Porphyrinyl molecular machine electrochemical luminescence biosensor
By modifying the potassium ion aptamer on the porphyrin molecular rotor and detecting the potassium ion concentration using the spin properties of the porphyrin molecular rotor, the shortcomings in sensitivity and response time of the existing electrochemical methods are solved, and efficient and sensitive potassium ion detection is achieved.
Patent Information
- Application Number
- CN202510260513.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-06
- Publication Date
- 2025-07-11
AI Technical Summary
Existing electrochemical methods have insufficient sensitivity, selectivity and response time in potassium ion detection, which is difficult to meet the fast, reliable and quantitative detection needs.
The spin electrochemiluminescence biosensor of the porphyrin molecular rotor is used to modify the potassium ion aptamer at the end of the spiral arm of the porphyrin molecular rotor, and the G-quadrilateral structure is used to form a G-quadrilateral structure to affect the spin properties, thereby detecting the potassium ion concentration.
It improves the efficiency and sensitivity of biosensors and provides an efficient and sensitive potassium ion detection method.
Smart Images
Figure CN120294099A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of biosensors, and particularly to a porphyrin-based molecular machine electrochemiluminescence biosensor. Background Art
[0002] Potassium ion is one of the essential trace elements in the human body. Although it accounts for less than 0.01% of the total body weight, it plays a crucial role in maintaining life activities. The subtle changes in potassium ion concentration are important biomarkers for evaluating the health status of the human body. Especially in the field of kidney diseases, the monitoring of potassium ion concentration is particularly critical. The kidney, as the main organ regulating potassium metabolism, its functional status directly affects the balance of potassium ions. In the case of acute kidney injury and chronic renal failure, due to the reduction of glomerular filtration rate or the disorder of renal tubular potassium excretion function, patients are prone to hyperkalemia. Therefore, the development of rapid, reliable, and quantitative potassium ion content determination technology is of crucial significance for medical diagnosis. It can not only provide a basis for the early diagnosis of kidney diseases, but also effectively monitor the treatment effect, so as to provide a more accurate treatment plan for patients. At present, the detection of potassium ions mainly uses electrochemical methods, fluorescence methods, atomic absorption / emission spectrometry, colorimetry, ion chromatography, etc. These methods have their own advantages and limitations. Among them, the electrochemical method has attracted wide attention due to its unique advantages, such as low cost of instruments and reagents, simple operation, short detection time, etc. However, traditional electrochemical methods still pose challenges in terms of sensitivity, selectivity, response time, and cost-effectiveness. In response to these challenges, a porphyrin molecular rotor spin electrochemiluminescence biosensor provides a new method for detecting potassium ions.
[0003] Porphyrin molecules have their unique optoelectrochemical properties and have a relatively high luminescence efficiency compared to other electrochemiluminescent substances. The porphyrin molecular rotor is a sandwich metal bilayer complex composed of porphyrin, phthalocyanine, and lanthanum ions, which has a higher luminescence efficiency than porphyrin molecules. Moreover, its electrochemiluminescence properties related to the spin speed and easily modified functional groups give it significant advantages in the field of electrochemiluminescence compared to other electrochemiluminescent substances. Therefore, the present invention constructs a biosensor for detecting potassium ion content by electrochemiluminescence intensity based on the unique electrochemiluminescence properties of porphyrin molecular rotors. Summary of the Invention
[0004] The purpose of the present invention is to provide a porphyrin-based molecular machine electrochemiluminescence biosensor to overcome the deficiencies of the prior art.
[0005] The object of the present invention is achieved by the following technical solutions: A porphyrin-based molecular machine electrochemiluminescence biosensor, comprising a working electrode, a reference electrode and a counter electrode; the test solution includes triethylamine, potassium ions, tetrabutylammonium perchlorate and a porphyrin molecular rotor modified with a potassium ion aptamer. Specifically, the aptamer of potassium ions is modified on the aminophenyl group of the porphyrin molecular rotor to form a corresponding spinning arm. Potassium ions bind to the aptamer to form a G-quadruplex structure, which affects the spin properties of the porphyrin rotor and further affects its electrochemiluminescence intensity, thereby realizing the detection of the potassium ion concentration.
