Potassium ion sensitive sensor based on conductive polymer gel and preparation method thereof

Abstract

The present invention relates to a preparation method of a potassium ion-sensitive sensor based on a conductive polymer gel, comprising the following steps: preparing a PEDOT:PSS dispersed aqueous solution; doping nano-gold particles in the PEDOT:PSS dispersed aqueous solution to form a uniform suspension; patterning the suspension and drying it into a gel-like microstructure; calcining and annealing the gel-like microstructure to form a stable gel microstructure; fixing potassium ion sieve molecules through the nano-gold particles in the stable gel microstructure to form a potassium ion-sensitive sensor. The potassium ion-sensitive sensor prepared by the preparation method according to the present invention is flexible, has good conductivity and is compatible with the patterning process, has high sensitivity and good structural stability.

Description

Technical Field

[0001] The present invention is applied to the field of chemistry, and particularly relates to a potassium ion-sensitive sensor based on a conductive polymer gel and a preparation method thereof. Background Art

[0002] Potassium ions widely exist in nature and the human body. Potassium ions have important physiological functions for organisms, so there is a need to measure potassium ions in many fields. For example, potassium ions are an important agricultural fertilizer, and it is necessary to measure the potassium ion content in the soil for scientific fertilization. Potassium ions are the main cations in human intracellular fluid, and the myocardium and neuromuscular require relatively constant potassium ion concentrations to maintain normal excitability. It is necessary to measure the potassium ion content in the blood to assist medical treatment.

[0003] Ion-sensitive sensors are electrochemistry sensor devices widely used in fields such as chemistry, environmental protection, medicine, food, and bioengineering. They use ion-selective electrodes to directly respond to target ions such as potassium ions in a complex analyte, convert the sensed ion amount into an available output signal, and quickly, sensitively, and quantitatively measure the volume concentration of the target ions.

[0004] Commonly used ion-sensitive electrodes include ion-sensitive field-effect transistors, membrane electrodes, and ion-sensitive electrodes. These ion-sensitive electrodes are all composed of multi-layer structures. The preparation method of the multi-layer structure is relatively complex, and impurities are easily introduced during the preparation process, interfering with the detection accuracy of the ion-sensitive sensor itself. In addition, limited by the conductive properties of the materials, ion-sensitive sensors generally use rigid or high-conductive materials with a large Young's modulus, which restricts the application scenarios of ion-sensitive sensors. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a preparation method for an integrally formed flexible potassium ion-sensitive sensor, and the preparation process is particularly simple and efficient.

[0006] To achieve the above purpose, the present invention provides a preparation method for a potassium ion-sensitive sensor based on a conductive polymer gel, which includes the following steps: preparing a PEDOT:PSS dispersed aqueous solution; doping nano-gold particles in the PEDOT:PSS dispersed aqueous solution to form a uniform suspension; patterning the suspension and drying it into a gel-like microstructure; calcining and annealing the microstructure to form a stable gel microstructure; fixing potassium ion sieve molecules through the nano-gold particles in the stable gel microstructure to form a potassium ion-sensitive sensor.

[0007] As described above, at the microscopic level, the present invention selects a polymer with high conductivity and prepares a gel state in which molecules are cross-linked with each other. Moreover, a large number of potassium ion sieve molecules can be fixed by gold nanoparticles. At the macroscopic level, it is prepared integrally. Compared with the multi-layer structure, the preparation method is simpler, reducing the possibility of impurity interference. It has the potential to be made at the nanoscale, compatible with the microelectronic mass production process, and has the property of shape bending, compatible with the flexible electronic process.

[0008] In a possible implementation manner of the present invention, the content of PEDOT:PSS in the aqueous dispersion solution of PEDOT:PSS is 1 μg / mL to 1 g / mL.

[0009] As described above, the gel microstructure of the prepared potassium ion sensitive sensor is particularly stable and porous, suitable for various application scenarios.

[0010] In a possible implementation manner of the present invention, the content of gold nanoparticles in the suspension is 1 μg / mL to 1 g / mL.

