Invasive multi-electrode electrochemical sensor

Abstract

An intrusive multi-electrode electrochemical sensor includes a substrate, a plurality of wire electrodes, a cover plate and a plurality of golden fingers, each wire electrode includes a conductive core and an insulating film, each insulating film substantially covers the corresponding conductive core but exposes a proximal end and a free end of the corresponding conductive core, and the conductive core is electrically connected to the cover plate. Each wire electrode is provided with a substrate section and an intruding section, the near-side end is positioned on the substrate section, the free end is positioned on the intruding section, the substrate section is arranged on the substrate, the intruding sections extend outwards from the edge of the substrate, at least parts of the intruding sections of the plurality of wire electrodes are spirally wound with one another, each golden finger is provided with an exposed section which is not covered by the cover plate, and the exposed section is provided with an exposed part which is not covered by the cover plate. The exposed section extends in an insertion direction, and the extending direction of the front side part of the intruding section is not parallel to the insertion direction.

Description

Technical Field

[0001] The present application relates to an invasive electrochemical sensor. Background Art

[0002] Existing electrochemical sensors can be used for fluid detection, with test strips being a common structural form. Electrochemical test strips typically have a detection area for dripping or immersing the test solution. However, existing electrochemical test strips cannot be used for invasive testing. However, for continuous monitoring of many biophysiological parameters, invasive detectors are more suitable than existing non-invasive electrochemical test strips.

[0003] Therefore, how to provide an invasive electrochemical sensor while having a lower production cost is indeed worthy of consideration by those skilled in the art. Summary of the Invention

[0004] The technical problem to be solved by the present application is to provide an invasive electrochemical sensor with low cost.

[0005] In order to achieve the above and other purposes, the present application provides an invasive multi-electrode electrochemical sensor (hereinafter sometimes referred to as an electrochemical sensor), which includes a substrate, a plurality of wire electrodes, a cover sheet, and a plurality of gold fingers provided on the substrate, each wire electrode includes a conductive core and an insulating film, each insulating film substantially covers its corresponding conductive core but exposes a proximal end and a free end of its corresponding conductive core, each wire electrode has a substrate section and an invasive section, the proximal end is located in the substrate section, the free end is located in the invasive section, the substrate section is provided on the substrate, and the invasive section Extending outward from the edge of the substrate, at least a portion of the intruding segments of the multiple wire-like electrodes are spirally wound around each other, a cover sheet is provided on the substrate and at least a portion of the substrate segments of the multiple wire-like electrodes is fixed between the cover sheet and the substrate, the conductive inner cores in the substrate segments of the multiple wire-like electrodes are respectively electrically connected to the multiple gold fingers, each gold finger has an exposed segment not covered by the cover sheet, the multiple exposed segments extend in an insertion direction, the intruding segment has a front side portion, the extension direction of the front side portion is not parallel to the insertion direction, and the free end is located at the front side portion.

[0006] The present application adopts a design in which the extension direction of the front part is inconsistent with that of the exposed section of the gold finger, so that the electrochemical sensor of the present application can adapt to more combined characteristics of the target to be detected.

[0007] The details of other functions and embodiments of the present application are described below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the embodiments of the present application 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 recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0009] Figure 1 A perspective view of the first embodiment of the present application;

[0010] Figure 2 This is an exploded view of the first embodiment of the present application;

[0011] Figure 3 This is an exploded view of the first embodiment of the present application, wherein the conductive core is electrically connected to the gold fingers by welding;

[0012] Figure 4 This is a partially enlarged schematic diagram of the first embodiment of the present application;

[0013] Figure 5 Schematic cross-sectional view of the free ends of four conductive inner cores;

[0014] Figure 6 is a schematic cross-sectional view of the free end of the conductive inner core according to another embodiment;

[0015] Figure 7 A schematic diagram of the electrochemical sensor of the present application combined with an electrochemical sensing relay;

[0016] Figure 8 A schematic diagram of one embodiment of the intrusive end of the wire electrode of the present application;

[0017] Figure 9 A schematic diagram of another embodiment of the invasive end of the wire electrode of the present application;

[0018] Figure 10 The reproducibility test results of the electrochemical sensor of this application;

[0019] Figure 11 Cyclic voltammograms of the electrochemical sensor of this application in aqueous hydrogen peroxide solutions with different concentrations;

[0020] Figure 12 The electrochemical sensor of this application detects the current-time spectrum of the hydrogen peroxide aqueous solution using the amperometric method;

[0021] Figure 13 This is a linear regression diagram of the current-concentration of the electrochemical sensor of the present application detecting the hydrogen peroxide aqueous solution using the amperometric method;

[0022] Figure 14A schematic diagram of another embodiment of the invasive end of the wire electrode of the present application;

[0023] Figure 15 A schematic diagram of another embodiment of the invasive end of the wire electrode of the present application;

[0024] Figure 16 This is a schematic diagram of another embodiment of the electrochemical sensor of the present application.

