrochemical sensor is to coat sensitive material with specific response to target analyte on the surface of microelectrode. The sensitive material will react specifically when it comes into contact with the target analyte. The microelectrode converts the concentration change of the target analyte in the reaction process into electrical signal such as resistance, current or potential, and outputs it to the external circuit. Usually within a limited concentration range, the converted electrical signal is proportional to the concentration of the target analyte. By analyzing the electrical signal value, qualitative or quantitative analysis of the concentration change of the target analyte can be realized.

[0004] Microelectrode is an electrochemical system including working electrode, counter electrode and reference electrode. The counter electrode and working electrode form a polarization loop and play a role in transmitting electrons. The working electrode and reference electrode form a measurement loop for testing electrochemical reaction process. The potential of the reference electrode is stable and known, and the electrode polarization and other pressure drop can be basically ignored. The potential of the working electrode can be more easily measured through the reference electrode, so that the concentration of the analyte to be analyzed can be more accurately calculated. The surface area of the microelectrode determines the accuracy of the electrochemical sensor in detecting target signal. The larger the surface area of the microelectrode, the larger the contact area between the electrochemical sensor and the target analyte, the stronger the target signal, and the higher the detection accuracy. However, it is necessary to ensure that the overall volume of the electrochemical sensor is as small as possible to meet the non-inductive requirements of implanting into the human body and improve user acceptance. Therefore, how to make a large-area microelectrode on the limited surface of the substrate is a technical problem to be solved by those skilled in the art. UTILITY MODEL CONTENTS

[0005] In view of the deficiencies of the prior art, the utility model innovatively provides a microelectrode structure and sensor. Electrodes are made on both sides of the flexible substrate to form one or two microelectrode systems, which maximizes the area of the microelectrode system on the limited surface of the flexible substrate, improves the detection sensitivity and enhances the detection accuracy of the sensor. It can realize double-channel double-substance monitoring, double-channel single-substance monitoring or single-channel single-substance monitoring, and realize the diversity of functions.

[0006] To achieve the above technical purposes, the utility model provides a first aspect provides a kind of microelectrode structure, including flexible substrate and the microelectrode system of being arranged on the surface of flexible substrate,

[0007] The microelectrode system includes three electrode units, respectively counter electrode, working electrode and reference electrode,

[0008] The upper surface and the lower surface of the flexible substrate are provided with electrode unit, the electrode unit on the upper surface of the flexible substrate includes at least one of counter electrode, working electrode and reference electrode, the electrode unit on the upper surface of the flexible substrate is horizontally tiled distribution on upper surface, the electrode unit on the lower surface of the flexible substrate includes at least one of counter electrode, working electrode and reference electrode, the electrode unit on the lower surface of the flexible substrate is horizontally tiled distribution on lower surface,

[0009] The electrode unit on the upper surface of the flexible substrate constitutes first microelectrode system, the electrode unit on the lower surface of the flexible substrate second microelectrode system, the first microelectrode system and the second microelectrode system are used to monitor same substance or different substance,

[0010] Further, the counter electrode of the first microelectrode system and the counter electrode of the second microelectrode system are symmetrically arranged about the flexible substrate, the working electrode of the first microelectrode system and the working electrode of the second microelectrode system are symmetrically arranged about the flexible substrate, the reference electrode of the first microelectrode system and the reference electrode of the second microelectrode system are symmetrically arranged about the flexible substrate.

[0011] Further, when the electrode unit on the upper surface of the flexible substrate and the electrode unit on the lower surface of the flexible substrate jointly constitute third microelectrode system,

[0012] The number of electrode units on the upper and lower surfaces of the flexible substrate is 3, the electrode unit on one of the upper and lower surfaces of the flexible substrate is counter electrode, and the electrode unit on the other surface is working electrode and reference electrode,

[0013] Alternatively, the number of electrode units on the upper and lower surfaces of the flexible substrate is 4-6, the upper and lower surfaces of the flexible substrate are provided with counter electrode, and at least one working electrode and reference electrode, the same electrode units on the upper surface and the lower surface of the flexible substrate are connected to each other.

[0014] Further, the total area of the counter electrode in the first microelectrode system, the second microelectrode system and the third microelectrode system is greater than the total area of the working electrode, which is greater than the total area of the reference electrode.

[0015] Further, the microelectrode structure further comprises an electrical connection part arranged on the surface of the flexible substrate and a lead wire, the electrical connection part is arranged one-to-one with the electrode unit, and the lead wire is connected with the electrode unit and the corresponding electrical connection part.

[0016] Further, the working electrode is provided with a biological sensitive substance layer on the surface away from the flexible substrate.

[0017] The upper surface of the flexible substrate is provided with a first biological functional layer, and the first biological functional layer covers the electrode unit and the biological sensitive substance layer on the upper surface of the flexible substrate.

[0018] The lower surface of the flexible substrate is provided with a second biological functional layer, and the second biological functional layer covers the electrode unit and the biological sensitive substance layer on the lower surface of the flexible substrate.

[0019] Further, the biological sensitive substance layers on the surfaces of the working electrodes of the first microelectrode system and the second microelectrode system are composed of the same or different biological sensitive substance components.

[0020] Further, the reference electrode comprises a bottom electrode and a chloridizing layer arranged on the surface of the bottom electrode away from the flexible substrate.

[0021] Further, the chloridizing layer is formed by depositing silver on the surface of the bottom electrode away from the flexible substrate and converting part of the silver into silver chloride.

[0022] The second aspect of the utility model provides a sensor, comprising the microelectrode structure of the first aspect.

[0023] The utility model discloses beneficial effects are:

[0024] The microelectrode structure of the utility model makes electrodes on both sides of the flexible substrate, thereby forming one or two microelectrode systems, realizes the maximization of the area of the microelectrode system on the limited surface of the flexible substrate, improves the detection sensitivity and the detection precision of the sensor, can realize double-channel double-substance monitoring, double-channel single-substance monitoring or single-channel single-substance monitoring, and realizes the diversity of functions. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is the front view of the microelectrode structure of the first embodiment of the utility model.

[0026] Figure 2 It is the back view of the microelectrode structure of the first embodiment of the utility model.

[0027] Figure 3is the longitudinal section view of the microelectrode structure of the first embodiment of the utility model. Figure 1 is the longitudinal section view of the microelectrode structure of the second embodiment of the utility model.

[0028] Figure 4 is the front view of the microelectrode structure of the second embodiment of the utility model.

[0029] Figure 5 is the back view of the microelectrode structure of the second embodiment of the utility model.

[0030] Figure 6 is the longitudinal section view of the microelectrode structure of the second embodiment of the utility model.

[0031] Figure 7 is the longitudinal section view of the microelectrode structure of the third embodiment of the utility model.

[0032] Figure 8 is the longitudinal section view of the microelectrode structure of the fourth embodiment of the utility model.

[0033] Figure 9 is the longitudinal section view of the microelectrode structure of the fifth embodiment of the utility model.

[0034] Figure 10 is the longitudinal section view of the microelectrode structure of the sixth embodiment of the utility model.

