Potassium ion sensing test strips, potassium ion concentration detection devices, systems and detection methods

Abstract

The application discloses a kind of potassium ion sensing test paper, potassium ion concentration detection device, system and detection method.Calibration-free potassium ion sensing test paper includes: sample chamber, when it is contacted with sample, can be automatically absorbed into sample by capillary force to complete sample collection and filling;Detection electrode is used to carry out electrochemical detection to the sample collected in thin layer chamber.The calibration-free potassium ion sensing test paper of thin layer coulomb method of the application can calculate the potassium ion concentration in sample according to the charge quantity change caused by potassium ion transfer combined with the volume of thin layer sample, and can be used for non-invasive detection of potassium ion concentration in body fluid, the detection result is not disturbed by temperature change, high accuracy, and test paper can be reused, without pre-measurement calibration curve.

Description

Technical Field

[0001] This invention specifically relates to a potassium ion sensing test strip, a potassium ion concentration detection device, a system, and a detection method, belonging to the field of body fluid ion detection technology. Background Technology

[0002] Potassium ions (K) + Potassium (K) is one of the most important electrolytes in the human body, playing a crucial role in maintaining cell membrane potential, regulating fluid homeostasis, and in physiological processes such as nerve signal transduction and muscle contraction. Abnormal K levels can lead to serious health problems: hyperkalemia (high blood potassium) can be caused by impaired kidney function, metabolic acidosis, or drug effects, and can lead to arrhythmias or even cardiac arrest; while hypokalemia (low blood potassium) may result from vomiting, diarrhea, diuretic use, or endocrine abnormalities, manifesting as symptoms such as muscle weakness and arrhythmia. Therefore, timely and accurate monitoring of potassium levels in body fluids is of great significance for assessing electrolyte balance and for the prevention and monitoring of related diseases.

[0003] Traditional potassium ion detection mainly relies on blood sample analysis. While the method is reliable, the blood collection process is invasive and usually requires specialized institutions such as hospitals, making it difficult to achieve routine dynamic monitoring. In recent years, with the rapid development of portable electrochemical sensing technology, non-invasive detection of physiological parameters in bodily fluids such as sweat, urine, and saliva has become possible, providing a new approach for personalized health management.

[0004] However, the response mechanisms of existing ion sensors are mostly based on the diffusion equilibrium between the sample and the ion-selective electrode. Their signal amplitude is easily affected by external factors such as temperature and convection, making it difficult to directly reflect the actual ion concentration. To obtain accurate results, a calibration curve is usually established using standard solutions before detection. However, this process not only increases the cost and complexity of the device, but also, if calibration is not timely, may lead to reading deviations and consequently, incorrect clinical judgments. Therefore, there is an urgent need to develop a portable potassium ion sensing device that requires no calibration to improve the accuracy of detection results and its practical application value. Summary of the Invention

[0005] The main objective of this invention is to provide a potassium ion sensing test strip, a potassium ion concentration detection device, a system, and a detection method, thereby overcoming the shortcomings of the prior art.

[0006] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0007] The first aspect of this invention provides a calibration-free potassium ion sensing test strip, comprising:

[0008] A sample chamber with an inlet for holding liquid samples;

[0009] A potassium ion detection electrode, a counter electrode, and a reference electrode, wherein at least the counter electrode and the reference electrode are partially exposed in the sample chamber, and the potassium ion detection electrode is completely exposed in the sample chamber;

[0010] When a liquid sample fills the sample chamber and is in contact with the potassium ion detection electrode, the counter electrode, and the reference electrode to form an electrochemical system, and the potassium ion detection electrode, the counter electrode, and the reference electrode are connected to an electrochemical testing device, a specified voltage can be applied to the electrochemical system to completely transfer potassium ions between the potassium ion detection electrode and the liquid sample. A voltammetric curve can be obtained by performing a voltammetric scan on the electrochemical system using the electrochemical testing device. The amount of potassium ion charge transferred can be calculated by integrating the potassium ion peak in the voltammetric curve. Based on the amount of potassium ion charge transferred, Faraday's law, and the effective volume of the sample chamber, the concentration of potassium ions in the liquid sample can be directly calculated.

[0011] Furthermore, the height of the sample chamber is less than the thickness of the diffusion layer of the liquid sample, and the sample chamber can draw the liquid sample into the sample chamber by capillary force.

[0012] Furthermore, the height of the sample chamber is 0.01mm to 0.1mm.

[0013] Furthermore, the potassium ion detection electrode is disposed on the first inner wall of the sample chamber, and the counter electrode and the reference electrode are disposed on the second inner wall of the sample chamber. The first inner wall and the second inner wall are disposed opposite each other along the height direction of the sample chamber, wherein the vertical distance between the potassium ion detection electrode and the counter electrode or the reference electrode is less than 0.1 mm.