[0011] As described above, the prepared potassium ion sensitive sensor has satisfactory sensitivity. In some detection scenarios, it is even more sensitive than traditional ion sensitive electrodes.

[0012] In a possible implementation manner of the present invention, the patterning is selected from inkjet printing, mask jetting, and pattern transfer. In the preparation method of the present invention, the homogeneous suspension composed of PEDOT:PSS, gold nanoparticles, and water can be easily applied to inkjet printing mask coating, pattern transfer, etc., which can form electrode films with particularly thin and complex patterns. In addition, after the suspension is dried for a period of time, due to the cross-linking between PEDOT:PSS molecules, the viscosity gradually increases, changing from a liquid state to a semi-gel state, and even to a gel state. Such a property enables mask jetting to be applicable as a patterning means, that is, a template such as copper foil can be used as a mask to apply the PEDOT:PSS mixture thereon. In some embodiments, the thickness of the electrode film can be as thin as 1 nm, and the gap in the pattern can be as small as 1 nm at the minimum. The preparation method of the present invention further improves the miniaturization of the potassium ion sensitive sensor, providing application possibilities for some usage scenarios that were previously limited due to poor miniaturization.

[0013] It is easily understandable that the patterning means that can be adopted in the preparation method of the present invention is not limited to the above-listed ways. Since the homogeneous suspension composed of PEDOT:PSS, gold nanoparticles, and water is in a liquid state, it can be widely used in various "molds" for configuration. And after the suspension is dried for a period of time, it changes from a liquid state to a semi-gel state, and even to a gel state. Such a property enables it to be applicable to some patterning means for solid configuration.

[0014] In a possible implementation of the present invention, the drying is carried out at a temperature ranging from room temperature to 200°C. In the preparation method of the present invention, the drying temperature mainly depends on the patterning means employed, and the drying can be carried out before or after patterning, or simultaneously with patterning. For example, if mask spraying is used, drying can be carried out at a relatively high temperature, such as 100 - 150°C, before patterning to rapidly evaporate the moisture in the suspension, thereby increasing the viscosity of the suspension to facilitate the formation of precise patterns through the mask. If inkjet printing is used, drying can be carried out at a relatively low temperature, such as 50 - 80°C, after inkjetting to avoid deformation of the gel-like microstructure due to rapid drying. If pattern transfer is used, it is possible to heat the substrate to be transferred while using the transfer member to dip and transfer the prepared homogeneous suspension. In some embodiments, for example, when using a mold with a complex structure, drying can even be carried out slowly at room temperature to ensure that the gel-like microstructure conforms to the shape of the mold.

[0015] In the preparation method of the present invention, drying is mainly to cooperate with patterning to form a gel-like microstructure of a predetermined shape. In the gel-like microstructure, PEDOT:PSS is partially crosslinked, however, its degree of crosslinking is still very low, and the mechanical properties are insufficient, and it is easy to dissociate into fragment microgels. Therefore, this gel-like microstructure can be regarded as metastable.

[0016] In a possible implementation of the present invention, the calcination annealing is to repeat N cycles of the following steps a and b: Step a: Maintain at a temperature between 60°C and 200°C for 30 minutes to 24 hours; Step b: After heating to 200°C within 15 minutes, gradually cool down to 20°C through n temperature gradients, where n is an integer selected from 1 to 20, and each temperature gradient lasts for 5 to 60 minutes.

[0017] In some embodiments, N is 2, 3, 4, 5 or 6. In some embodiments, n is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20. In some embodiments, each temperature gradient lasts for 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes or 60 minutes. In some embodiments, N is selected from 2, 3 or 4, n is selected from 2, 3, 4, 5, 6 or 9, and each temperature gradient lasts for 20 minutes, 25 minutes, 30 minutes, 35 minutes or 40 minutes. In some embodiments, N is selected from 3 or 4, n is selected from 3, 4 or 5, and each temperature gradient lasts for 25 minutes, 30 minutes or 35 minutes.

