A multi-ion sensor with zero-sense correction

Abstract

This invention discloses a non-intrusive multi-ion sensor, comprising a substrate on which a base electrode (AgCl / Ag electrode) is disposed; a Na ion electrode selectively reacting to Na ions; a K ion electrode selectively reacting to K ions; and a gel layer covering the Na and K ion electrodes, the gel layer containing Na and K ions at a concentration ratio of 1:2 to 4; both the Na and K ion electrodes are located on the base electrode; and the sensitivity of the Na ion electrode is equal to that of the K ion electrode. With this invention, the wetting and calibration steps typically performed during sensor use are completed imperceptibly by the user, reducing user time costs and potential operational errors.

Description

Technical Field

[0001] This invention belongs to the field of ion sensor technology, and particularly relates to a multi-ion sensor with non-sensory calibration. Background Technology

[0002] A low-sodium, high-potassium diet can lead to elevated blood pressure and increase the risk of cardiovascular disease. Currently, the World Health Organization (WHO) recommends that adults consume less than 2 grams of sodium and ≥3.5 grams of potassium per day per year, while children's daily salt and potassium intake should be determined based on their energy needs and age. A recent study published in the *Journal of the American Heart Association* [Monique Tan, et al. Twenty-Four-Hour Urinary Sodium and Potassium Excretion in China: A Systematic Review and Meta-Analysis. Journal of the American Heart Association, Originally published 16 Jul 2019] shows that over the past 40 years, salt intake across all age groups in China has remained at a high level, approximately twice the WHO's recommended upper limit. At the same time, potassium intake in China is severely insufficient, less than half the WHO's recommended standard. Therefore, managing the Na / K ratio in the diet is of great significance for health management.

[0003] For measuring the Na / K ion concentration ratio, the common practice is to first calibrate the sensor with one or two calibration solutions before measuring the sodium and potassium ion concentrations in the solution. In actual use, this requires a series of steps: wetting, washing, calibration, washing, sample collection, measurement, and washing to complete a single measurement operation. This involves numerous steps, increasing the user's time cost. Furthermore, using this type of sensor requires users to possess certain professional skills, as general users are prone to operational errors that affect measurement accuracy. Summary of the Invention

[0004] This invention overcomes the shortcomings of the prior art and provides a non-inductively calibrated multi-ion sensor to solve the problems existing in the prior art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a multi-ion sensor with non-inductive calibration, comprising...

[0006] A substrate on which a base electrode is disposed;

[0007] Na-ion electrode with selective reaction to Na-ions;

[0008] K-ion electrode with selective reaction to K-ions;

[0009] A gel layer covers the Na ion electrode and the K ion electrode, and the gel layer contains Na ions and K ions, with a Na ion to K ion concentration ratio of 1:2 to 4.

[0010] Both the Na ion electrode and the K ion electrode are located on the base electrode;

[0011] The sensitivity of the Na ion electrode is equal to that of the K ion electrode.

[0012] In a preferred embodiment of the present invention, the base electrode is an AgCl / Ag electrode. The base electrode is formed by printing an Ag pattern on the substrate with silver ink, and after sintering, the Ag pattern is treated with AgCl to form an AgCl / Ag electrode.

[0013] In a preferred embodiment of the present invention, a Na ion sensing film coating solution is applied to the base electrode to form a Na ion electrode, and a K ion sensing film coating solution is applied to the base electrode to form a K ion electrode.

[0014] In a preferred embodiment of the present invention, the Na ion sensing membrane coating liquid includes a Na ion carrier, an ion additive, a plasticizer, a neutral polymer, and a solvent;

[0015] The K-ion sensing membrane coating solution includes a K-ion carrier, ion additives, plasticizers, neutral polymers, and solvents.

[0016] In a preferred embodiment of the present invention, the Na ion-sensing membrane coating solution contains 1.5-2.5 wt% Na ion carrier; 25-50 mol% ion additive; and a mass ratio of neutral polymer to plasticizer of 1:1-3. The above components are completely dissolved using a solvent.

[0017] In a preferred embodiment of the present invention, the K ion carrier content in the K ion sensing membrane coating solution is 1.5-2.5 wt%; the ion additive content is 0-25 mol%; the mass ratio of neutral polymer to plasticizer is 1:1-3; and the above components are completely dissolved using a solvent.