[0035] Figure 11 is the longitudinal section view of the microelectrode structure of the seventh embodiment of the utility model.

[0036] Figure 12 is the longitudinal section view of the microelectrode structure of the eighth embodiment of the utility model.

[0037] Figure 13 is the flow chart of the manufacturing method of the microelectrode structure of the embodiment of the utility model.

[0038] Figure 14 is the specific flow chart of step S2 of the embodiment of the utility model.

[0039] Figure 15 is the specific flow chart of step S2 of another embodiment of the utility model.

[0040] Figure 16 is the manufacturing flow chart of the microelectrode structure of the seventh embodiment of the utility model.

[0041] Figure 17 is another manufacturing flow chart of the microelectrode structure of the seventh embodiment of the utility model.

[0042] Figure 18 is the manufacturing flow chart of the microelectrode structure of the eighth embodiment of the utility model.

[0043] In the drawings,

[0044] 1, flexible substrate; 2, counter electrode; 3, working electrode; 4, reference electrode; 41, bottom electrode; 42, chlorinated layer; 42', silver metal layer; 5, electrical connection part; 6, lead wire; 7, biological sensitive substance layer; 81, first biological functional layer; 82, second biological functional layer; 9, rigid substrate; 10, temporary bonding layer; 11, first microelectrode system; 22, second microelectrode system; 33, third microelectrode system. DETAILED DESCRIPTION

[0045] The microelectrode structure and sensor provided by the utility model are explained and described in detail below in combination with the drawings of the specification.

[0046] The embodiment specifically discloses a microelectrode structure, as Figures 1-10 shown, comprising a flexible substrate 1 and a microelectrode system arranged on the surface of the flexible substrate 1, the microelectrode system comprising three electrode units, namely a counter electrode 2, a working electrode 3 and a reference electrode 4. The upper surface and the lower surface of the flexible substrate 1 are both provided with electrode units, the electrode units on the upper surface of the flexible substrate 1 comprising at least one of the counter electrode 2, the working electrode 3 and the reference electrode 4, the electrode units on the upper surface of the flexible substrate 1 being horizontally laid out on the upper surface, the electrode units on the lower surface of the flexible substrate 1 comprising at least one of the counter electrode 2, the working electrode 3 and the reference electrode 4, the electrode units on the lower surface of the flexible substrate 1 being horizontally laid out on the lower surface. The upper surface of the flexible substrate 1 can be provided with 1-3 electrode units, the lower surface of the flexible substrate 1 can be provided with 1-3 electrode units, and when multiple electrode units are arranged on the same surface, the types of the electrode units are different.

[0047] In some embodiments, as Figures 1-3 shown, the electrode units on the upper surface of the flexible substrate 1 constitute a first microelectrode system 11, the electrode units on the lower surface of the flexible substrate 1 constitute a second microelectrode system 22, the three electrode units on the upper surface of the flexible substrate 1 are the counter electrode 2, the working electrode 3 and the reference electrode 4, and the three electrode units on the lower surface of the flexible substrate 1 are the counter electrode 2, the working electrode 3 and the reference electrode 4. The positions and areas of the same electrode units on the upper and lower surfaces of the flexible substrate 1 can be the same or different, the same electrode units on the upper and lower surfaces of the flexible substrate 1 can be arranged back to back, staggered or partially staggered, and the positions and areas of the electrode units can be arranged according to the monitoring needs.

[0048] The first microelectrode system 11 and the second microelectrode system 22 are used to monitor the same or different substances. When the first microelectrode system 11 and the second microelectrode system 22 monitor the same substance, the microelectrode structure can perform dual-channel monitoring of the same target analyte. The monitoring information from the first microelectrode system 11 and the second microelectrode system 22 can achieve complementary correction or redundant monitoring, thereby obtaining more accurate monitoring data. Even if one microelectrode system is damaged or malfunctions, the other microelectrode system can still perform the monitoring function, making the microelectrode structure more reliable and longer in service life. When the first microelectrode system 11 and the second microelectrode system 22 are used to monitor different substances, two different target analytes can be monitored, realizing dual-substance dual-channel monitoring, providing richer monitoring information and greater practicality.

[0049] Preferably, the counter electrode 2 of the first microelectrode system 11 and the counter electrode 2 of the second microelectrode system 22 are symmetrically arranged about the flexible substrate 1; the working electrode 3 of the first microelectrode system 11 and the working electrode 3 of the second microelectrode system 22 are symmetrically arranged about the flexible substrate 1; and the reference electrode 4 of the first microelectrode system 11 and the reference electrode 4 of the second microelectrode system 22 are symmetrically arranged about the flexible substrate 1. That is, similar electrode units are arranged back-to-back on the flexible substrate 1 with the same area, allowing the two microelectrode systems to monitor the same substance and target analytes at the same location, resulting in more accurate monitoring data and reduced errors.

[0050] In some embodiments, such as Figures 4-10 As shown, the electrode units on the upper surface of the flexible substrate 1 and the electrode units on the lower surface of the flexible substrate 1 together constitute the third microelectrode system 33, which is used to realize single-channel single-substance monitoring.

[0051] Optional, such as Figures 4-6 As shown, the flexible substrate 1 has three electrode units on its upper and lower surfaces. One electrode unit, designated as the counter electrode 2, is disposed on one of the upper and lower surfaces of the flexible substrate 1, while two electrode units, designated as the working electrode 3 and the reference electrode 4, are disposed on the other surface. Compared to distributing the three electrode units of the microelectrode system on a single side of the flexible substrate 1, this embodiment distributes the three electrode units of the microelectrode system on both the front and back surfaces of the flexible substrate 1, thereby increasing the area of ​​the microelectrode system. Furthermore, the counter electrode 2 in the third microelectrode system 33 has the largest area, thus optimizing the performance of the microelectrode structure and improving detection sensitivity.

[0052] Optional, such as Figures 7-10As shown, the number of electrode units on the upper and lower surfaces of the flexible substrate 1 is 4 to 6. Both the upper and lower surfaces of the flexible substrate 1 are provided with counter electrodes 2, at least one working electrode 3, and at least one reference electrode 4. The similar electrode units on the upper and lower surfaces of the flexible substrate 1 are interconnected, and the electrode units on the upper and lower surfaces of the flexible substrate 1 together constitute a microelectrode system for monitoring a target analyte, achieving single-substance single-channel monitoring. In this embodiment, the similar electrode units on the upper and lower surfaces of the flexible substrate 1 are connected as a whole to achieve the corresponding function. This is equivalent to distributing one electrode unit of the microelectrode system on the upper and lower surfaces of the flexible substrate 1. Compared to setting three electrode units of the microelectrode system on a single side of the flexible substrate 1, this increases the area of ​​such electrode units and reduces the area restriction of such electrode units on other electrode units, thereby increasing the area of ​​other electrode units and increasing the overall area of ​​the microelectrode system. Furthermore, the presence of counter electrodes 2 on both the upper and lower surfaces of the flexible substrate 1 maximizes the area of ​​the counter electrodes 2 in the third microelectrode system 33, optimizing the performance of the microelectrode structure and improving detection sensitivity.

