Preparation method and application of electrochemiluminescence sensor for selective detection of trilobatin

Abstract

The application belongs to the technical field of electrochemical analysis and detection, and discloses a preparation method and application of an electrochemiluminescence sensor for selectively detecting trilobatin. The specific operation includes: (1) preparing a composite material (ZnPTC@MoS2) of a rhombus sheet-shaped zinc-based metal organic framework (ZnPTC) and molybdenum disulfide (MoS2); (2) modifying the ZnPTC@MoS2 on a glassy carbon electrode to obtain a ZnPTC@MoS2 / GCE; and (3) based on a three-electrode system, constructing an electrochemiluminescence sensor for specifically detecting trilobatin by taking the ZnPTC@MoS2 / GCE as a working electrode, a platinum wire as an auxiliary electrode, and Ag / AgCl as a reference electrode. The preparation of the electrochemiluminescence sensor is simple, the analysis speed is relatively fast, the detection range is relatively wide, the selectivity is relatively good, and the sensitivity is relatively high.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrochemical analysis and detection, and particularly relates to a method for selectively detecting trilobatin by using an electrochemiluminescence sensor. BACKGROUND

[0002] Trilobatin is a natural dihydrochalcone compound, which can be used as a sweetener and has biological activities such as anti-diabetes, anti-inflammatory and anti-tumor, and can be used for the development of new drugs. Trilobatin has a broad application prospect, and its dosage should be strictly controlled during application. Therefore, the detection of the content of trilobatin should also be paid attention to. Traditional methods for detecting trilobatin mainly include high performance liquid chromatography, high performance liquid chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy. However, these methods have some shortcomings, such as high detection cost, complex operation and long detection time. Therefore, it has high application value to develop a simple, inexpensive, rapid and sensitive method for detecting trilobatin.

[0003] The disclosed Chinese patent CN116429865A is based on AuNBs and Poly-L-cys to construct an electrochemical sensor for detecting trilobatin, which uses differential pulse voltammetry for detection. When the modified electrode detects trilobatin, the electrochemical signal will be enhanced, while when the electrochemiluminescence method detects trilobatin, the electrochemical signal will be quenched. The detection principles of the two methods are different, and there is an essential difference in the electrochemical signal of trilobatin.

[0004] Electrochemiluminescence is a kind of electrochemical detection method combining the controllability of electrochemistry and the high sensitivity of chemiluminescence, which is widely used in the field of analysis. At present, there are few reports on the detection of trilobatin by electrochemiluminescence method. It is a better new way to construct an electrochemiluminescence sensor for detecting trilobatin. The disclosed Chinese patent CN117233229A is based on g-C3N4@NiMOF to construct a molecularly imprinted electrochemiluminescence sensor for detecting trilobatin, which has a low detection limit. However, the molecular imprinting not only has a complex preparation process, including the polymerization of functional monomers, the elution of template molecules and the recombination process of the detected substance, but also consumes a large amount of trilobatin standard, which has a high cost. The molecularly imprinted electrochemiluminescence sensor for detecting trilobatin needs to spend a certain amount of time to enrich trilobatin, and after reaching adsorption equilibrium, quantitative testing is carried out, which is relatively complicated and time-consuming.

[0005] The key of electrochemiluminescence sensor lies in the electrochemiluminescence performance electrode material, i.e. luminophore, used. Perylene compounds with π-π conjugated system have attracted the interest of many electrochemiluminescence sensor researchers due to their excellent photoelectric performance, chemical stability and easy chemical modification. 3,4,9,10-perylene tetracarboxylic dianhydride (PTCDA) as a perylene compound has certain electrochemiluminescence performance when K2S2O8 is used as a co-reactant, but its stability is poor, which limits its application in the field of electrochemiluminescence. Zn 2+ is combined with PTCDA, effectively increasing the distance between PTCDA ligands and reducing the π-π stacking interaction, which not only improves the stability of the material, but also increases the specific surface area of the material and provides more active sites. The catalytic activity of Zn 2+ promotes the reaction between ZnPTC and K2S2O8 and enhances the electrochemiluminescence of the material. Therefore, how to use ZnPTC as a luminophore to construct an electrochemical sensor to further improve the detection performance of the ZnPTC sensor and improve the sensitivity and selectivity of the constructed sensor is the problem to be solved by the present application. SUMMARY