[0018] In a preferred embodiment of the present invention, the Na ion carrier is one of sodium ion carrier IV (2,6,13,16,19-Pentaoxapentacyclo[18.4.4.4.0.0]dotriacontane) and sodium ion carrier X (Tetraethyl 4-tert-Butylcalix[4]arene-O,O',O'',O'''-tetraacetate);

[0019] The K ion carrier is one of valproic acid and potassium ion carrier II (Bis(benzo-15-crown-5));

[0020] The ionic additive is one of KTpClPB (Potassium tetrakis(4-chlorophenyl)borate) and NaTPB (Sodium tetraphenylborate);

[0021] The plasticizer is one or a mixture of two of 2-nitrophenyl octyl ether (o-NPOE) and Bis(2-ethylhexyl) sebacate (DOS);

[0022] The neutral polymer is one or a mixture of polyvinyl chloride and polyurethane, and carboxylated polyvinyl chloride;

[0023] The solvent is one of tetrahydrofuran and cyclohexanone.

[0024] In a preferred embodiment of the present invention, the gel layer contains a hydrophilic gel and a salt of Na and K ions, and when the gel layer is placed in a solution, Na and K ions can freely pass through the gel layer.

[0025] This invention addresses the shortcomings of the prior art and has the following beneficial effects:

[0026] In the multi-ion sensor of the present invention, the immersion and calibration steps of a typical sensor are completed without the user's awareness during measurement, simplifying the user's operation and reducing the user's measurement time.

[0027] By reducing the number of operation steps, the probability of errors caused by improper operation can be reduced. Furthermore, the multi-ion sensor of this invention does not require users to have certain professional skills, and ordinary users can start using it directly, reducing the user's learning cost. Attached Figure Description

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0029] Figure 1 This is a schematic diagram of the overall structure of a preferred embodiment of the present invention;

[0030] Figure 2 Characteristic diagrams of the Na ion electrode and K ion electrode according to preferred embodiments of the present invention;

[0031] Figure 3 This is a schematic diagram showing the potential-time change between the Na ion electrode and the K ion electrode after water wetting treatment in a preferred embodiment of the present invention.

[0032] Figure 4 This is a schematic diagram showing the potential-time change between the sodium ion electrode and the potassium ion electrode after 30 seconds of cleaning with the correction solution in a preferred embodiment of the present invention.

[0033] Figure 5 This is a schematic diagram of the potential-time changes between the sodium ion electrode and the potassium ion electrode at each stage in a preferred embodiment of the present invention;

[0034] Figure 6 This is a characteristic graph showing the potential between the Na ion electrode and the K ion electrode and the ratio of Na to K ion concentrations in the evaluation solution during non-inductive calibration in a preferred embodiment of the present invention (used repeatedly).

[0035] Figure 7 This is a diagram showing the distribution of corrected potentials between the Na ion electrode and the K ion electrode in a preferred embodiment of the present invention (for single use only).

[0036] Figure 8 This is a characteristic graph showing the potential between the Na ion electrode and the K ion electrode and the ratio of Na to K ion concentrations in the evaluation solution during non-inductive calibration in a preferred embodiment of the present invention (for single use only).

[0037] In the figure: 10, substrate; 11, basic electrode; 20, Na ion electrode; 30, K ion electrode; 40, gel layer. Detailed Implementation

[0038] The following drawings disclose several embodiments of the present invention. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not essential. Furthermore, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.

[0039] Furthermore, in this invention, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the invention. They are merely used to distinguish components or operations described using the same technical terms, and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If a combination of technical solutions is contradictory or impossible to implement, such a combination should be considered nonexistent and not within the scope of protection claimed by this invention.

[0040] In this embodiment, a silver pattern is formed by printing silver ink on a ceramic substrate (10), and after sintering, the silver pattern is treated with AgCl to form an AgCl / Ag electrode, which serves as the base electrode (11). A 20-40 μm thick Na ion electrode (20) is formed by dispensing Na ion sensing film coating solution onto the AgCl / Ag electrode, and a 20-40 μm thick K ion electrode (30) is formed by dispensing K ion sensing film coating solution onto the AgCl / Ag electrode. After being placed at 15-30°C for 24 hours, a gel solution containing KCl and NaCl solutions is dispensed onto the Na ion electrode (20) and the K ion electrode (30) to form a 60-100 μm thick gel layer (40). Figure 1 As shown, the gel layer (40) completely covers the Na ion electrode (20) and the K ion electrode (30). Through the gel layer (40), the Na ion electrode (20) and the K ion electrode (30) remain connected in the absence of external solution. After the gel layer (40) is applied, it is placed under an incandescent lamp at 15-30°C for 24 hours to air dry naturally.