[0014] Furthermore, the potassium ion detection electrode comprises a metal layer, a poly(3-octylthiophene) layer, and a potassium ion selective film layer sequentially stacked on the first inner wall, wherein the thickness of the metal layer is 80 nm to 120 nm, the thickness of the poly(3-octylthiophene) layer is 60 nm to 80 nm, and the thickness of the potassium ion selective film layer is 150 nm to 400 nm; when a specified voltage is applied to the electrochemical system, potassium ions in the liquid sample can be completely transferred between the potassium ion selective film layer and the liquid sample.

[0015] Furthermore, the specified voltage includes a first voltage and a second voltage. When the first voltage is applied to the electrochemical system, potassium ions in the liquid sample are completely transferred to the potassium ion detection electrode and accumulate in the potassium ion selective membrane layer. The first voltage is lower than the open circuit potential of the potassium ion detection electrode. When the second voltage is applied to the electrochemical system for voltammetric scanning, the potassium ions accumulated in the potassium ion selective membrane layer are completely transferred to the liquid sample.

[0016] Furthermore, the calibration-free potassium ion sensing test paper includes: a first substrate, a second substrate, and a gasket. The gasket is fixedly disposed between the first substrate and the second substrate. The first substrate, the second substrate, and the gasket enclose the sample chamber. The gap between the edges of the first substrate and the second substrate serves as an inlet for liquid samples to enter the sample chamber. The surface of the first substrate facing the second substrate is the first inner wall, and the surface of the second substrate facing the first substrate is the second inner wall.

[0017] Furthermore, the sample chamber also has a vent hole for venting air from the chamber during the process of liquid sample entering the sample chamber.

[0018] Furthermore, the vent hole is disposed on the first substrate or the second substrate.

[0019] A second aspect of this invention provides a calibration-free potassium ion concentration detection device, comprising: an electrochemical testing device and the calibration-free potassium ion sensing test paper. The electrochemical testing device is electrically connected to the potassium ion detection electrode, the counter electrode, and the reference electrode. The electrochemical testing device is used to apply a specified voltage to an electrochemical system containing the potassium ion detection electrode, the counter electrode, the reference electrode, and a liquid sample and perform a voltammetric scan to obtain a voltammetric curve. The amount of potassium ion transferred charge can be calculated by integrating the potassium ion peak in the voltammetric curve. Based on the amount of potassium ion transferred charge, Faraday's law, and the effective volume of the sample chamber, the potassium ion concentration in the liquid sample can be directly calculated.

[0020] A third aspect of the present invention provides a calibration-free potassium ion concentration detection system, comprising: the calibration-free potassium ion concentration detection device, and a data processing device connected to the electrochemical testing device. The data processing device is used to calculate the potassium ion transfer charge by integrating the potassium ion peak in the voltammetric curve, and to calculate the potassium ion concentration in the liquid sample based on the potassium ion transfer charge, Faraday's law, and the effective volume of the sample chamber.

[0021] The amount of charge transferred by potassium ions is the amount of charge corresponding to the potassium ion peak. In the data processing device, the amount of charge corresponding to the potassium ion peak... The calculation model is as follows: ,in, Let v be the current at a certain potential E on the volt-ampere curve, and v be the scan rate. , The integral interval covering the potassium ion peak region;

[0022] The potassium ion concentration C in the data processing device k The calculation model is as follows: ,in, Let n be the charge corresponding to the potassium ion peak, n be the molar coefficient of electrons involved in the potassium ion transfer process (n=1), and F be the Faraday constant (F=96485C·mol). -1 V is the effective volume of the sample chamber, that is, the volume of the liquid sample in the sample chamber.

[0023] A fourth aspect of this invention provides a calibration-free method for detecting potassium ion concentration, comprising:

[0024] The calibration-free potassium ion sensing test strip, or the calibration-free potassium ion concentration detection device, or the calibration-free potassium ion concentration detection system;

[0025] The liquid sample fills the sample chamber and comes into contact with the potassium ion detection electrode, the counter electrode, and the reference electrode, forming an electrochemical system.

[0026] First, an electrochemical testing device is used to apply a first voltage to the electrochemical system, causing potassium ions in the liquid sample to be completely transferred and accumulated in the potassium ion detection electrode. The first voltage is lower than the open circuit potential of the potassium ion detection electrode. Then, an electrochemical testing device is used to apply a second voltage to the electrochemical system to perform a voltammetric scan, causing the potassium ions accumulated in the potassium ion detection electrode to be completely transferred to the liquid sample, and a voltammetric curve is obtained.

[0027] The amount of potassium ion charge transferred is obtained by integrating the potassium ion peak in the voltammetry curve: the amount of potassium ion charge transferred is the charge corresponding to the potassium ion peak. , ,in, Let v be the current at a certain potential E on the volt-ampere curve, and v be the scan rate. , The integral interval covering the potassium ion peak region;

[0028] Furthermore, the potassium ion concentration in the liquid sample is calculated based on the potassium ion transfer charge, Faraday's law, and the effective volume of the sample chamber.

[0029] Potassium ion concentration C k for: ,in, Let n be the charge corresponding to the potassium ion peak, n be the molar coefficient of electrons involved in the potassium ion transfer process (n=1), and F be the Faraday constant (F=96485 C·mol). -1 V is the effective volume of the sample chamber, that is, the volume of the liquid sample in the sample chamber.