[0006] In order to solve the above problems, the present application first prepares ZnPTC with a rhombic sheet structure, and then loads two-dimensional MoS2 material on it. Zn 2+ is combined with MoS2 through Zn-S bond, so that MoS2 is uniformly distributed on the rhombic sheet ZnPTC, effectively solving the stacking phenomenon of MoS2 and further increasing the effective specific surface area of the material and providing more effective active sites. At the same time, the catalytic effect of MoS2 further stimulates the synergistic effect between the rhombic sheet ZnPTC and MoS2, and more SO4 ·- can be generated under the dual catalysis of ZnPTC and MoS2, SO4 ·- further reacts with ZnPTC ·- to generate more ZnPTC * , so that the electrochemiluminescence performance of the material is significantly enhanced. Based on the ZnPTC@MoS2 composite material modified GCE, the electrochemiluminescence sensor can sensitively and selectively detect trilobatin.

[0007] The first object of the present application is to provide a preparation method of an electrochemiluminescence sensor for selectively detecting trilobatin, and the second object is to provide an application method of the electrochemiluminescence sensor for selectively detecting trilobatin.

[0008] The above technical objective of the present application is achieved by the following technical solutions:

[0009] The application provides a preparation method of a ZnPTC@MoS2 / GCE electrochemical luminescence sensor for selectively detecting trilobatin, and specifically comprises the following steps:

[0010] The glassy carbon electrode is polished, and then ultrasonically cleaned with anhydrous ethanol and deionized water; the glassy carbon electrode is dried at room temperature, and a pretreated glassy carbon electrode is obtained for standby use; the DMF dispersion solution of ZnPTC@MoS2 is moved to the surface of the pretreated glassy carbon electrode by using a microsyringe, and dried under an infrared lamp to obtain a ZnPTC@MoS2 / GCE.

[0011] Further, the diameter of the glassy carbon electrode is 3 mm; the concentration of the DMF dispersion solution of ZnPTC@MoS2 is 0.5-3.0 mg / mL, and the drop coating amount is 2.5-10 μL.

[0012] Further, the preparation method of ZnPTC@MoS2 comprises the following steps:

[0013] S1. 3,4,9,10-perylenetetracarboxylic dianhydride and potassium hydroxide are dispersed in deionized water, and then stirred and reacted in a water bath at 55 ℃; ethanol is added, and then stirred to generate a yellow solid substance; the yellow solid substance is centrifuged and washed with ethanol, and then vacuum dried to obtain K4PTC powder;

[0014] In the preparation method, the molar ratio of 3,4,9,10-perylenetetracarboxylic dianhydride to potassium hydroxide is 1:1-1:10, the molar mass of 3,4,9,10-perylenetetracarboxylic dianhydride is 0.5-1.5 mmol, the stirring time is 6-24 h, the stirring rate is 120-720 rpm, and the amount of ethanol is 15-45 mL.

[0015] S2. K4PTC and MoS2 are added to a zinc acetate dihydrate solution, and then stirred uniformly at room temperature; the solution is moved to a reaction kettle for hydrothermal reaction, the hydrothermal reaction temperature is 75-125 ℃, the hydrothermal reaction time is 6-24 h, and then the solution is cooled to room temperature; the solution is centrifuged and washed with deionized water, and then vacuum dried to obtain ZnPTC@MoS2 powder;

[0016] In the preparation method, the molar ratio of K4PTC, zinc acetate dihydrate and MoS2 is 1:1:1-1:5:5, and the molar mass of K4PTC is 0.01-0.1 mmol.

[0017] The second objective of the present application is to provide an application method of an electrochemical luminescence sensor for selectively detecting trilobatin.

[0018] The ZnPTC@MoS2 / GCE is used as a working electrode, a platinum wire electrode is used as an auxiliary electrode, and Ag / AgCl is used as a reference electrode, an electrolyte solution containing different concentrations of trilobatin is detected by an electrochemiluminescence method, and the electrochemiluminescence intensity of the sensor is detected in a three-electrode system.

[0019] As a preferred embodiment of the above technical solution, the specific steps are as follows:

[0020] A1. Preparation of trilobatin standard solution with different concentrations:

[0021] The trilobatin standard solution is prepared into a 1×10 -3 M solution by using a 0.1M PBS buffer solution containing 0.05M potassium persulfate with pH 7.4, and a series of trilobatin standard solutions with different concentrations are diluted, and the concentration range is 5×10 -8 ~ 1×10 - 3 M;

[0022] A2. Drawing of standard curve:

[0023] The ZnPTC@MoS2 / GCE is used as a working electrode, a platinum wire electrode is used as an auxiliary electrode, and Ag / AgCl is used as a reference electrode, an electrolyte solution containing different concentrations of trilobatin is detected by an electrochemiluminescence method, and the electrochemiluminescence intensity of the sensor is detected in a three-electrode system.

