All-solid-state miniature ion electrode and preparation method thereof

Abstract

The invention provides an all-solid-state miniature ion electrode and a preparation method thereof, and relates to the technical field of electrodes. The all-solid-state miniature ion electrode provided by the invention comprises the electrode substrate, the electrode conductor layer, the composite carbon paste layer and the ion selective membrane, and polytetrafluoroethylene is added into the composite carbon paste layer, so that the hydrophobic performance of the ion electrode is enhanced, and formation of a water layer between the composite carbon paste layer and the ion selective membrane is reduced; the phase interface potential between the ion selective membrane and the conductive substrate can be stabilized, and the problem of potential drift of the ion selective electrode is solved. The preparation method of the all-solid-state miniature ion electrode is simple and convenient, the prepared all-solid-state miniature ion electrode is high in sensitivity, the problem of leakage of an electrolyte layer aqueous solution is avoided, and the all-solid-state miniature ion electrode can be applied to continuous sample injection.

Description

Technical Field

[0001] The present invention relates to the technical field of electrodes, and in particular to a all-solid-state micro ion electrode and a preparation method thereof. Background Art

[0002] The detection of electrolytes in body fluids has important clinical significance. Accurate measurement results of electrolyte concentrations help doctors evaluate the electrolyte balance of patients and guide the formulation of treatment plans. For example, potassium ions (K+): The normal reference value in blood is 3.6 - 5.5 mmol / L. An increase is seen in renal failure, adrenocortical hypofunction, etc.; a decrease is seen in adrenocortical hyperfunction, severe vomiting, diarrhea, etc. At present, the measurement of electrolyte ion concentrations such as sodium, potassium, calcium, and chlorine in blood is mainly carried out using an electrolyte module in a biochemical analyzer or a separate electrolyte analyzer, that is, all use ion selective electrode technology, and the open circuit potential between the test ion electrode and the reference electrode is used to quantitatively measure the concentration of each ion in body fluids.

[0003] The structure of traditional ion selective electrodes mainly consists of Ag / AgCl, PVA hydrogel containing saturated salt, and a selective membrane layer. The Ag / AgCl and the salt-containing hydrogel layer mainly play the roles of electron conduction and potential balance. The main disadvantage of this type of ion electrode is that the volume change of the hydrogel layer caused by water loss in the hydrogel leads to a change in the concentration of the internal electrolyte, resulting in unstable potential, and it is not suitable for continuous multiple sample detections.

[0004] In view of this, the present invention is specifically proposed. Summary of the Invention

[0005] The first object of the present invention is to provide a all-solid-state micro ion electrode to solve the above technical problems.

[0006] The second object of the present invention is to provide a preparation method of the above all-solid-state micro ion electrode.

[0007] The third object of the present invention is to provide a sensor.

[0008] In order to achieve the above objects, the following technical solutions are specifically adopted:

[0009] In the first aspect, the present invention provides a all-solid-state micro ion electrode, including an electrode substrate, an electrode conductor layer, a composite carbon paste layer, and an ion selective membrane;

[0010] The electrode conductor layer is disposed on the electrode substrate, the composite carbon paste layer covers the electrode conductor layer, and the ion selective membrane covers the composite carbon paste layer;

[0011] The composite carbon paste layer is obtained by coating with a carbon paste containing polytetrafluoroethylene, and the mass ratio of polytetrafluoroethylene in the composite carbon paste layer is 0.25%-1%.

[0012] As a further technical solution, the material of the electrode substrate includes at least one of PVC, ceramic, PCB, single crystal silicon or PET;

[0013] The thickness of the electrode substrate is 1-1.8 mm.

[0014] As a further technical solution, the electrode conductor of the electrode conductor layer includes at least one of Au, Ag, Pt, C;

[0015] The thickness of the electrode conductor layer is 0.1-1.5 um.

[0016] As a further technical solution, the carbon paste is mainly composed of a conductive carbon material, a binder, a filler and an organic solvent;

[0017] The mass ratio of the conductive carbon material, the binder, the filler and the organic solvent is (40-45):(20-25):(15-20):(15-20);

[0018] The conductive carbon material includes carbon fiber;

[0019] The binder includes acrylic resin;

[0020] The filler includes silicon dioxide;

[0021] The organic solvent includes N-methylpyrrolidone.

