Electrochemical sensor testing system

Abstract

The utility model provides an electrochemical sensor testing system which is applied to testing an electrochemical sensor to be tested, and the electrochemical sensor to be tested comprises a plurality of working contacts. The electrochemical sensor testing system comprises a conductive lead corresponding to the working contact and electrochemical performance testing equipment, the first end of the conductive lead is fixedly connected with the working contact through a conductive connecting layer, and the second end of the conductive lead is electrically connected with the electrochemical performance testing equipment. According to the utility model, the conductive lead and the working contact are combined with the conductive connecting layer, so that the electrochemical sensor to be tested and the electrochemical performance testing equipment can form stable electric connection; the problems of short circuit, poor contact, electrode damage and the like caused by small size of the sensor in the electric combination of the current electrochemical performance testing equipment and the sensor are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of electrochemical sensors, in particular to an electrochemical sensor testing system. Background Art

[0002] Subcutaneous implantable continuous glucose monitoring system (CGM) can be used to monitor changes in human blood sugar. CGM integrates multiple technologies such as electrochemical sensors, circuits, and Bluetooth. Among them, the electrochemical sensor, as the subcutaneous implant probe of CGM, is the core component of CGM technology. Its performance will directly determine the accuracy of blood sugar monitoring results. However, the sensor is small in size, the electrode is highly integrated, and the working contacts are close, which leads to problems such as short circuits, poor contact, and damage to electrodes when the detection equipment is connected to the sensor, which has many shortcomings. Utility Model Content

[0003] In order to solve the problems of small sensor size and high electrode integration, short circuit, poor contact and electrode damage are very likely to occur when connecting the detection equipment to the sensor.

[0004] The utility model provides an electrochemical sensor testing system, which is used for testing an electrochemical sensor to be tested, wherein the electrochemical sensor to be tested comprises a plurality of working contacts, and the electrochemical sensor testing system comprises: conductive leads corresponding to the working contacts and an electrochemical performance testing device, wherein a first end of the conductive lead is fixedly connected to the working contact through a conductive connecting layer, and a second end is electrically connected to the electrochemical performance testing device.

[0005] In one embodiment, the conductive lead includes a flexible substrate layer and a conductive film layer stacked together, and the thickness of the conductive film layer is 50-100 nm.

[0006] In one embodiment, the width of the conductive lead is 1 mm-5 mm.

[0007] In one of the embodiments, an insulating layer is formed on the surface of the conductive lead, and the insulating layer covers the connection area between the conductive lead and the working contact.

[0008] In one embodiment, the insulating layer is provided as one or more layers.

[0009] In one embodiment, the electrochemical performance testing device includes an electrical signal output unit, which is connected to the second end of the conductive lead; and a control circuit, which is electrically connected to the electrical signal output unit.

[0010] In one of the embodiments, the electrical signal output unit is connected to the conductive lead via a conductive clip.

[0011] In one of the embodiments, the electrochemical performance testing device further includes a detection circuit, and the detection circuit is electrically connected to the working contact through the conductive lead.

[0012] In one embodiment, it further comprises a buffer solution pool, in which the probe of the electrochemical sensor to be tested is placed.

[0013] In one embodiment, the conductive connection layer is conductive glue.

[0014] The utility model configures one end of a conductive lead to be fixedly connected to a working contact and the other end to be electrically connected to an electrochemical performance testing device to construct a testing environment, thereby solving the problems of short circuit, poor contact and electrode damage caused by the small size of the sensor in the electrical connection between the current electrochemical performance testing device and the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 One of the structural schematic diagrams of the electrochemical sensor to be tested provided in the embodiment of the utility model;

[0016] Figure 2 The second structural schematic diagram of the electrochemical sensor to be tested provided by the embodiment of the utility model;

[0017] Figure 3 To include Figure 1 Schematic diagram of the structure of the electrochemical sensor test system;

[0018] Figure 4 To include Figure 2 Schematic diagram of the structure of the electrochemical sensor test system;

[0019] Figure 5 To use Figure 3 Schematic diagram of the test results of applying alternating current to the electrochemical sensor test system to study the surface properties of the sensor;