[0024] A3. Actual sample detection:

[0025] The leaf sample of Lithocarpus polystachyus is crushed, sieved, and weighed, and then added to deionized water under the condition of a solid-liquid ratio of 1:20 (g / mL), and then refluxed for 3h, and then filtered under reduced pressure to obtain a filtrate, and then the filtrate is diluted to obtain a trilobatin crude extract for use.

[0026] The crude extract is diluted with a 0.1M PBS buffer solution containing 0.05M K2S2O8 with pH 7.4 to obtain a sample to be tested, different concentrations of standard samples are added by a standard addition method, and the electrochemiluminescence performance is tested, and the concentration of trilobatin in the sample to be tested is calculated according to the linear regression equation obtained in A2.

[0027] As a preferred embodiment of the above technical solution, the detection range of trilobatin is 5×10-8 ~1x10 -3 M, the minimum detection limit is 5.6x10 -9 M.

[0028] Compared with the prior art, the present application has the following beneficial effects:

[0029] The present application can obtain ZnPTC@MoS2 composite material by compounding two-dimensional MoS2 with ZnPTC, MoS2 is uniformly loaded on the rhombic sheet-shaped ZnPTC which has larger specific surface area and better stability, not only reduces the stacking of MoS2, increases the effective active area of the sensing platform, but also the catalytic performance of MoS2 makes the co-reagent K2S2O8 can generate more SO4 ·- , promotes the reaction of the luminophore ZnPTC with it to generate more excited state ZnPTC * , enhances the electrochemiluminescence response of the material, and further improves the sensitivity of the constructed sensor. In addition, there is not only electrostatic adsorption between ZnPTC@MoS2 and trilobatin, but also π-π conjugation effect between them, when the sensor is used for detecting trilobatin, the material ZnPTC@MoS2 on the sensor and trilobatin are combined by electrostatic adsorption and π-π conjugation effect, so that the electrochemiluminescence intensity is significantly reduced, and finally the electrochemiluminescence sensor can selectively detect trilobatin.

[0030] The present application prepares and stores ZnPTC@MoS2 material in advance, and only needs to modify the material on the electrode for selective detection of trilobatin when testing. The preparation process of the electrochemiluminescence sensor of the present application is simple and low in cost, and the detection of trilobatin only needs to place the prepared electrode in a little electrolyte for direct testing, the detection speed is fast, and the selective detection of trilobatin can be realized only in 1-3 minutes. Compared with traditional detection methods (such as high performance liquid chromatography, liquid chromatography-mass spectrometry, nuclear magnetic resonance spectroscopy, etc.), it has the advantages of simple operation, fast detection speed, wide linear range, low detection limit, high sensitivity, good selectivity, low cost, etc., which lays a solid foundation for the electrochemiluminescence sensor to detect trilobatin. BRIEF DESCRIPTION OF DRAWINGS

[0031] The accompanying drawings are used to provide further understanding of the present application, and constitute a part of the specification, together with the embodiments of the present application, to explain the present application, and do not constitute a limitation on the present application.

[0032] Figure 1 is a brief flow chart of the preparation of ZnPTC@MoS2 / GCE electrochemiluminescence sensor and the detection of trilobatin;

[0033] Figure 2ECL curves of ZnPTC@MoS2 / GCE electrochemiluminescence sensor for detecting different concentrations of trioside (the concentration range of trioside: 5 x 10-8~ 1 x 10-5M) are shown in Figure 6. -4 ECL curves of ZnPTC@MoS2 / GCE electrochemiluminescence sensor for detecting different concentrations of trioside (the concentration range of trioside: 5 x 10-8~ 1 x 10-5M) are shown in Figure 6.

[0034] Figure 3 ECL curves of ZnPTC@MoS2 / GCE electrochemiluminescence sensor for detecting different concentrations of trioside (the concentration range of trioside: 5 x 10-8~ 1 x 10-5M) are shown in Figure 6. -8 ~1 x 10-5M) are shown in Figure 6. -3 ECL curves of ZnPTC@MoS2 / GCE electrochemiluminescence sensor for detecting different concentrations of trioside (the concentration range of trioside: 5 x 10-8~ 1 x 10-5M) are shown in Figure 6.