[0018] As described above, PEDOT:PSS extends from a folded state into linear long chains in step a, and then forms a nanofiber network in which PEDOT-rich crystalline regions intersect with PSS regions in step b. Steps a and b are repeated to increase the crosslinking degree of PEDOT:PSS and strengthen the formed nanofiber network. Therefore, after the "calcination annealing" process of the present invention, the originally loose PEDOT:PSS in the gel-like microstructure crosslinks to form a nanofiber network, thereby forming a stable gel microstructure. Due to the interconnected nanofiber connection morphology, this stable gel microstructure can maintain mechanical integrity when PEDOT:PSS absorbs water and swells without dissociating into fragments. Therefore, it can be ensured that the potassium ion-sensitive sensor prepared therefrom can also work stably and continuously in a liquid environment, is not easily broken or detached, and provides a stable reaction environment for the potassium ion reaction.

[0019] In a possible implementation manner of the present invention, the potassium ion sieve molecule is valinomycin or 18-crown-6.

[0020] Valinomycin and 18-crown-6 are excellent potassium ion sieve molecules that can quickly chelate with potassium ions in the solution to form stable complexes. In addition, valinomycin and 18-crown-6 can be relatively stably fixed on gold nanoparticles through electrostatic adsorption, and thus are largely fixed in the gel. It is easy to understand that the potassium ion sieve molecules that can be used in the preparation method of the present invention are not limited to valinomycin and 18-crown-6. Without other limiting factors or constraints, molecules that can quickly react with potassium ions and be adsorbed by gold nanoparticles all have the potential to be used as the potassium ion sieve molecules of the present invention.

[0021] Compared with the ion-sensitive electrodes with multi-layer structures and their preparation methods in the prior art, the present invention has the following characteristics: (1) The ion-sensitive sensor is a stable conductive polymer gel microstructure mainly composed of PEDOT:PSS and gold nanoparticles, which has good conductivity while maintaining flexibility, is compatible with the patterning process, and can form an electrochemical microelectrode. Depending on the patterning process, the potassium ion-sensitive sensor can form an electrode film with a thickness in the range of 1 nm - 1 mm, and the electrode spacing and line width can reach a minimum of 1 nm. (2) The gold nanoparticles have a large specific surface area, so that the prepared potassium ion-sensitive electrode has an exponentially increased number of potassium ion sieve molecules, greatly improving the sensitivity of the potassium ion-sensitive sensor; in addition, the gold nanoparticles help to improve the ion mobility and enhance the electrical signal of the potassium ion reaction of the potassium ion sieve molecules fixed thereon. (3) After the calcination annealing treatment, PEDPT:PSS is fully crosslinked, so that the formed stable gel microstructure can also work reliably in a liquid environment, has good structural stability, is not easily broken or detached, provides a good reaction environment for the potassium ion reaction of the potassium ion sieve molecules fixed thereon, and further improves the sensitivity of the potassium ion-sensitive sensor. Brief Description of the Drawings

[0022] The following further describes each technical feature of the present invention and the relationships between them with reference to the drawings. The drawings are exemplary. Some technical features are not shown in actual proportions, and in some drawings, technical features that are customary in the technical field to which the present invention pertains and are not essential for understanding and implementing the present invention may be omitted, or technical features that are not essential for understanding and implementing the present invention may be additionally shown. That is, the combination of the various technical features shown in the drawings is not used to limit the present invention. Additionally, throughout the present invention, the content referred to by the same reference numerals is also the same. The specific description of the drawings is as follows:

[0023] Figure 1 Schematic diagram of the microstructure of the products of each step according to an embodiment of the preparation method of the present invention.

[0024] Figure 2 Graph showing the variation of current with voltage in a potassium ion-sensitive sensor prepared according to an embodiment of the preparation method of the present invention.