[0006] Further, the preparation method of the porphyrin molecular rotor modified with a potassium ion aptamer includes the following steps:
[0007] Step 1. Preparation of La(PC)(TAPP): Dissolve dilithium phthalocyanine and lanthanum acetylacetonate in 1,2,4-trichlorobenzene, and stir in a constant temperature oil bath at 120-130 °C for 3-5 h; after cooling to room temperature, add 5,10,15,20-tetraaminophenyl porphyrin; reflux in an oil bath at 220-230 °C for 10-14 h to obtain a solution containing La(PC)(TAPP); dry the powder through a rotary evaporator; redissolve with dichloromethane; separate impurities by column chromatography, collect the green solution; finally obtain La(PC)(TAPP) through vacuum drying;
[0008] Step 2. Porphyrin molecular rotor modified with a potassium ion aptamer: Weigh La(PC)(TAPP), EDC and NHS at a molar ratio of 1:50:100. Dissolve La(PC)(TAPP) in methanol; dissolve EDC and NHS in methanol; dissolve the potassium ion aptamer in methanol, and then mix the EDC / NHS solution with the aptamer solution; then add the La(PC)(TAPP) solution; mix it evenly and place it in an oven at 37 °C for reaction for 20-28 h; centrifuge the obtained liquid, the rotation speed in the centrifuge is 6000-10000 rpm, and the centrifugation time is 10-20 min; remove the supernatant and dry the precipitate with nitrogen to obtain a porphyrin molecular rotor modified with a potassium ion aptamer.
[0009] Further, the chromatographic column packing for column chromatography is silica gel, and the eluent is a mixed solvent of dichloromethane and methanol.
[0010] Further, in the process of column chromatography, first wash down the blue solution with an eluent of 100:0 as La(PC)2; the green solution washed down with an eluent of 99:1 is La(PC)(TAPP); the red solution washed down with an eluent of 95:5 is TAPP.
[0011] Further, the molar ratio of 5,10,15,20-tetraaminophenyl porphyrin, dilithium phthalocyanine and lanthanum acetylacetonate is 2:3:5;
[0012] The molar ratio of La(PC)(TAPP), EDC, and NHS is 1:50:100.
[0013] Furthermore, the concentration of triethylamine in the test solution is 30 mM, the concentration of tetrabutylammonium perchlorate is 0.1 M, and the potassium ion concentration is 1 - 10000 nM.
[0014] Furthermore, the working electrode is a glassy carbon electrode; the reference electrode is an Ag / AgCl electrode; the counter electrode is a platinum wire electrode.
[0015] Furthermore, the glassy carbon electrode should be polished and cleaned before detection, including the following steps:
[0016] Step 1. Pretreatment: Moisten the lens paper with deionized water, and then gently wipe the electrode surface to ensure the smoothness of the electrode surface.
[0017] Step 2. Polishing: Use polishing powder (AL2O3) to repeatedly polish on the suede until the surface of the glassy carbon electrode becomes mirror-like.
[0018] Step 3. Rinsing: Rinse the electrode surface with deionized water
[0019] Step 4. Ultrasonic cleaning: Vertically place the polished electrode head in a small beaker containing a small amount of distilled water, noting that the water should not cover the metal at the rear end of the electrode, and the glassy carbon should not touch the bottom of the beaker to avoid scratching. Place the small beaker in an ultrasonic cleaner and ultrasonicate for 30 seconds. Wash alternately with distilled water and ethanol twice, and finally rinse once with ethanol. Leave it to dry at room temperature
[0020] Step 5. Chemical cleaning: Ultrasonically clean the treated electrode successively with 1:1 HNO3 and deionized water, 1:1 ethanol and deionized water solution, and deionized water for 2 - 3 minutes
[0021] Step 6. Chemical cleaning: Place the electrode in a 0.5 - 1.0 mol / l H2SO4 solution and activate it by cyclic voltammetry. Scan repeatedly until the cyclic voltammogram is stable. Clean the electrode surface with deionized water and dry it with nitrogen.
[0022] The present invention also provides a preparation method of a porphyrin molecular rotor modified with a potassium ion aptamer, including the following steps.
[0023] Step 1. Preparation of La(PC)(TAPP): Weigh 5,10,15,20 - tetraaminophenylporphyrin, dilithium phthalocyanine, and lanthanum acetylacetonate in a molar ratio of 2:3:5. First, add dilithium phthalocyanine and lanthanum acetylacetonate into a 250 mL three - necked flask; add 15 - 25 mL of 1,2,4 - trichlorobenzene; mix well by ultrasound; stir in a constant - temperature oil bath at 120 - 130 °C for 3 - 5 h; add 5,10,15,20 - tetraaminophenylporphyrin after the three - necked flask cools to room temperature; reflux in the oil bath for 10 - 14 h to obtain a solution containing La(PC)(TAPP); dry the powder through a rotary evaporator; redissolve it with dichloromethane; separate impurities by column chromatography and collect the green solution. Finally, obtain the solid powder product through vacuum drying.
