A magnetic printed electrode

Abstract

The present invention discloses a magnetic printed electrode, which belongs to the field of electrochemical detection technology. The electrode includes an electrode substrate, a working electrode and a reference electrode, wherein the working electrode and the reference electrode are respectively fixed on the surface of the electrode substrate; the working electrode has at least one magnetic layer and at least one conductive layer, the conductive layer is located on the top surface of the working electrode, and the magnetic layer and the conductive layer overlap in the direction perpendicular to the electrode substrate; the conductive layer of the working electrode and the reference electrode constitute a dual-electrode system. In this printed electrode, since no external magnet is required, it can be immersed in a small amount of test liquid to work, thereby greatly saving the amount of test liquid. When the electrode is in use, since the magnetic layer and the conductive layer overlap in the direction perpendicular to the electrode substrate, under the action of the magnetic field force of the working electrode itself, the nanoparticles will be adsorbed on the surface of the working electrode, while they will not be adsorbed on the other electrodes, thereby greatly improving the accuracy of the test.

Description

Technical Field

[0001] The present invention relates to the field of electrochemistry, and in particular to a magnetic printed electrode. Background Art

[0002] Currently, most detection methods that use magnetic fields to immobilize nanoparticles rely on applying a magnetic field to the back of an electrode, typically using a device to secure a magnet to the electrode's backside. For example, patent application number CN201310167469.X discloses a method for preparing and detecting a screen-printed electrode immunosensor for the rapid detection of microcystins. This approach uses a magnetic field generated by a magnet beneath the screen-printed electrode to immobilize core-shell magnetic nanoparticles, Fe3O4@Au, to the surface of the working electrode.

[0003] During the detection process, this type of printed electrode with an external magnetic field requires the entire device, magnet, and electrode to be added to the test liquid. However, this method makes the entire device larger, and a large amount of test liquid is required to completely immerse the electrode area. Moreover, in actual use, it is usually only necessary to attach nanoparticles to specific electrodes (generally working electrodes), and the magnetic field area generated by the external magnetic field cannot be controlled. During use, it is easy for some nanoparticles to be adsorbed to the outside of the electrode, and the signal cannot be detected, thereby causing measurement errors. At the same time, the magnetic field generated by this method is uneven, and the nanoparticles will be enriched in certain areas of the electrode, which greatly reduces the detection effect. In addition, different electrodes will produce certain deviations in the process of adding an external magnetic field, resulting in poor consistency of the electrodes, which is not conducive to the repetition of the experiment. Therefore, the above technical problems are in urgent need of being solved. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that traditional electrodes require the use of external magnets, which leads to the inability to accurately control the fixed position of nanoparticles and waste of test fluid, and to provide a magnetic printed electrode and a method for manufacturing the same.

[0005] In order to achieve the above-mentioned object of the invention, the technical solutions specifically adopted by the present invention are as follows:

[0006] A magnetic screen-printed electrode comprises an electrode substrate, a working electrode and a reference electrode, wherein the working electrode and the reference electrode are respectively fixed on the surface of the electrode substrate; the working electrode has at least one magnetic layer and at least one conductive layer, the conductive layer is located on the top surface of the working electrode, and the magnetic layer and the conductive layer overlap in a direction perpendicular to the electrode substrate; the conductive layer of the working electrode and the reference electrode constitute a dual-electrode system.

[0007] It should be noted that in the present invention, the magnetic layer and the conductive layer can be the same layer or different layers, but the contour boundaries of both layers are consistent with the contour boundaries of the working electrode. "Overlapping" in a direction perpendicular to the electrode substrate means that the projected contours of the two electrode layers in the direction perpendicular to the electrode substrate overlap, thereby ensuring that the magnetic force applied by the magnetic layer is within the range of the working electrode. Of course, "overlapping" here does not mean that there is no deviation or slight margin difference; as long as the two layers are substantially overlapped, it is sufficient.

[0008] As a first preferred embodiment, the magnetic layer and the conductive layer are the same layer, which is a conductive magnetic layer having both conductivity and magnetism, and the conductive magnetic layer is attached to the surface of the electrode substrate on the same side as the reference electrode.