[0030] Furthermore, the first voltage is -0.1 V and lasts for 10 seconds, and the second voltage is a set of linear scanning voltages, with the range of the linear scanning voltages being -0.1 V to 1.1 V (the second voltage is greater than -0.1 V).

[0031] Furthermore, the duration of the first voltage is 10 seconds, and the duration of the second voltage is 12 seconds.

[0032] Compared with the prior art, the advantages of the present invention include:

[0033] The calibration-free ion sensing test strip provided by this invention effectively shortens the ion mass transfer distance by constructing a thin sample chamber with a thickness lower than that of the diffusion layer. This allows the target ions in the liquid sample to be tested to accumulate rapidly and completely into the ultrathin ion-selective membrane. By monitoring the change in the amount of charge caused by the target ions during the transfer process, and combining this with the known volume of the sample chamber, the concentration of the target ions can be calculated according to Faraday's law. No calibration curve measurement is required, and the detection is not affected by temperature.

[0034] The calibration-free ion sensing test strip provided by this invention has good portability and ease of operation, can realize instant ion concentration measurement, and requires very little sample. It can perform non-invasive detection of various bodily fluids such as sweat, urine, and saliva, and is suitable for home testing and personalized health management. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic cross-sectional view of a calibration-free potassium ion sensing test paper provided in a typical embodiment of the present invention.

[0037] Figure 2 This is a top view of a calibration-free potassium ion sensing test strip provided in a typical embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the structural composition of a calibration-free potassium ion sensing test paper provided in a typical embodiment of the present invention;

[0039] Figure 4a , Figure 4b This is a schematic diagram of the thin-layer coulometric calibration-free detection principle of a calibration-free potassium ion sensing test paper provided in a typical embodiment of the present invention;

[0040] Figure 5 This is a cross-sectional view of an ultrathin film ion-selective electrode in a calibration-free potassium ion sensing test paper provided in a typical embodiment of the present invention;

[0041] Figure 6 This is a cross-sectional view of the sample chamber of a calibration-free potassium ion sensing test strip provided in Embodiment 1 of the present invention;

[0042] Figure 7 This is a schematic diagram of the thin-layer chamber filling of a calibration-free potassium ion sensing test paper provided in a typical embodiment of the present invention;

[0043] Figure 8 These are cyclic voltammetry curves of the K3[Fe(CN)6] redox probe measured in a thin-layer sample chamber with a thickness of 50 micrometers.

[0044] Figure 9 This is a schematic diagram illustrating an application scenario of a calibration-free potassium ion sensing test strip for testing body fluid samples, provided in a typical embodiment of the present invention.

[0045] Figure 10a The voltammetric curve obtained by using a calibration-free potassium ion sensing test strip provided in Embodiment 1 of the present invention to detect potassium ions in human sweat is shown.

[0046] Figure 10b The voltammetric curve obtained by using a calibration-free potassium ion sensing test strip provided in Embodiment 1 of the present invention to detect potassium ions in human urine is shown.

[0047] Figure 10c The voltammetric curve obtained by using a calibration-free potassium ion sensing test strip provided in Embodiment 1 of the present invention to detect potassium ions in human saliva is shown.

[0048] Figure 10d This is the result of potassium ion concentration detection performed on the same set of samples using the potassium ion sensing test paper and the ICP-OES detection instrument in Embodiment 1 of the present invention to avoid calibration.

[0049] Figure 11a The voltammetric curves obtained by performing a single linear voltammetric scan on 2.2 μL of 10 mM KCl standard solution at different scan rates in Example 2 of the present invention are as follows:

[0050] Figure 11b This is the curve showing the relationship between the potassium ion peak current and the scan rate in Example 2 of this invention;

[0051] Figure 12a These are the voltammetric curves obtained by performing a single linear voltammetric scan on KCl solutions of different concentrations in Example 3 of this invention.

[0052] Figure 12b It is based on the third embodiment of the present invention. Figure 12a A series of potassium ion concentrations were obtained by calculating multiple voltammetric curves.

[0053] Figure 13 These are the voltammetric curves obtained by performing a single linear voltammetric scan on solutions with the same potassium ion concentration under different temperature conditions in Example 4 of this invention.

[0054] Figure 14 The voltammetric curves are obtained by alternating single linear voltammetric scans of potassium ion solutions of different concentrations in Example 5 of this invention. Detailed Implementation

[0055] In view of the shortcomings of the prior art, the inventors of this case, through long-term research and extensive practice, have proposed the technical solution of this invention. The technical solutions of the embodiments of this invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0056] Explanation of terms used in the embodiments of this invention:

[0057] Diffusion layer of liquid sample: This refers to the region of concentration difference in the liquid layer on and near the electrode surface, where mass transfer mainly occurs through electromigration and diffusion, with less effect from convection.