[0053] like Figure 7 As shown, the flexible substrate 1 has four electrode units on its upper and lower surfaces. One electrode unit, the counter electrode 2, is disposed on one side of the flexible substrate 1. Three electrode units, namely the counter electrode 2, the working electrode 3, and the reference electrode 4, are disposed on the other side of the flexible substrate 1. The counter electrodes 2 on the upper and lower surfaces are interconnected as a whole. Compared with the prior art, which places the three electrode units of the microelectrode system on a single side of the flexible substrate 1, this embodiment of the application distributes the counter electrodes 2 of the microelectrode system on the upper and lower surfaces of the flexible substrate 1, which increases the area of ​​the counter electrodes 2 and reduces the restriction of the counter electrodes 2 on the area of ​​the other two electrode units. As a result, the area of ​​the other two electrode units also increases accordingly, thereby increasing the overall area of ​​the microelectrode system.

[0054] like Figure 8 As shown, the flexible substrate 1 has four electrode units on its upper and lower surfaces. Two electrode units are set on the upper surface of the flexible substrate 1, namely the counter electrode 2 and the working electrode 3. Two electrode units are set on the lower surface of the flexible substrate 1, namely the counter electrode 2 and the reference electrode 4. The counter electrodes 2 on the upper and lower surfaces are connected to each other as a whole. That is, the counter electrodes 2 of the microelectrode system are distributed on the upper and lower surfaces of the flexible substrate 1. The remaining two electrode units are each distributed on one side of the flexible substrate 1. This reduces the area limitation between electrode units when three electrode units are set on one side. The area of ​​the three electrode units is increased, thus increasing the overall area of ​​the microelectrode system.

[0055] like Figure 9As shown in the figure, the number of electrode units on the upper and lower surfaces of the flexible substrate 1 is 5, two electrode units are arranged on one surface of the flexible substrate 1, one of which is the counter electrode 2, and the other is any one of the working electrode 3 and the reference electrode 4, and three electrode units are arranged on the other surface of the flexible substrate 1, which are the counter electrode 2, the working electrode 3 and the reference electrode 4 respectively. By distributing two electrode units of the microelectrode system on the upper and lower surfaces of the flexible substrate 1 respectively, the area of the two electrode units is increased, and the area limitation of the two electrode units on the remaining one electrode unit is reduced, and the area of the remaining one electrode unit is also increased accordingly, thereby increasing the overall area of the microelectrode system.

[0056] As shown in the figure, the number of electrode units on the upper and lower surfaces of the flexible substrate 1 is 5, two electrode units are arranged on one surface of the flexible substrate 1, one of which is the counter electrode 2, and the other is any one of the working electrode 3 and the reference electrode 4, and three electrode units are arranged on the other surface of the flexible substrate 1, which are the counter electrode 2, the working electrode 3 and the reference electrode 4 respectively. By distributing two electrode units of the microelectrode system on the upper and lower surfaces of the flexible substrate 1 respectively, the area of the two electrode units is increased, and the area limitation of the two electrode units on the remaining one electrode unit is reduced, and the area of the remaining one electrode unit is also increased accordingly, thereby increasing the overall area of the microelectrode system. Figure 10 As shown in the figure, the number of electrode units on the upper and lower surfaces of the flexible substrate 1 is 6, three electrode units are arranged on one surface of the flexible substrate 1, which are the counter electrode 2, the working electrode 3 and the reference electrode 4 respectively, and three electrode units are arranged on the other surface of the flexible substrate 1, which are the counter electrode 2, the working electrode 3 and the reference electrode 4 respectively. By electrically connecting the same electrode units on the upper and lower surfaces of the flexible substrate 1, compared with arranging three electrode units of the microelectrode system on one surface of the flexible substrate 1, the area of each type of electrode unit can be doubled in the embodiment of the application, thereby doubling the area of the microelectrode system. Preferably, the counter electrode 2, the working electrode 3 and the reference electrode 4 on the upper and lower surfaces of the flexible substrate 1 are arranged symmetrically about the flexible substrate 1, and the two working electrodes 3 monitor the target analyte at the same position, so that the monitoring result is more accurate.

[0057] Preferably, the total area of the counter electrode 2 in the first microelectrode system 11, the second microelectrode system 22 and the third microelectrode system 33 is greater than the total area of the working electrode 3, which is greater than the total area of the reference electrode 4, so that the performance of the microelectrode structure is optimal under the condition of limited substrate area, and the detection sensitivity is improved.

[0058] In summary, compared with the prior art of manufacturing microelectrodes on one surface of the flexible substrate 1, the electrodes are manufactured on both surfaces of the flexible substrate 1 in the present application, which is equivalent to doubling the available area for manufacturing the microelectrode system, thereby increasing the area of the manufactured microelectrode system by at most one time. The maximization of the area of the microelectrode system is realized on the limited surface of the flexible substrate, the detection sensitivity is improved, and the detection precision of the sensor is improved. Moreover, the flexibility of the microelectrode system design is improved, and the diversity and multifunctional design of the microelectrode system can be realized.

[0059] The present application does not limit the specific product type of the sensor to which the microelectrode structure is applied. For example, in some embodiments, the microelectrode structure is applied to an electrochemical biosensor, the surface of the working electrode 3 of which is coated with a layer of a biological sensitive substance (such as an enzyme, an antibody, or a nucleic acid, etc.), so that the electrochemical biosensor can realize the function of biological monitoring of a target analyte (such as monitoring of blood glucose, blood ketone, lactic acid, or uric acid, etc.). For example, in some embodiments, the microelectrode structure is applied to an electrochemical sensor, the surface of the working electrode 3 of which is coated with a layer of a chemical sensitive substance, so that the electrochemical sensor can realize the function of chemical monitoring of a target analyte (such as monitoring of pH, ammonia, oxygen saturation, etc.). For example, in some embodiments, the microelectrode structure is applied to an electrochemical sensor, the working electrode 3 of which is made of a specific material or doped with a specific component, so that the working electrode 3 can directly electrochemically react with a certain component of the target analyte and be converted into a corresponding electrical signal, in these embodiments, the surface of the working electrode 3 can not necessarily be provided with a layer of a chemical sensitive substance.

[0060] Optionally, the flexible substrate 1 can be made of a polyimide film, a polymethyl methacrylate film, a polyethylene terephthalate film, a polyethylene naphthalate film, etc., so that the microelectrode structure is flexible and foldable, and can be implanted in the body, meeting the need of being non-invasive for implantation in the human body and improving the user's acceptability.

[0061] Optionally, the counter electrode 2, the working electrode 3, and the reference electrode 4 can have one of a rectangular shape, a circular shape, an elliptical shape, an interdigital shape, a regular polygonal shape, or an irregular polygonal shape, which is not specifically limited by the present application.

[0062] In the present embodiment, the reference electrode 4 includes a bottom electrode 41 and a chloridizing layer 42 on the surface of the bottom electrode 41 away from the flexible substrate 1, the chloridizing layer 42 being formed by depositing silver on the surface of the bottom electrode 41 away from the flexible substrate 1 and converting part of the silver into silver chloride. Preferably, the ratio of silver to silver chloride in the chloridizing layer 42 is 1:1.

