Biosensor and preparation method thereof, and wearable device

Abstract

The present invention discloses a biosensor, a preparation method thereof, and a wearable device, relating to the field of health detection technology. The biosensor comprises a circuit board and a microneedle electrode array. The circuit board comprises a substrate and a circuit, the circuit being provided on a first surface of the substrate, the substrate being provided with at least three through-holes extending through two opposing surfaces, the microneedle electrode array comprising at least one working electrode, a reference electrode, and a counter electrode, the working electrode, the reference electrode, and the counter electrode all extending from the first surface through corresponding through-holes toward the second surface, the working electrode comprising an electrode body and a sensitive layer provided on the surface of the electrode body, the electrode body, the reference electrode, and the counter electrode all comprising an insulating portion and a conductive portion connected to each other, the insulating portion and the conductive portion both extending from the first surface toward the second surface, the insulating portion and the substrate forming an integral structure, and the conductive portion being connected to the circuit. The technical solution provided by the present invention can improve the accuracy of the detection results of the biosensor.

Description

Technical Field

[0001] The present invention relates to the field of health detection technology, and in particular to a biosensor and a preparation method thereof, and a wearable device. Background Art

[0002] Diabetes, a chronic metabolic disease characterized by high blood sugar levels, has become the third most common health hazard after cardiovascular and cerebrovascular diseases and malignant tumors. Blood sugar testing, a crucial component of diabetes management, helps assess the extent of glucose metabolism disorders in diabetic patients and develop glucose-lowering strategies.

[0003] Fingerstick blood tests and continuous glucose monitoring (CGM) are the most commonly used blood glucose monitoring devices, but they face many challenges. For example, fingerstick blood tests can only detect discrete blood glucose values ​​and cannot detect hyperglycemia or hypoglycemia. CGM also presents challenges such as tissue damage, pain, signal time delay, and poor accuracy. Microneedle electrodes are the most promising alternative electrodes for CGM sensors. At only 0.2-0.3 mm in length, they are 1 / 30 the length of traditional CGM sensors.

[0004] At present, microneedle array glucose sensors mainly include a microneedle electrode array and a circuit board. Among them, the microneedle electrode array is generally a separate split structure, which needs to be connected and assembled together through connectors. However, during use, this connection structure often has the following problems: loose connectors lead to poor electrical contact between the microneedle electrode array and the circuit board, which in turn leads to low accuracy of its detection results. Summary of the Invention

[0005] The main purpose of the present invention is to provide a biosensor and a preparation method thereof, and a wearable device, aiming to improve the accuracy of the detection results of the biosensor.

[0006] To achieve the above objectives, the present invention provides a biosensor comprising:

[0007] A circuit board comprises a substrate and a circuit, wherein the substrate has a first surface and a second surface opposite to each other and is provided with at least three through holes penetrating the first surface and the second surface, and the circuit is provided on the first surface;

[0008] and a microneedle electrode array, comprising at least one working electrode, a reference electrode and a counter electrode, wherein the working electrode, the reference electrode and the counter electrode are all bent and extended from the first surface through the corresponding through holes toward the second surface, the working electrode comprises an electrode body and a sensitive layer provided on the surface of the electrode body, the electrode body, the reference electrode and the counter electrode are all connected to each other and comprise an insulating portion and a conductive portion, the insulating portion and the conductive portion are all bent and extended from the first surface toward the second surface, and the insulating portion and the substrate are an integral structure, and the conductive portion is connected to the circuit.

[0009] In one embodiment, the electrode body, the reference electrode and the counter electrode all include a first bending section and a second bending section connected to each other, the end of the first bending section away from the second bending section is connected to the side wall of the corresponding through hole, the first bending section and the second bending section both include an insulating portion and a conductive portion connected to each other, and the length of the first bending section is less than the length of the second bending section.

[0010] In one embodiment, the surface of the first bending section is a curved surface; and / or,

[0011] The surface of the second bending section is a flat surface, and the angle between the second bending section and the substrate is in the range of 80° to 100°.

[0012] In one embodiment, the working electrode is provided in plurality, the plurality of working electrodes are arranged in parallel, and the sensitive layers of the plurality of working electrodes are made of different materials.

[0013] In one embodiment, the microneedle electrode array further includes a blank electrode, the structure of the blank electrode is the same as that of the electrode body, and the material of the conductive portion of the blank electrode is the same as that of the conductive portion of the electrode body.

[0014] The present invention also provides a method for preparing a biosensor, comprising the following steps:

[0015] providing a substrate;

[0016] Prepare a circuit and at least three conductive parts connected to the circuit on the first surface of the substrate;

[0017] At least one of the conductive parts is cut, bent and modified to prepare at least one working electrode, and two of the conductive parts are cut and bent respectively to prepare a reference electrode and a counter electrode.