[0041] Specifically, in this embodiment, the Na ion-sensing membrane coating solution contains 1.5-2.5 wt% Na ion carrier; 25-50 mol% ion additive; and a mass ratio of neutral polymer to plasticizer of 1:1-3; the above components are completely dissolved using a solvent. In the K ion-sensing membrane coating solution, the K ion carrier content is 1.5-2.5 wt%; the ion additive is 0-25 mol%; and a mass ratio of neutral polymer to plasticizer of 1:1-3; the above components are completely dissolved using a solvent.

[0042] Furthermore, the Na ion carrier is one of sodium ion carrier IV (2,6,13,16,19-Pentaoxapentacyclo[18.4.4.4.0.0]dotriacontane) and sodium ion carrier X (Tetraethyl 4-tert-Butylcalix[4]arene-O,O',O'',O'''-tetraacetate); the K ion carrier is one of valproic acid and potassium ion carrier II (Bis(benzo-15-crown-5)); the ion additive is one of KTpClPB (Potassium tetrakis(4-chlorophenyl)borate) and NaTPB (Sodium tetraphenylborate); and the plasticizer is 2-nitrophenyloctyl ether (o-NPOE) and Bis(2-ethylhexyl) One or a mixture of two of the sebacate (DOS); the neutral polymer is one or a mixture of polyvinyl chloride and polyurethane, or carboxylated polyvinyl chloride; the solvent is one of tetrahydrofuran and cyclohexanone.

[0043] A preferred formulation of the Na ion-sensing membrane coating solution is as follows:

[0044] Na ion carrier X 12.3mg

[0045] KTpClPB 1.6mg

[0046] NPOE 409mg

[0047] PVC 200mg

[0048] Weigh the above-mentioned drugs and add them sequentially to a 4mL reagent bottle. Then add 2mL of THF or cyclohexanone and use a spiral shaker to fully dissolve the drugs.

[0049] A preferred formulation of the K-ion sensing membrane coating solution is as follows:

[0050] Valium 12.0 mg

[0051] KTpClPB 1.4mg

[0052] NPOE 395mg

[0053] PVC 200mg

[0054] Weigh the above-mentioned drugs and add them sequentially to a 4mL reagent bottle. Then add 2mL of THF or cyclohexanone and use a spiral shaker to fully dissolve the drugs.

[0055] The characteristics of the Na-ion electrode and K-ion electrode prepared using the above preferred formulation were evaluated, and the specific evaluation is as follows:

[0056] Measuring instrument: Beidou HZ-7000 potentiostat

[0057] Reference electrode: Commercially available AgCl reference electrode (saturated with KCl)

[0058] Test environment: 25℃ water bath

[0059] Na ion testing solutions: 1, 3, 10, 30, 100, 300 mM NaCl, with 20 mM CaCl2 added to maintain the ionic strength of the solution.

[0060] K ion evaluation solutions: 1, 3, 10, 30, 100 mM KCl, with 20 mM CaCl2 added to maintain the ionic strength of the solution.

[0061] The testing sequence was as follows: after soaking the Na ion selective electrode in deionized water for 1 hour, the potential change between the Na ion selective electrode and the reference electrode was measured in the order of 100, 1, 3, 10, 30, 100, and 300 mM NaCl solutions. After each solution measurement, the electrode surface was washed with deionized water and the water droplets were wiped off with a paper towel before starting the measurement in the next solution.

[0062] After soaking the K-ion selective electrode in deionized water for 1 hour, the potential change between the K-ion selective electrode and the reference electrode was measured sequentially using KCl solutions of 30, 1, 3, 10, 30, and 100 mL. After each measurement, the electrode surface was rinsed with deionized water and the water droplets were wiped off with a paper towel before starting the measurement in the next solution.

[0063] Take the potential data after potential equilibrium (potential change within 0.1 mV within 5 seconds) as potential E, and plot it against the concentration gradient of Na+ and K+ ions in the solution as lg[Na+] or lg[K+], as shown in the figure. Figure 2 As shown, the sensitivities of the Na ion electrode and the K ion electrode were calculated to be 59.2 mV / decade and 59.1 mV / decade, respectively. The sensitivities of the Na ion and K ion sensors differ by 0.1 mV, which is within ±1 mV, indicating that their sensitivities are equal.