[0035] Figure 4 ECL curves of ZnPTC@MoS2 / GCE electrochemiluminescence sensor for detecting different concentrations of trioside (the concentration range of trioside: 5 x 10-8~ 1 x 10-5M) are shown in Figure 6.

[0036] Figure 5 ECL curves of ZnPTC@MoS2 / GCE electrochemiluminescence sensor for detecting different concentrations of trioside (the concentration range of trioside: 5 x 10-8~ 1 x 10-5M) are shown in Figure 6. DETAILED DESCRIPTION

[0037] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined object, the specific implementation, features and effects of the preparation method and application of a novel electrochemiluminescence sensor for detecting trioside according to the present application are described in detail as follows.

[0038] Example 1: Preparation method and application method of an electrochemiluminescence sensor for selectively detecting trioside.

[0039] Preparation method of an electrochemiluminescence sensor for selectively detecting trioside:

[0040] (1) Preparation method of ZnPTC@MoS2:

[0041] S1. 3,4,9,10-perylenetetracarboxylic dianhydride and potassium hydroxide were dispersed in 5 mL of deionized water, and after stirring and reacting in a 55°C water bath, ethanol was added, and after stirring to form a yellow solid substance, centrifugation and ethanol washing were performed, and the obtained precipitate was vacuum dried to obtain K4PTC powder;

[0042] wherein the molar ratio of 3,4,9,10-perylenetetracarboxylic dianhydride to potassium hydroxide is 1:5, the molar mass of 3,4,9,10-perylenetetracarboxylic dianhydride is 1 mmol, the stirring reaction time is 12 h, and the amount of ethanol used is 30 mL;

[0043] S2. K4PTC and MoS2 were added to 15 mL of zinc acetate dihydrate solution, after stirring uniformly at room temperature, the solution was moved to a reaction kettle for hydrothermal reaction, the temperature of the hydrothermal reaction was 100℃, the time of the hydrothermal reaction was 12 h, after cooling to room temperature, centrifugation and washing with deionized water, the obtained precipitate was vacuum dried to obtain ZnPTC@MoS2 powder;

[0044] The molar ratio of K4PTC, zinc acetate dihydrate and MoS2 is 1:2:2, and the molar mass of K4PTC is 0.05 mmol.

[0045] (2) The preparation method of ZnPTC@MoS2 / GCE is:

[0046] The glassy carbon electrode was polished and ultrasonically cleaned with anhydrous ethanol solution and deionized water for 15 min, and then dried at room temperature to obtain a pretreated glassy carbon electrode; 4 μL of 1 mg / mL ZnPTC@MoS2 DMF dispersion liquid was moved to the surface of a clean glassy carbon electrode with a diameter of 3 mm by using a microsyringe, and dried under an infrared lamp to obtain ZnPTC@MoS2 / GCE; the prepared electrochemiluminescence sensor was named ZnPTC@MoS2 / GCE;

[0047] An application method of the electrochemiluminescence sensor for selectively detecting trilobatin;

[0048] ZnPTC@MoS2 / GCE was used as the working electrode, a platinum wire electrode was used as the auxiliary electrode, and Ag / AgCl was used as the reference electrode, and the electrochemiluminescence intensity of the modified electrode before and after detecting trilobatin was tested by cyclic voltammetry scanning (electrochemical window: -1.6 V-0 V; photomultiplier high voltage: 700 V; scan rate: 0.1 V / s) in a three-electrode system;

[0049] The signals of the electrochemiluminescence sensors prepared by different molar ratios (1:1:1, 1:2:2, 1:3:3, 1:4:4, 1:5:5) of K4PTC, zinc acetate dihydrate and MoS2 for detecting trilobatin were compared, and when the molar ratio was 1:2:2, the response of the sensor to trilobatin was the most obvious, so the molar ratio of K4PTC, zinc acetate dihydrate and MoS2 was preferably 1:2:2.

[0050] In Example 1, ZnPTC@MoS2 prepared according to the preferred molar ratio (1:2:2) of K4PTC, zinc acetate dihydrate and MoS2 was used to modify the electrode, and the electrochemiluminescence sensor based on ZnPTC@MoS2 / GCE was used to detect trilobatin, and the electrochemiluminescence intensity of the sensor in the electrolyte containing trilobatin was compared with the electrochemiluminescence intensity of the sensor in the electrolyte without trilobatin, and the intensity of the electrochemiluminescence signal was obviously reduced, that is, the quenching value of the electrochemiluminescence intensity of the sensor for detecting trilobatin was larger, and the results were as follows:Figure 2 As shown by d and e, it indicates that the sensitivity of the constructed ZnPTC@MoS2 / GCE electrochemiluminescence sensor for detecting trilostane is high.