[0018] In one embodiment, the step of cutting, bending and modifying at least one of the conductive portions to prepare at least one working electrode comprises:

[0019] A sensitive material is applied to the surface of at least one of the conductive portions to form a sensitive layer, the substrate is cut according to the outer contour of the sensitive layer to penetrate the second surface to obtain at least one working electrode substrate, and the working electrode substrate is bent toward the second surface to obtain at least one working electrode; or

[0020] The substrate is cut according to the outer contour of at least one of the conductive parts to penetrate the second surface, and is bent toward the second surface to obtain at least one electrode body, and a sensitive material is dipped on the surface of the electrode body to form a sensitive layer to obtain at least one working electrode.

[0021] In one embodiment, the bending step includes:

[0022] The connection between the conductive portion and the circuit is marked as a first position, the end of the conductive portion away from the circuit is marked as a second position, and the portion between the first position and the second position and close to the first position is marked as a third position;

[0023] Bending is performed with the first position and the third position as bending starting points to form a first bending section and a second bending section.

[0024] In one embodiment, the method for preparing the biosensor comprises the following steps:

[0025] Prepare a circuit and at least four conductive parts connected to the circuit on the first surface of the substrate;

[0026] At least one of the conductive parts is cut, bent and modified to prepare at least one working electrode, and three of the conductive parts are cut and bent respectively to prepare a reference electrode, a counter electrode and a blank electrode.

[0027] The present invention also proposes a wearable device, comprising a shell and a biosensor as described above or a biosensor prepared according to the biosensor preparation method as described above, wherein the substrate of the biosensor is arranged on or inside the shell, the circuit is located inside the shell, and the working electrode, the reference electrode and the counter electrode are located outside the shell.

[0028] The biosensor provided by the present invention includes a circuit board and a microneedle electrode array. The circuit board includes a substrate and a circuit. The circuit is provided on the first surface of the substrate. The substrate is provided with at least three through-holes penetrating two opposite surfaces. The microneedle electrode array includes at least one working electrode, a reference electrode and a counter electrode. The working electrode, the reference electrode and the counter electrode are all bent and extended from the first surface through the corresponding through-holes toward the second surface. The working electrode includes an electrode body and a sensitive layer provided on the surface of the electrode body. The electrode body, the reference electrode and the counter electrode are all connected to an insulating portion and a conductive portion. The insulating portion and the conductive portion are all bent and extended from the first surface toward the second surface. The insulating portion and the substrate are an integral structure, and the conductive portion is connected to the circuit. The present invention designs the electrode body of the working electrode, the insulating portion of the reference electrode and the counter electrode and the substrate of the circuit board into an integrated structure, and the conductive portion of each electrode is connected to the circuit of the circuit board, that is, the microneedle electrode array and the circuit board adopt an integrated structure. Compared with the existing separate connection structure, the electrical contact between the microneedle electrode array and the circuit board in the present invention is good, and the problem of poor contact is less likely to occur during use. Therefore, the detection results of the biosensor of the present invention are more accurate, and at the same time, it can achieve high-sensitivity and high-stability continuous detection of the concentration of the substance to be measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0030] Figure 1 A schematic structural diagram of an embodiment of a biosensor provided by the present invention;

[0031] Figure 2 A schematic structural diagram of an embodiment of a wearable device provided by the present invention;

[0032] Figure 3 A schematic flow chart of an embodiment of a method for preparing a biosensor provided by the present invention;

[0033] Figure 4 A schematic flow chart of another embodiment of the method for preparing a biosensor provided by the present invention;

[0034] Figure 5 This is a schematic diagram of the structure involved in the preparation method of the biosensor provided by the present invention.

[0035] Description of Figure Numbers:

[0036] 100. Biosensor; 1. Circuit board; 11. Substrate; 111. Through hole; 13. Circuit; 2. Microneedle electrode array; 21. Working electrode; 22. Reference electrode; 23. Counter electrode; 24. Blank electrode; 2a. Conductive portion; 2b. Insulating portion; 2c. First bend section; 2d. Second bend section; 2e. Connection point; 200. Housing; 201. Baseboard; 201a. Mounting port; 202. Cover.

[0037] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0039] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0040] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0041] Blood sugar levels are a key indicator of human health. Traditional fingerstick blood tests and continuous glucose monitors (CGM) are the most commonly used blood sugar monitoring devices, but both face numerous challenges. For example, fingerstick blood tests can only detect discrete blood sugar levels and cannot detect hyperglycemia or hypoglycemia. CGMs also present challenges such as tissue damage, pain, signal delays, and poor accuracy.

[0042] Microneedle array electrodes are a promising alternative to CGM sensors, measuring only 0.2-0.3 mm in length, 1 / 30 the length of traditional CGM sensors. Microneedle arrays can be inserted shallowly into the upper dermis of the skin, obtaining dermal interstitial fluid (DIF) to support glucose monitoring. Furthermore, studies have found that analytes in DERIF are closely correlated with those in blood, with minimal time delay (less than 5 minutes), providing more accurate real-time or near-real-time results, especially during rapid blood glucose changes. Microneedle array electrodes are inserted very shallowly into the tissue, lacking pain receptors in the upper dermis, providing a more comfortable and convenient user experience for patients.