[0064] In this embodiment, the gel component of the gel layer (40) is one or a mixture of two of EVA (ethylene-vinyl acetate copolymer) and PVA-SBQ (polyvinyl alcohol-styrene pyridinium salt condensate), water and NaCl and KCl (the concentration ratio of Na ions to K ions is 1:2 to 4).

[0065] The preferred preparation method of the gel layer (40) in this embodiment is as follows:

[0066] EVA adhesive (44wt% EVA, the remainder is water) 1g

[0067] PVA-SBQ (6wt% PVA-SBQ, the remainder is water) 2g

[0068] 0.5g of 160mM NaCl / 40mM KCl solution

[0069] Weigh the above ingredients, add them to a 4mL reagent bottle, stir with a spiral shaker for 1 hour before use.

[0070] The evaluation of the multi-ion sensor in this embodiment is as follows:

[0071] Measuring instrument: Beidou HZ-7000 potentiostat

[0072] Test environment: 25℃ water bath

[0073] A few drops of deionized water were placed on the gel layer (40) of the multi-ion sensor to fully wet the sensor, and excess water droplets were wiped away. Potential data between the Na ion electrode (20) and the K ion electrode (30) were collected at a frequency of 1 point / 10 seconds for 36 hours. After about 10-20 minutes, the potential between the Na ion electrode (20) and the K ion electrode (30) began to stabilize. Five adjacent data points were taken at 0.5 hours, 2 hours, 4 hours, 8 hours, 24 hours, and 36 hours (e.g., the five adjacent data points at the 0.5 hour time point are 29 minutes 40 seconds, 29 minutes 50 seconds, 30 minutes, 30 minutes 10 seconds, and 30 minutes 20 seconds after the start of the measurement). Figure 3 As shown, although there are differences in the data at different time points, the values ​​of five adjacent data points differ by less than 0.2 mV. Therefore, the potential between the Na ion electrode (20) and the K ion electrode (30) remains stable after drip treatment for 0.5–36 hours.

[0074] The sensor was rinsed with water to remove water droplets. Then, the sensor surface was cleaned with a calibration solution (160mM NaCl, 40mM KCl) for 30 seconds. Excess water droplets were removed. Potential data between the Na ion electrode (20) and the K ion electrode (30) were collected at a frequency of 1 point / 10 seconds for 36 consecutive hours. After approximately 10-20 minutes, the potential between the Na ion electrode (20) and the K ion electrode (30) began to stabilize. Five adjacent data points were collected at 0.5 hours, 2 hours, 4 hours, 8 hours, 24 hours, and 36 hours. Figure 4As shown, although the data at different time points are slightly different, the values ​​of five adjacent data points at each time point differ by less than 0.2 mV. Therefore, the potential between the Na ion electrode (20) and the K ion electrode (30) remains stable after 0.5-36 hours of cleaning with the calibration solution.

[0075] The above experiments show that after the sensor is cleaned with deionized water or calibration solution and the surface water droplets are wiped off, the potential between the Na ion electrode and the K ion electrode remains stable after 0.5-36 hours, and there is no need to wet the sensor again.

[0076] Next, the sensor's non-inductive calibration was evaluated. First, the sensor's performance under repeated use was evaluated. At the start of the measurement, the data reading frequency was changed to 1 point / second. Before use, the sensor was cleaned with water or calibration solution and left to stand for 0.5-36 hours. Within 5 seconds of the start of the measurement, the sensor was immersed in the test solution, stirred for 5 seconds, and allowed to stand until the measurement was complete. After the measurement, the sensor was cleaned with water, and the water droplets on the sensor surface were wiped away. Next, the sensor was cleaned with calibration solution (160mM NaCl, 40mM KCl) for 30 seconds, the water droplets on the sensor surface were wiped away, and after 0.5 hours, the measurement of the second test solution began. This process was repeated, measuring the potential change of the sodium-potassium sensor in each test solution in turn. The concentration and order of the test solutions are shown in the table below. (Each solution contained 10mM CaCl2 as an ionic strength preservative).