[0058] For a more specific implementation plan, please refer to Figures 1-3 A calibration-free potassium ion sensing test strip includes: a sample chamber (also referred to as a thin-layer chamber or thin-layer sample chamber, hereinafter the same) 11 and a detection electrode. The sample chamber 11 is used to contain a liquid sample. The liquid sample fills the sample chamber 11 to form a thin-layer sample detection area (also referred to as a thin-layer sample, hereinafter the same) 13. The detection electrode is disposed in the sample chamber 11 and is used to electrically connect with an electrochemical testing device to cooperate with the electrochemical testing device to detect the liquid sample in the sample chamber 11 and obtain the electrical signal corresponding to the potassium ion concentration in the liquid sample. The detection electrode and the liquid sample form an electrochemical system.

[0059] Specifically, the height / thickness of the sample chamber 11 is less than the thickness of the diffusion layer of the liquid sample. When the inlet of the sample chamber 11 comes into direct contact with the liquid sample, the sample chamber 11 can draw the liquid sample into it through capillary force. More specifically, the height of the sample chamber 11 is 0.01 mm to 0.1 mm. Please refer to [link to relevant documentation]. Figure 7 and Figure 8 ,Depend on Figure 7 It can be determined that the height / thickness of sample chamber 11 is less than the thickness of the diffusion layer of the liquid sample. Figure 8 The cyclic voltammetry (CV) curves (scanning voltages of -0.1 V to 1.1 V) of the K3[Fe(CN)6] redox probe were measured in a thin-layer sample chamber with a thickness of 50 μm. The working electrode was a PET-Au electrode (without the poly(3-octylthiophene) layer and the selective film layer). The measured cyclic voltammetry curves exhibit an S-shape, with obvious current plateaus at the beginning and end of the curve (approximately -0.2 V to 0.15 V and 0.26 V to 0.6 V), rather than the typical duckbill-shaped CV curves observed under conventional large-volume solution testing conditions (non-thin-layer sample chamber). This is because the thin-layer sample chamber significantly shortens the mass transfer distance of redox substances, allowing the generated oxidized / reduced substances to quickly reach the counter electrode and undergo a reverse reaction. This observation further confirms that we have successfully constructed a thin-layer electrochemical domain in the ion-sensing test paper.

[0060] More specifically, the sample chamber 11 is also provided with a vent 9 that communicates with its internal space. The vent 9 is used to expel the air in the sample chamber 11 during the process of liquid sample aspiration, so as to avoid air resistance and ensure that the liquid sample can be smoothly filled into the sample chamber 11 under the drive of capillary force.

[0061] As a typical implementation, the calibration-free potassium ion sensing test strip includes a first substrate 3, a second substrate 8, and a gasket 2. The gasket 2 is disposed between the first substrate 3 and the second substrate 8. The first surface of the first substrate 3 and the second surface of the second substrate 8 are arranged face to face and separated by the gasket 2 and tightly joined together. The first substrate 3, the second substrate 8, and the gasket 2 enclose the sample chamber 11. The gap between the edges of the first substrate 3 and the second substrate 8 serves as an inlet for liquid samples to enter the sample chamber 11. The portion between the first surface of the first substrate 3 and the second surface of the second substrate 8 serves as a liquid chamber for containing liquid samples. The gasket 2 is used to limit the height of the liquid chamber and realize the encapsulation and sealing structure between the first substrate 3 and the second substrate 8, thereby preventing liquid leakage after sample aspiration. The first surface of the first substrate 3 serves as the first inner wall of the liquid chamber, and the second surface of the second substrate 8 serves as the second inner wall of the liquid chamber. The ventilation hole 9 can be provided on the first substrate 3 and / or the second substrate 8. For example, the ventilation hole 9 can be formed on the second substrate 8 by laser cutting, template or mechanical drilling.

[0062] For example, the gasket 2 can be fixed and sealed to the first substrate 3 and the second substrate 8 using an adhesive material. It is understood that the height of the sample chamber 11 is the sum of the thickness of the gasket 2 and the thickness of the adhesive material between the gasket 2 and the first substrate 3 and the second substrate 8. As another typical implementation, the gasket 2 can also achieve tight bonding between adjacent layers by surface modification with chemical reagents, such as silane reagent treatment and plasma treatment, which tightly bond the first substrate 3, the second substrate 8, and the gasket 2. As another typical implementation, the sample chamber 11 can also be obtained by etching a substrate, but this method is not conducive to the subsequent electrode setup and is generally not preferred. The first substrate 3, the second substrate 8, and the gasket 2 are all insulating materials, and their materials are not specifically limited.