[0025] Explanation of symbols

[0026] 1: Electrochemical sensing repeater 2: Electrochemical sensor

[0027] 10: Base plate 11: Working surface

[0028] 20, 20c: Wire electrode 21: Conductive core

[0029] 211: proximal end 212: free end

[0030] 22: Insulation film 221: End surface

[0031] 23: Substrate section 24: Intrusion section

[0032] 241: Front part 30: Gold finger

[0033] 31: exposed section 40: cover

[0034] 50: spindle 51: end

[0035] L: Insertion direction Hw: Depth

[0036] Φ: diameter DETAILED DESCRIPTION

[0037] The positional relationships described in the following embodiments include up, down, left, and right. Unless otherwise specified, they are based on the directions of the components shown in the drawings.

[0038] Please refer to Figures 1 to 4, illustrated is the first embodiment of the present application. The electrochemical sensor of the present application can be used for invasive detection of a host, which can be a human or other animal or plant. The electrochemical sensor can be used to detect whether the host contains a target analyte, the concentration of the target analyte and / or other values required for detection. The target analyte can be, but is not limited to, glycosylated hemoglobin, blood sugar, heavy metals, nitrates, nitrites, allergens, formaldehyde, dissolved oxygen, uric acid, dopamine, ascorbic acid, hemoglobin, acetaminophen, halogen ions, sulfide ions, hydrogen peroxide, trivalent arsenic ions, lead ions, zinc ions, chromium ions, phenols, amino acids and other compounds. The values to be detected can be, but are not limited to, physical parameters such as pH and conductivity. In a possible embodiment, the electrochemical sensor of the present application can also be applied to non-invasive detection environments, for example, for detecting aqueous solutions such as environmental water samples. In this embodiment, the electrochemical sensor includes a substrate 10, three filament electrodes 20, three gold fingers 30 and a cover sheet 40.

[0039] The material of the substrate 10 may be, but is not limited to, polypropylene, polyethylene terephthalate, polyimide, polyethylene, polyurethane, or polycarbonate.

[0040] Each wire electrode 20 includes a conductive core 21 and an insulating film 22 (please refer to Figure 5 ), each insulating film 22 substantially covers the corresponding conductive core 21 but exposes a proximal end 211 and a free end 212 of the corresponding conductive core 21. In addition, each wire-shaped electrode 20 has a substrate segment 23 and an intrusion segment 24, the proximal end 211 is located at the substrate segment 23, and the free end 212 is located at the intrusion segment 24. The substrate segment 23 is provided on the substrate 10, and the intrusion segment 24 extends outward from the edge of the substrate 10. The outward extension length of the intrusion segment 24 can be greater than 10 mm. In this embodiment, the intrusion segments 24 of the three wire-shaped electrodes 20 are spirally wound around each other. The advantage of spiral winding is that the distance between the electrodes is short, the resistance is small, and the detection accuracy is improved. Among them, the material of the conductive core 21 of the intrusion segment 24 of at least one wire-shaped electrode 20 is different from the material of the conductive core 21 of the other wire-shaped electrodes 20. For example, the conductive cores of the three filament electrodes of this embodiment serve as the working electrode, auxiliary electrode, and pseudo / reference electrode, respectively. Depending on the analyte, the conductive cores of the three filament electrodes may be made of, but are not limited to, the materials listed in Table 1. Furthermore, the insulating film 22 is made of an insulating material to prevent direct electrical connection between the conductive cores of different filament electrodes, which could result in a short circuit.

[0041] Table 1

[0042]

[0043] When the diameter Φ of the conductive core 21 is ≤ 25 μm, it can be used as a metallic wire ultramicroelectrode (MWUME). When the diameter Φ of the conductive core 21 satisfies the following relationship: 25 μm < Φ < 1000 μm, it can be used as a metallic wire microelectrode (MWME). When the diameter Φ of the conductive core 21 is ≥ 1000 μm, it can be used as a metallic wire electrode (MWE).