[0043] At present, microneedle array glucose sensors mainly include a microneedle electrode array and a circuit board. Among them, the microneedle electrode array is generally a separate split structure, which needs to be connected and assembled together through connectors. However, during use, this connection structure often has the following problems: loose connectors lead to poor electrical contact between the microneedle electrode array and the circuit board, which in turn leads to low accuracy of its detection results.

[0044] In order to solve the above technical problems, the present invention provides a biosensor.

[0045] See also Figure 1 In one embodiment of the present invention, a biosensor 100 includes a circuit board 1 and a microneedle electrode array 2. The circuit board 1 includes a substrate 11 and a circuit 13. The substrate 11 has a first surface and a second surface opposite to each other. The circuit 13 is provided on the first surface of the substrate 11. The substrate 11 is provided with at least three through-holes 111 penetrating the two opposite surfaces. The microneedle electrode array 2 includes at least one working electrode 21, a reference electrode 22, and a counter electrode 23. The working electrode 21, the reference electrode 22, and the counter electrode 23 all bend and extend from the first surface through the corresponding through-holes 111 toward the second surface. The working electrode 21 includes an electrode body and a sensitive layer (not shown) provided on the surface of the electrode body. The electrode body, the reference electrode 22, and the counter electrode 23 all include an insulating portion 2b and a conductive portion 2a connected to each other. The insulating portion 2b and the conductive portion 2a all bend and extend from the first surface toward the second surface, and the insulating portion 2b and the substrate 11 are an integral structure. The conductive portion 2a is connected to the circuit 13.

[0046] In an embodiment of the present invention, substrate 11 is made of a flexible polymer material. Optionally, the material of substrate 11 includes, but is not limited to, polyimide or polyethylene terephthalate. Circuit 13 can be manufactured using processes such as screen printing, electroplating, or ion sputtering. The resulting circuit board 1 is a flexible printed circuit (FPC). Substrate 11 is provided with at least three through-holes 111 extending through two opposing surfaces, each of which is roughly elongated, and circuit 13 partially extends to a sidewall of through-hole 111. A working electrode 21, a reference electrode 22, and a counter electrode 23 are each provided corresponding to a through-hole 111, and the dimensions of the working electrode 21, reference electrode 22, and counter electrode 23 are no larger than the dimensions of the corresponding through-hole 111. Thus, each electrode can be bent and extended from the first surface through the corresponding through-hole 111 toward the second surface. The working electrode 21 includes an electrode body and a sensitive layer provided on the surface of the electrode body. The electrode body, the reference electrode 22, and the counter electrode 23 have the same structure, and all include an insulating portion 2b and a conductive portion 2a extending and connected along the length direction. That is, the insulating portion 2b and the conductive portion 2a are both bent and extended from the first surface toward the second surface. The insulating portion 2b is located on the side facing away from the through hole 111, and the conductive portion 2a is located on the side facing the through hole 111. The insulating portion 2b is made of the same material as the substrate 11, and the two are an integral structure. The conductive portion 2a is connected to the circuit 13. The conductive portion 2a and the circuit 13 are both made of conductive materials. The conductive materials used for the two can be the same or different, and are not limited here. Since the insulating portion 2b and the substrate 11 are an integral structure and the connection is relatively firm, the connection between the conductive portion 2a and the circuit 13 is more reliable and is less likely to have poor contact problems. The sensitive layer is formed of a sensitive material and can be used to detect the concentration of the substance to be tested. Optionally, the sensitive material includes but is not limited to a glucose-sensitive material, a protein-sensitive material, and a tumor marker-sensitive material. Among them, the glucose-sensitive material can be used to detect the concentration of glucose, the protein-sensitive material can be used to detect the concentration of protein, and the tumor marker-sensitive material can be used to detect the concentration of tumor markers.

[0047] It should be noted that the sensitive layer covers at least the conductive portion 2a of the working electrode 21. Specifically, the sensitive layer covers the conductive portion 2a, or alternatively, the sensitive layer covers both the conductive portion 2a and the insulating portion 2b. The specific design depends on the method of forming the sensitive layer (e.g., brush coating or dip coating), and is not limited here. Methods for forming the sensitive layer include brush coating and dip coating.

[0048] The working electrode 21, reference electrode 22, and counter electrode 23 are all electrically connected to the circuit 13 via their conductive portions 2a. The working electrode 21 is the site of the redox reaction, where the analyte is oxidized or reduced, generating an electrical signal related to the analyte's concentration. The conductive portion 2a of the working electrode 21 can be made of carbon or metal, with its surface modified with a sensitive layer. The counter electrode 23 is connected in series with the working electrode 21 to form a circuit, where an electrode reaction opposite to that of the working electrode 21 occurs to maintain charge balance. The conductive portion 2a of the counter electrode 23 can be made of platinum (Pt), gold (Au), carbon (C), stainless steel, or other materials. The reference electrode 22 is connected in parallel with the working electrode 21 to provide a stable reference potential for calibrating the potential of the working electrode 21 and ensuring accuracy during detection. The conductive portion 2a of the reference electrode 22 can be made of Ag / AgCl, saturated calomel, or other materials.