[0063] Specifically, the detection electrode is a three-electrode system, including a potassium ion detection electrode, a counter electrode 10, and a reference electrode 12. At least a portion of the counter electrode 10 and the reference electrode 12 are exposed within the sample chamber 11, while the potassium ion detection electrode is completely exposed within the sample chamber 11. The potassium ion detection electrode, the counter electrode 10, and the reference electrode 12 can contact the liquid sample located within the sample chamber 11, forming an electrochemical circuit (i.e., an electrochemical system). When the liquid sample fills the sample chamber 11 and contacts the potassium ion detection electrode, the counter electrode 10, and the reference electrode 12... When the potassium ion detection electrode, the counter electrode 10, and the reference electrode 12 are connected to the electrochemical testing device, a specified voltage is applied to the electrochemical system through the electrochemical testing device, which can completely transfer potassium ions between the potassium ion detection electrode and the liquid sample. A voltammetric curve can be obtained by performing a voltammetric scan on the electrochemical system using the electrochemical testing device. The amount of potassium ion transferred charge can be calculated by integrating the potassium ion peak in the voltammetric curve. Based on the amount of potassium ion transferred charge, Faraday's law, and the effective volume of the sample chamber 11, the concentration of potassium ions in the liquid sample can be directly calculated.

[0064] It should be noted that the present invention can obtain the voltammetric curve by a single linear voltammetric scan, a single (i.e., one cycle) cyclic voltammetric scan (CV), or a single differential pulse voltammetric scan (DPV), with a single linear voltammetric scan being preferred. The voltammetric scans mentioned below all refer to the single linear voltammetric scan as an example.

[0065] Specifically, the potassium ion detection electrode and the counter electrode 10 are arranged opposite each other along the height direction of the sample chamber 11, and the distance between the potassium ion detection electrode and the counter electrode 10 is less than 0.1 mm to ensure that the potassium ion diffusion distance can be effectively shortened. Under the application of a suitable voltage, potassium ions can be completely and rapidly transferred between the potassium ion detection electrode and the liquid sample. Specifically, the potassium ion detection electrode is disposed on the first surface of the first substrate 3, and the counter electrode 10 and the reference electrode 12 are disposed at intervals on the second surface of the second substrate 8.

[0066] Specifically, the potassium ion detection electrode comprises a metal layer 4, a poly(3-octylthiophene) layer 5, and a potassium ion selective film layer (i.e., potassium ion selective membrane, hereinafter the same) 6, which are sequentially stacked on the first substrate 3. The metal layer 4 acts as an electronic conductor, primarily providing a channel for electron collection and transport. The poly(3-octylthiophene) layer 5 connects the metal layer 4 and the potassium ion selective film layer 6, primarily used to achieve stable conversion between ion and electron signals. The potassium ion selective film layer 6 is in direct contact with the liquid sample and is responsible for the selective binding of potassium ions. More specifically, the thickness of the metal layer 4 is 80 nm to 120 nm, the thickness of the poly(3-octylthiophene) layer 5 is 60 nm to 80 nm, and the thickness of the potassium ion selective film layer 6 is 150 nm to 400 nm. Potassium ions in the liquid sample can be completely transferred between the poly(3-octylthiophene) layer 5 and the liquid sample.

[0067] For example, the metal layer 4 can be a gold layer, specifically a gold layer obtained by magnetron sputtering. Specifically, the poly(3-octylthiophene) layer 5 can be obtained by electrochemical monomer polymerization processes, including cyclic voltammetry or galvanostatic polymerization. Specifically, the potassium ion-selective film layer 6 can be obtained by spin coating, and its components are a polymer matrix, a plasticizer, a potassium ion carrier, and an ion exchanger. The polymer matrix material includes polyvinyl chloride and / or polyurethane, the plasticizer includes dioctyl sebacate and / or o-nitrophenyl octyl ether, the potassium ion carrier material is valine, and the ion exchanger material is sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, etc.

[0068] As a preferred embodiment, the potassium ion detection electrode may further include an insulating substrate disposed on the first substrate 3, with a metal layer 4 stacked on the insulating substrate. The insulating substrate provides mechanical support and maintains the stability of the entire electrode structure. For example, the insulating substrate may be made of polyethylene terephthalate, polyimide, polyurethane, glass, silicon, or ceramics.

[0069] For example, the counter electrode 10 can be a carbon electrode, and the reference electrode 12 can be a silver / silver chloride electrode. The counter electrode 10 and the reference electrode 12 can be obtained by screen printing, spraying, scraping or inkjet printing processes known in the art. Preferably, the counter electrode 10 and the reference electrode 12 can be hydrophilic, for example, by treating the surfaces of the counter electrode 10 and the reference electrode 12 with Plasma treatment before assembling the device to achieve hydrophilicity.

[0070] Specifically, electrode pins 7 are also provided on the outer surfaces of the first substrate 3 and the second substrate 8 facing away from the sample chamber 11. The electrode pins 7 are electrically connected to the detection electrode and are used to realize the electrical signal connection and transmission between the detection electrode and the external electrochemical testing device. Among them, the electrode pins 7 include a working electrode pin 73, a counter electrode pin 72, and a reference electrode pin 71. The working electrode pin 73, the counter electrode pin 72, and the reference electrode pin 71 can be electrically connected to the potassium ion detection electrode 10, the counter electrode 10, and the reference electrode 12 respectively through conductive adhesive 1, etc.