[0022] As a further technical solution, the composite carbon paste layer is coated on the electrode conductor layer by a dispensing process;

[0023] The thickness of the composite carbon paste layer is 180-220 um.

[0024] As a further technical solution, the ion-selective membrane includes a potassium ion-selective membrane, a sodium ion-selective membrane, a chloride ion-selective membrane, a calcium ion-selective membrane, a magnesium ion-selective membrane or a lithium ion-selective membrane;

[0025] The thickness of the ion-selective membrane is 135-165 um.

[0026] As a further technical solution, the potassium ion-selective membrane is obtained by coating a potassium ion-selective membrane paste by a dispensing process;

[0027] By mass percentage, the slurry of the potassium ion selective membrane comprises 14%-18% plasticizer, 5%-9% polymer, 0.8%-1.2% potassium ion carrier, 0.8%-1.2% ion exchanger, and the balance is solvent.

[0028] As a further technical solution, the plasticizer comprises at least one of DOS (dioctyl sebacate), DOA (dioctyl adipate), o-NPOE (o-nitrophenyl octyl ether), or DOP (dioctyl phthalate);

[0029] The polymer comprises at least one of polyurethane, PVC, polycarbonate, or silicone rubber;

[0030] The potassium ion carrier comprises at least one of potassium ion carrier I, potassium ion carrier II, potassium ion carrier III, or valinomycin;

[0031] The ion exchanger comprises at least one of KTpClPB (potassium tetrakis(4-chlorophenyl)borate), NaTFPB (sodium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate), sodium tetraborate, or potassium tetrakis(4-chlorophenyl)borate;

[0032] The solvent comprises at least one of acetophenone, cyclohexanone, or tetrahydrofuran.

[0033] In a second aspect, the present invention provides a method for preparing the above-mentioned all-solid-state micro ion electrode, comprising the following steps:

[0034] Fix the electrode conductor on the electrode substrate to form an electrode conductor layer, then coat a carbon paste containing polytetrafluoroethylene on the electrode conductor layer, and after drying, form a composite carbon paste layer. Then coat the slurry of the ion selective membrane on the composite carbon paste layer, and after drying, an all-solid-state micro ion electrode is prepared.

[0035] In a third aspect, the present invention provides a sensor comprising the above-mentioned all-solid-state micro ion electrode.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The all-solid-state micro ion electrode provided by the present invention comprises an electrode substrate, an electrode conductor layer, a composite carbon paste layer, and an ion selective membrane. By adding polytetrafluoroethylene to the composite carbon paste layer to enhance its hydrophobic property, the formation of a "water layer" between the composite carbon paste layer and the ion selective membrane is reduced, the phase interface potential between the ion selective membrane and the conductive matrix can be stabilized, and the problem of potential drift of the ion selective electrode is solved.

[0038] The preparation method of the all-solid-state micro ion electrode of the present invention is simple and convenient. The prepared all-solid-state micro ion electrode has high sensitivity, avoids the problem of leakage of the aqueous solution of the electrolyte layer, and can be applied to continuous sample injection. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0040] Figure 1 It is the electrode structure diagram provided by Embodiment 1 of the present invention;

[0041] Figure 2 It is the test diagram of the potassium ion electrode liquid path;

[0042] Figure 3 It is the sensor potential response.

[0043] Reference numerals: 1 - electrode substrate; 2 - electrode conductor layer; 3 - composite carbon paste layer; 4 - ion selective membrane. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] The following will describe the implementation schemes of the present invention in detail in combination with the embodiments and examples. However, those skilled in the art will understand that the following embodiments and examples are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention. Those not specified in specific conditions are carried out according to conventional conditions or conditions recommended by the manufacturer. Those reagents or instruments not specified in the manufacturer are all conventional products that can be obtained through commercial purchase.