[0051] As the preferred technical solution, the specific steps are as follows:

[0052] A1. Preparation of trilostane standard solution with different concentrations:

[0053] The trilostane standard solution is prepared into a 1×10 -3 M solution by using 0.1M PBS buffer solution with 0.05M potassium persulfate and pH 7.4, and a series of trilostane standard solutions with different concentrations are diluted, with the concentration range being 5×10 -8 ~ 1×10 - 3 M;

[0054] A2. Drawing of standard curve:

[0055] The ZnPTC@MoS2 / GCE is used as a working electrode, a platinum wire electrode is used as an auxiliary electrode, and an Ag / AgCl is used as a reference electrode to form a three-electrode system, and the electrochemiluminescence intensity is detected by using 0.1M PBS buffer solution with 0.05M K2S2O8 and pH 7.4 as a blank solution, and then the three-electrode system is placed in a series of trilostane standard solutions with different concentrations prepared in step A1, and cyclic voltammetry scanning is performed in an electrochemical window range of -1.6V~0V, with a photomultiplier high voltage of 700V and a scanning speed of 0.1V / s, and an electrochemiluminescence intensity-time curve (ECL-Time) is recorded, and a linear relationship between the difference (△ECL) of the luminescence intensity before and after the sensor detects trilostane and the logarithm value of the trilostane concentration is established, and a corresponding linear regression equation is obtained; when the concentration of trilostane is in the range of 5×10 -8 ~ 1×10 -3 M, the electrochemiluminescence intensity decreases with the increase of the trilostane concentration, as shown in Figure 3 , and the △ECL has a good linear relationship with the logarithm of the trilostane concentration Figure 4 , and the linear regression equation is △ECL=3339.04LogC(M)+27409.67, the correlation coefficient (R 2 ) is 0.995, and the detection limit is 5.6×10 -9 M;

[0056] A3. Actual sample detection:

[0057] A 5g sample of L. triflora leaf powder was added to 100mL of deionized water under the condition of a solid-liquid ratio of 1:20, and then extracted by refluxing in an oil bath for 3h. After filtration under reduced pressure, the filtrate was obtained, and then the filtrate was diluted to 100mL to obtain a crude extract of trilobatin for use; 0.1mL of the crude extract of trilobatin was diluted to 100mL with a 0.1M PBS buffer solution containing 0.05M K2S2O8 at pH 7.4 to obtain a test sample, which was used for ECL detection of the actual sample. The concentration of trilobatin in the test sample was calculated according to the linear regression equation obtained in A2 above, and the results are shown in Table 1.

[0058] Example 1 uses ZnPTC@MoS2 as an electrode modification material. The rhombic sheet-shaped ZnPTC has a large specific surface area, good electrochemical luminescence performance, and better stability. The two-dimensional MoS2 has a large specific surface area and excellent catalytic activity. The ZnPTC@MoS2 material after compounding has strong and stable electrochemical luminescence performance. The electrochemical luminescence sensor based on ZnPTC@MoS2 / GCE has excellent performance for detecting trilobatin, and has good stability, high sensitivity, a wide linear range, a low detection limit, and good selectivity.

[0059] Comparative Example 1: A preparation method and application method of an electrochemical luminescence sensor for detecting trilobatin.

[0060] A preparation method of an electrochemical luminescence sensor for detecting trilobatin:

[0061] (1) A preparation method of ZnPTC@MoS 2(2) :

[0062] The preparation method of K4PTC is the same as S1 in step (1) of Example 1.

[0063] A preparation method of ZnPTC@MoS 2(2) : 2(2) ;

[0064] (2) A preparation method of ZnPTC@MoS 2(2) / GCE:

[0065] A preparation method of ZnPTC@MoS 2(2) / GCE is the same as step (2) of Example 1, wherein the microsyringe moves the dispersion liquid which is a 1mg / mL ZnPTC@MoS 2(2) / DMF dispersion liquid;

[0066] An application method of an electrochemiluminescence sensor for detecting trilobatin

[0067] ZnPTC@MoS 2(2) / GCE as the working electrode, platinum wire electrode as the auxiliary electrode, Ag / AgCl as the reference electrode, under the three-electrode system, the electrochemiluminescence intensity before and after the modified electrode detecting trilobatin was tested by cyclic voltammetry scanning (electrochemical window: -1.6V-0V; photomultiplier high voltage: 700V; scan rate: 0.1V / s);

[0068] The specific application method is the same as that in Example 1, and the results of the sensor detecting trilobatin in actual samples are shown in Table 1.