[0020] Figure 6 To use Figure 3 One of the schematic diagrams of the sensor standard curve in the electrochemical sensor test system applying constant potential to study the sensor detection performance;

[0021] Figure 7 To use Figure 3 The second schematic diagram of the sensor standard curve in the electrochemical sensor test system applying constant potential to study the sensor detection performance;

[0022] Figure 8 To use Figure 3 One of the schematic diagrams of the sensor standard curve in the study of sensor temperature response using the electrochemical sensor test system;

[0023] Fig. 9 To use Figure 3 Schematic diagram of the sensor standard curve used in the study of sensor temperature response using the electrochemical sensor test system;

[0024] Fig.10 To use Figure 4 Schematic diagram of test results in electrochemical testing of sensors performed by an electrochemical sensor testing system;

[0025] Fig.11 To use Figure 4 One of the schematic diagrams of the sensor standard curve in the electrochemical test of the sensor performed by the electrochemical sensor test system;

[0026] Fig.12 To use Figure 4 The second schematic diagram of the sensor standard curve in the electrochemical test of the sensor performed by the electrochemical sensor test system;

[0027] Figure numerals: 110, 111, 112-working contacts; 113-conductive connecting layer, 114-conductive lead, 1141-first end, 1142-second end, 115-insulating layer; 116-electrochemical performance testing equipment. Specific embodiments

[0028] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the specific technical solution of the utility model will be further described in detail below in conjunction with the drawings in the embodiment of the utility model. The following embodiments are used to illustrate the utility model, but are not used to limit the scope of the utility model.

[0029] The utility model discloses an electrochemical sensor testing system, comprising: an electrochemical sensor to be tested, a conductive lead and an electrochemical performance testing device, wherein the electrochemical sensor to be tested comprises a plurality of working contacts, a first end of the conductive lead is fixedly connected to the working contacts by conductive glue, and a second end is electrically connected to the electrochemical performance testing device.

[0030] The utility model provides an electrochemical sensor testing system, which can form a stable electrical connection between the electrochemical sensor to be tested and the electrochemical performance testing equipment through the configuration of the conductive lead and the working contact combined with the conductive connection layer, thereby solving the problems of short circuit, poor contact and electrode damage caused by the small size of the sensor in the electrical connection between the electrochemical performance testing equipment and the sensor.

[0031] In an optional embodiment, the conductive lead comprises a stacked flexible substrate layer and a conductive film layer, the thickness of the conductive film layer is 50-100 nm. The flexible substrate layer provides support, and the conductive film layer provides a smaller size than conventional wires, which can match the size of the electrochemical sensor to be detected.

[0032] In an optional embodiment, the width of the conductive lead is 1 mm-5 mm. By setting this width range, the conductive lead is smaller than a conventional wire and can match the size of the sensor of the utility model.

[0033] In an optional embodiment, an insulating layer is formed on the surface of the electrochemical sensor to be tested, and the insulating layer covers the connection area between the conductive lead and the working contact. The insulating layer can protect the connection area from contact with the outside air and can also play a fixing role.

[0034] In an optional embodiment, the insulating layer is configured as one or more layers, which is not limited in the present application.

[0035] In an optional embodiment, the electrochemical performance testing device includes an electrical signal output unit, the electrical signal output unit is connected to the second end of the conductive lead; and a control circuit is electrically connected to the electrical signal output unit. In this embodiment, the control circuit can control the electrical signal output unit to provide an alternating or constant electrical signal, so that various performance parameters of the electrochemical sensor to be tested can be tested by the electrochemical testing device.

[0036] In an optional embodiment, the electrical signal output unit is connected to the conductive lead via a conductive clip. On the one hand, the conductive clip can connect the electrical signal output unit and the conductive lead. On the other hand, the conductive clip is flexibly fixed and can be disconnected at any time as needed.

[0037] In an optional embodiment, the electrochemical performance testing equipment also includes a detection circuit, which is electrically connected to the working contact. The detection circuit is used to detect the change value of the electrical signal of the working contact and generate an electrochemical curve. Of course, this application does not limit or protect the processing of the electrochemical curve.