[0025] Figure 3 Schematically shows the micrographs of potassium ion-sensitive sensors prepared according to an embodiment of the preparation method of the present invention and two comparative examples after a structural stability test. Detailed Description of the Invention

[0026] The following provides a detailed description of the specific embodiments of the present invention with reference to the drawings.

[0027] Unless otherwise defined, all technical and scientific terms used throughout the present invention have the same meaning as commonly understood by those skilled in the technical field to which the present invention pertains. In case of inconsistency, the meaning stated in the present invention or the meaning derived from the content recorded in the present invention shall prevail. Additionally, the terms used in this description are only for the purpose of describing the embodiments of the present invention and are not intended to limit the present invention.

[0028] The term "comprising" used throughout the present invention should not be construed as being limited to the content listed thereafter; it does not exclude other structural elements or steps. Therefore, it should be construed as specifying the existence of the stated technical features, wholes, steps, or components, but does not exclude the existence or addition of one or more other technical features, wholes, steps, or components and their groups.

[0029] Figure 1 Schematic diagram of the microstructure of the products of each step according to an embodiment of the preparation method of the present invention.

[0030] A PEDOT:PSS dispersion aqueous solution was prepared by adding the PEDOT:PSS polymer represented by black S-shaped chains to water. Nanogold particles represented by dark gray dots were added to the PEDOT:PSS dispersion aqueous solution to form a homogeneous suspension. The suspension was patterned into a circle and dried into a circular gel-like microstructure. The gel-like microstructure was calcined and annealed to fully crosslink PEDOT:PSS to form a nanofiber network, thereby forming a stable gel microstructure. Potassium ion sieve molecules represented by light gray ellipses were immobilized by the nanogold particles in the stable gel microstructure to form a potassium ion sensitive sensor.

[0031] Example 1

[0032] PEDOT:PSS was dissolved in pure water at a rate of 1 mg / mL, and stirred thoroughly to obtain a PEDOT:PSS dispersion aqueous solution. Nanogold particles were added to the PEDOT:PSS dispersion aqueous solution at a rate of 1 mg / mL, and stirred thoroughly to obtain a homogeneous suspension. A linear array of electrodes was printed on a substrate using an inkjet printer, and then dried in an oven at 60 °C for 20 hours to obtain a rectangular gel-like microelectrode with an average thickness of 200 μm. The following steps a1 and b1 were repeated three cycles: a1) The oven was adjusted to 150 °C and maintained for 6 hours, b1) The temperature was gradually increased to 200 °C within 5 minutes and then gradually decreased to 20 °C through 6 temperature gradients each lasting 30 minutes, to obtain a stable gel microelectrode. The stable gel microelectrode was immersed in a solution containing valinomycin, stirred, so that valinomycin was adsorbed inside the stable gel microelectrode and immobilized by the internal nanogold particles, to obtain a potassium ion sensitive sensor S1.

[0033] Example 2

[0034] PEDOT:PSS was dissolved in pure water at a rate of 0.8 g / mL, and stirred thoroughly to obtain a PEDOT:PSS dispersion aqueous solution. Nanogold particles were added to the PEDOT:PSS dispersion aqueous solution at a rate of 1 mg / mL, and stirred thoroughly to obtain a homogeneous suspension. Using a photoresist mask sputtering technique, it was dried at 120 °C for 0.5 hours to increase the viscosity of the suspension to a semi-gel state, and then it was configured into a circular gel-like microelectrode with grooved gaps through a copper foil template, where the minimum spacing of the gaps reached 50 nm. The following steps a2 and b2 were repeated five cycles: a2) The oven was adjusted to 130 °C and maintained for 4 hours, b2) The temperature was gradually increased to 200 °C within 10 minutes and then gradually decreased to 20 °C through 4 temperature gradients each lasting 45 minutes, to obtain a stable gel microelectrode. The stable gel microelectrode was immersed in a solution containing valinomycin, stirred, so that valinomycin was adsorbed inside the stable gel microelectrode and immobilized by the internal nanogold particles, to obtain a potassium ion sensitive sensor S2.