[0077] Measurement sequence ① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ NaK ratio 4 1 2 8 8 10 1 2 4 NaCl / mM 160 6 40 80 160 100 100 200 160 KCl / mM 40 6 20 10 20 10 100 100 40

[0078] Measurement steps and potential changes are as follows Figure 5 As shown. The criterion for determining the completion of the measurement is that the maximum potential change (maximum - minimum) over 5 seconds is less than 0.1mV. The actual measurement time is 40-60 seconds.

[0079] The calibration value is the average of five data points (potentials between the Na and K ion electrodes) before the start of measurement (the maximum potential change (maximum - minimum) of these five data points must be less than 0.2 mV; otherwise, the sensor is considered not yet stable and requires further calibration solution cleaning). The measured value is the average of the potentials between the Na and K ion electrodes 5 seconds prior to the end of the measurement. The difference between the measured value and the calibration value is the characteristic value corresponding to the sodium-potassium concentration ratio of the test solution. The relationship between the measured characteristic value and the sodium-potassium concentration ratio in the test solution is as follows: Figure 6 As shown, the sensor exhibits good Nernst characteristics.

[0080] The above experiments demonstrate that by applying water or cleaning the sensor gel layer with calibration solution 0.5-36 hours before the start of measurement, the sodium-potassium sensor of this embodiment can be repeatedly used to achieve non-sensory calibration.

[0081] Next, we evaluated the sensors' performance under single-use conditions. Forty-five sensors were taken, and a few drops of deionized water were placed on the gel surface of each sensor to fully wet it. The water droplets were then wiped away. The sensors were evaluated within 0.5–36 hours after the water treatment. Within 5 seconds of the measurement starting, the sensor was immersed in the test solution, stirred for 5 seconds, and then allowed to stand until the measurement was complete. After the measurement was completed, the used sensor was discarded, and a new sensor was used for the next measurement. As shown in the table below, five data points were collected for each solution.

[0082] Types of solutions ① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ NaK ratio 4 1 2 8 8 10 1 2 4 NaCl / mM 160 6 40 80 160 100 100 200 160 KCl / mM 40 6 20 10 20 10 100 100 40

[0083] Measurement steps and potential changes are as follows Figure 5 As shown. The criterion for determining the completion of the measurement is that the maximum value of the potential change (maximum - minimum) over 5 seconds is less than 0.1mV, and the actual measurement time is 40-60 seconds.

[0084] The calibration value is the average of five data points (potentials between the Na and K ion electrodes) before the start of measurement (the maximum potential change (maximum - minimum) of these five data points must be less than 0.2mV; otherwise, the sensor is considered not yet stable and is treated as a defective product). The measured value is the average of the potentials between the Na and K ion electrodes 5 seconds prior to the end of the measurement. During the calibration value calculation process, no defects were found among the 45 sensors. The distribution of the 45 calibration values ​​is as follows: Figure 7 As shown, the voltage distribution ranges from -30 to -80 mV, but after sensor calibration, individual differences are offset and do not affect measurement accuracy. The measured value is the average value at the time of measurement completion (5 seconds prior to the measurement completion time, the average potential between the Na ion electrode and the K ion electrode within these 5 seconds). The difference between the measured value and the calibrated value is the characteristic value corresponding to the sodium-potassium concentration ratio of the test solution. The relationship between the measured characteristic value and the sodium-potassium concentration ratio in the test solution is as follows: Figure 8 As shown, the sensor exhibits good Nernst characteristics.

[0085] The above experiments demonstrate that by pre-treating the sensor gel layer with water droplets 0.5-36 hours before the start of measurement, the disposable sodium-potassium sensor of this embodiment can achieve non-sensory calibration.

[0086] While the invention has been described above with reference to various embodiments, it should be understood that many changes and modifications can be made without departing from the scope of the invention. That is, the methods, systems, or devices discussed above are merely examples. Various configurations can be appropriately omitted, substituted, or added to various processes or components. For example, in alternative configurations, methods can be performed in a different order than described, and / or various stages can be added, omitted, and / or combined. Moreover, features described with respect to certain configurations can be combined in various other configurations. Different aspects and elements of the configuration can be combined in a similar manner. Furthermore, as technology develops, many elements are merely examples and do not limit the scope of this disclosure or the claims.