[0063] Optionally, the material of the bottom electrode 41 of the counter electrode 2, the working electrode 3, and the reference electrode 4 can be one of chromium, gold, or platinum. Preferably, the materials of the bottom electrodes 41 of the counter electrode 2, the working electrode 3, and the reference electrode 4 are the same, and they can be fabricated at the same time.

[0064] Optionally, the bottom electrode 41 of the counter electrode 2, the working electrode 3, and the reference electrode 4 can each be formed by first depositing a metal layer on the flexible substrate 1 using a photolithography technique and then patterning, the method of depositing the metal layer on the flexible substrate 1 being one of electroplating, evaporation, or sputtering, preferably sputtering. The method of patterning is one of dry etching, wet etching, or metal lift-off, preferably wet etching.

[0065] Optionally, the method for depositing silver on the surface of the bottom electrode 41 is one of sputtering, electroplating or chemical plating, and the method for converting silver into silver chloride is one of electroconversion or chemical conversion, and preferably chemical conversion. The conversion solution used in chemical conversion is one of FeCl3 solution, KCl solution or NaClO solution, and the concentration of the conversion solution is 0.1-3 mol / L.

[0066] In some embodiments, as shown in Figs. 4 and 5, the microelectrode structure further comprises electrical connection portions 5 arranged on the surface of the flexible substrate 1 and leads 6, the electrical connection portions 5 are arranged one-to-one corresponding to the electrode units, and the leads 6 are connected to the electrode units and the corresponding electrical connection portions 5. The electrical connection portions 5 are used to connect the microelectrode structure to external circuits. Figure 1 、 2

[0067] When the same type of electrode units are arranged on the upper and lower surfaces of the flexible substrate 1, the electrical connection portions 5 corresponding to two electrode units of the same type can be electrically connected, thereby realizing the mutual connection of the electrode units of the same type.

[0068] The material of the leads 6 and the electrical connection portions 5 is one of chromium, gold or platinum, and preferably, the leads 6 and the electrical connection portions 5 are made of the same material and can be made at the same time. The electrical connection portions 5 and the leads 6 are formed by first depositing a metal layer on the flexible substrate 1 and then patterning by using photolithography technology. The method for depositing the metal layer on the substrate 1 is one of electroplating, evaporation or sputtering, and preferably sputtering, and the method for patterning is one of dry etching, wet etching or metal stripping, and preferably wet etching. More preferably, the leads 6 and the electrical connection portions 5 are made of the same material as the bottom electrode 41 of the counter electrode 2, the working electrode 3 and the reference electrode 4, and can be made at the same time.

[0069] The electrode units on the same surface of the flexible substrate 1, the leads 6 and the electrical connection portions 5 have a spacing from each other, and the arrangement of the leads 6 and the electrical connection portions 5 limits the area of the electrode units. When the electrode units on the upper and lower surfaces of the flexible substrate 1 collectively constitute the third microelectrode system 33, one or two electrode units can be arranged on one or both surfaces of the flexible substrate 1, and the number of the corresponding leads 6 and the electrical connection portions 5 is reduced, which can avoid the limitation of the area of the corresponding electrode units by the multiple leads 6, so that the area of the electrode units can be larger, thereby increasing the accuracy of signal detection and reducing the complexity of production.

[0070] In some embodiments, as shown in Figs. 4 and 5, the microelectrode structure further comprises electrical connection portions 5 arranged on the surface of the flexible substrate 1 and leads 6, the electrical connection portions 5 are arranged one-to-one corresponding to the electrode units, and the leads 6 are connected to the electrode units and the corresponding electrical connection portions 5. The electrical connection portions 5 are used to connect the microelectrode structure to external circuits. Figure 11 and 12 ​As shown, the working electrode 3 is provided with a bio-sensitive substance layer 7 on the surface away from the flexible substrate 1; the upper surface of the flexible substrate 1 is provided with a first bio-functional layer 81, the first bio-functional layer 81 covering the electrode units and the bio-sensitive substance layer 7 on the upper surface of the flexible substrate 1; the lower surface of the flexible substrate 1 is provided with a second bio-functional layer 82, the second bio-functional layer 82 covering the electrode units and the bio-sensitive substance layer 7 on the lower surface of the flexible substrate 1. The microelectrode structure can be applied to an electrochemical microbial sensor.

[0071] The bio-sensitive substance contained in the bio-sensitive substance layer 7 is set according to the monitoring function, such as glucose oxidase for blood glucose monitoring, lactate dehydrogenase for lactate monitoring, and other target analyte corresponding enzyme layer, such as uric acid, blood ketone corresponding bio-sensitive substance.

[0072] The first bio-functional layer 81 and the second bio-functional layer 82 are used to protect each electrode unit and the bio-sensitive substance layer 7 on the flexible substrate 1, anti-interference (ensure that only the target analyte enters the bio-sensitive substance layer 7, and exclude the interference of other substances), and limit the total amount and / or rate of the target analyte entering the bio-sensitive substance layer 7. Optionally, the first bio-functional layer 81 and the second bio-functional layer 82 can adopt one or more layers of selective permeation membrane, and the specific number of layers of the selective permeation membrane is set according to the actual monitoring needs. The first bio-functional layer 81 and the second bio-functional layer 82 can also include a hydrophilic polymer layer, the hydrophilic polymer layer is provided on the surface of the selective permeation membrane away from the flexible substrate 1, the hydrophilic polymer layer has good biocompatibility and can be well compatible with the biological tissue.

[0073] Optionally, the biological sensitive substance layers 7 on the surfaces of the working electrodes 3 of the first microelectrode system 11 and the second microelectrode system 22 contain the same or different biological sensitive substance components. When the biological sensitive substance layers 7 on the surfaces of the two working electrodes 3 contain the same biological sensitive substance components, double-channel monitoring of the same target analyte can be achieved, and the two sets of collected data can be complementary to each other for deviation correction, effectively preventing the phenomenon that the detection result of the target analyte is inaccurate due to the performance fluctuation of a single microelectrode system, and meanwhile, the damage of one microelectrode system does not affect the normal use of the other, thereby improving the reliability of the microelectrode structure. When the biological sensitive substance layers 7 on the surfaces of the working electrodes 3 contain different biological sensitive substance components, double-channel monitoring of two target analytes in the body fluid, i.e., double-channel double-substance monitoring, can be achieved, for example, monitoring of blood glucose and uric acid at the same time, thereby improving the practicability of the microelectrode structure. Whether it is double-channel single-substance monitoring or double-channel double-substance monitoring, the microelectrode system is made on the front and back surfaces of the same substrate and then implanted in the body at the same time, and the monitoring data are more accurate. When it is double-channel single-substance monitoring, the area of the microelectrode is twice the area of the single-surface microelectrode system on the same substrate, and the detection is more accurate. When it is double-channel double-substance monitoring, the simultaneous monitoring of double target analytes is achieved, and the application of the microelectrode structure is more extensive.