[0071] In a more specific implementation, the method for detecting potassium ion concentration using the calibration-free potassium ion sensing test strip includes:

[0072] The sample chamber 11 is filled with liquid sample. The potassium ion detection electrode, counter electrode 10, and reference electrode 12 are all in contact with the liquid sample. For details, please refer to [link to relevant documentation]. Figure 7 This allows the inlet of the sample chamber 11 to come into direct contact with the liquid sample, and the liquid sample is drawn into the sample chamber 11 under the action of capillary force.

[0073] Connect the potassium ion detection electrode, counter electrode 10, and reference electrode 12 to an external electrochemical workstation or other electrochemical testing device, such as the Brush Core® USB flash drive electrochemical workstation;

[0074] First, apply -0.1 V using an electrochemical testing device and maintain it for 10 s. During this process, if... Figure 4a As shown on the left, cations in the liquid sample enter the potassium ion selective membrane layer 6 of the potassium ion detection electrode through diffusion. Due to the preferential binding effect of potassium ion carriers on potassium ions in the potassium ion selective membrane layer 6, potassium ions preferentially occupy the cation binding sites in the membrane (i.e., in the potassium ion selective membrane layer, the same below), and the remaining sites are occupied by other cations. The total number of cation binding sites in the membrane is provided by the ion exchanger and kept constant, so that potassium ions in the liquid sample are completely transferred and accumulated in the potassium ion detection electrode.

[0075] A single linear voltammetric scan was then performed using an electrochemical testing device. The voltage range for the single linear voltammetric scan was -0.1 V to 1.1 V, and the duration was 12 s. Figure 4a Right side of the picture Figure 4b As shown, the conductive polymer in the potassium ion selective electrode loses electrons and undergoes oxidation during the scanning process, forming a positive charge. This attracts anions from the potassium ion selective membrane layer 6 into the poly(3-octylthiophene) layer 5. To maintain electroneutrality, the cations accumulated in the potassium ion selective membrane layer 6 are transferred to the liquid sample outside the membrane. This allows the cations accumulated in the potassium ion detection electrode to be completely transferred to the liquid sample, generating a real-time current and obtaining a voltammetric curve with a voltammetric ion transfer peak.

[0076] Due to the binding effect of potassium ion carriers, the driving force required for potassium ion migration is relatively large, and its transfer peak potential is higher than that of other cations. By integrating the potassium ion transfer peak, the total charge related to potassium ion transfer can be obtained. According to Faraday's law and combined with the known volume of the liquid sample in sample chamber 11, the potassium ion concentration can be calculated without the need to establish a calibration curve.

[0077] Specifically, the amount of charge transferred by potassium ions is the amount of charge corresponding to the potassium ion peak. , ,in, Let v be the current at a certain potential E on the volt-ampere curve, and v be the scan rate. , The integral interval covering the potassium ion peak region;

[0078] Furthermore, the potassium ion concentration in the liquid sample is calculated based on the potassium ion transfer charge, Faraday's law, and the effective volume of the sample chamber.

[0079] Potassium ion concentration C k for: ,in, Let n be the charge corresponding to the potassium ion peak, n be the molar coefficient of electrons involved in the potassium ion transfer process (n=1), and F be the Faraday constant (F=96485 C·mol). -1 V is the effective volume of the sample chamber, that is, the volume of the liquid sample in the sample chamber.

[0080] It should be noted that the calibration-free potassium ion sensing test strip of the present invention can be reused. For example, a new liquid sample can be pumped into the sample chamber 11 through a microfluidic pump or a peristaltic pump. During this process, a voltage of 1 V or higher is applied to the electrochemical system to remove the potassium ions accumulated in the potassium ion detection electrode. After the liquid sample fills the sample chamber 11, the pumping of the liquid sample is stopped, and the application of the 1 V voltage is also stopped. A constant voltage of -0.1 V is applied to the electrochemical system for 10 s, followed by a single linear voltammetric scan. Then, based on the same principle, the potassium ion concentration information of the detected liquid is calculated according to the measured amount of potassium ion transfer charge.

[0081] Example 1

[0082] Please see Figures 1-3 The calibration-free potassium ion sensing test strip in this embodiment includes a sample chamber 11, a detection electrode, and an electrode pin 7. The detection electrode is disposed inside the sample chamber 11, and the electrode pin 7 is disposed outside the sample chamber 11 and is electrically connected to the detection electrode through conductive adhesive 1.

[0083] Please refer to the following: Figure 6In this embodiment, the sample chamber 11 is formed by the first substrate 3, the second substrate 8 and the gasket 2. The sample chamber 11 has a cuboid structure with a height / thickness of 51.3 μm, a width of 3 mm and a length of 1.25 cm.

[0084] The detection electrode in this embodiment includes a potassium ion detection electrode, a counter electrode 10, and a reference electrode 12. The potassium ion detection electrode is disposed on a first substrate 3, and the counter electrode 10 and the reference electrode 12 are disposed on a second substrate. The potassium ion detection electrode, the counter electrode 10, and the reference electrode 12 are arranged face-to-face and form a three-electrode system. The three-electrode system forms an electrochemical system with the liquid sample. The vertical distance between the potassium ion detection electrode and the counter electrode 10 / reference electrode 12 is 51.3 μm.