[0045] In the first aspect, the present invention provides an all-solid-state micro ion electrode, including an electrode substrate 1, an electrode conductor layer 2, a composite carbon paste layer 3, and an ion selective membrane 4;

[0046] The electrode conductor layer 2 is disposed on the electrode substrate 1, the composite carbon paste layer 3 covers the electrode conductor layer 2, and the ion selective membrane 4 covers the composite carbon paste layer 3;

[0047] The composite carbon paste layer 3 is obtained by coating a carbon paste containing polytetrafluoroethylene. The mass ratio of polytetrafluoroethylene in the composite carbon paste layer 3 can be, for example, but not limited to, 0.25%, 0.5%, or 1%.

[0048] It has been discovered by the inventor that the "water layer" between the ion-selective membrane 4 and the conductive matrix is the main cause of potential drift or unstable measured potential. In the present invention, the hydrophobic property is enhanced by adding polytetrafluoroethylene to the carbon paste, reducing the formation of the "water layer" between the composite carbon paste layer 3 and the ion-selective membrane 4. Experiments have shown that after adding polytetrafluoroethylene, the potential drift is smaller, and the appropriate addition amount does not loss the conductivity of the carbon paste.

[0049] Adding polytetrafluoroethylene to the carbon paste improves the large capacitance property of the carbon paste transduction layer, which can stabilize the phase interface potential between the ion-selective membrane 4 and the conductive matrix, and solve the problem of potential drift of the ion-selective electrode.

[0050] The all-solid-state micro ion electrode provided by the present invention has high sensitivity, and the all-solid-state micro ion electrode avoids the problem of leakage of the electrolyte layer aqueous solution and can be applied to continuous sample injection.

[0051] In some alternative embodiments, the material of the electrode substrate 1 includes, but is not limited to, PVC, ceramic, PCB, single crystal silicon or PET, to provide good mechanical and insulating properties. Preferably, PCB-FR4 is used as the electrode substrate 1, which is mainly composed of glass fiber, binder and epoxy resin;

[0052] The thickness of the electrode substrate 1 can be, for example, but not limited to, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm or 1.8 mm, and preferably 1.6 mm.

[0053] In some alternative embodiments, the electrode conductor of the electrode conductor layer 2 includes, but is not limited to, Au, Ag, Pt or C, and preferably Au;

[0054] The thickness of the electrode conductor layer 2 can be, for example, but not limited to, 0.1 um, 0.6 um, 1 um, 1.2 um or 1.5 um, and preferably 0.6 um.

[0055] In some alternative embodiments, the electrode conductor is Au, and Au is deposited on the electrode substrate 1 by an electroplating process.

[0056] In some alternative embodiments, the carbon paste

[0057] mainly consists of a conductive carbon material, a binder, a filler and an organic solvent;

[0058] The mass ratio of the conductive carbon material, the binder, the filler and the organic solvent can be, for example, but not limited to, 40:25:15:20, 45:20:20:15 or 42:23:18:17;

[0059] The conductive carbon material includes, but is not limited to, carbon fiber;

[0060] The binder includes, but is not limited to, acrylic resin;

[0061] The filler includes, but is not limited to, silica;

[0062] The organic solvent includes, but is not limited to, N-methylpyrrolidone.

[0063] In some alternative embodiments, the composite carbon paste layer 3 is coated on the electrode conductor layer 2 by a dispensing process;

[0064] The thickness of the composite carbon paste layer 3 can be, for example, but is not limited to, 180um, 200um or 220um.

[0065] In some alternative embodiments, the ion-selective membrane 4 includes, but is not limited to, a potassium ion-selective membrane, a sodium ion-selective membrane, a chloride ion-selective membrane, a calcium ion-selective membrane, a magnesium ion-selective membrane or a lithium ion-selective membrane, and the corresponding ion-selective membrane can be selected according to the ion to be detected.

[0066] The thickness of the ion-selective membrane 4 can be, for example, but is not limited to, 135um, 150um or 165um.

