A screen-printed electrode on a magnetic and flexible substrate

Abstract

The present invention discloses a screen-printed electrode with magnetism and a flexible substrate, belonging to the technical field of electrochemical detection. The printed electrode 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 to form a two-electrode system; the electrode substrate has magnetism and flexibility. The present invention can attract magnetic nanoparticles without an external magnetic field, is more suitable for the field of rapid diagnosis, and the flexible substrate can be used in fields such as body surface detection.

Description

Technical Field

[0001] The present invention relates to the field of electrochemistry, and particularly to a screen-printed electrode on a magnetic substrate and a preparation method thereof. Background Art

[0002] Currently, most of the detection principles involving the use of a magnetic field to fix nanoparticles are to apply an external magnetic field on the back of the electrode. Generally, a magnet is fixed on the back of the electrode through a device. For example, in the invention patent with the application number CN201310167469.X, a preparation and detection method of a screen-printed electrode immunosensor for rapid detection of microcystin is disclosed. In this scheme, the core-shell magnetic nanoparticles Fe3O4@Au are fixed on the surface of the working electrode by the magnetic field formed by the magnet under the screen-printed electrode.

[0003] In the detection process of such printed electrodes with an external magnetic field, the entire device, including the magnet and the electrode, needs to be added to the test solution. However, the magnetic field area generated by this method cannot completely coincide with the electrode area, and some nanoparticles will adsorb to the outside of the electrode, resulting in an inability to detect signals and thus generating measurement errors. At the same time, the magnetic field generated by this method is uneven, and the nanoparticles will accumulate in some areas of the electrode, thus greatly reducing the detection effect. In addition, certain deviations will occur during the process of adding an external magnetic field to different electrodes, resulting in poor consistency of the electrodes and being not conducive to the repetition of experiments. Moreover, the entire device has a large volume, and a large amount of test solution is required to completely immerse the electrode area. Therefore, the above technical problems need to be solved urgently. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems that traditional electrodes need to use an external magnet to fix nanoparticles, resulting in uneven particle distribution and waste of test solution, and to provide an electrode based on screen printing on a magnetic and flexible substrate that is convenient for detection and has stable performance.

[0005] In order to achieve the above invention purpose, the specific technical solution adopted by the present invention is as follows:

[0006] A screen-printed electrode on a magnetic and flexible substrate, 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 to form a two-electrode system; the electrode substrate has magnetism and flexibility.

[0007] Preferably, the base material of the electrode substrate is a flexible plate body, and ferromagnetic particles are embedded in the flexible plate body, and the ferromagnetic particles are uniformly distributed in the electrode covering area of the plate body.

[0008] Furthermore, the ferromagnetic particles are soft magnetic material particles or hard magnetic material particles.

[0009] Further, the ferromagnetic particles are ferrite permanent magnets or metal alloy magnets, and the diameter of the particles is less than 50 microns.

[0010] Further, the material of the flexible plate body is rubber, silica gel or PDMS.

[0011] Preferably, the electrode substrate is a magnetic rubber layer.

[0012] Preferably, the thickness of the electrode substrate is less than 1 mm.

[0013] Preferably, an auxiliary electrode is further provided on the surface of the electrode substrate, and the auxiliary electrode, the working electrode and the reference electrode form a three-electrode system.

[0014] Preferably, each electrode on the electrode substrate is connected to an electrode terminal through a wire, and the surface of the wire is covered with an insulating layer.

[0015] Preferably, the insulating layer is a hydrophobic insulating layer.

[0016] The present invention has the following beneficial effects compared with the prior art:

[0017] The magnetic screen-printed electrode of the present invention integrates the magnetic field on the substrate of the printed electrode, thereby ensuring that the magnetic field can be evenly applied to the electrodes on the surface of the substrate during the use of the electrode, avoiding the defect of poor detection results caused by uneven magnetic fields, and improving the consistency and stability of the detection results. At the same time, compared with the traditional electrode that requires an external magnet, the magnetic screen electrode of the present invention has a greatly reduced electrode volume, which is convenient to operate and saves the test solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 are the front and back appearance schematic diagrams of the screen-printed electrode with magnetic and flexible substrates in an example of the present invention.