[0009] Furthermore, a conductive layer is provided on the upper surface of the conductive magnetic layer, or a conductive layer is provided between the lower surface and the electrode substrate.

[0010] As a second preferred embodiment, the magnetic layer and the conductive layer are independent layers, and the magnetic layer is attached to the surface of the electrode substrate on the same side as the reference electrode, and the conductive layer is attached to the upper surface of the magnetic layer.

[0011] As a third preferred embodiment, the magnetic layer and the conductive layer are independent layers, and the magnetic layer is attached to the surface of the electrode substrate on a different side from the reference electrode, and the conductive layer is attached to the surface of the electrode substrate on the same side as the reference electrode.

[0012] As a fourth preferred embodiment, the working electrode comprises a magnetic layer, an insulating layer and a conductive layer, and the magnetic layer, the insulating layer and the conductive layer are stacked from bottom to top and attached to the surface of the electrode substrate on the same side as the reference electrode.

[0013] As a further improvement of the above four preferred embodiments, the magnetic layer is a slurry layer embedded with magnetic particles.

[0014] Further preferably, the magnetic particles are magnetized or unmagnetized hard magnetic material particles.

[0015] Furthermore, the hard magnetic material is preferably a ferrite permanent magnet or a metal alloy magnet;

[0016] Furthermore, the printing paste of the paste layer is a conductive paste or a non-conductive paste. The conductive paste may be a carbon paste, a gold paste or a silver paste, and the non-conductive paste may be an insulating ink.

[0017] As a further improvement of the above four preferred embodiments, the printing paste of the conductive layer is carbon paste, gold paste or silver paste.

[0018] As a further improvement of the above four preferred embodiments, the conductive magnetic layer is a conductive slurry layer embedded with magnetic particles.

[0019] As a further improvement of the above four preferred embodiments, an auxiliary electrode is further provided on the electrode substrate, and the auxiliary electrode, the working electrode and the reference electrode form a three-electrode system.

[0020] As a further improvement of the above four preferred embodiments, each electrode on the surface of the electrode substrate is connected to an electrode terminal via a wire, and the surface of the wire is covered with an insulating layer.

[0021] Furthermore, the insulating layer is preferably a hydrophobic insulating layer. For example, the insulating layer can be printed using an organic solvent containing epoxy resin.

[0022] As a further improvement of the above four preferred embodiments, the reference electrode is a silver coating, a silver chloride coating, or a mixture coating of silver and silver chloride attached to the electrode substrate.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] Because this printed electrode does not require an external magnet, it can be immersed in a small amount of test fluid to operate, significantly reducing the amount of test fluid used. When the electrode is in use, because the magnetic layer and the conductive layer overlap in a direction perpendicular to the electrode substrate, the magnetic force of the working electrode itself attracts the nanoparticles to the surface of the working electrode, while not attracting the remaining electrodes, thus greatly improving the accuracy of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the front and back appearance of a magnetic screen-printed electrode in one embodiment of the present invention.

[0026] Figure 2 yes Figure 1 Cross-section of the magnetic screen-printed electrode along AA.

[0027] Figure 3 yes Figure 2 Schematic diagram of the exploded structure of the substrate, conductor layer, electrode layer, and insulation layer of the magnetic screen-printed electrode.

[0028] Figure 4 yes Figure 1 Cross-section of the magnetic screen-printed electrode along AA.

[0029] Figure 5 Schematic diagram of the front and back appearance of a magnetic screen-printed electrode in one embodiment of the present invention.

[0030] Figure 6 yes Figure 5 Cross-section of the magnetic screen-printed electrode along the BB.

[0031] Figure 7yes Figure 6 Schematic diagram of the exploded structure of the substrate, conductor layer, electrode layer, and insulation layer of the magnetic screen-printed electrode.

[0032] Figure 8 yes Figure 5 Cross-section of the magnetic screen-printed electrode along the BB.

[0033] Figure 9 Schematic diagram of the front and back appearance of a magnetic screen-printed electrode in one embodiment of the present invention.

[0034] Figure 10 yes Figure 9 Cross-section of the magnetic screen-printed electrode along the CC.