[0035] Example 3

[0036] Dissolve PEDOT:PSS in pure water at a rate of 0.1 g / mL, and stir well to obtain a dispersed aqueous solution of PEDOT:PSS. Add gold nanoparticles to the dispersed aqueous solution of PEDOT:PSS at a rate of 6 mg / mL, and stir well to obtain a homogeneous suspension. Use an inkjet printer to print a linear array of electrodes on a substrate, and then dry it in an oven at 60 °C for 20 hours to obtain a rectangular gel-like microelectrode with an average thickness of 200 μm. Repeat the following steps a1 and b1 for four cycles: a1) Set the oven to 150 °C and hold for 6 hours, b1) Gradually heat up to 200 °C within 5 minutes and then cool down to 20 °C through six temperature gradients with a duration of 30 minutes each to obtain a stable gel microelectrode. Immerse the stable gel microelectrode in a solution containing 18-crown-6, stir, and allow 18-crown-6 to adsorb inside the stable gel microelectrode and be fixed by the internal gold nanoparticles to obtain a potassium ion sensitive sensor S3.

[0037] Example 4

[0038] Dissolve PEDOT:PSS in pure water at a rate of 0.8 g / mL, and stir well to obtain a dispersed aqueous solution of PEDOT:PSS. Add gold nanoparticles to the dispersed aqueous solution of PEDOT:PSS at a rate of 1 mg / mL, and stir well to obtain a homogeneous suspension. Use a photoresist mask sputtering technique to dry the suspension at 120 °C for 0.5 hours to increase its viscosity to a semi-gel state, and then configure it into a circular gel-like microelectrode with grooved gaps through a copper foil template, where the minimum spacing of the gaps reaches 50 nm. Repeat the following steps a2 and b2 for five cycles: a2) Set the oven to 130 °C and hold for 4 hours, b2) Gradually heat up to 200 °C within 10 minutes and then cool down to 20 °C through four temperature gradients with a duration of 45 minutes each to obtain a stable gel microelectrode. Immerse the stable gel microelectrode in a solution containing 18-crown-6, stir, and allow 18-crown-6 to adsorb inside the stable gel microelectrode and be fixed by the internal gold nanoparticles to obtain a potassium ion sensitive sensor S4.

[0039] Example 5

[0040] Dissolve PEDOT:PSS in pure water at a quantity of 200 μg / mL, and stir well to obtain a dispersed aqueous solution of PEDOT:PSS. Add gold nanoparticles to the dispersed aqueous solution of PEDOT:PSS at a quantity of 50 μg / mL, and stir well to obtain a homogeneous suspension. Use pattern transfer to prepare a thin-film gel-like microstructure with a thickness of 100 nm under the condition that the substrate temperature is 120 ± 2 °C. Repeat the following steps a3 and b3 for three cycles: a3) Set the oven to 120 °C and keep it for 2 hours, b3) Gradually heat up to 200 °C within 15 minutes and then cool down step by step through 10 temperature gradients with a duration of 20 minutes each to 20 °C to obtain a stable gel microelectrode. Immerse the stable gel microelectrode into a solution containing 18-crown-6, stir, so that 18-crown-6 is adsorbed inside the stable gel microelectrode and fixed by the internal gold nanoparticles to obtain a potassium ion-sensitive sensor S5.

[0041] Example 6

[0042] Dissolve PEDOT:PSS in pure water at a quantity of 100 μg / mL, and stir well to obtain a dispersed aqueous solution of PEDOT:PSS. Add gold nanoparticles to the dispersed aqueous solution of PEDOT:PSS at a quantity of 10 μg / mL, and stir well to obtain a homogeneous suspension. Use pattern transfer to prepare a thin-film gel-like microstructure with a thickness of 50 nm under the condition that the substrate temperature is 100 ± 2 °C. Repeat the following steps a4 and b4 for two cycles: a4) Set the oven to 130 °C and keep it for 1 hour, b4) Gradually heat up to 200 °C within 15 minutes and then cool down step by step through 10 temperature gradients with a duration of 15 minutes each to 20 °C to obtain a stable gel microelectrode. Immerse the stable gel microelectrode into a solution containing valinomycin, stir, so that valinomycin is adsorbed inside the stable gel microelectrode and fixed by the internal gold nanoparticles to obtain a potassium ion-sensitive sensor S7.