[0019] Figure 2 is Figure 1 the sectional view of the screen-printed electrode with magnetic and flexible substrates along A-A.

[0020] Figure 3 is Figure 2 the exploded schematic diagram of the substrate, wire layer, electrode layer and insulating layer of the screen-printed electrode with magnetic and flexible substrates.

[0021] Figure 4 is the schematic diagram of the distribution of ferromagnetic particles in the flexible plate body of the electrode substrate.

[0022] The reference numerals in the figure are: 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, counter electrode 10, working electrode 11, first wire 12, second wire 13, third wire 14. Detailed implementation mode

[0023] The present invention will be further described and explained below in conjunction with the drawings and specific implementation modes. Under the premise that there is no conflict between the technical features of each implementation mode of the present invention, corresponding combinations can be made.

[0024] As Figure 1 、 Figure 2 and Figure 3 shown, in a preferred embodiment of the present invention, a screen-printed electrode with a magnetic and flexible substrate is provided, which includes an electrode substrate 1, a wire layer, an electrode layer, and an insulating layer stacked in sequence. Among them, the wire layer and the electrode layer are both fixed on the surface of the electrode substrate 1, and the insulating layer is stacked above the wire layer.

[0025] In this embodiment, the electrode layer includes a counter electrode 10, a reference electrode 8, and a working electrode 11. The three form a three-electrode system on the surface of the electrode substrate 1. The working electrode 11 is located in the middle, and the counter electrode 10 and the reference electrode 8 surround the circumference of the working electrode 11 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 counter electrode 10 is a carbon paste layer, and the material of the working electrode 11 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.

[0026] The function of the wire layer is to form terminals for external wiring on the surface of the electrode substrate 1. It includes a first electrode terminal 2, a second electrode terminal 3, a third electrode terminal 4, a first wire 12, a second wire 13, and a third wire 14. One ends of the first wire 12, the second wire 13, and the third wire 14 are respectively connected to the reference electrode 8, the working electrode 11, and the counter electrode 10, and the other ends of the first wire 12, the second wire 13, and the third wire 14 are respectively connected to the third electrode terminal 4, the first electrode terminal 2, and the second electrode terminal 3. An insulating layer can be covered on the surface of each wire. The insulating layers on the surfaces of the first wire 12, the second wire 13, and the third wire 14 are the first insulating layer 5, the second insulating layer 6, and the third insulating layer 7 respectively. 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.

[0027] In this printed electrode, there is no need for an external magnet, and the application of the magnetic field is realized through the electrode substrate 1 itself, that is, the electrode substrate 1 has magnetism and flexibility. In this embodiment, as Figure 4As shown in the figure, the base material of the electrode substrate is a flat flexible plate made of flexible material, and ferromagnetic particles are embedded in the flexible plate. And in order to ensure the uniformity of the magnetic field, the ferromagnetic particles are evenly distributed in the electrode covering area of the plate body. The so-called electrode covering area refers to the area where electrodes are printed on the flexible plate body. Ideally, the ferromagnetic particles only need to be distributed under the electrodes that need to load nanoparticles during subsequent use. For example, if only the working electrode needs to magnetically load nanoparticles, then the ferromagnetic particles only need to be evenly distributed in the electrode substrate 1 area under the working electrode. However, considering the actual processing technology, ferromagnetic particles can also be embedded in the gap area between the electrodes in the plate body. Generally, they can be Figure 1 ferromagnetic particles are evenly distributed throughout the long strip-shaped electrode substrate 1 to reduce the complexity of the processing technology.