[0067] In some alternative embodiments, the potassium ion-selective membrane is obtained by coating a slurry of the potassium ion-selective membrane by a dispensing process;

[0068] By mass percentage, the slurry of the potassium ion-selective membrane includes 14%-18% plasticizer, 5%-9% polymer, 0.8%-1.2% potassium ion carrier, 0.8%-1.2% ion exchanger, and the balance is solvent.

[0069] In some alternative embodiments, the plasticizer includes, but is not limited to, DOS, DOA, o-NPOE or DOP, and preferably DOS, which has a lower polarity;

[0070] The polymer includes, but is not limited to, polyurethane, PVC, polycarbonate or silicone rubber, and preferably PVC;

[0071] The potassium ion carrier includes, but is not limited to, potassium ion carrier I, potassium ion carrier II, potassium ion carrier III or valinomycin, and preferably valinomycin;

[0072] The ion exchanger includes, but is not limited to, KTpClPB, NaTFPB, sodium tetraborate or potassium tetrakis(4-chlorophenyl)borate, and preferably NaTFPB;

[0073] The solvent includes, but is not limited to, acetophenone, cyclohexanone or tetrahydrofuran, and preferably tetrahydrofuran.

[0074] Second aspect, the present invention provides a method for preparing the above-mentioned all-solid-state micro ion electrode, comprising the following steps:

[0075] Fix the electrode conductor on the electrode substrate 1 to form an electrode conductor layer 2, then coat a carbon paste containing polytetrafluoroethylene on the electrode conductor layer 2, and after drying, form a composite carbon paste layer 3. Then coat a slurry of the ion-selective membrane 4 on the composite carbon paste layer 3, and after drying, the all-solid-state micro ion electrode is prepared.

[0076] The method for preparing the all-solid-state micro ion electrode of the present invention is simple and convenient. The prepared all-solid-state micro ion electrode has high sensitivity, avoids the problem of leakage of the electrolyte layer aqueous solution, and can be applied to continuous sample injection.

[0077] Third aspect, the present invention provides a sensor comprising the above-mentioned all-solid-state micro ion electrode.

[0078] The sensor has high sensitivity.

[0079] The present invention will be further illustrated below by specific examples and comparative examples. However, it should be understood that these examples are only for more detailed illustration and should not be construed as limiting the present invention in any way.

[0080] In the following examples and comparative examples, high molecular weight PVC refers to PVC with a molecular weight greater than or equal to 233k. Unless otherwise specified, the molecular weight of the high molecular weight PVC used is about 240k.

[0081] In the following examples and comparative examples, unless otherwise specified, by mass percentage, the composition of the carbon paste is: 42% carbon fiber, 23% acrylic resin, 17% N-methylpyrrolidone, and 18% silica.

[0082] Example 1

[0083] An all-solid-state micro ion electrode, as Figure 1 shown, comprises an electrode substrate 1 (PCB-FR4), an electrode conductor layer 2 (Au), a composite carbon paste layer 3, and an ion-selective membrane 4 (potassium ion-selective membrane); wherein the electrode conductor layer 2 is disposed on the electrode substrate 1, the composite carbon paste layer 3 covers the electrode conductor layer 2, and the ion-selective membrane 4 covers the composite carbon paste layer 3.

[0084] Among them, the mass ratio of polytetrafluoroethylene in the composite carbon paste layer 3 is 1%.

[0085] The preparation method is as follows:

[0086] Preparation of composite carbon paste: Dissolve 10% polytetrafluoroethylene in tetrahydrofuran and stir at 600 rpm / min for 1 h to obtain a polytetrafluoroethylene solution. Add the polytetrafluoroethylene solution to the carbon paste and stir mechanically for 30 min.

[0087] Preparation of the paste for potassium ion selective membrane: Mix 75% tetrahydrofuran, 16% DOS, 7% high molecular weight PVC, 1% valinomycin, and 1% NaTFPB by mass percentage and stir at room temperature for 30 min.