[0049] In the present invention, the electrode body of the working electrode 21, the insulating portion 2b of the reference electrode 22 and the counter electrode 23 are designed to be an integrated structure with the substrate 11 of the circuit board 1, and the conductive portion 2a of each electrode is connected to the circuit 13 of the circuit board 1, that is, the microneedle electrode array 2 and the circuit board 1 adopt an integrated structure. Compared with the existing split connection structure, the electrical contact between the microneedle electrode array 2 and the circuit board 1 in the present invention is good, and poor contact problems are not likely to occur during use. Therefore, the detection results of the biosensor 100 of the present invention are more accurate, and at the same time, it can achieve high-sensitivity and high-stability continuous detection of the concentration of the substance to be measured.

[0050] Of course, the circuit board 1 may also include a connecting device, which is arranged on the first surface of the substrate 11 and connected to the circuit 13. The connecting device includes but is not limited to at least one of a chip, a resistor, a capacitor, and an inductor. The chip, resistor, capacitor, and inductor are all devices that can be connected to the circuit 13, and each plays a different role. Different circuits 13 can be designed according to the different types of substances monitored by the biosensor 100 or the monitoring needs of the circuit 13, and appropriate connecting devices can be selected to access the circuit 13.

[0051] In an optional embodiment, the insulating portion 2b of each electrode is made of the same flexible high molecular polymer material as the substrate 11, so that each electrode can not only be inserted into the upper dermis area of ​​the skin without being easily broken or damaged, but can also better fit the surface of human skin. Even when the skin has a certain degree of movement or deformation, it can maintain close contact with the skin, thereby enabling the biosensor 100 to achieve long-term and stable detection.

[0052] See again Figure 1In one embodiment of the present invention, the electrode body, the reference electrode 22 and the counter electrode 23 all include a first bent segment 2c and a second bent segment 2d connected to each other, and the end of the first bent segment 2c away from the second bent segment 2d is connected to the side wall of the corresponding through hole 111. The first bent segment 2c and the second bent segment 2d both include an insulating portion 2b and a conductive portion 2a connected to each other, and the length of the first bent segment 2c is less than the length of the second bent segment 2d.

[0053] In the embodiment of the present invention, the electrode body, the reference electrode 22, and the counter electrode 23 have the same structure, all of which adopt a two-section bending structure, wherein the length of the first bending section 2c is less than the length of the second bending section 2d. The first bending section 2c is used to enable the conductive portion 2a of the electrode to achieve a preliminary transition connection with the circuit 13, and the second bending section 2d is used to adjust the angle of the electrode, so that the conductive portion 2a of the electrode can be more closely contacted and connected with the circuit 13 on the surface of the substrate 11, thereby improving the stability of the connection between the two, thereby further improving the accuracy of the detection results. At the same time, in the subsequent electrode detection process, when the electrode has a certain degree of movement or deformation on the skin, the two-section bending structure design can disperse the stress at the connection between the electrode and the substrate 11, effectively ensuring the stability and reliability of the detection.

[0054] See again Figure 1 In some embodiments, the surface of the first bending section 2c is an arc surface. Such a design can achieve a smoother transition connection between the conductive portion 2a of the electrode and the circuit 13, thereby further improving the connection stability between the two and improving the accuracy of the detection results; at the same time, it also better disperses the stress at the connection between the electrode and the substrate 11, and more effectively ensures the stability and reliability of the detection.

[0055] See again Figure 1 In some embodiments, the surface of the second bent segment 2d is flat, and the angle between the second bent segment 2d and the substrate 11 ranges from 80° to 100° (e.g., 80°, 85°, 90°, 95°, 100°, and any range between these two endpoints). The angle between the second bent segment 2d and the substrate 11 can reflect the angle at which each electrode is inserted into the skin. Designing this angle range facilitates quick and effective insertion of the electrodes into the skin for testing, enhancing the convenience of the testing operation.

[0056] In an optional embodiment of the present invention, a plurality of working electrodes 21 are provided, the plurality of working electrodes 21 are arranged in parallel, and the materials of the sensitive layers of the plurality of working electrodes 21 are different.

[0057] In the embodiment of the present invention, different working electrodes 21 are designed with different sensitive materials in the sensitive layers, enabling simultaneous detection of different concentrations of analytes, thereby enriching the detection capabilities of the biosensor 100. It should be noted that the thickness of the sensitive layer, the region where the sensitive layer is located, and the material of the electrode body in each working electrode 21 can be the same or different, and are not limited here, as long as the detection of the corresponding substance concentration is achieved. The region where the sensitive layer is located can be the region where the sensitive layer covers the conductive portion 2a, or the region where the sensitive layer covers both the conductive portion 2a and the insulating portion 2b.

[0058] See again Figure 1 In a specific embodiment of the present invention, two working electrodes 21 are provided, and the two working electrodes 21 are provided in parallel. The materials of the sensitive layers in the two working electrodes 21 are different. For example, the materials of the sensitive layers of the two working electrodes 21 are respectively selected from two of glucose-sensitive materials, protein-sensitive materials, and tumor marker-sensitive materials. Thus, the biosensor 100 can detect the concentrations of two substances at the same time.