[0035] The figures in the figure are marked as: electrode substrate 1, first electrode terminal 2, second electrode terminal 3, third electrode terminal 4, first insulating layer 5, second insulating layer 6, third insulating layer 7, reference electrode 8, working electrode 9, auxiliary electrode 10, working electrode conductive layer 11, conductive magnetic layer 12, first wire 13, second wire 14, third wire 15, fourth insulating layer 16, conductive layer 17, electrode layer 18, and insulating protective layer 19. DETAILED DESCRIPTION

[0036] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention may be combined accordingly, provided that there is no conflict between them.

[0037] The present invention provides a magnetic screen-printed electrode with controllable magnetic attraction area, the basic structure of which includes an electrode substrate, a working electrode and a reference electrode. The working electrode and the reference electrode are respectively fixed on the surface of the electrode substrate. The working electrode has at least one magnetic layer and at least one conductive layer. The conductive layer is located on the top surface of the working electrode and is used to contact the object to be detected. The conductive layer of the working electrode and the reference electrode constitute a dual-electrode system. The magnetic layer is used to apply magnetic force to the nanoparticles that need to be adsorbed on the surface of the conductive layer. In order to ensure that the magnetic attraction area is concentrated on the working electrode, the magnetic layer and the conductive layer overlap in the direction perpendicular to the electrode substrate.

[0038] In the printed electrode, the magnetic layer and the conductive layer may be two independent layers or the same layer.

[0039] When the two layers are the same, the layered structure has both electrical conductivity and magnetic properties, i.e., a conductive magnetic layer. The conductive magnetic layer is attached to the surface of the electrode substrate on the same side as the reference electrode. Of course, a conductive layer is also provided on the upper surface of the conductive magnetic layer, or a conductive layer is also provided between the lower surface and the electrode substrate.

[0040] When the magnetic layer and the conductive layer are independent layers, with the magnetic layer at the bottom and the conductive layer at the top, the conductive layer is always attached to the electrode substrate surface on the same side as the reference electrode, while the magnetic attraction layer can be on the same side or the other side. Furthermore, an insulating layer can be provided between the magnetic layer and the conductive layer.

[0041] Therefore, the working electrode has different forms, which can be a conductive magnetic layer on a substrate; or, the working electrode includes a conductive layer printed on the substrate, and a conductive magnetic layer on the conductive layer; or, the working electrode includes a magnetic layer printed on the substrate, and a conductive layer on the magnetic layer; or, the working electrode includes a magnetic layer printed on the back of the substrate, and a conductive layer on the front of the substrate.

[0042] In addition, each electrode on the surface of the electrode substrate can have its own electrode terminal to facilitate analysis. Each electrode is connected to its own electrode terminal through a wire, and the surface of the wire is covered with an insulating layer. The insulating layer is preferably made of a hydrophobic material, for example, it can be printed with an organic solvent dissolved in epoxy resin. The wire can be coated with silver chloride, and the electrode terminal can be printed on the substrate by silver paste to form a silver paste layer. The material of the working electrode needs to be selected according to the detection object. Common materials include carbon paste, gold paste, silver paste, etc., and its surface can be modified as needed.

[0043] The magnetic layer of the working electrode of the present invention is a slurry layer embedded with magnetic particles. It can be formed by doping unmagnetized hard magnetic material particles or magnetized hard magnetic material particles into a printing paste and then printing. If non-magnetic hard magnetic material particles are used, they are doped into a conductive slurry and screen-printed onto the electrode substrate. After drying, magnetization is performed. If magnetized hard magnetic material particles are used, they are doped into a conductive slurry and screen-printed onto the electrode substrate. After drying, they are then ready for use.

[0044] The magnetic particles in the magnetic layer are preferably less than 50 microns in diameter, preferably ferromagnetic particles, including either or both ferrite permanent magnets and metal alloy magnets. The printing paste for the magnetic layer can be either a conductive paste or a non-conductive paste. Conductive pastes include, but are not limited to, carbon paste, gold paste, or silver paste, while non-conductive pastes include, but are not limited to, insulating ink.

[0045] The printing paste of the conductive layer of the working electrode is a conductive paste, including but not limited to carbon paste, gold paste or silver paste, and can also be a magnetic paste doped with hard magnetic material particles, that is, a conductive magnetic paste.