[0038] In an optional embodiment, a buffer solution pool is further included, in which the probe of the electrochemical sensor to be tested is placed, so that various electrochemical performance test items can be carried out.

[0039] In an optional embodiment, the conductive connection layer may be conductive glue.

[0040] The electrochemical sensor testing system of the present application is described in detail below. In a preferred embodiment of the present utility model, the structure of the electrochemical sensor to be tested includes a plurality of working contacts; the electrochemical sensor testing system includes a plurality of conductive leads, the first end of each conductive lead is correspondingly fixed on one of the working contacts, and the second end is used to electrically connect to the electrochemical performance testing equipment; the surface of the conductive lead is provided with an insulating layer, covering the first end of each of the conductive leads. In an optional embodiment, the insulating layer covers all the working contacts at the same time. In this way, covering the electrode working contacts of the entire sensor with a piece of insulating layer is beneficial to protecting the entire electrode working contact area. Of course, in other embodiments, there are multiple insulating layers, and each insulating layer covers one of the working contacts. In an optional embodiment, an insulating layer is provided in the connection area between each conductive lead and the working contact, that is, the insulating layer covers the connection area between the conductive lead and the working contact. Figure 1 As shown, the conductive leads are covered by an insulating layer and then wrapped in the same "wire", so that the layout of the conductive leads of the sensor can be optimized.

[0041] In order to firmly fix the conductive lead and the working contact, the embodiment of the utility model further includes a conductive connection layer, each conductive connection layer is used to electrically connect the conductive lead and the working contact so that the end of the corresponding conductive lead is fixed to the working contact.

[0042] The conductive connecting layer can be formed by curing a conductive glue, which is a conductive carbon glue, a conductive silver glue, a conductive polymer dispersion, a silver nanowire dispersion, etc. This application is not limited to this, and the material of the conductive glue itself belongs to the known technology, and the core concept of this application does not lie in this.

[0043] The embodiments of the utility model are described in detail below with reference to the accompanying drawings.

[0044] Figure 1 FIG. 1 shows one of the structural schematic diagrams of an electrochemical sensor testing system in an embodiment of the present utility model. Figure 1As shown, the electrochemical sensor testing system of the utility model includes: the electrochemical sensor testing system is used to test the electrochemical sensor to be tested, the electrochemical sensor to be tested includes a plurality of working contacts, the working contacts include: working contact 110, working contact 111 and working contact 112; the electrochemical sensor testing system includes conductive leads corresponding to the working contacts, in the embodiment, three conductive leads 114 are provided, the first end 1141 of each conductive lead 114 is correspondingly fixed on one of the working contacts, and the second end 1142 is used to be electrically connected to the electrochemical performance testing equipment; and three conductive connection layers 113, each conductive connection layer 113 is correspondingly covered on one of the working contacts so that the end of the corresponding conductive lead 114 is fixed to the working contact; an insulating layer 115, covering the first end 1141 of each of the conductive leads 114.

[0045] In this embodiment, the conductive lead 114 can be formed by existing conductive ink, etc. The electrochemical sensor testing system of the present invention can be prepared by well-known preparation techniques. In order to clearly illustrate the core concept of the present invention, the present invention briefly describes its preparation process. However, it should be understood that the core of the present invention does not lie in the process steps, but in the configuration structure of the present invention. The description of the process part is only for the convenience of understanding the present invention, and is not a limitation on the present invention.

[0046] Figure 1 The preparation process of the electrochemical sensor test system shown is as follows:

[0047] (1) A certain volume of 1.3 wt% PEDOT:PSS (poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid) aqueous solution was taken and placed in a clean sample bottle, 5 wt% DMSO (dimethyl sulfoxide) was added, and stirred at room temperature for 10 min to prepare PEDOT conductive ink; the PEDOT conductive ink was dropped onto a flexible substrate (such as PDMS), and spin-coated at 1500 rpm for 30 s to make the conductive ink evenly and continuously dispersed, and heated at 100°C for 30 min to solidify the PEDOT into a film;

[0048] (2) Cut the above PEDOT film into strips (width 2 mm), add a drop of conductive connection layer 113 (such as conductive carbon glue) to one end of the conductive lead 114, connect the strip conductive film to the three working contacts (110, 111 and 112) of the sensor through the conductive connection layer 113, and cure at room temperature for 10 minutes;

[0049] (3) A liquid insulating layer 115 (such as epoxy resin) is dripped onto the working contacts of the sensor and the surface of the conductive film, and cured at room temperature for 20 minutes, so that the working contact area of ​​the sensor is fully insulated and fixed.