[0085] Please refer to the following: Figure 5 In this embodiment, the potassium ion detection electrode includes a PET substrate, a gold electrode, a poly(3-octylthiophene) layer, and a potassium ion selective film layer stacked sequentially. The thickness of the gold electrode is 110 nm, the thickness of the poly(3-octylthiophene) layer is 60 nm, and the thickness of the potassium ion selective film layer 6 is 277 nm. The counter electrode 10 is a hydrophilically treated carbon electrode, and the reference electrode 12 is a hydrophilically treated silver / silver chloride electrode.

[0086] Please see Figure 9 The potassium ion concentration in human sweat, urine, and saliva was detected using the calibration-free potassium ion sensing test strip in this embodiment. The obtained voltammetric curves are shown below. Figure 10a , Figure 10b , Figure 10c As shown, potassium ion concentration was also measured using an ICP-OES instrument on the same group of samples. The ICP-OES results were compared with those of the calibration-free potassium ion sensing test strip. Figure 10d As shown, the detection results of the calibration-free potassium ion sensing test strip in this embodiment are consistent with the ICP-OES detection results.

[0087] Example 2

[0088] A single linear voltammetric scan was performed on a 10 mM KCl standard solution using the calibration-free potassium ion sensing paper described in Example 1. Following the procedure in Example 1, 2.2 μL of KCl standard solution was drawn into the sample chamber 11 via capillary action. Subsequently, voltammetric scans were performed at different scan rates (50 mV / s, 75 mV / s, 100 mV / s, 125 mV / s, and 150 mV / s) within a voltage range of -0.1 V to 1.1 V.

[0089] The test results are shown in Figure 11a. Figure 11b As shown, Figure 11a The figures show voltammetric curves obtained at different scan rates. The voltammetric ion peaks in the figure correspond to potassium ions. Figure 11b The curve showing the correlation between the potassium ion peak current and the scan rate is given by... Figure 11a It can be seen that the potassium ion peak potential remains basically consistent at different scan rates. Figure 11b It can be seen that the potassium ion peak current is proportional to the scanning rate, indicating that there is no diffusion limitation in the potassium ion selective film (i.e., the current response is only controlled by kinetics and is not limited by the mass transfer process of potassium ions in the potassium ion selective film). This result proves the thin-film nature of the nanoscale potassium ion selective film.

[0090] Example 3

[0091] To further verify the calibration-free characteristics of the calibration-free potassium ion sensing test strip, this embodiment tested KCl solutions of different concentrations using three calibration-free potassium ion sensing test strips. The potassium ion concentrations were 0 μM (containing only 10 mM NaCl background solution), 1 μM, 5 μM, 10 μM, 20 μM, 30 μM, 50 μM, and 80 μM. Before each test, a new test liquid was pumped into the sample chamber 11 through the sample port using a microfluidic pump. During this process, a voltage of 1 V or higher was applied to the three-electrode system to expel potassium ions accumulated in the potassium ion detection electrode. After the test liquid filled the sample chamber 11, the pumping was stopped, and the 1 V voltage was also stopped. A constant voltage of -0.1 V was applied to the three-electrode system for 10 s, followed by a single linear voltammetric scan at a scan rate of 100 mV / s. The obtained voltammetric curves are shown below. Figure 12a As shown, the potassium ion concentration calculated from this is as follows: Figure 12b As shown, by Figure 12a It can be seen that in the case containing only Na + A single Na appears + Peak, following K + The addition of [a specific element] results in a second K with a higher potential. + Peak, following K + As the concentration increases, Na + The peak gradually decreases, K + The peak gradually increases, indicating that the cation exchange sites within the potassium ion selective membrane are gradually destroyed by K. + Replace, when K + When the concentration reaches 80 µM, only K appears. + A peak with a charge equal to the total exchange capacity of the membrane indicates that the cation sites within the potassium-selective membrane have been completely converted by K+. + To occupy. By Figure 12bIt can be seen that, at different potassium ion concentrations, the detected potassium ion transfer charge is basically consistent with the theoretical potassium ion charge in the thin-layer sample (solution). Subsequently, the potassium ion concentration information of the detected liquid was calculated based on the measured potassium ion transfer charge, and the concentration value calculated from the charge deviated from the actual concentration by less than 11%.

[0092] Example 4

[0093] In this embodiment, solutions with the same potassium ion concentration (30 μM KCl + 10 mM NaCl) were tested under different temperature conditions (20℃, 30℃, and 40℃). Following the procedures in Example 1, 2.2 μL of the solution sample was drawn into sample chamber 11 via capillary action. Then, the calibration-free potassium ion sensing paper was placed in a constant temperature chamber, and after setting the appropriate temperature, it was allowed to stand for 15 minutes. Under constant temperature conditions, the solution sample was subjected to LSV testing at a scan rate of 100 mV / s.