[0046] The specific implementation of the present invention is described below through several embodiments to facilitate a better understanding of the present invention.

[0047] Example 1

[0048] like Figure 1、 Figure 2 and Figure 3 Figure 1 shows a magnetic screen-printed electrode according to this embodiment, comprising an electrode substrate 1, a conductive layer 17, an electrode layer 18, and an insulating protective layer 19 stacked in sequence. The conductive layer 17 and the electrode layer 18 are both located on the front surface of the electrode substrate 1. The electrode layer 18 includes an auxiliary electrode 10, a reference electrode 8, and a working electrode 9. The conductive layer 17 includes a first electrode terminal 2, a second electrode terminal 3, a third electrode terminal 4, a first wire 13, a second wire 14, and a third wire 15. The insulating protective layer 19 includes a first insulating layer 5, a second insulating layer 6, and a third insulating layer 7.

[0049] like Figure 2 The figure shows the cross-sectional plane of the electrode along AA. The working electrode has two layers. A conductive layer 11 is first printed on the front of the electrode substrate 1, and then a conductive magnetic layer 12 of the same shape and size is printed on the conductive layer 11. The auxiliary electrode 10, the reference electrode 8, and the working electrode 9 constitute a three-electrode system on the surface of the electrode substrate 1. The working electrode 9 is located in the middle. The auxiliary electrode 10 and the reference electrode 8 surround the working electrode 9 in the circumferential direction and do not contact each other and are not directly conductive. The specific materials of the three electrodes can be adjusted as needed. In this embodiment, the reference electrode 8 is a silver chloride layer, the auxiliary electrode 10 is a carbon paste layer, and the material of the working electrode 9 needs to be selected according to the detection object. Common materials include carbon paste, gold paste, silver paste, etc., and its surface can be modified as needed.

[0050] like Figure 3 As shown, the function of the wire layer is to form terminals for external wiring on the surface of the electrode substrate 1, which includes a first electrode terminal 2, a second electrode terminal 3, a third electrode terminal 4, a first wire 13, a second wire 14, and a third wire 15. One end of the first wire 13, the second wire 14, and the third wire 15 are respectively connected to the reference electrode 8, the working electrode conductive layer 11 of the working electrode 9, and the auxiliary electrode 10, and the other ends of the first wire 13, the second wire 14, and the third wire 15 are respectively connected to the third electrode terminal 4, the first electrode terminal 2, and the second electrode terminal 3. The surface of each wire can be covered with an insulating layer. The insulating layers on the surfaces of the first wire 13, the second wire 14, and the third wire 15 are respectively a first insulating layer 5, a second insulating layer 6, and a third insulating layer 7. The above-mentioned electrode terminals can be formed by printing silver paste on the electrode substrate 1, and the insulating layer can be further printed on the wires.

[0051] Because this printed electrode does not require an external magnet, it can be immersed in a small amount of test fluid to operate, significantly reducing the amount of test fluid used. When the electrode is in use, the magnetic field of the working electrode itself attracts the nanoparticles to the surface of the working electrode, while the remaining electrodes remain unattracted, greatly improving the accuracy of the test.

[0052] Example 2

[0053] In this embodiment, except that the working electrode does not have the working electrode conductive layer 11 but only has the conductive magnetic layer 12, the rest of the structure is the same as the magnetic printing electrode in embodiment 1. Figure 1 and Figure 4 As shown, the working electrode 9 has only a single conductive magnetic layer 12 .

[0054] Example 3

[0055] In this embodiment, except that the conductive magnetic layer 12, the fourth insulating layer 16 and the working electrode conductive layer 11 are sequentially stacked on the working electrode 9, the rest of the structure is the same as the magnetic printed electrode in embodiment 1. Figure 5 、 Figure 6 and Figure 7 As shown, the working electrode 9 is divided into three layers. First, a conductive magnetic layer 12 is printed on the electrode substrate 1, and then a fourth insulating layer 16 of the same size and shape is printed on the printed conductive magnetic layer 12. Finally, a working electrode conductive layer 11 of the same size and shape is printed on the fourth insulating layer 16.