[0088] Take an electrode substrate 1 with a thickness of 1.6 mm, then deposit Au onto the electrode substrate 1 by electroplating gold to form an electrode conductor layer 2 with a thickness of 0.6 μm and a diameter of 1 mm. Then, cover the electrode conductor layer 2 with the composite carbon paste by dispensing to form a composite carbon paste layer 3 with a thickness of 200 μm ± 20 μm and a diameter of 1.2 mm. Next, cover the composite carbon paste layer 3 with the paste for potassium ion selective membrane by dispensing to form a potassium ion selective membrane with a thickness of 150 μm ± 15 μm and a diameter of 1.5 mm.

[0089] Example 2

[0090] The difference from Example 1 is that by adjusting the concentration of the polytetrafluoroethylene solution in tetrahydrofuran, the mass ratio of polytetrafluoroethylene in the composite carbon paste layer 3 is 0.5%.

[0091] Example 3

[0092] The difference from Example 1 is that by adjusting the concentration of the polytetrafluoroethylene solution in tetrahydrofuran, the mass ratio of polytetrafluoroethylene in the composite carbon paste layer 3 is 0.25%.

[0093] Example 4

[0094] A fully solid-state micro ion electrode includes an electrode substrate 1 (single crystal silicon), an electrode conductor layer 2 (Au), a composite carbon paste layer 3, and an ion selective membrane 4 (potassium ion selective membrane); wherein the electrode conductor layer 2 is disposed on the electrode substrate 1, the composite carbon paste layer 3 covers the electrode conductor layer 2, and the ion selective membrane 4 covers the composite carbon paste layer 3.

[0095] The preparation method is as follows:

[0096] Preparation of composite carbon paste: Dissolve 10% polytetrafluoroethylene in tetrahydrofuran and stir at 600 rpm / min for 1 h to obtain a polytetrafluoroethylene solution. Add the polytetrafluoroethylene solution to the carbon paste and stir mechanically for 30 min.

[0097] Preparation of the slurry for the potassium ion selective membrane: By mass percentage, mix 79.4% cyclohexanone, 14% DOA, 5% polycarbonate, 0.8% potassium ionophore I, and 0.8% KTpClPB and stir at room temperature for 30 min.

[0098] Take an electrode substrate 1 with a thickness of 1 mm, then deposit Au onto the electrode substrate 1 by electroplating gold to form an electrode conductor layer 2 with a thickness of 0.1 μm and a diameter of 1 mm. Then, cover the electrode conductor layer 2 with a composite carbon paste by dispensing to form a composite carbon paste layer 3 with a thickness of 200 μm ± 20 μm and a diameter of 1.2 mm. Then, cover the composite carbon paste layer 3 with the slurry for the potassium ion selective membrane by dispensing to form a potassium ion selective membrane with a thickness of 150 μm ± 15 μm and a diameter of 1.5 mm.

[0099] Example 5

[0100] A fully solid-state micro ion electrode includes an electrode substrate 1 (PVC), an electrode conductor layer 2 (Au), a composite carbon paste layer 3, and an ion selective membrane 4 (potassium ion selective membrane); wherein the electrode conductor layer 2 is disposed on the electrode substrate 1, the composite carbon paste layer 3 covers the electrode conductor layer 2, and the ion selective membrane 4 covers the composite carbon paste layer 3.

[0101] The preparation method is as follows:

[0102] Preparation of the composite carbon paste: Dissolve 10% polytetrafluoroethylene in tetrahydrofuran and stir at 600 rpm / min for 1 h to obtain a polytetrafluoroethylene solution. Add the 10% polytetrafluoroethylene solution to the carbon paste and stir mechanically for 30 min.

[0103] Preparation of the slurry for the potassium ion selective membrane: By mass percentage, mix 70.6% phenylacetone, 18% DOP, 9% polyurethane, 1.2% potassium ionophore II, and 1.2% sodium tetraborate and stir at room temperature for 30 min.

[0104] Take an electrode substrate 1 with a thickness of 1.8 mm, then deposit Au onto the electrode substrate 1 by electroplating gold to form an electrode conductor layer 2 with a thickness of 1.5 μm and a diameter of 1 mm. Then, cover the electrode conductor layer 2 with a composite carbon paste by dispensing to form a composite carbon paste layer 3 with a thickness of 200 μm ± 20 μm and a diameter of 1.2 mm. Then, cover the composite carbon paste layer 3 with the slurry for the potassium ion selective membrane by dispensing to form a potassium ion selective membrane with a thickness of 150 μm ± 15 μm and a diameter of 1.5 mm.