[0059] In the glucose detection of complex samples (such as blood and body fluids), substances such as uric acid and ascorbic acid in the serum may undergo oxidation reactions on the surface of the working electrode 21, generating false positive currents, i.e., interference signals. In order to suppress nonspecific interference and improve detection accuracy, in some embodiments of the present invention, reference is again made to Figure 1 The microneedle electrode array 2 also includes a blank electrode 24. The structure of the blank electrode 24 is the same as that of the electrode body. The material of the conductive part 2a of the blank electrode 24 is the same as that of the conductive part 2a of the electrode body, and the blank electrode 24 is arranged in parallel with the working electrode 21.

[0060] In an embodiment of the present invention, the blank electrode 24 has the same electrode body structure as the working electrode 21, that is, the blank electrode 24 bends and extends from the first surface through the corresponding through hole 111 toward the second surface. The blank electrode 24 includes an insulating portion 2b and a conductive portion 2a connected to each other. The insulating portion 2b and the conductive portion 2a both bend and extend from the first surface toward the second surface. The insulating portion 2b and the substrate 11 are integrally formed and made of the same material, both of which are flexible polymer materials. At the same time, the conductive portion 2a of the blank electrode 24 is made of the same material as the conductive portion 2a of the electrode body. The blank electrode 24 is arranged in parallel with the working electrode 21. Thus, the working electrode 21 is used to detect the concentration of the substance to be detected, and the blank electrode 24 is used to detect the concentration of interfering substances other than the substance to be detected. That is, the biosensor 100 can simultaneously detect the concentration of the substance to be detected and the concentration of interfering substances other than the substance to be detected. In this way, the test data of the working electrode 21 can be dynamically calibrated using the signal from the blank electrode 24, avoiding detection errors caused by interfering substances and thereby improving detection accuracy. It is understandable that the blank electrode 24 detects a control signal, which is used to evaluate the specificity of the detection, reduce the risk of false positives, and improve the stability and accuracy of the detection.

[0061] In some embodiments of the present invention, the microneedle electrode array 2 includes multiple working electrodes 21 and a blank electrode 24. The sensitive layers of the multiple working electrodes 21 are made of different materials, while the conductive portion 2a of the blank electrode 24 is made of the same material as the conductive portion 2a of each working electrode 21. The multiple working electrodes 21 are arranged in parallel, and the blank electrode 24 is arranged in parallel with the working electrode 21. With this design, the biosensor 100 can simultaneously detect the concentrations of multiple analytes and interfering substances other than the analytes. This not only enriches the detection capabilities of the biosensor 100, but also effectively avoids detection errors caused by interfering substances, thereby improving detection accuracy.

[0062] The present invention also provides a method for preparing the biosensor 100 , which is used to prepare the biosensor 100 described above.

[0063] Reference Figure 3 and Figure 5 In one embodiment of the present invention, the method for preparing the biosensor 100 includes the following steps:

[0064] In step S10 , a substrate 11 is provided.

[0065] Specifically, the substrate 11 may be made of a flexible polymer material. Optionally, the material of the substrate 11 includes but is not limited to polyimide or polyethylene terephthalate.

[0066] Step S20 , preparing a circuit 13 and at least three conductive parts 2 a connected to the circuit 13 on the first surface of the substrate 11 .

[0067] Specifically, the first surface of the substrate 11 is divided into a circuit 13 area and a microneedle electrode array 2 area, and the outline of the circuit 13 is drawn in the circuit 13 area. At least three origins are marked on the boundary between the circuit 13 area and the microneedle electrode array 2 area. The origins are connection points 2e. The outlines of at least three conductive parts 2a are drawn starting from each origin. Optionally, the outlines of the conductive parts 2a are the same size to facilitate the simultaneous preparation of multiple conductive parts 2a at one time. According to the outlines of the circuit 13 and the conductive parts 2a that have been drawn, the circuit 13 and the at least three conductive parts 2a are prepared on the first surface of the substrate 11 using at least one method selected from screen printing, electroplating, and ion sputtering. Among them, screen printing is to make a shape corresponding to the circuit 13 and the conductive part 2a on a screen printing plate, and then print the conductive material through the mesh on the screen printing plate onto the substrate 11. Electroplating is a process in which the conductive material to be made into the circuit 13 and the conductive part 2a is used as an anode to make these conductive materials adhere to the surface of the substrate 11. Ion sputtering is the process of sputtering the circuit 13 and the conductive portion 2a on the surface of the substrate 11. Optionally, the same conductive material is used to prepare the circuit 13 and the conductive portion 2a, and the circuit 13 and the conductive portion 2a can be prepared at the same time. The circuit 13 and the conductive portion 2a having a specific shape and size can be prepared by at least one method selected from screen printing, electroplating, and ion sputtering. Of course, various connecting devices for connecting the circuit 13 can also be prepared on the first surface of the substrate 11, wherein the connecting devices include but are not limited to at least one of a chip, a resistor, a capacitor, and an inductor.

[0068] In step S30 , at least one conductive portion 2 a is cut, bent, and modified to obtain at least one working electrode 21 , and two conductive portions 2 a are cut and bent to obtain a reference electrode 22 and a counter electrode 23 .