[0024] Step 2. Modification of potassium ion aptamer with porphyrin molecular rotor: Weigh La(PC)(TAPP), EDC, and NHS in a molar ratio of 1:50:100. Dissolve La(PC)(TAPP) in methanol solution to form a 0.1 M solution, and then place it in the refrigerator for later use. Add EDC and NHS into a 5 mL centrifuge tube, add 400 μL of methanol to dissolve (EDC concentration is 5 M, NHS concentration is 10 M); take 50 nmol of potassium ion aptamer and dissolve it in 500 μL of methanol, then mix 400 μL of the EDC / NHS solution with the aptamer solution; take 100 μL of the La(PC)(TAPP) solution and add it; mix it well and place it in an oven at 37 °C for reaction; centrifuge the obtained liquid; remove the supernatant and dry the precipitate with nitrogen.
[0025] The present invention also provides an electrochemiluminescence detection method for potassium ion concentration, including:
[0026] Dilute the sample solution in the electrolyte, add triethylamine, tetrabutylammonium perchlorate, and the porphyrin molecular rotor modified with potassium ion aptamer to form a test solution;
[0027] Measure the potassium ion concentration by cyclic voltammetry using the above - mentioned porphyrin - based electrochemiluminescence biosensor.
[0028] The beneficial effects of the present invention are as follows: The present invention provides a novel biosensor. Its beneficial effects lie in that through the coupling reaction on the amino group at the rotating arm end of the porphyrin molecular rotor, an aptamer with recognition function is successfully modified, realizing the enhanced correlation between the self - rotation speed of the porphyrin molecular rotor and electrochemiluminescence. This innovative method not only improves the efficiency and sensitivity of the biosensor but also brings an efficient and sensitive detection means to the field of biosensing. Description of the Drawings
[0029] The accompanying drawings of the present invention are intended to provide a deep understanding of the present invention. The embodiments shown in these drawings and their descriptions are intended to illustrate various aspects of the present invention, but do not impose any undue limitation on the scope of the present invention.
[0030] Figure 1 It is the preparation process of the porphyrin molecular rotor in the embodiment of the present invention;
[0031] Figure 2 It is the comparison chart of the ultraviolet–visible absorption spectra of the porphyrin molecular rotor, tetraaminophenylporphyrin, dilithium phthalocyanine, and lanthanum acetylacetonate prepared in the embodiment of the present invention;
[0032] Figure 3 It is the fluorescence comparison chart of the porphyrin molecular rotor, tetraaminophenylporphyrin, dilithium phthalocyanine, and lanthanum acetylacetonate prepared in the embodiment of the present invention;
[0033] Figure 4 It is the ultraviolet–visible absorption spectrum diagram of the modified aptamer porphyrin molecular rotor prepared in the embodiment of the present invention;
[0034] Figure 5 It is the fluorescence spectrum diagram of the modified aptamer porphyrin molecular rotor prepared in the embodiment of the present invention;
[0035] Figure 6 It is the response relationship diagram of the electrochemiluminescence biosensor for detecting potassium ions in different potassium ion concentrations in the embodiment of the present invention. Detailed Embodiments
[0036] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.
[0037] The present invention will be described in detail below with reference to the accompanying drawings. Without conflict, the features in the following embodiments and implementation manners can be combined with each other.
[0038] A modified aptamer porphyrin molecular rotor of the present invention is obtained by the following preparation method:
[0039] As Figure 1As shown, weigh 5,10,15,20 - tetraaminophenylporphyrin, dilithium phthalocyanine, and lanthanum acetylacetonate with a molar ratio of 2:3:5. First, add dilithium phthalocyanine and lanthanum acetylacetonate into a 250 mL three - necked flask; add 15 - 25 mL of 1,2,4 - trichlorobenzene; mix well by ultrasonic; stir in a constant - temperature oil bath at 120 - 130 °C for 3 - 5 h; add 5,10,15,20 - tetraaminophenylporphyrin after the three - necked flask cools to room temperature; reflux in the oil bath for 10 - 14 h to obtain a solution containing La(PC)(TAPP); dry the powder with a rotary evaporator; redissolve it with dichloromethane; separate impurities by column chromatography and collect the green solution. Finally, obtain the solid powder product by vacuum drying. The reflux temperature of the oil bath is 220 - 230 °C. The packing of the chromatographic column for column chromatography is silica gel, and the developing agent is a mixed solvent of dichloromethane and methanol; during column chromatography, first elute the blue solution of La(PC)2 with a developing agent of 100:0; elute the green solution of La(PC)(TAPP) with a developing agent of 99:1; elute the red solution of TAPP with a developing agent of 95:5.