[0094] Test results are as follows Figure 13 As shown, by Figure 13 As can be seen, the voltammetric curves obtained under different temperature conditions almost overlap, the peak potential and peak area of ​​the potassium ion peak remain consistent, and the change in integrated charge is within 0.5%, almost unaffected by temperature. This result indicates that although temperature affects the kinetics of the potassium ion mass transfer process, the calibration-free potassium ion sensing test paper adopts a thin-layer sample chamber structure, which enables complete transfer and absolute quantitative detection of potassium ions in the sample chamber. Therefore, the final charge obtained is entirely determined by the total amount of potassium ions in the liquid sample, and is almost unaffected by the test temperature. This embodiment further verifies the temperature independence of the device of the present invention, enabling it to achieve calibration-free potassium ion detection.

[0095] For traditional potentiometric ion-selective electrodes, temperature changes have a significant impact, primarily because the potential response of traditional electrodes follows the Nernst equation, where the Nernst slope is proportional to temperature. Increased temperature leads to a larger slope, thus altering the potential reading. Furthermore, temperature affects the ion exchange equilibrium and diffusion rate at the membrane / solution interface, potentially causing potential drift, changes in response time, and alterations in selectivity. Based on these two points, any temperature change will disrupt the stability of traditional ion sensors, requiring frequent calibration to compensate for temperature-induced potential shifts. The potassium ion sensing test strip provided by this invention quantitatively transfers all ions and measures the required charge, without relying on the Nernst potential. Temperature alters the kinetics but not the final charge quantity; therefore, the temperature effect is significantly reduced, enabling calibration-free operation.

[0096] Example 5

[0097] This embodiment verifies the repeatability and reversibility of the device by alternately testing potassium ion solutions of different concentrations. Two solutions were used: 10 μM KCl and 30 μM KCl. The same injection method as in Example 3 was employed, and the tests were performed six times in the following alternating order: 10 μM → 30 μM → 10 μM → 30 μM → 10 μM → 30 μM. The resulting voltammetric curves are shown below. Figure 14 As shown in the figure, the peak shape of the same concentration is consistent and has good reproducibility in the six sets of voltammetric curves, which proves that the response of the potassium ion sensing paper is reversible and reusable.

[0098] The calibration-free ion sensing test strip provided by this invention does not require the establishment of a calibration curve. By detecting the change in charge in the voltammetric curve, potassium ion concentration information can be directly calculated from a single detection. At the same time, the calibration-free ion sensing test strip provided by this invention has the characteristics and advantages of being unaffected by temperature and being reusable. This invention can help assess the potassium ion concentration in human body fluids and realize risk warning and monitoring of related diseases.

[0099] As used herein, the term "including" and its variations are open terms meaning "including but not limited to". The terms "based on", "according to", etc., mean "at least partially based on" or "at least partially based on". The terms "first", "second", etc., can refer to different or the same objects.

[0100] It should be understood that the above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A calibration-free potassium ion sensing test strip, characterized in that, The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper.

2. The calibration-free potassium ion sensing test strip of claim 1, wherein: The application relates to a calibration-free potassium ion sensing test paper.

3. The calibration-free potassium ion sensing test strip of claim 1, wherein, The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. 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The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free potassium ion sensing test paper. The application relates to a calibration-free 4. The calibration-free potassium ion sensing test strip of claim 3, wherein, The sample chamber also has a vent hole for venting air in the chamber during the process of the liquid sample entering the sample chamber.

5. The calibration-free potassium ion sensing test strip of claim 4, wherein, The vent hole is arranged on the first substrate or the second substrate.

6. A calibrant-free potassium ion concentration detection device, characterized by, The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5.

7. A calibration-free potassium ion concentration detection system, characterized by, The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The potassium ion transfer charge quantity is the charge quantity corresponding to the potassium ion peak, and the charge quantity corresponding to the potassium ion peak in the data processing device The calculation model is: wherein, is the current at a certain potential E on the voltammetry curve, v is the scanning rate, , is the integral interval covering the potassium ion peak region; The concentration C of potassium ions in the data processing device k The calculation model is: wherein, is the charge amount corresponding to the potassium ion peak, n is the electron molar coefficient involved in the potassium ion transfer process, n = 1, F is the Faraday constant, F = 96485 C·mol -1 , and V is the effective volume of the sample chamber, that is, the volume of the liquid sample in the sample chamber.

8. A calibration-free method of detecting potassium ion concentration, characterized by, The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The potassium ion transfer charge quantity is obtained by integrating the potassium ion peak in the voltammetry curve: the potassium ion transfer charge quantity is the charge quantity corresponding to the potassium ion peak , wherein, is the current at a certain potential E on the voltammetry curve, v is the scanning rate, , is the integral interval covering the potassium ion peak region; The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. Potassium ion concentration C k is: wherein, is the charge amount corresponding to the potassium ion peak, n is the molar coefficient of electrons involved in the potassium ion transfer process, n = 1, F is the Faraday constant, F = 96485 C·mol -1 V is the effective volume of the sample chamber, i.e. the volume of the liquid sample in the sample chamber.

9. The method of claim 8, wherein: The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free potassium ion concentration detection device, which comprises the calibrating-free potassium ion sensor strip according to any one of claims 1-5. The application also provides a calibrating-free

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