[0056] Example 4

[0057] In this embodiment, except that there is no fourth insulating layer 16 on the working electrode 9, the rest of the structure is the same as the magnetic printed electrode of embodiment 3. Figure 5 and Figure 8 As shown, the working electrode 9 is divided into two layers. First, the conductive magnetic layer 12 is printed on the electrode substrate 1, and then the working electrode conductive layer 11 of the same size and shape is printed on the conductive magnetic layer 12.

[0058] Example 5

[0059] Except that the magnetic layer is on the back of the substrate, the rest of the structure of this embodiment is the same as the printed electrode of embodiment 4. Figure 9 and Figure 10 As shown, the working electrode 9 is divided into two layers. The working electrode conductive layer 11 is printed on the front of the electrode substrate 1, and the conductive magnetic layer 12 is on the back of the substrate. The two layers are the same in size and shape and their projections along the direction perpendicular to the substrate overlap.

[0060] Furthermore, in the printed electrodes of the aforementioned embodiments, auxiliary electrodes on the surface of the electrode substrate can be added or removed as needed. When an auxiliary electrode is present, it forms a three-electrode system with the working electrode and the reference electrode. When an auxiliary electrode is absent, the working electrode and the reference electrode form a two-electrode system for detection. The specific electrode configuration is adjusted based on detection needs.

[0061] The embodiment described above is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Persons skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent substitution or equivalent transformation falls within the scope of protection of the present invention.

Claims

1. A magnetic printed electrode, characterized in that: The device comprises an electrode substrate, a working electrode and a reference electrode, wherein the working electrode and the reference electrode are respectively fixed on the surface of the electrode substrate; the working electrode has at least one magnetic layer and at least one conductive layer, the conductive layer is located on the top surface of the working electrode, and the magnetic layer and the conductive layer overlap in a direction perpendicular to the electrode substrate; the conductive layer of the working electrode and the reference electrode form a dual-electrode system; The magnetic layer and the conductive layer are the same layer, which is a conductive magnetic layer that has both conductivity and magnetism, and the conductive magnetic layer is attached to the surface of the electrode substrate on the same side as the reference electrode; a conductive layer is also provided on the upper surface of the conductive magnetic layer, or a conductive layer is also provided between the lower surface and the electrode substrate; the magnetic layer is a slurry layer embedded with magnetic particles; the magnetic particles are magnetized or unmagnetized hard magnetic material particles.

2. The magnetic printed electrode according to claim 1, wherein: The magnetic layer and the conductive layer are both independent layers, and the magnetic layer is attached to the surface of the electrode substrate on the same side as the reference electrode, and the conductive layer is attached to the upper surface of the magnetic layer.

3. The magnetic printed electrode according to claim 1, wherein: The magnetic layer and the conductive layer are both independent layers, and the magnetic layer is attached to the surface of the electrode substrate on a different side from the reference electrode, and the conductive layer is attached to the surface of the electrode substrate on the same side as the reference electrode.

4. The magnetic printed electrode according to claim 1, wherein: The working electrode comprises a magnetic layer, an insulating layer and a conductive layer, which are stacked from bottom to top and attached to the surface of the electrode substrate on the same side as the reference electrode.

5. The magnetic printed electrode according to claim 1, wherein: The printing paste of the paste layer is conductive paste or non-conductive paste, the conductive paste is carbon paste, gold paste or silver paste, and the non-conductive paste is insulating ink.

6. The magnetic printed electrode according to claim 1, wherein: The magnetic particles are ferrite permanent magnets or metal alloy magnets.

7. The magnetic printed electrode according to any one of claims 1 to 4, characterized in that: The printing paste of the conductive layer is carbon paste, gold paste or silver paste.

8. The magnetic printed electrode according to any one of claims 1 to 4, characterized in that: An auxiliary electrode is also provided on the electrode substrate, and the auxiliary electrode, the working electrode and the reference electrode form a three-electrode system.

9. The magnetic printed electrode according to any one of claims 1 to 4, characterized in that: Each electrode on the surface of the electrode substrate is connected to an electrode terminal via a wire, and the surface of the wire is covered with an insulating layer, which is a hydrophobic insulating layer.

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