[0069] In step S30, when preparing the working electrode 21, the order of cutting, bending and modifying operations may not be limited, and the specific order of operations may be determined according to the specific process of modification, wherein the specific process of modification includes but is not limited to dipping and brushing.

[0070] Since the size of each electrode is small and the cutting process requires high precision, a laser cutting process can be used to cut the substrate 11 to penetrate the second surface to obtain an electrode structure consisting of a conductive portion 2a and an insulating portion 2b formed by cutting the substrate 11.

[0071] In some embodiments, the modification adopts a brushing process, and the working electrode 21 can be prepared by the following steps: first, a sensitive material is brushed on the surface of at least one conductive part 2a to form a sensitive layer, and then the substrate 11 is cut according to the outer contour of the sensitive layer to penetrate the second surface to obtain at least one working electrode 21 base, and then the working electrode 21 base is bent toward the second surface to obtain at least one working electrode 21.

[0072] In this embodiment, the working electrode 21 is prepared by sequentially modifying, cutting, and bending. The modification of the sensitive material is performed before bending, which can facilitate the modification operation and is conducive to forming a more uniform and stable sensitive layer. The electrode body of the working electrode 21 prepared in this embodiment includes a conductive portion 2a and an insulating portion 2b formed by cutting the substrate 11. The sensitive layer only covers the surface of the conductive portion 2a, but does not cover the insulating portion 2b. This can not only achieve the detection function, but also save the amount of sensitive material to a certain extent, reducing the preparation cost. In addition, after the working electrode 21 is prepared, the substrate 11 also forms a through hole 111, and the size of the through hole 111 is adapted to the outer contour size of the sensitive layer.

[0073] In some other embodiments, the modification adopts a dip-coating process, and the working electrode 21 can be prepared by the following steps: first, the substrate 11 is cut according to the outer contour of at least one conductive part 2a to penetrate the second surface, and is bent toward the second surface to obtain at least one electrode body, and a sensitive material is dip-coated on the surface of the electrode body to form a sensitive layer to obtain at least one working electrode 21.

[0074] In this embodiment, the working electrode 21 is prepared by cutting, bending and modifying in sequence. The modification of the sensitive material is carried out after bending, and the modification is carried out by a dip coating process. The operation is relatively simple, and a sensitive layer can be formed on the entire surface of the electrode body. The electrode body of the working electrode 21 prepared in this embodiment includes a conductive portion 2a and an insulating portion 2b formed by cutting the substrate 11. The sensitive covering covers the entire surface of the conductive portion 2a and the insulating layer, that is, covers the entire surface of the electrode body. In addition, after the working electrode 21 is prepared, the substrate 11 also forms a through hole 111, and the size of the through hole 111 is adapted to the outer contour size of the conductive portion 2a.

[0075] In step S30 , when preparing the reference electrode 22 and the counter electrode 23 , the substrate 11 is first cut along the outline of the conductive portion 2 a to penetrate the second surface, and then bent and extended toward the second surface to obtain the reference electrode 22 and the counter electrode 23 .

[0076] It should be noted that the specific material selection and connection method of the working electrode 21, the reference electrode 22 and the counter electrode 23 can refer to the above embodiments and will not be described in detail here.

[0077] The bending operations involved in the preparation of the working electrode 21, the reference electrode 22, and the counter electrode 23 in the present invention are the same. In one embodiment of the present invention, in step S30, the bending step includes:

[0078] The connection between the conductive portion 2a and the circuit 13 is marked as the first position, the end of the conductive portion 2a away from the circuit 13 is marked as the second position, and the portion between the first position and the second position and close to the first position is marked as the third position;

[0079] The first position and the third position are used as bending starting points to form a first bending section 2c and a second bending section 2d.

[0080] In this embodiment, the first position is the position of the connection point 2e, and the second position is designed to be close to the first position, that is, the distance between the first position and the second position is smaller than the distance between the second position and the third position. Thus, through two bends, a first bend section 2c and a second bend section 2d can be formed, wherein the length of the first bend section 2c is smaller than the length of the second bend section 2d. That is, each electrode of the present invention adopts a two-stage bending structure, wherein the length of the first bend section 2c is smaller than the length of the second bend section 2d. The first bend section 2c is used to achieve a preliminary transition connection between the conductive portion 2a of the electrode and the circuit 13, and the second bend section 2d is used to adjust the angle of the electrode. In this way, the conductive portion 2a of the electrode can be more closely connected to the circuit 13 on the surface of the substrate 11, thereby improving the stability of the connection between the two and further improving the accuracy of the detection results. At the same time, in the subsequent use of the electrode detection process, when the electrode has a certain degree of movement or deformation on the skin, the two-stage bending structure design can disperse the stress at the connection between the electrode and the substrate 11, effectively ensuring the stability and reliability of the detection.

[0081] The specific bending process can be manual bending, specifically using flat-nose pliers or a bench vise with simple tooling (such as a customized metal block or mold that matches the bending angle), or directly using needle-nose pliers or bending pliers (if the electrode is small or thin) to form the first and second bent segments 2c and 2d. Of course, laser-assisted bending or other reasonable methods can also be used to form the first and second bent segments 2c and 2d.