[0074] When the electrode units on the upper and lower surfaces of the flexible substrate 1 jointly form a microelectrode system (the third microelectrode system 33) and are each provided with a working electrode 3, the microelectrode system is used for single-channel single-substance monitoring, the biological sensitive substance layers 7 on the surfaces of the two working electrodes 3 contain the same biological sensitive substance components, and the materials of the corresponding first biological functional layer 81 and the second biological functional layer 82 are the same. When the first microelectrode system 11 and the second microelectrode system 22 are used for monitoring the same substance, i.e., when it is double-channel single-substance monitoring, the biological sensitive substance layers 7 on the surfaces of the two working electrodes 3 contain the same biological sensitive substance components, and the materials of the corresponding first biological functional layer 81 and the second biological functional layer 82 are the same. When the first microelectrode system 11 and the second microelectrode system 22 are used for monitoring different substances, i.e., when it is double-channel double-substance monitoring, the biological sensitive substance layers 7 on the surfaces of the two working electrodes 3 contain different biological sensitive substance components, and the materials of the corresponding first biological functional layer 81 and the second biological functional layer 82 are different. When the electrode units on the upper and lower surfaces of the flexible substrate 1 jointly form the third microelectrode system 33 and only one of the surfaces is provided with a working electrode 3, the materials of the first biological functional layer 81 and the second biological functional layer 82 are the same.

[0075] The microelectrode structure of the present application has the characteristics of good flexibility, small size, high sensitivity, strong anti-interference, high accuracy, good biological compatibility, etc., and can realize health monitoring of the human body without feeling and with high precision.

[0076] The present application also provides a method for manufacturing the microelectrode structure, as shown in Figure 13As shown, the manufacturing method specifically includes:

[0077] S1, providing a flexible substrate 1; the flexible substrate 1 can be made of polyimide film, polymethyl methacrylate film, polyethylene terephthalate film, polyethylene naphthalate film, etc.

[0078] S2, manufacturing corresponding electrode units on the upper surface and the lower surface of the flexible substrate 1, wherein the electrode units on the upper surface of the flexible substrate 1 include at least one of the counter electrode 2, the working electrode 3 and the reference electrode 4, the electrode units on the lower surface of the flexible substrate 1 include at least one of the counter electrode 2, the working electrode 3 and the reference electrode 4, the electrode units on the upper surface of the flexible substrate 1 constitute a microelectrode system, the electrode units on the lower surface of the flexible substrate 1 constitute a microelectrode system, or the electrode units on the upper surface of the flexible substrate 1 and the electrode units on the lower surface of the flexible substrate 1 jointly constitute a microelectrode system.

[0079] In some embodiments, as Figure 14 shown, step S2 specifically includes:

[0080] S21, providing a rigid substrate 9, and manufacturing a temporary bonding layer 10 on the rigid substrate 9 ， The flexible substrate 1 is attached to the temporary bonding layer 10, and the rigid substrate 9 is used to support the flexible substrate 1, so as to facilitate the subsequent manufacturing of the electrode units on the flexible substrate 1. The rigid substrate 9 can be made of silicon, glass, ceramic, etc. The material of the temporary bonding layer 10 is selected from organic silicone glue or acrylic material, which is used to adhere the flexible substrate 1. The flexible substrate 1 is covered above the temporary bonding layer 10, and the adhesion of the temporary bonding layer 10 can be eliminated by light or heating, so as to facilitate the separation of the flexible substrate 1 and the rigid substrate 9.

[0081] S22, manufacturing the electrode units on one surface of the flexible substrate 1 away from the rigid substrate 9.

[0082] The reference electrode 4 includes a bottom electrode 41 and a chlorination layer 42 arranged on the surface of the bottom electrode 41 away from the flexible substrate 1. The chlorination layer 42 is formed by depositing silver on the surface of the bottom electrode 41 away from the flexible substrate 1 and converting part of the silver into silver chloride.

[0083] If the electrode units on the surface only include the reference electrode 4, the bottom electrode 41 of the reference electrode 4 can be manufactured on the surface of the flexible substrate 1 away from the rigid substrate 9 (i.e. the upper surface of the flexible substrate 1 at this time), and then a silver layer 42' is deposited on the upper surface of the bottom electrode 41 of the reference electrode 4, and part of the silver in the silver layer 42' is converted into silver chloride (for example, the whole structure is immersed in a chlorination solution), so as to form the chlorination layer 42.

[0084] If the face is provided with two or three electrode units and one of them is the reference electrode 4, the bottom electrode 41 of the reference electrode 4 and the other electrode units can be made on the surface of the flexible substrate 1 opposite to the rigid substrate 9 (i.e. the upper surface of the flexible substrate 1 at this time), and then a silver layer 42' is deposited on the bottom electrode 41 of the reference electrode 4, and part of the silver in the silver layer 42' is converted into silver chloride (for example, the whole structure is immersed in a chloride solution), to form a chloride layer 42.

[0085] If the face is not provided with the reference electrode 4, the counter electrode 2 and / or the working electrode 3 can be made on the surface of the flexible substrate 1 opposite to the rigid substrate 9 (i.e. the upper surface of the flexible substrate 1 at this time).

[0086] S23, the flexible substrate 1, the temporary bonding layer 10 and the rigid substrate 9 are separated, the adhesion of the temporary bonding layer 10 is eliminated by light or heating, the separation of the flexible substrate 1 and the rigid substrate 9 is realized, a new temporary bonding layer 10 is made on the upper surface of the rigid substrate 9, the flexible substrate 1 and the electrode units thereon are turned over, and the flexible substrate 1 provided with the electrode units is attached to the temporary bonding layer 10 on the rigid substrate 9, so that the electrode units and the lower surface of the flexible substrate 1 at this time are adhered to the temporary bonding layer 10.

[0087] S24, the electrode units of the other face are made on the surface of the flexible substrate 1 opposite to the rigid substrate 9, and the specific making method of the electrode units is the same as that of the step S22.

[0088] S25, the flexible substrate 1 and the electrode units thereon, the temporary bonding layer 10 and the rigid substrate 9 are separated. Specifically, the adhesion of the temporary bonding layer 10 is eliminated by light or heating, and the separation of the flexible substrate 1 and the electrode units and the rigid substrate 9 is realized.

[0089] In some embodiments, the upper and lower surfaces of the flexible substrate 1 are both provided with the reference electrode 4, and at this time, as shown in FIG. 2, the step S2 specifically includes: Figure 15

[0090] S21', a rigid substrate 9 is provided, a temporary bonding layer 10 is made on the rigid substrate 9, and a flexible substrate 1 is attached to the temporary bonding layer 10.

[0091] ​S22', the bottom electrode 41 of one of the reference electrodes 4 and the rest of the electrode units on the same side of the reference electrode 4 are made on the surface of the flexible substrate 1 facing away from the rigid substrate 9. If only the reference electrode 4 is arranged on the surface, the bottom electrode 41 of the reference electrode 4 is made on the upper surface of the flexible substrate 1 at this time, and then a metal silver layer 42' is deposited on the bottom electrode 41 of the reference electrode 4. If the counter electrode 2 and / or the working electrode 3 are also arranged on the surface, the bottom electrode 41 of the reference electrode 4 and the other electrodes are made on the upper surface of the flexible substrate 1 at this time, and then a metal silver layer 42' is deposited on the bottom electrode 41 of the reference electrode 4.