[0105] Comparative Example 1

[0106] The difference from Example 1 is that the composite carbon paste layer 3 does not contain polytetrafluoroethylene.

[0107] Comparative Example 2

[0108] The difference from Example 1 is that by adjusting the concentration of the polytetrafluoroethylene solution in tetrahydrofuran, the mass ratio of polytetrafluoroethylene in the composite carbon paste layer 3 is 10%.

[0109] Comparative Example 3

[0110] The difference from Example 2 is that the polytetrafluoroethylene in the composite carbon paste layer 3 is replaced with an equal amount of polyaniline. The preparation of the composite carbon paste is as follows: Dissolve 5% of polyaniline in tetrahydrofuran and stir at 600 rpm / min for 1 h to obtain a polyaniline solution. Add the polyaniline solution to the carbon paste and stir mechanically for 30 min.

[0111] Comparative Example 4

[0112] The difference from Example 2 is that the polytetrafluoroethylene in the composite carbon paste layer 3 is replaced with an equal amount of graphene. The preparation of the composite carbon paste is as follows: Dissolve 5% of graphene in DMF and stir at 600 rpm / min for 1 h to obtain a graphene solution. Add the graphene solution to the carbon paste and stir mechanically for 30 min.

[0113] Comparative Example 5

[0114] The difference from Example 2 is that the polytetrafluoroethylene in the composite carbon paste layer 3 is replaced with an equal amount of potassium ferricyanide. The preparation of the composite carbon paste is as follows: Dissolve 5% of potassium ferricyanide in DMF and stir at 600 rpm / min for 1 h to obtain a potassium ferricyanide solution. Add the potassium ferricyanide solution to the carbon paste and stir mechanically for 30 min.

[0115] Test Example 1

[0116] The all-solid-state micro ion electrodes provided in Examples 1-3 and Comparative Example 1 were respectively used to detect potassium chloride solutions with different concentrations. As Figure 2 shown, the pipe connected to the sample injection inlet is the sample tube, and the one connected to the reference solution inlet is the reference solution tube. Place the all-solid-state micro ion electrode in the sample tube and the reference electrode in the reference solution tube. Then turn on the peristaltic pump, introduce the reference solution into the reference solution tube, and at the same time introduce potassium chloride aqueous solutions with concentrations of 4.6 mmol / L, 9.0 mmol / L, and 1.2 mmol / L into the sample tube respectively. After each sample is introduced into the sample tube, turn off the peristaltic pump and detect the voltage. The excessive potassium chloride aqueous solution and the reference solution introduced will flow out from the waste liquid port. During the experiment, the open circuit potential between the potassium ion test electrode and the reference electrode was measured using an electrochemical workstation. The results are as Figure 3 shown.

[0117] Test Example 2

[0118] The performance of the electrodes in the above-mentioned examples and comparative examples was detected as follows:

[0119] Using the method of Test Example 1, the electrodes of the above-mentioned examples and comparative examples were respectively used to detect potassium chloride aqueous solutions with concentrations of 1.2 mmol / L, 4.6 mmol / L, and 9.0 mmol / L, and the sensitivity and potential drift were calculated.

[0120] Sensitivity calculation: Plot the detection results, with the abscissa being lg(C1), lg(C2), lg(C3), where C1, C2, and C3 are the K ion concentrations of the samples respectively, and the ordinate being the test potentials E1, E2, and E3; the slope of the corresponding curve is the sensitivity of the electrode.

[0121] Potential drift calculation: After the test sample solution and the reference solution are introduced into the sample tube and the reference solution tube, the peristaltic pump is closed, and the absolute value of the potential change from the 5th second to the 15th second is detected, which is the potential drift. The results are shown in Table 1.