[0082] In some embodiments, the first bent section 2c formed by the bending is configured in an arc shape. Specifically, the arc-shaped first bent section 2c can be formed using a heat-assisted forming method or other reasonable methods. Designing the first bent section 2c as an arc shape can achieve a smoother transition between the conductive portion 2a of the electrode and the circuit 13, thereby further improving the connection stability between the two and enhancing the accuracy of the detection results. It also better disperses the stress at the connection between the electrode and the substrate 11, more effectively ensuring the stability and reliability of the detection.

[0083] In some embodiments, the surface of the second bending section 2d formed by bending is a flat surface, and the angle range between the second bending section 2d and the substrate 11 is designed to be 80°~100°, which makes it convenient for the electrode to be quickly and effectively inserted into the skin for detection, thereby improving the convenience of the detection operation.

[0084] Of course, in some other embodiments, multiple working electrodes 21 are prepared, and during the preparation process, the sensitive materials modified in each working electrode 21 are different. The biosensor 100 prepared in this way can realize the detection of different concentrations of substances to be tested at one time, thereby enriching the detection function of the biosensor 100.

[0085] Reference Figure 4 and Figure 5 In some embodiments of the present invention, the method for preparing the biosensor 100 includes the following steps:

[0086] Step S10, providing a substrate 11;

[0087] Step S20a, preparing a circuit 13 and at least four conductive parts 2a connected to the circuit 13 on the first surface of the substrate 11;

[0088] In step S30a, at least one conductive portion 2a is cut, bent, and modified to obtain at least one working electrode 21, and three conductive portions 2a are cut and bent to obtain a reference electrode 22, a counter electrode 23, and a blank electrode 24.

[0089] In this embodiment, the preparation of the blank electrode 24 is the same as that of the reference electrode 22 and the counter electrode 23. For details, please refer to the above embodiments and will not be described in detail here. The biosensor 100 prepared in this embodiment includes a circuit board 1 and a microneedle electrode array 2, wherein the microneedle electrode array 2 includes a working electrode 21, a reference electrode 22, a counter electrode 23 and a blank electrode 24. The specific structure and connection method of each electrode can refer to the above embodiments and will not be described in detail here. The biosensor 100 of this embodiment can simultaneously detect the concentration of the substance to be measured and the concentration of interfering substances other than the substance to be measured. In this way, the test data of the working electrode 21 can be dynamically calibrated by the signal of the blank electrode 24, thereby avoiding detection errors caused by interfering substances and improving the accuracy of detection.

[0090] Of course, in other embodiments, multiple working electrodes 21, a reference electrode 22, a counter electrode 23, and a blank electrode 24 can be prepared. The structure and connection method of each electrode can refer to the above embodiment and will not be described in detail here. The resulting biosensor 100 can simultaneously detect the concentrations of multiple analytes and the concentrations of multiple interfering substances other than the analytes. This can not only enrich the detection function of the biosensor 100, but also effectively avoid detection errors caused by interfering substances, thereby improving detection accuracy.

[0091] The present invention also provides a wearable device comprising a housing 200 and a biosensor 100. The specific structure of the biosensor 100 is similar to that of the aforementioned embodiments. Since the present wearable device utilizes all of the technical solutions of all of the aforementioned embodiments, it at least possesses all of the beneficial effects brought about by the technical solutions of the aforementioned embodiments, which will not be further detailed here. The substrate 11 of the biosensor 100 is disposed on or within the housing 200, the circuit 13 is located within the housing 200, and the working electrode 21, reference electrode 22, and counter electrode 23 are located outside the housing 200.

[0092] In the present invention, the housing 200 can be a split structure, and the shape of the housing 200 is not limited. The housing 200 is used to encapsulate the biosensor 100 to obtain a wearable device, which is convenient for users to carry.

[0093] Reference Figure 2 In one embodiment of the present invention, the shell 200 adopts a split structure, including a substrate 201 and a cover 202 covering one surface of the substrate 201. The substrate 201 and the cover 202 together enclose a receiving cavity; the substrate 201 is provided with an installation opening 201a connected to the receiving cavity. The shape and size of the installation opening 201a are adapted to the shape and size of the substrate 11. The substrate 11 is installed in the installation opening 201a, the circuit 13 is located in the receiving cavity, and the microneedle electrode array 2 is located outside the receiving cavity.

[0094] In this embodiment of the present invention, substrate 11 is fixedly mounted (optionally by adhesive) within mounting opening 201a of base plate 201. After installation, the first surface of substrate 11 faces the accommodating cavity, i.e., circuit 13 is positioned within the accommodating cavity, thereby protecting circuit 13. The second surface of substrate 11 faces away from the accommodating cavity, with microneedle electrode array 2 positioned outside the accommodating cavity, allowing direct insertion into the skin for detection. Naturally, through-holes 111 corresponding to the microneedle electrode array 2 in substrate 11 of biosensor 100 communicate with the accommodating cavity. These through-holes 111 can be used to subsequently position a needle guide or other auxiliary device.