[0028] The material of the flexible plate body can be diverse, and common materials can be selected such as rubber, silica gel, or PDMS, etc. The ferromagnetic particles in the flexible plate body can be soft magnetic material particles or hard magnetic material particles, preferably ferrite permanent magnets or metal alloy magnets, and the diameter of the particles is preferably less than 50 microns.

[0029] In order to ensure the flexibility of the entire electrode, the thickness of the electrode substrate of the present invention should not be too thick, preferably less than 1 mm.

[0030] In a preferred implementation manner of the present invention, the electrode substrate can directly adopt magnetorubber processed into a layered structure. Magnetorubber can be a commercially available product, generally prepared from raw rubber, magnetic particle powder, and other additives. The rubber itself is not magnetic, and its magnetism comes from the filling of a large amount of magnetic powder inside the rubber.

[0031] In a preferred implementation manner of the present invention, the insulating layer can be prepared from a hydrophobic material. For example, the insulating layer can be printed with an organic solvent dissolved with epoxy resin.

[0032] In addition, in the printed electrodes shown in the drawings, the auxiliary electrodes on the surface of the electrode substrate can be added or deleted as needed. When there are auxiliary electrodes, they form a three-electrode system with the working electrode and the reference electrode. When there are no auxiliary electrodes, the working electrode and the reference electrode form a two-electrode system for detection work. The specific electrode form is adjusted according to the detection needs.

[0033] The printing method of the printed electrode can adopt the existing technology. Print the electrode layer and the wire layer on the surface of the electrode substrate 1, and then print the insulating layer on the wire layer.

[0034] In this printed electrode, since no external magnet is required, it can be immersed in a small amount of test liquid for operation, thus greatly saving the consumption of the test liquid. When the electrode is in use, under the action of the magnetic force of the electrode substrate 1 itself, the nanoparticles will be adsorbed on the surface of the working electrode, and then relevant test work will be carried out. It can be seen from this that the present invention can attract magnetic nanoparticles without applying an external magnetic field, is more suitable for the field of rapid diagnosis, and the substrate is a flexible material and can be used in fields such as body surface detection.

[0035] The above-described embodiments are only a preferred solution of the present invention, but they are not intended to limit the present invention. Those of ordinary skill in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all technical solutions obtained by means of equivalent replacement or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A screen-printed electrode on a magnetic and flexible substrate, characterized in that: It 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 to form a two-electrode system; the electrode substrate has magnetism and flexibility; The base material of the electrode substrate is a flexible plate body, and ferromagnetic particles are embedded in the flexible plate body, and the ferromagnetic particles are evenly distributed in the electrode covering area of the plate body; Each electrode on the electrode substrate is connected to an electrode terminal through a wire, and the surface of the wire is covered with an insulating layer. The working electrode and the reference electrode form a two-electrode system to carry out detection work.

2. The screen-printed electrode on the magnetic and flexible substrate according to claim 1, characterized in that: The ferromagnetic particles are soft magnetic material particles or hard magnetic material particles.

3. The screen-printed electrode on the magnetic and flexible substrate according to claim 1, characterized in that: The ferromagnetic particles are ferrite permanent magnets or metal alloy magnets, and the diameter of the particles is less than 50 microns.

4. The screen-printed electrode on a magnetic and flexible substrate according to claim 1, characterized in that: The material of the flexible plate body is rubber, silica gel or PDMS.

5. The screen-printed electrode on the magnetic and flexible substrate according to claim 1, characterized in that: The electrode substrate is a magnetic rubber layer.

6. The screen-printed electrode on the magnetic and flexible substrate according to claim 1, characterized in that: The thickness of the electrode substrate is less than 1 mm.

7. The screen-printed electrode on the magnetic and flexible substrate according to claim 1, wherein: An auxiliary electrode is further provided on the surface of the electrode substrate, and the auxiliary electrode, the working electrode and the reference electrode form a three-electrode system.

8. The screen-printed electrode on the magnetic and flexible substrate according to claim 1, wherein: The insulating layer is a hydrophobic insulating layer.

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