[0044] Gold fingers 30 are provided on the substrate 10. The conductive cores 21 (e.g., the proximal ends 211) in the substrate segments 23 of the plurality of filament electrodes 20 are electrically connected to the plurality of gold fingers 30. The electrical connection between the conductive cores 21 and the gold fingers 30 may be achieved by, but is not limited to, soldering or adhering conductive tape. The gold fingers 30 are, for example, screen-printed on the substrate 10. The gold fingers 30 are made of, for example, printed carbon paste or printed silver paste. The printed carbon paste or printed silver paste may also be subjected to surface treatment, such as additional sputtering of a metal material such as platinum, gold, copper, or silver. In this embodiment, the gold fingers 30 extend to the edge of the substrate 10.

[0045] The cover plate 40 is disposed on the substrate 10 and completely fixes the substrate segments 23 of the plurality of wire electrodes 20 between the cover plate 40 and the substrate 10 .

[0046] Please refer to Figure 5 The free end of the conductive core 21 may be surface-treated to exhibit different shapes such as being flush with the end surface of the insulating film 22, protruding from the end surface of the insulating film 22, having an irregular surface, and being recessed into the end surface of the insulating film 22. In one embodiment, the free end 212 of the conductive core 21 is recessed into one end surface 221 of the insulating film 22, and satisfies the following relationship: H w / Φ<50, where H w The depth of the free end 212 sunken into the end surface 221 can reserve space for subsequent chemical modification of the free end of the conductive core, for example, an enzyme layer (not shown) can be filled in the groove formed on the end surface of the insulating film. Figure 6 As shown, the free end 212 of at least one of the conductive cores 21 is made of a material different from that of the other parts of the conductive core 21 , for example, the free end of the conductive core is made of carbon while the other parts are made of copper, so as to adapt to different detection environments.

[0047] Please refer to Figure 7 , Figures 1 to 4 The electrochemical sensor of the illustrated embodiment can be used in conjunction with an electrochemical sensing repeater 1 . The electrochemical sensing repeater 1 can electrically connect to each of the gold fingers of the electrochemical sensor 2 and transmit the signal sensed by the electrochemical sensor to a remote receiving unit (e.g., a smartphone, computer, or cloud server) for further calculation and / or display of the calculation results.

[0048] It should be noted that the number of wire electrodes can be adjusted, for example Figure 8 In the embodiment shown, the invasive ends of four spirally wound wire electrodes 20 can be used to detect more analytes simultaneously; in addition, as shown in FIG. Figure 9 As shown, the intrusive ends of the six wire electrodes 20 can be spirally wound around the intrusive end of the linearly extending central wire electrode 20c, that is, the intrusive end of at least one linearly extending wire electrode can serve as the axis for the spiral winding of the intrusive ends of the other wire electrodes.

[0049] Please refer to Figure 10 , in a reproducibility test, multiple Figure 1 The electrochemical sensor was immersed in two different aqueous solutions three times in turn. The results showed that the electrochemical sensor of the present application exhibited good reproducibility in the detection results of the respective aqueous solutions.

[0050] Please refer to Figure 11 An electrochemical sensor with three wire electrodes was immersed in a 0.1M PBS (phosphate-buffered saline) aqueous solution, a 500μM hydrogen peroxide (H2O2) aqueous solution, and a 1000M hydrogen peroxide aqueous solution in sequence. The main part of the conductive inner core of the wire electrode was made of carbon, and the free end was made of platinum. The results showed that the electrochemical sensor of the present application can indeed measure different oxidation and reduction potentials in hydrogen peroxide aqueous solutions of different concentrations.

[0051] See also Figure 12 The applicant used the amperometric method to test the performance of the electrochemical sensor of the present application in detecting aqueous hydrogen peroxide solution. The electrochemical sensor used had three wire electrodes. The main part of the conductive inner core of the wire electrode was made of carbon, and the free end was made of platinum. The applicant used the amperometric method to detect aqueous hydrogen peroxide solutions of different concentrations under the operating parameters shown in Table 2 below. That is, the concentration of the aqueous hydrogen peroxide solution was adjusted every 50 seconds, with an increase of 100 μM each time for the first ten times and 200 μM each time for the last five times, for a final concentration of 2000 μM. The oxidation operating voltage was fixed at 600 mV. The results showed that the electrochemical sensor of the present application could sensitively detect changes in the concentration of aqueous hydrogen peroxide solution, and the measured current value was highly linear with the concentration change (e.g., Figure 13 As shown), it shows that the electrochemical sensor of the present application has good accuracy.