[0043] Comparative Example 1

[0044] Dissolve PEDOT:PSS in pure water at a quantity of 1 mg / mL, and stir well to obtain a dispersed aqueous solution of PEDOT:PSS. Add gold nanoparticles to the dispersed aqueous solution of PEDOT:PSS at a quantity of 1 mg / mL, and stir well to obtain a homogeneous suspension. Print a linear array electrode on the substrate using an inkjet printer, and then dry it in an oven at 60 °C for 20 hours to obtain a rectangular gel-like microelectrode with an average thickness of 200 μm. Then raise the oven temperature to 120 °C and keep it for 3 hours, and cool it naturally to room temperature. Immerse the obtained product into a solution containing valinomycin, stir, so that valinomycin is adsorbed inside the stable gel microelectrode and fixed by the internal gold nanoparticles to obtain a potassium ion-sensitive sensor C1.

[0045] Comparative Example 2

[0046] Dissolve PEDOT:PSS in pure water at a dosage of 1 mg / mL, and stir well to obtain a PEDOT:PSS dispersed aqueous solution. Add gold nanoparticles to the PEDOT:PSS dispersed aqueous solution at a dosage of 1 mg / mL, and stir well to obtain a homogeneous suspension. Use an inkjet printer to print a linear array electrode on a substrate, and then dry it in an oven at a temperature of 60 °C for 24 hours to obtain a rectangular gel-like microelectrode with an average thickness of 200 μm. Slowly dropwise add a solution containing valinomycin to the obtained product, so that valinomycin is adsorbed inside the stable gel microelectrode and fixed by the internal gold nanoparticles to prepare a potassium ion sensitive sensor C2.

[0047] Experimental Example 1

[0048] Apply a voltage of -1 V to 1 V to both ends of the potassium ion sensitive sensors S1 to S7 prepared by the preparation method according to the present invention, and measure the current generated in the potassium ion sensitive sensors S1 to S7 thereby. Figure 2 Shows the change of current with voltage in the potassium ion sensitive sensor S1 prepared according to Example 1. Figure 2 It can be seen that as the voltage increases from -1 V to +1 V, the current increases accordingly, and the straight line passes through the origin. This indicates that the electrode has good conductivity, which shows that adding gold nanoparticles helps to improve the conductivity of the conductive polymer gel, thereby improving the ion mobility of the potassium ion sensitive sensor S1 prepared therefrom and enhancing the electrical signal of the potassium ion reaction. The potassium ion sensitive sensors S2 to S7 also exhibit similar electrical properties.

[0049] Experimental Example 2

[0050] Immerse the potassium ion sensitive sensor S1 and the potassium ion sensitive sensors C1 to C2 in the same potassium ion aqueous solution for half an hour respectively, take them out, dry them, and observe their patterned structures with a microscope. Figure 3 Is a schematic diagram of the microscopic structure of the potassium ion sensitive sensor S1 example and the potassium ion sensitive sensors C1 to C2 after the above-mentioned immersion structure stability test. Figure 3 As can be seen from (a), after the "calcination annealing" process of the present invention, the potassium ion sensitive sensor S1 can maintain structural stability even after long-term immersion. On the contrary, as can be seen from Figure 3 (b), even after a certain degree of heat treatment, the potassium ion sensitive sensor C2 still shows a phenomenon of partial fracture and shedding of its structure after immersion. And Figure 3 (c) shows that the structure of the potassium ion sensitive sensor C1 without any heat treatment is completely broken into pieces after immersion, so it cannot provide a stable reaction environment for the potassium ion reaction.