[0087] Specific details are provided in the specification to offer a thorough understanding of exemplary configurations, including implementations. However, configurations can be practiced without these specific details; for example, well-known circuits, processes, algorithms, structures, and techniques have been shown without unnecessary detail to avoid obscuring the configuration. This description provides only exemplary configurations and does not limit the scope, applicability, or configuration of the claims. Rather, the foregoing description of the configurations will provide those skilled in the art with an enabling description for implementing the described techniques. Various changes can be made to the function and arrangement of the elements without departing from the spirit or scope of this disclosure.

[0088] Furthermore, although each operation can be described as a sequential process, many operations can be executed in parallel or simultaneously. Additionally, the order of operations can be rearranged. A process may have additional steps. Moreover, examples of methods can be implemented using hardware, software, firmware, middleware, code, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware, or code, the program code or code segments used to perform the necessary tasks can be stored in a non-transitory computer-readable medium such as a storage medium and executed by a processor.

[0089] In summary, the above detailed description is intended to be illustrative rather than restrictive, and it should be understood that the claims (including all equivalents) are intended to define the spirit and scope of the invention. These embodiments should be understood as illustrative only and not as limiting the scope of protection of the invention. After reading the description of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent changes and modifications also fall within the scope defined by the claims of this invention.

Claims

1. A non-inductively calibrated multi-ion sensor, characterized in that, include A substrate (10) on which a base electrode (11) is disposed; Na ion electrode (20) with selective reaction to Na ions; K-ion electrode (30) with selective reaction to K-ions; A gel layer (40) covers the Na ion electrode (20) and the K ion electrode (30). The gel layer (40) contains salts of Na ions and K ions, and the concentration ratio of Na ions to K ions is 1:2 to 4. The Na ion electrode (20) and the K ion electrode (30) are both located on the base electrode (11); The sensitivity of the Na ion electrode (20) is equal to the sensitivity of the K ion electrode (30); The base electrode (11) is an AgCl / Ag electrode. The base electrode (11) is formed by printing an Ag pattern on the substrate (10) with silver ink. After sintering, the Ag pattern is treated with AgCl to form an AgCl / Ag electrode. The gel layer (40) contains a hydrophilic gel and contains salts of Na ions and K ions. When the gel layer (40) is placed in a solution, Na ions and K ions can freely pass through the gel layer (40).

2. The non-inductively calibrated multi-ion sensor according to claim 1, characterized in that, A Na ion electrode (20) is formed by applying Na ion sensing film coating liquid to the base electrode (11), and a K ion electrode (30) is formed by applying K ion sensing film coating liquid to the base electrode (11).

3. The non-inductively calibrated multi-ion sensor according to claim 2, characterized in that, The Na ion sensing film coating solution includes a Na ion carrier, ion additives, plasticizers, neutral polymers, and solvents. The K-ion sensing membrane coating solution includes a K-ion carrier, ion additives, plasticizers, neutral polymers, and solvents.

4. The non-inductively calibrated multi-ion sensor according to claim 3, characterized in that, In the Na ion sensing film coating solution, the Na ion carrier content is 1.5-2.5 wt%; the ion additive content is 25-50 mol%; the mass ratio of neutral polymer to plasticizer is 1:1-3; and the above components are completely dissolved using a solvent.

5. The non-inductively calibrated multi-ion sensor according to claim 3, characterized in that, In the K-ion sensing membrane coating solution, the content of the K-ion carrier is 1.5-2.5 wt%; the ion additive is 0-25 mol%; the mass ratio of neutral polymer to plasticizer is 1:1-3; and the above components are completely dissolved using a solvent.

6. The non-inductively calibrated multi-ion sensor according to claim 3, characterized in that, The Na ion carrier is one of sodium ion carrier IV (2,6,13,16,19-Pentaoxapentacyclo[18.4.4.4.0.0]dotriacontane) and sodium ion carrier X (Tetraethyl 4-tert-Butylcalix[4]arene-O,O',O'',O'''-tetraacetate); The K ion carrier is one of valproic acid and potassium ion carrier II (Bis(benzo-15-crown-5)); The ionic additive is one of KTpClPB (Potassium tetrakis(4-chlorophenyl)borate) and NaTPB (Sodium tetraphenylborate); The plasticizer is one or a mixture of two of 2-nitrophenyl octyl ether (o-NPOE) and Bis(2-ethylhexyl) sebacate (DOS); The neutral polymer is one or a mixture of polyvinyl chloride and polyurethane, and carboxylated polyvinyl chloride; The solvent is one of tetrahydrofuran and cyclohexanone.

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