[0122] Table 1

[0123] electrode sensitivity Potential drift (mv / 10s) Comparative Example 1 55.2 0.57 Example 1 56.7 -0.023 Example 2 59.4 -0.024 Example 3 59.8 0.16 Comparative Example 2 60.3 0.33 Example 4 59.2 0.16 Example 5 58.6 0.21 Comparative Example 3 50.2 0.23 Comparative Example 4 55.3 0.36 Comparative Example 5 51.7 0.40

[0124] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An all-solid-state micro-ion electrode, characterized in that: It includes an electrode substrate, an electrode conductor layer, a composite carbon slurry layer and an ion selective membrane; The electrode conductor layer is arranged on the electrode substrate, the composite carbon slurry layer covers the electrode conductor layer, and the ion selective membrane covers the composite carbon slurry layer; The composite carbon slurry layer is obtained by coating carbon slurry containing polytetrafluoroethylene, and the mass proportion of polytetrafluoroethylene in the composite carbon slurry layer is 0.25%-1%.

2. The all-solid-state micro-ion electrode according to claim 1, characterized in that: The material of the electrode substrate includes at least one of PVC, ceramic, PCB, single crystal silicon or PET; The thickness of the electrode substrate is 1-1.8 mm.

3. The all-solid-state micro-ion electrode according to claim 1, characterized in that: The electrode conductor of the electrode conductor layer includes at least one of Au, Ag, Pt, and C; The thickness of the electrode conductor layer is 0.1-1.5 um.

4. The all-solid-state micro-ion electrode according to claim 1, characterized in that: The carbon slurry is mainly composed of conductive carbon material, binder, filler and organic solvent; The mass ratio of the conductive carbon material, the binder, the filler and the organic solvent is (40-45): (20-25): (15-20): (15-20); The conductive carbon material includes carbon fiber; The binder includes acrylic resin; The filler includes silicon dioxide; The organic solvent includes N-methylpyrrolidone.

5. The all-solid-state micro-ion electrode according to claim 1, characterized in that: The composite carbon slurry layer is coated on the electrode conductor layer by a dispensing process; The thickness of the composite carbon slurry layer is 180-220 um.

6. The all-solid-state micro-ion electrode according to claim 1, characterized in that: The ion selective membrane includes a potassium ion selective membrane, a sodium ion selective membrane, a chloride ion selective membrane, a calcium ion selective membrane, a magnesium ion selective membrane or a lithium ion selective membrane; The thickness of the ion selective membrane is 135-165 um.

7. The all-solid-state micro-ion electrode according to claim 6, characterized in that: The potassium ion selective membrane is obtained by coating the slurry of the potassium ion selective membrane through a dispensing process; In terms of mass percentage, the slurry of the potassium ion selective membrane comprises 14%-18% plasticizer, 5%-9% high molecular polymer, 0.8%-1.2% potassium ion carrier, 0.8%-1.2% ion exchanger, and the balance is solvent.

8. The all-solid-state micro-ion electrode according to claim 7, characterized in that: The plasticizer includes at least one of DOS, DOA, o-NPOE or DOP; The high molecular polymer includes at least one of polyurethane, PVC, polycarbonate or silicone rubber; The potassium ion carrier includes at least one of potassium ion carrier I, potassium ion carrier II, potassium ion carrier III or valinomycin; The ion exchanger includes at least one of KTpClPB, NaTFPB, sodium tetraborate or potassium tetrakis(4-chlorophenyl)borate; The solvent includes at least one of propiophenone, cyclohexanone or tetrahydrofuran.

9. The method for preparing the all-solid-state micro-ion electrode according to any one of claims 1 to 8, characterized in that: The following steps are involved: The electrode conductor is fixed on the electrode substrate to form an electrode conductor layer, and then a carbon slurry containing polytetrafluoroethylene is coated on the electrode conductor layer. After drying, a composite carbon slurry layer is formed. Then, an ion selective membrane slurry is coated on the composite carbon slurry layer. After drying, an all-solid-state micro ion electrode is prepared.

10. A sensor, characterized in that: The invention comprises the all-solid-state micro-ion electrode as described in any one of claims 1 to 8.

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