[0051] Experimental Example 3

[0052] a) The potassium ion sensors S1 to S7 prepared by using the preparation method according to the present invention of the present application and a commercially available potassium ion kit for blood potassium were used to test potassium ion solutions with potassium ion concentrations of 0.1 mM respectively, and all were successful.

[0053] b) The potassium ion sensors S1 to S7 prepared by using the preparation method according to the present invention of the present application and another same commercially available potassium ion kit for blood potassium were used to test potassium ion solutions with potassium ion concentrations of 10 μM respectively. The commercially available potassium ion kit for blood potassium failed the test, while the potassium ion sensors S1, S3, and S5 were all successful in the test, and the potassium ion sensors S2, S4, and S6 failed the test.

[0054] c) The potassium ion sensors S1 to S7 prepared by using the preparation method according to the present invention of the present application and another same commercially available potassium ion kit for blood potassium were used to test potassium ion solutions with potassium ion concentrations of 1 μM respectively. Only the potassium ion sensor S1 was successful in the test.

[0055] The above results show that the potassium ion sensor prepared by the method according to the present invention has a lower detection limit compared with the commercially available potassium ion kit for blood potassium, that is, it has higher sensitivity.

[0056] Although the numerical ranges and parameters claimed in the present invention are approximate values, the numerical values set forth in specific examples are as precise as possible. However, any numerical value inherently has some errors that are inevitable in individual measurements. In the present invention, "about" generally means within 10%, 5%, 3%, 1%, 0.5% or 0.1% of a given value or range, or within the average standard deviation acceptable to those skilled in the art. Outside of specific embodiments, unless otherwise specified, all numerical ranges, quantities, values and ratios in the present application, such as the amount of materials, duration, temperature, operating conditions, ratio of quantities, etc. should be understood to be modified by the word "about". In the present application, a range can be expressed as from one endpoint to the other endpoint, or between the two endpoints. Unless otherwise specified, all ranges of the present invention include the endpoints.

[0057] It can be understood that those skilled in the art can combine the features mentioned in one or more of the embodiments mentioned throughout the present invention with the features in other embodiments in any appropriate manner to implement the present invention.

[0058] Note that the above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the technical concept of the present invention, more other equivalent embodiments can be included, all of which fall within the protection scope of the present invention.

Claims

1. A preparation method of a potassium ion-sensitive sensor based on a conductive polymer gel, characterized in that, It includes the following steps: Prepare a PEDOT:PSS dispersed aqueous solution; Dope nano-gold particles in the PEDOT:PSS dispersed aqueous solution to form a homogeneous suspension; Pattern the suspension and dry it into a gel-like microstructure; Calcine and anneal the gel-like microstructure to form a stable gel microstructure; Fix potassium ion sieve molecules through the nano-gold particles in the stable gel microstructure to form a potassium ion sensitive sensor; Wherein, the calcination and annealing is to repeat N cycles of the following steps a and b: Step a: Maintain at a temperature between 60 °C and 200 °C for 30 minutes to 24 hours; Step b: After heating to 200 °C within 15 minutes, cool down to 20 °C step by step through n temperature gradients; Wherein N is an integer between 2 and 6, n is an integer selected from 1 to 20, and each temperature gradient lasts for 5 to 60 minutes; The potassium ion sieve molecule is valinomycin or 18-crown-6.

2. The preparation method according to claim 1, characterized in that, The content of PEDOT:PSS in the PEDOT:PSS dispersed aqueous solution is 1 μg / mL to 1 g / mL.

3. The preparation method according to claim 1, characterized in that, The content of nano-gold particles in the suspension is 1 μg / mL to 1 g / mL.

4. The preparation method according to claim 1, characterized in that, The patterning is selected from inkjet printing, mask jetting or pattern transfer.

5. The preparation method according to claim 1, characterized in that, The drying is carried out at a temperature from room temperature to 200 °C.

6. A potassium ion-sensitive sensor based on a conductive polymer gel, characterized in that, Prepared by the preparation method according to any one of claims 1 to 5.

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