[0095] In another embodiment of the present invention, the shell 200 adopts a split structure, including a substrate 201 and a cover body 202 covering one surface of the substrate 201. The substrate 201 and the cover body 202 together enclose a accommodating cavity. The substrate 201 is provided with a plurality of avoidance holes connected to the accommodating cavity. The substrate 11 is fixedly mounted on the surface of the substrate 201 located in the accommodating cavity, with the first surface facing the accommodating cavity and the second surface facing the substrate 201. The working electrode 21, the reference electrode 22 and the counter electrode 23 respectively pass through the corresponding avoidance holes and are exposed on the outer surface of the shell 200.

[0096] In this embodiment, the circuit board 1 is encapsulated within the housing 200, thereby protecting the circuit 13. The number of clearance holes in the housing 200 matches the number of electrodes in the biosensor 100, and their sizes are also adapted. Thus, each electrode can be exposed on the outer surface of the housing 200 through the corresponding clearance hole, allowing direct insertion into the skin for detection.

[0097] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformation made by utilizing the contents of the present invention's description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A method for preparing a biosensor, characterized in that: The biosensor comprises: A circuit board, comprising a substrate and a circuit, wherein the substrate has a first surface and a second surface opposite to each other and is provided with at least three through holes penetrating the first surface and the second surface, and the circuit is provided on the first surface; and A microneedle electrode array, comprising at least one working electrode, a reference electrode, and a counter electrode, wherein the working electrode, the reference electrode, and the counter electrode all extend from the first surface through corresponding through-holes toward the second surface, the working electrode comprising an electrode body and a sensitive layer disposed on the surface of the electrode body, the electrode body, the reference electrode, and the counter electrode all comprising an insulating portion and a conductive portion connected thereto, the insulating portion and the conductive portion all extend from the first surface toward the second surface, the insulating portion being an integral structure with the substrate, and the conductive portion being connected to the circuit; The method for preparing the biosensor comprises the following steps: providing a substrate; Prepare a circuit and at least three conductive parts connected to the circuit on the first surface of the substrate; At least one of the conductive parts is cut, bent and modified to prepare at least one working electrode, and two of the conductive parts are cut and bent respectively to prepare a reference electrode and a counter electrode.

2. The method for preparing a biosensor according to claim 1, wherein: The electrode body, the reference electrode and the counter electrode all include a first bending section and a second bending section connected to each other, the end of the first bending section away from the second bending section is connected to the side wall of the corresponding through hole, the first bending section and the second bending section both include an insulating portion and a conductive portion connected to each other, and the length of the first bending section is less than the length of the second bending section.

3. The method for preparing a biosensor according to claim 2, wherein: The surface of the first bending section is a curved surface; and / or, The surface of the second bending section is a flat surface, and the angle between the second bending section and the substrate is in the range of 80° to 100°.

4. The method for preparing a biosensor according to claim 1, wherein: The working electrodes are provided in plurality, the plurality of working electrodes are arranged in parallel, and the sensitive layers of the plurality of working electrodes are made of different materials.

5. The method for preparing a biosensor according to any one of claims 1 to 4, wherein: The microneedle electrode array further includes a blank electrode. The structure of the blank electrode is the same as that of the electrode body, and the material of the conductive portion of the blank electrode is the same as that of the conductive portion of the electrode body.

6. The method for preparing a biosensor according to claim 1, wherein: The step of cutting, bending and modifying at least one of the conductive portions to obtain at least one working electrode comprises: A sensitive material is applied to the surface of at least one of the conductive portions to form a sensitive layer, the substrate is cut according to the outer contour of the sensitive layer to penetrate the second surface to obtain at least one working electrode substrate, and the working electrode substrate is bent toward the second surface to obtain at least one working electrode; or The substrate is cut according to the outer contour of at least one of the conductive parts to penetrate the second surface, and is bent toward the second surface to obtain at least one electrode body, and a sensitive material is dipped on the surface of the electrode body to form a sensitive layer to obtain at least one working electrode.

7. The method for preparing a biosensor according to claim 1, wherein: The bending step includes: The connection between the conductive portion and the circuit is marked as a first position, the end of the conductive portion away from the circuit is marked as a second position, and the portion between the first position and the second position and close to the first position is marked as a third position; Bending is performed with the first position and the third position as bending starting points to form a first bending section and a second bending section.

8. The method for preparing a biosensor according to any one of claims 6 to 7, wherein: The preparation method of the biosensor comprises the following steps: Prepare a circuit and at least four conductive parts connected to the circuit on the first surface of the substrate; At least one of the conductive parts is cut, bent and modified to prepare at least one working electrode, and three of the conductive parts are cut and bent respectively to prepare a reference electrode, a counter electrode and a blank electrode.

9. A wearable device, characterized in that: include: case; and The biosensor prepared by the method for preparing a biosensor according to any one of claims 1 to 8, wherein the substrate of the biosensor is provided on or within the shell, the circuit is located within the shell, and the working electrode, the reference electrode, and the counter electrode are all located outside the shell.

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