[0092] S23', the flexible substrate 1, the temporary bonding layer 10 and the rigid substrate 9 are separated, specifically, the adhesion of the temporary bonding layer 10 is eliminated by light or heating, so that the flexible substrate 1 and the rigid substrate 9 are separated; then a temporary bonding layer 10 is made on the rigid substrate 9, the flexible substrate 1 and the electrode units thereon are turned over, and the flexible substrate 1 with the electrode units is attached to the temporary bonding layer 10 on the rigid substrate 9, so that the electrode units and the lower surface of the flexible substrate 1 at this time are bonded to the temporary bonding layer 10.

[0093] S24', the bottom electrode 41 of the other reference electrode 4 and the rest of the electrode units on the same side of the reference electrode 4 are made on the surface of the flexible substrate 1 facing away from the rigid substrate 9. The specific method of making the electrode units is the same as that in step S22'.

[0094] S25', the flexible substrate 1 and the electrode units on the flexible substrate 1, the temporary bonding layer 10 and the rigid substrate 9 are separated, and the adhesion of the temporary bonding layer 10 is eliminated by light or heating, so that the flexible substrate 1 and the electrode units are separated from the rigid substrate 9.

[0095] S26', the chloridizing layer 42 is made on the surface of the two bottom electrodes 41 facing away from the rigid substrate 9. At this time, the surfaces of the two bottom electrodes 41 away from the rigid substrate 9 are both metal silver layers 42', and the silver in the metal silver layers 42' on both sides of the flexible substrate 1 can be converted into silver chloride (for example, the flexible substrate 1 and the electrode units on both sides are immersed in a chloridizing solution at the same time), so that the chloridizing layer 42 is formed.

[0096] Optionally, the counter electrode 2, the working electrode 3 and the bottom electrode 41 of the reference electrode 4 are all formed by depositing a metal layer on the flexible substrate 1 by using a photolithography technology, and then patterning. The method of depositing the metal layer on the flexible substrate is one of electroplating, evaporation or sputtering, and the sputtering is preferred. The method of patterning is one of dry etching, wet etching or metal stripping, and the wet etching is preferred.

[0097] Optionally, the method for depositing silver on the surface of the bottom electrode 41 is one of sputtering, electroplating or chemical plating, and the method for converting silver into silver chloride is one of electroconversion or chemical conversion, and preferably chemical conversion. The conversion solution used in chemical conversion is one of FeCl3 solution, KCl solution or NaClO solution, and the concentration of the conversion solution is 0.1-3 mol / L.

[0098] In some embodiments, the method further comprises:

[0099] The method further comprises: S2, fabricating an electrical connection part 5 corresponding to each electrode unit on the surface of the flexible substrate 1, and connecting the electrical connection part 5 with the electrode unit; and S3, fabricating a biological sensitive substance layer 7 on the surface of the working electrode 3 away from the flexible substrate 1, and fabricating a first biological functional layer 81 on the upper surface of the flexible substrate 1, the first biological functional layer 81 covering the electrode unit and the biological sensitive substance layer 7 on the upper surface of the flexible substrate 1; and fabricating a second biological functional layer 82 on the lower surface of the flexible substrate 1, the second biological functional layer 82 covering the electrode unit and the biological sensitive substance layer 7 on the lower surface of the flexible substrate 1.

[0100] In some embodiments, the method further comprises:

[0101] S3, fabricating a biological sensitive substance layer 7 on the surface of the working electrode 3 away from the flexible substrate 1, and fabricating a first biological functional layer 81 on the upper surface of the flexible substrate 1, the first biological functional layer 81 covering the electrode unit and the biological sensitive substance layer 7 on the upper surface of the flexible substrate 1; and fabricating a second biological functional layer 82 on the lower surface of the flexible substrate 1, the second biological functional layer 82 covering the electrode unit and the biological sensitive substance layer 7 on the lower surface of the flexible substrate 1.

[0102] As Figure 16As shown, it is the manufacturing flow chart of the microelectrode structure of the seventh embodiment of the present application, wherein the electrode units on the upper surface of the flexible substrate 1 constitute the first microelectrode system 11, the electrode units on the lower surface of the flexible substrate 1 constitute the second microelectrode system 22, the opposite electrode 2, the working electrode 3 and the reference electrode 4 are arranged on one side of the flexible substrate 1, and the opposite electrode 2, the working electrode 3 and the reference electrode 4 are arranged on the other side of the flexible substrate 1, and the manufacturing method specifically comprises the following steps:

[0103] S1, providing a flexible substrate 1.

[0104] S2, manufacturing the electrode units corresponding to the upper surface and the lower surface of the flexible substrate 1, specifically:

[0105] S21, providing a rigid substrate 9, first manufacturing a temporary bonding layer 10 on the rigid substrate 9, and then covering the flexible substrate 1 on the temporary bonding layer 10.

[0106] S22, manufacturing the bottom electrode 41 of the opposite electrode 2, the working electrode 3 and the reference electrode 4 on the surface of the flexible substrate 1 away from the rigid substrate 9, and the lead wire 6 and the electrical connection part 5 corresponding to the connection of the opposite electrode 2, the working electrode 3 and the reference electrode 4, then depositing a metal silver layer 42' on the upper surface of the bottom electrode 41, and then immersing the whole structure into a chlorination solution, converting part of the silver in the metal silver layer 42' into silver chloride to form a chlorination layer 42, to obtain the structure shown in Figure a.

[0107] S23, eliminating the viscosity of the temporary bonding layer 10 by light or heating, separating the flexible substrate 1, the temporary bonding layer 10 and the rigid substrate 9, and then manufacturing a temporary bonding layer 10 on the rigid substrate 9, turning over the flexible substrate 1 and the electrode units thereon, and attaching the flexible substrate 1 provided with the electrode units to the temporary bonding layer 10 on the rigid substrate 9.

[0108] S24, manufacturing the bottom electrode 41 of the opposite electrode 2, the working electrode 3 and the reference electrode 4 on the surface of the flexible substrate 1 away from the rigid substrate 9, and the lead wire 6 and the electrical connection part 5 corresponding to the connection of the opposite electrode 2, the working electrode 3 and the reference electrode 4, then depositing a metal silver layer 42' on the upper surface of the bottom electrode 41, and then immersing the whole structure into a chlorination solution, converting part of the silver in the metal silver layer 42' into silver chloride to form a chlorination layer 42, to obtain the structure shown in Figure b.

[0109] S25, eliminating the viscosity of the temporary bonding layer 10 by light or heating, separating the flexible substrate 1 and the electrode units on the flexible substrate 1, the temporary bonding layer 10 and the rigid substrate 9, to obtain the structure shown in Figure c.