[0050] In some embodiments, the conductive ink may be PEDOT:PSS (poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid), polyaniline, polypyrrole, silver nanowires, gold nanotubes, carbon nanotubes, graphene, graphyne, Mxene (transition metal carbonitride), etc. The flexible substrate may be PDMS (polydimethylsiloxane), PI (polyimide), PET (polyethylene terephthalate), PVC (polyvinyl chloride), PC (polycarbonate), etc.

[0051] In some embodiments, the electrode working contact may be electrically connected to the electrode via a conductive lead, and the conductive lead may be a flexible conductive flying lead, a metal wire, or the like.

[0052] In some embodiments, the conductive connection layer 113 may be conductive carbon glue, conductive silver glue, conductive polymer dispersion, silver nanowire dispersion, etc. The insulating layer 115 may be epoxy resin, 502 glue, nail polish, paraffin, arbutus wax, PDMS, etc.

[0053] Please continue to combine Figure 1 In the embodiment shown, in this embodiment, when the number of electrode working contacts is greater than three, the distances between any two adjacent working contacts can be set equal for spatial uniformity. In this way, when the number of electrode working contacts is greater than three, the distances between the three electrode working contacts can be made uniform and unaffected by each other, which is conducive to configuring more electrode working contacts in a smaller area, and when the number of electrode working contacts is the same, the area required for configuration can be reduced.

[0054] Figure 3 Yes Figure 1 In the electrochemical sensor testing system, the electrochemical performance testing device clamps the second end 1142 of the conductive lead 114 of the electrochemical sensor testing system of the utility model through a wire and a clamp to perform an electrochemical performance test. At this time, since the electrochemical performance testing device does not need to directly contact the working contacts of the electrochemical sensor, problems such as electrode short circuit, poor contact and damage to the electrode can be avoided.

[0055] The utility model is described below. Figure 3The specific scenario of the test of the electrochemical sensor testing system shown is illustrated. It should be noted that the description of the electrochemical performance test of the present invention is only for illustrating in detail the technical effect of the electrochemical sensor testing system of the present invention. The electrochemical performance test itself is not within the protection scope of the present invention, and the electrochemical performance test exemplified in the present invention should not be regarded as a limitation on the protection scope of the present invention.

[0056] Sensor electrochemical activity test

[0057] The three conductive leads of the sensor of Example 1 are respectively connected to the electrochemical testing equipment, and the sensor probe is fixed and immersed in the buffer solution ( Figure 3 ). The electrochemical testing equipment can be an electrochemical workstation, a potentiostat, a galvanostat, a printed circuit board, etc.; the buffer solution can be a phosphate buffer solution (PBS), a HEPES buffer solution, a Hank's buffer solution, an artificial tissue fluid, an artificial cerebrospinal fluid, a cell culture medium, etc.

[0058] In some embodiments, the surface properties of the sensor can be studied by applying alternating current. For example, the sensor lead of Example 1 is connected to the three-electrode alligator clip of the electrochemical workstation, and the electrochemical method is selected as "cyclic voltammetry" on the workstation software page. The initial voltage is set to -0.3V, the end voltage is set to +0.6V, and the potential scanning speed is set to 0.1V / s to apply a triangular wave voltage of -0.3V to +0.6V to the sensor. Figure 5 As shown in the figure, the electrode has obvious redox peaks at around 0V and -0.12V, which is attributed to the reversible redox process of the electron mediator of the second-generation enzyme sensor. Based on the electrochemical signal of this cyclic voltammetry spectrum, according to the electrochemical formulas (1) and (2), the adsorption modification amount of the electron mediator can be calculated. This result is crucial for the evaluation of sensor performance and is important information that cannot be obtained by CGM whole machine testing.