[0040] Porphyrin molecular rotor - modified potassium ion aptamer: Weigh La(PC)(TAPP), EDC, and NHS with a molar ratio of 1:50:100. Dissolve La(PC)(TAPP) in a methanol solution to prepare a 0.1 M solution, and then place it in the refrigerator for later use. Add EDC and NHS into a 5 mL centrifuge tube, add 400 μL of methanol to dissolve (the concentration of EDC is 5 M, and the concentration of NHS is 10 M); take 50 nmol of potassium ion aptamer and dissolve it in 500 μL of methanol, then mix 400 μL of the EDC / NHS solution with the aptamer solution; add 100 μL of the La(PC)(TAPP) solution; mix it well and place it in an oven at 37 °C for reaction; centrifuge the obtained liquid; remove the supernatant and dry the precipitate with nitrogen. The reaction time in the oven at 37 °C is 20 - 28 h; the rotation speed in the centrifuge is 6000 - 10000 rpm, and the centrifugation time is 10 - 20 min.
[0041] Example 1: Detection of potassium ion concentration
[0042] 1. The specific operation of polishing and cleaning the glassy carbon electrode is as follows:
[0043] (1) Pretreatment: Moisten a lens cleaning paper with deionized water, and then gently wipe the electrode surface to ensure the smoothness of the electrode surface.
[0044] (2) Polishing: Use polishing powder (AL2O3) to repeatedly polish on suede until the surface of the glassy carbon electrode becomes mirror - like.
[0045] (3) Rinsing: Rinse the electrode surface with deionized water
[0046] (4) Ultrasonic cleaning: Vertically place the polished electrode head in a small beaker containing a small amount of distilled water, noting that the water should not cover the metal at the back end of the electrode and the glassy carbon should not touch the bottom of the beaker to avoid scratching. Place the small beaker in an ultrasonic cleaner and ultrasonicate for 30 seconds, wash twice alternately with distilled water and ethanol, and finally rinse once with ethanol. Let it stand and dry at room temperature.
[0047] (5) Chemical cleaning: Ultrasonically clean the treated electrode successively with 1:1 HNO3 and deionized water, 1:1 ethanol and deionized water solution, and deionized water for 2 - 3 minutes.
[0048] (6) Chemical cleaning: Place the electrode in a 0.5 - 1.0 mol / L H2SO4 solution and activate it by cyclic voltammetry, scanning repeatedly until the cyclic voltammogram is stable. Wash the electrode surface with deionized water and dry it with nitrogen.
[0049] 2. Preparation of the reaction solution: Dissolve the synthesized La(PC)(TAPP) molecular rotor modified with potassium ion aptamer in methanol to form a 1 μmol / L solution. Weigh 68.4 mg of tetrabutylammonium perchlorate and add it to the solution. Use a pipette to take 11.28 μL of tripropylamine and add it to the solution. Mix well and set aside.
[0050] 3. Detection: Dilute the sample solution into the electrolyte, add the reaction solution, and detect the electrochemiluminescence intensity. Among them, the ECL detection uses a three - electrode system, with a platinum wire electrode as the counter electrode, Ag / AgCl as the reference electrode, and a glassy carbon electrode as the working electrode. The scanning range of cyclic voltammetry is 0 - 2 V, and the photomultiplier tube is at - 1000 V.
[0051] Characterization of porphyrin molecular rotor
[0052] Prepare the prepared porphyrin molecular rotor into a 0.1 mM solution, use a pipette to take 200 μL and put it into a 96 - well plate, and use a microplate reader to detect the ultraviolet - visible absorption spectrum and fluorescence spectrum of the porphyrin molecular rotor. From Figure 2 The ultraviolet - visible absorption spectrum shows that the absorption peak of the porphyrin molecular rotor (La(PC)(TAPP)) appears at 425 nm, and the absorption peaks and intensities are changed compared with those of tetraminophenylporphyrin (TAPP), dilithium phthalocyanine (Li2PC), and lanthanum acetylacetonate (La(acac)3). From Figure 3 The fluorescence spectrum shows that the fluorescence intensities of dilithium phthalocyanine and lanthanum acetylacetonate are very weak, the fluorescence intensity of tetraminophenylporphyrin is very high, and the fluorescence intensity of the porphyrin molecular rotor is in the middle. Among them, the fluorescence emission peak of the porphyrin molecular rotor is at 675 nm, and the emission peaks and intensities are changed compared with those of tetraminophenylporphyrin, dilithium phthalocyanine, and lanthanum acetylacetonate. This indicates that the porphyrin molecular rotor is successfully synthesized.