[0110] S3, fabricate two bio-sensitive substance layers 7 on the surfaces of the two working electrodes 3 away from the surface of the flexible substrate 1, the two bio-sensitive substance layers 7 contain bio-sensitive substances with same or different compositions; fabricate a first bio-functional layer 81 on the upper surface of the flexible substrate 1, the first bio-functional layer 81 covers all the electrode units and bio-sensitive substance layers 7 on the upper surface of the flexible substrate 1; fabricate a second bio-functional layer 82 on the lower surface of the flexible substrate 1, the second bio-functional layer 82 covers all the electrode units and bio-sensitive substance layers 7 on the lower surface of the flexible substrate 1. If the two bio-sensitive substance layers 7 contain bio-sensitive substances with same compositions, the first bio-functional layer 81 and the second bio-functional layer 82 are made of same material; if the two bio-sensitive substance layers 7 contain bio-sensitive substances with different compositions, the first bio-functional layer 81 and the second bio-functional layer 82 are made of different materials. Finally, the structure shown in FIG. d is obtained.

[0111] As shown in FIG. d, the electrode units on the upper surface of the flexible substrate 1 constitute a first micro-electrode system 11, the electrode units on the lower surface of the flexible substrate 1 constitute a second micro-electrode system 22, the working electrode 3 and the reference electrode 4 are arranged on one side of the flexible substrate 1, and the working electrode 3 and the reference electrode 4 are arranged on the other side of the flexible substrate 1. Figure 17 As shown in FIG. d, the electrode units on the upper surface of the flexible substrate 1 constitute a first micro-electrode system 11, the electrode units on the lower surface of the flexible substrate 1 constitute a second micro-electrode system 22, the working electrode 3 and the reference electrode 4 are arranged on one side of the flexible substrate 1, and the working electrode 3 and the reference electrode 4 are arranged on the other side of the flexible substrate 1.

[0112] S1, provide a flexible substrate 1.

[0113] S2, fabricate corresponding electrode units on the upper surface and the lower surface of the flexible substrate 1. Specifically:

[0114] S21', provide a rigid substrate 9, first fabricate a temporary bonding layer 10 on the rigid substrate 9, and then cover the flexible substrate 1 on the temporary bonding layer 10.

[0115] S22', fabricate the bottom electrode 41 of the counter electrode 2, the working electrode 3 and the reference electrode 4 and the corresponding lead 6 and the electrical connection part 5 of the counter electrode 2, the working electrode 3 and the reference electrode 4 on the surface of the flexible substrate 1 away from the rigid substrate 9, and deposit a silver layer 42' on the bottom electrode 41 of the reference electrode 4, to obtain the structure shown in FIG. a.

[0116] S23', eliminate the viscosity of the temporary bonding layer 10 by light or heating, separate the flexible substrate 1, the temporary bonding layer 10 and the rigid substrate 9, and then fabricate a temporary bonding layer 10 on the rigid substrate 9, flip the flexible substrate 1 and the electrode units thereon, and attach the flexible substrate 1 provided with the electrode units to the temporary bonding layer 10 on the rigid substrate 9.

[0117] S24', making the bottom electrode 41 of the counter electrode 2, the working electrode 3 and the reference electrode 4 and the lead 6 and the electrical connection 5 corresponding to the counter electrode 2, the working electrode 3 and the reference electrode 4 on the surface of the flexible substrate 1 away from the rigid substrate 9, depositing a layer of silver 42' on the bottom electrode 41 of the reference electrode 4, obtaining the structure shown in Fig. b.

[0118] S25', eliminating the adhesion of the temporary bonding layer 10 by light or heat, separating the flexible substrate 1 and the electrode units on the flexible substrate 1, the temporary bonding layer 10 and the rigid substrate 9.

[0119] S26', making the chloridizing layer 42 of the reference electrode 4 on the surface of the two bottom electrodes 41 away from the rigid substrate 9, at this time, the two bottom electrodes 41 away from the surface of the rigid substrate 9 are both the layer of silver 42', immersing the flexible substrate 1 and the electrode units on both sides of the flexible substrate 1 into the chloridizing solution at the same time, converting part of the silver in the layer of silver 42' on both sides of the flexible substrate 1 into silver chloride to form the chloridizing layer 42, obtaining the structure shown in Fig. c.

[0120] S3, making the biological sensitive substance layer 7 on the surface of the two working electrodes 3 away from the flexible substrate 1 respectively, the two biological sensitive substance layers 7 contain the same or different biological sensitive substance components; making the first biological functional layer 81 on the upper surface of the flexible substrate 1, the first biological functional layer 81 covering all the electrode units and the biological sensitive substance layers 7 on the upper surface of the flexible substrate 1; making the second biological functional layer 82 on the lower surface of the flexible substrate 1, the second biological functional layer 82 covering all the electrode units and the biological sensitive substance layers 7 on the lower surface of the flexible substrate 1. If the two biological sensitive substance layers 7 contain the same biological sensitive substance components, the first biological functional layer 81 and the second biological functional layer 82 are of the same material; if the two biological sensitive substance layers 7 contain different biological sensitive substance components, the first biological functional layer 81 and the second biological functional layer 82 are also of different materials. Finally, the structure shown in Fig. d is obtained.

[0121] As shown in Fig. d, the flexible substrate 1 is provided with the counter electrode 2 on one side and the working electrode 3 and the reference electrode 4 on the other side. Figure 18 The manufacturing process of the microelectrode structure of the eighth embodiment of the present application is shown in Fig. d, which specifically includes the following steps:

[0122] S1, providing the flexible substrate 1.

[0123] S2, making the corresponding electrode units on the upper surface and the lower surface of the flexible substrate 1, specifically:

[0124] S21, providing the rigid substrate 9, first making a layer of temporary bonding layer 10 on the rigid substrate 9, and then laminating the flexible substrate 1 above the temporary bonding layer 10.

[0125] S22, making the counter electrode 2 on the surface of the flexible substrate 1 facing away from the rigid substrate 9, and the lead 6 and the electrical connection 5 connected to the counter electrode 2, to obtain the structure shown in Fig. a.

[0126] S23, eliminating the adhesion of the temporary bonding layer 10 by means of light or heat, separating the flexible substrate 1, the temporary bonding layer 10 and the rigid substrate 9, and then making a layer of temporary bonding layer 10 on the rigid substrate 9, turning over the flexible substrate 1 and the counter electrode 2 thereon, and attaching the flexible substrate 1 with the counter electrode 2 to the temporary bonding layer 10 on the rigid substrate 9.

[0127] S24, making the working electrode 3, the bottom electrode 41 of the reference electrode 4 and the lead 6 and the electrical connection 5 corresponding to the working electrode 3 and the reference electrode 4 on the surface of the flexible substrate 1 facing away from the rigid substrate 9, then depositing a layer of metal silver 42' on the upper surface of the bottom electrode 41, and then immersing the entire structure in a chlorinated solution to convert part of the silver in the metal silver layer 42' into silver chloride to form a chlorinated layer 42, to obtain the structure shown in Fig. b.