[0052] Table 2

[0053]

[0054]

[0055] Please refer to Figure 14 , and Figure 9 The embodiment shown is similar, the main difference being that the electrochemical sensor further comprises an axle 50, and Figure 9 The central wire electrode 20c shown is replaced by a mandrel 50, and the intrusion segments 24 of the remaining wire electrodes 20 are spirally wound around the mandrel 50. A portion of the mandrel can be fixed to a substrate (not shown), and the portion of the mandrel 50 around which the intrusion segment 24 is spirally wound extends in a straight line. The mandrel 50 has a tip 51 that protrudes from the free end 212 of the intrusion segment 24. In this embodiment, the tip 51 is solid and sharp, which can be used to change the structural strength of the intrusion segment 24, allowing the intrusion segment 24 to be more easily inserted into the detection target (such as soil, plants, etc.) without the aid of an additional inserter. Please refer to Figure 15 , and Figure 14 The embodiment shown is similar, with the primary difference being that the distal end 51 of the mandrel 50 is hollow and sharp, which can also be used to alter the structural strength of the invasive section 24. Furthermore, the hollow distal end 51 helps to agitate the tissue at the insertion site, for example, by enabling capillary action to facilitate tissue contact with the free end 212 of the invasive section 24 for easier detection. The mandrel 50 can be a non-metallic, non-conductive wire, such as ceramic, silicon oxide, plastic, acrylic, or a polymer (e.g., PP, PC, PE, etc.).

[0056] Please refer to Figure 16 , and Figure 1 The illustrated embodiment is similar, wherein the portion of the gold finger 30 not covered by the cover sheet 40 is an exposed segment 31. The exposed segments 31 are parallel to each other and extend in an insertion direction L, and the gold finger 30 is disposed on a working surface 11 of the substrate 10. The intrusion segment 24 has a front portion 241 with a free end 212 located in the front portion. The extension direction of the front portion 241 is not parallel to the insertion direction L and the working surface 11. In this embodiment, the front portion 241 is perpendicular to the working surface 11. In other possible embodiments, the intrusion segment 24 is flexible, allowing the user to adjust the extension direction of the front portion 241 based on the geometric characteristics of the target to be detected.

[0057] The embodiments and / or implementation methods described above are only used to illustrate the preferred embodiments and / or implementation methods for realizing the technology of the present application, and do not impose any form of limitation on the implementation methods of the technology of the present application. Any person skilled in the art may make slight changes or modifications to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present application, but they should still be regarded as technologies or embodiments that are essentially the same as those of the present application.

Claims

1. An invasive multi-electrode electrochemical sensor, characterized in that: The invasive multi-electrode electrochemical sensor comprises: a substrate; a plurality of wire-like electrodes, each comprising a conductive core and an insulating film, each insulating film substantially covering its corresponding conductive core but leaving a proximal end and a free end of the corresponding conductive core exposed; each wire-like electrode having a substrate segment and an intrusive segment, the proximal end being located within the substrate segment, the free end being located within the intrusive segment, the substrate segment being disposed on the substrate, the intrusive segment extending outward from an edge of the substrate, and at least a portion of the intrusive segments of the plurality of wire-like electrodes being spirally wound around one another; a cover plate disposed on the substrate and fixing at least a portion of the substrate segments of the plurality of wire electrodes between the cover plate and the substrate; and a plurality of gold fingers provided on the substrate, the conductive cores in the substrate sections of the plurality of wire-shaped electrodes being electrically connected to the plurality of gold fingers, each of the gold fingers having an exposed section not covered by the cover sheet, the exposed sections extending in an insertion direction; The intrusion section has a front portion, the extension direction of the front portion is not parallel to the insertion direction, and the free end is located at the front portion.

2. The invasive multi-electrode electrochemical sensor according to claim 1, characterized in that: The plurality of gold fingers are arranged on a working surface of the substrate, and the extending direction of the front portion is not parallel to the working surface.

3. The invasive multi-electrode electrochemical sensor according to claim 1, characterized in that: The plurality of gold fingers are arranged on a working surface of the substrate, and the extending direction of the front portion is perpendicular to the working surface.

4. The invasive multi-electrode electrochemical sensor according to claim 1, characterized in that: The plurality of intrusion segments are flexible.

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