[0053] Characterization of the porphyrin molecular rotor modified with aptamer
[0054] The prepared porphyrin molecular rotor was formulated into a 1 μM solution. 200 μL was taken with a pipette and placed into a 96-well plate. A microplate reader was used to detect the ultraviolet-visible absorption spectrum and fluorescence spectrum of the porphyrin molecular rotor modified with the aptamer. From Figure 4 the ultraviolet-visible absorption spectrum, it can be seen that the absorption peak at 425 nm of the original molecular rotor disappeared after the aptamer was modified. From Figure 5 the fluorescence spectrum, it can be seen that after the aptamer was modified, the position of the emission peak of the original molecular rotor remained unchanged, but the fluorescence intensity decreased. This indicates that the aptamer was successfully modified.
[0055] Electrochemiluminescence detection of potassium ion concentration
[0056] Figure 6 It is a correlation diagram of different concentrations of potassium ions and electrochemiluminescence intensity in a three-electrode system. It can be seen from the figure that the electrochemiluminescence intensity increases with the increase in potassium ion concentration. This is attributed to the fact that potassium ions form a G-quadruplex structure with the aptamer, which reduces the moment of inertia of the molecular rotor, thereby increasing the rotational speed and ultimately enhancing the electrochemiluminescence intensity. This shows that the biosensor has the function of detecting potassium ions.
[0057] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.
[0058] The above embodiments are only used to illustrate the design concept and characteristics of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The protection scope of the present invention is not limited to the above embodiments. Therefore, all equivalent changes or modifications made according to the principles and design ideas disclosed by the present invention are within the protection scope of the present invention.
Claims
1. A porphyrin-based molecular machine electrochemiluminescence biosensor, characterized in that It includes a working electrode, a reference electrode and a counter electrode; the test solution includes triethylamine, potassium ions, tetrabutylammonium perchlorate and a porphyrin molecular rotor modified with a potassium ion aptamer.
2. The porphyrin-based molecular machine electrochemiluminescence biosensor according to claim 1, wherein The preparation method of the porphyrin molecular rotor modified with a potassium ion aptamer includes the following steps: Step 1. Preparation of La(PC)(TAPP): Dissolve dilithium phthalocyanine and lanthanum acetylacetonate in 1,2,4–trichlorobenzene, and stir in a constant temperature oil bath at 120–130 °C for 3–5 h; after cooling to room temperature, add 5,10,15,20–tetraaminophenyl porphyrin; reflux in an oil bath at 220–230 °C for 10–14 h to obtain a solution containing La(PC)(TAPP); dry the powder with a rotary evaporator; redissolve with dichloromethane; separate impurities by column chromatography, and collect the green solution; finally, obtain La(PC)(TAPP) by vacuum drying; Step 2. Porphyrin molecular rotor modified with a potassium ion aptamer: Weigh La(PC)(TAPP), EDC and NHS at a molar ratio of 1:50:100; dissolve La(PC)(TAPP) in methanol; dissolve EDC and NHS in methanol; dissolve the potassium ion aptamer in methanol, and then mix the EDC / NHS solution with the aptamer solution; then add the La(PC)(TAPP) solution; mix it evenly and place it in an oven at 37 °C for reaction for 20–28 h; centrifuge the obtained liquid in a centrifuge at a rotational speed of 6000–10000 rpm for 10–20 min; remove the supernatant and dry the precipitate with nitrogen to obtain a porphyrin molecular rotor modified with a potassium ion aptamer.
3. The porphyrin-based molecular machine electrochemiluminescence biosensor according to claim 2, wherein The packing material of the chromatographic column for column chromatography is silica gel, and the developing agent is a mixed solvent of dichloromethane and methanol.
4. The porphyrin-based molecular machine electrochemiluminescence biosensor according to claim 3, characterized in that During column chromatography, the blue solution eluted by the developing agent of 100:0 is La(PC)2; the green solution eluted by the developing agent of 99:1 is La(PC)(TAPP); the red solution eluted by the developing agent of 95:5 is TAPP.