[0059] i p =n 2 F 2 νAΓ / 4RT (1)

[0060] Q=nFAΓ (2)

[0061] Sensor standard curve and anti-interference research

[0062] In some embodiments, the sensor detection performance can be studied by applying a constant potential. For example, the sensor lead of Example 1 is connected to the three-electrode alligator clip of the electrochemical workstation, and the electrochemical method is selected as "chronoamperometry" on the workstation software page. The initial voltage is set to +50mV, and the sampling point is set to 0.1s / point to apply a constant voltage of +50mV to the sensor. A stirring bar is added to the container containing the buffer solution, and the container is fixed on a magnetic stirring table. Different volumes of 1M glucose mother solution are gradually added to the buffer solution under magnetic stirring conditions, and the current response of the sensor to 1mM, 2mM, 3mM, 5mM, 10mM, 20mM, and 30mM glucose solutions is measured to obtain the standard curve of the sensor ( Figure 6 , Figure 7 ). Based on this result, important performance indicators such as the linear detection range, response time, noise signal, consistency, reproducibility, and stability of the sensor can be quantitatively analyzed.

[0063] In addition to adding glucose mother solution, reduced substances such as ascorbic acid, acetaminophen, uric acid, dopamine, etc. can also be gradually added to study the anti-interference performance of the sensor.

[0064] Sensor Temperature Response Study

[0065] In some embodiments, the buffer solution and the sensor can be placed in a temperature control device to study the current response of the sensor at different temperatures. For example, the sensor leads of Example 1 are connected to the three-electrode alligator clips of the electrochemical workstation, and the electrochemical method is selected as "chronoamperometry" on the workstation software page. The initial voltage is set to +50mV, and the sampling point is set to 0.1s / point to apply a constant voltage of +50mV to the sensor. The sensor and the temperature probe are fixed in a sealed container containing 10mM glucose solution, and the container is placed in a temperature control device. The sensor leads are connected to the electrochemical device, and the glucose solution is heated to a specified temperature. Figure 8 and Fig. 9 As shown, with the increase of temperature, the current response of the sensor gradually increases and increases linearly in the range of 35℃~39℃.

[0066] Figure 2 A schematic diagram of another electrochemical sensor testing system in an embodiment of the present utility model is shown. Figure 1 The difference is Figure 2 The electrode has two working contacts and two electrodes. Specifically, the electrode includes a working electrode and a reference electrode. The reference electrode is configured as an inner ring sleeve rod, and the working electrode is configured as an outer ring sleeve surrounding the side wall surface of the inner ring sleeve rod, and the two ends of the inner ring sleeve rod expose the outer ring sleeve, and the two working contacts are respectively located on the end side wall of the outer ring sleeve and the end side wall of the inner ring sleeve rod.

[0067] In this embodiment, the preparation process of the electrochemical sensor testing system is as follows:

[0068] (1) A certain volume of silver nanowire dispersion (5 mg / mL) was dripped onto a flexible substrate (such as PET), and the silver nanowires were evenly and continuously dispersed by spin coating at 1500 rpm for 30 seconds, and then heated at 100°C for 30 minutes to solidify the silver nanowires into a film;

[0069] (2) cutting the silver nanowire film into strips (width 2 mm), dropping a drop of conductive connection layer 113 (such as conductive silver glue) onto one end of the strip-shaped conductive film 114, connecting the strip-shaped conductive film to two electrode contacts (110 and 111) of the sensor through the conductive connection layer 113, and curing at room temperature for 10 min;

[0070] (3) A liquid insulating layer 115 (such as PDMS) is dripped onto the working contacts of the sensor and the surface of the conductive film, and cured at room temperature for 20 minutes, so that the working contact area of ​​the sensor is fully insulated and fixed.

[0071] Sensor electrochemical testing

[0072] The two conductive leads of the sensor of variation 1 are connected to the electrochemical testing equipment respectively, and the sensor probe is fixed and immersed in the buffer solution ( Figure 4 ).