[0128] S25, eliminating the adhesion of the temporary bonding layer 10 by means of light or heat, separating the flexible substrate 1 and the electrode unit on the flexible substrate 1, the temporary bonding layer 10 and the rigid substrate 9, to obtain the structure shown in Fig. c.

[0129] S3, making the biological sensitive substance layer 7 on the surface of the working electrode 3 facing away from the flexible substrate 1, making the first biological functional layer 81 on the upper surface of the flexible substrate 1, and the first biological functional layer 81 covering the working electrode 3, the reference electrode 4 and the biological sensitive substance layer 7 on the upper surface of the flexible substrate 1; making the second biological functional layer 82 on the lower surface of the flexible substrate 1, and the second biological functional layer 82 covering the counter electrode 2 on the lower surface of the flexible substrate 1; the first biological functional layer 81 and the second biological functional layer 82 are of the same material, to obtain the structure shown in Fig. d.

[0130] When making the microelectrode structure of the eighth embodiment, if the working electrode 3 and the reference electrode 4 are made first and then the counter electrode 2 is made, step S22 is specifically: making the working electrode 3 and the bottom electrode 41 of the reference electrode 4 on the surface of the flexible substrate 1 facing away from the rigid substrate 9, and the lead 6 and the electrical connection 5 connected to the working electrode 3 and the reference electrode 4, then depositing a layer of metal silver 42' on the upper surface of the bottom electrode 41, and then immersing the entire structure in a chlorinated solution to convert part of the silver in the metal silver layer 42' into silver chloride to form a chlorinated layer 42. Then step S23 is performed.

[0131] The application further provides a sensor comprising the microelectrode structure described in the above embodiments or the microelectrode structure manufactured by the manufacturing method of the microelectrode structure described in the above embodiments. The specific product type of the sensor is not limited, for example, can be an electrochemical biosensor or an electrochemical sensor, etc., wherein the electrochemical biosensor can be an implantable electrochemical biosensor for implanting into a living body, or an in-vitro electrochemical biosensor for immersing into a solution containing a target analyte.

[0132] The application arranges the electrode units on both sides of the flexible substrate 1, increases the area of the microelectrode system while only increasing the thickness of one layer of electrode units, so that the volume of the entire microelectrode structure and the corresponding sensor is small, reduces the rejection reaction of the human body when implanted into the human body, meets the non-sensing requirement of implanting into the human body, and improves the user's acceptability.

[0133] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0134] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0135] In the description of the present specification, the description of the terms "the embodiment", "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in at least one embodiment or example. In addition, those skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0136] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0137] The above is only the preferred embodiment of the present application and does not limit the present application. Any modification, equivalent replacement and simple improvement made on the essential content of the present application shall be included in the protection scope of the present application.

Claims

1. A microelectrode structure, characterized in that, It includes a flexible substrate (1) and a microelectrode system disposed on the surface of the flexible substrate (1). The microelectrode system includes three electrode units: a counter electrode (2), a working electrode (3), and a reference electrode (4). Electrode units are provided on both the upper and lower surfaces of the flexible substrate (1). The electrode units on the upper surface of the flexible substrate (1) include at least one of a counter electrode (2), a working electrode (3), and a reference electrode (4). The electrode units on the upper surface of the flexible substrate (1) are horizontally distributed. The electrode units on the lower surface of the flexible substrate (1) include at least one of a counter electrode (2), a working electrode (3), and a reference electrode (4). The electrode units on the lower surface of the flexible substrate (1) are horizontally distributed. The electrode units on the upper surface of the flexible substrate (1) constitute a first microelectrode system (11), and the electrode units on the lower surface of the flexible substrate (1) constitute a second microelectrode system (22). The first microelectrode system (11) and the second microelectrode system (22) are used to monitor the same or different substances. Alternatively, the electrode units on the upper surface of the flexible substrate (1) and the electrode units on the lower surface of the flexible substrate (1) together constitute a third microelectrode system (33).

2. The microelectrode structure according to claim 1, characterized in that, The counter electrode (2) of the first microelectrode system (11) and the counter electrode (2) of the second microelectrode system (22) are symmetrically arranged with respect to the flexible substrate (1). The working electrode (3) of the first microelectrode system (11) and the working electrode (3) of the second microelectrode system (22) are symmetrically arranged with respect to the flexible substrate (1). The reference electrode (4) of the first microelectrode system (11) and the reference electrode (4) of the second microelectrode system (22) are symmetrically arranged with respect to the flexible substrate (1).

3. The microelectrode structure according to claim 1, characterized in that, When the electrode units on the upper surface of the flexible substrate (1) and the electrode units on the lower surface of the flexible substrate (1) together constitute the third microelectrode system (33), The flexible substrate (1) has three electrode units on its upper and lower surfaces. One electrode unit on one surface of the flexible substrate (1) is a counter electrode (2), and the other electrode unit on the other surface is a working electrode (3) and a reference electrode (4). Alternatively, the number of electrode units on the upper and lower surfaces of the flexible substrate (1) is 4 to 6. The upper and lower surfaces of the flexible substrate (1) are provided with counter electrodes (2), at least one working electrode (3) and a reference electrode (4). The same type of electrode units on the upper and lower surfaces of the flexible substrate (1) are interconnected.

4. The microelectrode structure according to any one of claims 1-3, characterized in that, The total area of ​​the counter electrode (2) in the first microelectrode system (11), the second microelectrode system (22) and the third microelectrode system (33) is greater than the total area of ​​the working electrode (3) and the total area of ​​the reference electrode (4).

5. The microelectrode structure according to claim 1, characterized in that, The microelectrode structure further includes an electrical connection portion (5) and a lead wire (6) disposed on the surface of the flexible substrate (1). The electrical connection portion (5) is disposed in a one-to-one correspondence with the electrode unit, and the lead wire (6) connects the electrode unit to the corresponding electrical connection portion (5).

6. The microelectrode structure according to claim 1, characterized in that, The working electrode (3) has a biosensitive material layer (7) disposed on the surface facing away from the flexible substrate (1); The upper surface of the flexible substrate (1) is provided with a first biofunctional layer (81), which covers the electrode unit and the biosensitive material layer (7) on the upper surface of the flexible substrate (1). The lower surface of the flexible substrate (1) is provided with a second biofunctional layer (82), which covers the electrode unit and the biosensitive material layer (7) on the lower surface of the flexible substrate (1).

7. The microelectrode structure according to claim 6, characterized in that, The biosensitive material components contained in the biosensitive material layer (7) on the surface of the working electrode (3) of the first microelectrode system (11) and the second microelectrode system (22) are the same or different.

8. The microelectrode structure according to claim 1, characterized in that, The reference electrode (4) includes a bottom electrode (41) and a chloride layer (42) disposed on the surface of the bottom electrode (41) facing away from the flexible substrate (1).

9. The microelectrode structure according to claim 8, characterized in that, The chloride layer (42) is formed by depositing silver on the surface of the bottom electrode (41) facing away from the flexible substrate (1) and converting part of the silver into silver chloride.

10. A sensor, characterized in that, Includes the microelectrode structure according to any one of claims 1-9.

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