5. The porphyrin-based molecular machine electrochemiluminescence biosensor according to claim 2, characterized in that, The molar ratio of 5,10,15,20–tetraaminophenyl porphyrin, dilithium phthalocyanine and lanthanum acetylacetonate is 2:3:5; The molar ratio of La(PC)(TAPP), EDC and NHS is 1:50:
100.
6. The porphyrin-based molecular machine electrochemiluminescence biosensor according to claim 1, wherein The concentration of triethylamine in the test solution is 30 mM, the concentration of tetrabutylammonium perchlorate is 0.1 M, and the potassium ion concentration is 1–10000 nM.
7. The porphyrin-based molecular machine electrochemiluminescence biosensor according to claim 1, wherein The working electrode is a glassy carbon electrode; the reference electrode is an Ag / AgCl electrode; the counter electrode is a platinum wire electrode.
8. The porphyrin-based molecular machine electrochemiluminescence biosensor according to claim 7, wherein The glassy carbon electrode should be polished and cleaned before detection, including the following steps: Step 1. Pretreatment: Moisten a lens cleaning paper with deionized water, and then gently wipe the electrode surface to ensure that the surface of the electrode is smooth; Step 2. Polishing: Use polishing powder (AL2O3) to polish repeatedly on suede until the surface of the glassy carbon electrode becomes mirror-like; Step 3. Rinsing: Rinse the electrode surface with deionized water; Step 4. Ultrasonic cleaning: Vertically place the polished electrode tip in a small beaker containing a small amount of distilled water, taking care that the water does not submerge the metal at the rear end of the electrode and the glassy carbon does not touch the bottom of the beaker to avoid scratching; place the small beaker in an ultrasonic cleaner and ultrasonicate for 30 seconds, wash alternately with distilled water and ethanol twice, and finally rinse once with ethanol, and leave it to dry at room temperature Step 5. Chemical cleaning: Ultrasonically clean the treated electrode successively with 1:1 HNO3 and deionized water, 1:1 ethanol and deionized water solution, and deionized water for 2 - 3 minutes Step 6. Chemical cleaning: Place the electrode in a 0.5 - 1.0 mol / l H2SO4 solution and activate it by cyclic voltammetry, repeatedly scan until the cyclic voltammogram is stable; clean the surface of the electrode with deionized water and dry it with nitrogen 9. A preparation method of a porphyrin molecular rotor modified with a potassium ion aptamer, characterized in that, The method includes the following steps: Step 1. Preparation of La(PC)(TAPP): Weigh 5,10,15,20 - tetramino phenyl porphyrin, lithium phthalocyanine, and lanthanum acetylacetonate in a molar ratio of 2:3:5; first add lithium phthalocyanine and lanthanum acetylacetonate into a 250 mL three - necked flask; add 15 - 25 mL of 1,2,4 - trichlorobenzene; mix well by ultrasonic; stir in a constant temperature oil bath at 120 - 130 °C for 3 - 5 h; add 5,10,15,20 - tetramino phenyl porphyrin after the three - necked flask cools to room temperature; reflux in the oil bath for 10 - 14 h to obtain a solution containing La(PC)(TAPP); dry the powder through a rotary evaporator; redissolve it with dichloromethane; separate impurities by column chromatography and collect the green solution; finally obtain a solid powder product through vacuum drying; Step 2. Modification of potassium ion aptamer with porphyrin molecular rotor: Weigh La(PC)(TAPP), EDC, and NHS in a molar ratio of 1:50:100; dissolve La(PC)(TAPP) in a methanol solution to prepare a 0.1 M solution and then put it in the refrigerator for standby; add EDC and NHS into a 5 mL centrifuge tube, add 400 μL of methanol to dissolve (EDC concentration is 5 M, NHS concentration is 10 M); take 50 nmol of potassium ion aptamer and dissolve it in 500 μL of methanol, then mix 400 μL of the EDC / NHS solution with the aptamer solution; add 100 μL of the La(PC)(TAPP) solution; mix it well and place it in an oven at 37 °C for reaction; centrifuge the resulting liquid; remove the supernatant and dry the precipitate with nitrogen 10. An electrochemiluminescence detection method for potassium ion concentration, characterized in that, It includes: Dilute the sample solution in the electrolyte, add triethylamine, tetrabutylammonium perchlorate, and the porphyrin molecular rotor modified with potassium ion aptamer to form a test solution; The porphyrin - based electrochemiluminescence biosensor according to any one of claims 1 - 7 detects the potassium ion concentration by cyclic voltammetry.