[0073] In some embodiments, the surface properties of the sensor can be studied by applying alternating current. For example, the sensor lead of variation 1 is connected to the electrode clip of the constant potential instrument, and the electrochemical method is selected as "cyclic voltammetry" on the constant potential instrument software page, and the initial voltage is set to 0V, the end voltage is set to +0.8V, and the potential scanning speed is set to 0.1V / s to apply a triangular wave voltage of 0V to +0.8V to the sensor. Fig.10 As shown in the figure, the electrode only presents non-Faraday polarization current. This is because this type of two-electrode sensor is based on the first-generation enzyme sensing principle, and the quantitative detection of glucose is achieved by detecting hydrogen peroxide, a byproduct of glucose oxidation catalyzed by glucose oxidase, through a platinum electrode. This method can quickly determine the sensor detection principle and type, and this important information cannot be obtained by testing the entire CGM.

[0074] In some embodiments, the sensor detection performance can be studied by applying a constant potential. For example, the sensor lead of variation example 1 is connected to the electrode clip of the constant potential instrument, and the electrochemical method is selected as "chronoamperometry" on the software page of the constant potential instrument. The initial voltage is set to +600mV, and the sampling point is set to 0.1s / point to apply a constant voltage of +600mV to the sensor. A stirring bar is placed in a container containing a buffer solution, and the container is fixed on a magnetic stirring table. Different volumes of 1M glucose mother solution are gradually added to the buffer solution under magnetic stirring conditions, and the current response of the sensor to 1mM, 2mM, 3mM, 5mM, 7mM, 10mM, 15mM, 20mM, 25mM, and 30mM glucose solutions is measured to obtain the standard curve of the sensor ( Fig.11 , Fig.12 ). Based on this result, important performance indicators such as the linear detection range, response time, noise signal, consistency, reproducibility, stability, and anti-interference of the sensor can be quantitatively analyzed.

[0075] Specifically, the electrochemical sensor test system is as follows Figure 3 and Figure 4 As shown, the electrochemical performance testing device clamps the second end 1142 of the conductive lead 114 of the electrochemical sensor testing system of the present invention through the conductive lead and the clamp to perform an electrochemical performance test. At this time, since the electrochemical performance testing device does not need to directly contact the working contacts of the electrochemical sensor, problems such as electrode short circuit, poor contact and damage to the electrode can be avoided.

[0076] The present invention uses specific embodiments to illustrate the principles and embodiments of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific embodiments and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. An electrochemical sensor testing system, characterized in that: The electrochemical sensor testing system is used to test an electrochemical sensor to be tested, and the electrochemical sensor to be tested includes a plurality of working contacts. The electrochemical sensor testing system includes: conductive leads corresponding to the working contacts and an electrochemical performance testing device, wherein a first end of the conductive lead is fixedly connected to the working contact through a conductive connecting layer, and a second end is electrically connected to the electrochemical performance testing device.

2. The electrochemical sensor testing system according to claim 1, characterized in that: The conductive lead comprises a flexible substrate layer and a conductive film layer which are stacked, and the thickness of the conductive film layer is 50-100 nm.

3. The electrochemical sensor testing system according to claim 2, characterized in that: The width of the conductive lead is 1 mm-5 mm.

4. The electrochemical sensor testing system according to any one of claims 1 to 3, characterized in that: An insulating layer is formed on the surface of the conductive lead, and the insulating layer covers the connection area between the conductive lead and the working contact.

5. The electrochemical sensor testing system according to claim 4, characterized in that: The insulating layer is provided as one layer or multiple layers.

6. The electrochemical sensor testing system according to claim 4, characterized in that: The electrochemical performance testing device comprises an electrical signal output unit, and the electrical signal output unit is connected to the second end of the conductive lead; The control circuit is electrically connected to the electrical signal output unit.

7. The electrochemical sensor testing system according to claim 6, characterized in that: The electrical signal output unit is connected to the conductive lead through a conductive clip.

8. The electrochemical sensor testing system according to claim 1, characterized in that: The electrochemical performance testing device further comprises a detection circuit, and the detection circuit is electrically connected to the working contact through the conductive lead.

9. The electrochemical sensor testing system according to claim 1, characterized in that: It also includes a buffer solution pool, in which the probe of the electrochemical sensor to be tested is placed.

10. The electrochemical sensor testing system according to claim 1, characterized in that: The conductive connection layer is conductive glue.

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