[0069] Preparation method and application method of an electrochemiluminescence sensor for detecting trilobatin.

[0070] A preparation method of an electrochemiluminescence sensor for detecting trilobatin

[0071] (1) Preparation method of ZnPTC@MoS 2(3) ;

[0072] The preparation method of K4PTC is the same as S1 in step (1) of Example 1;

[0073] Preparation method of ZnPTC@MoS 2(3) ; 2(3)

[0074] (2) Preparation method of ZnPTC@MoS 2(3) / GCE is as follows:

[0075] Preparation method of ZnPTC@MoS 2(3) / GCE is the same as step (2) of Example 1, wherein 4μL of 1mg / mL ZnPTC@MoS 2(3) DMF dispersion solution is taken out by a microsyringe;

[0076] An application method of an electrochemiluminescence sensor for detecting trilobatin

[0077] ZnPTC@MoS 2(3) / GCE as the working electrode, platinum wire electrode as the auxiliary electrode, Ag / AgCl as the reference electrode, under the three-electrode system, the electrochemiluminescence intensity before and after the modified electrode detecting trilobatin was tested by cyclic voltammetry scanning (electrochemical window: -1.6V-0V; photomultiplier high voltage: 700V; scan rate: 0.1V / s);​

[0078] The specific application method is the same as that in Example 1, and the results of the sensor in detecting trilobatin in actual samples are shown in Table 1.

[0079] Preparation method and application method of an electrochemiluminescence sensor for detecting trilobatin.

[0080] Preparation method of an electrochemiluminescence sensor for detecting trilobatin:

[0081] (1) Preparation method of ZnPTC:

[0082] The preparation method of K4PTC is the same as S1 in step (1) of Example 1;

[0083] Preparation method of ZnPTC: K4PTC is added to 15 mL of zinc acetate dihydrate solution, and after stirring uniformly at room temperature, the solution is moved to a reaction kettle for hydrothermal reaction, and after cooling to room temperature, centrifugation and washing with deionized water are performed, and the obtained precipitate is vacuum dried to obtain ZnPTC powder;

[0084] The molar ratio of K4PTC to zinc acetate dihydrate is 1:2, the molar mass of K4PTC is 0.05 mmol, the hydrothermal reaction temperature is 100°C, and the hydrothermal reaction time is 12 h.

[0085] (2) Preparation method of ZnPTC / GCE is:

[0086] The glassy carbon electrode is polished and ultrasonically cleaned with anhydrous ethanol solution and deionized water for 15 min, and dried at room temperature to obtain a pretreated glassy carbon electrode for standby use; 4 μL of 1 mg / mL ZnPTC DMF dispersion liquid is moved to the surface of a clean glassy carbon electrode with a diameter of 3 mm using a microsyringe, dried under an infrared lamp to obtain a ZnPTC / GCE; and the prepared electrochemiluminescence sensor is named ZnPTC / GCE.

[0087] Application method of an electrochemiluminescence sensor for detecting trilobatin:

[0088] ZnPTC / GCE is used as a working electrode, a platinum wire electrode is used as an auxiliary electrode, and Ag / AgCl is used as a reference electrode, and the electrochemiluminescence intensity of the modified electrode before and after detecting trilobatin is tested by cyclic voltammetry scanning (electrochemical window: -1.6 V-0 V; photomultiplier high voltage: 700 V; scan rate: 0.1 V / s) in a three-electrode system.

[0089] The specific application method is the same as that in Example 1, and the electrochemiluminescence intensity of the sensor is shown in curve c of Figure 2 The results of the sensor in detecting trilobatin in actual samples are shown in Table 1.

[0090] Preparation method and application method of an electrochemiluminescence sensor for detecting trilobatin.

[0091] Preparation method of an electrochemiluminescence sensor for detecting trilobatin:

[0092] (1) Preparation method of ZnPTC:

[0093] Preparation method of K4PTC is same as S1 of step (1) of Example 1;

[0094] Preparation method of ZnPTC is same as S2 of step (1) of Comparative Example 3;

[0095] (2) Preparation method of ZnPTC / MoS2 / GCE is:

[0096] The glassy carbon electrode was polished and cleaned with anhydrous ethanol solution and deionized water for 15 min under ultrasonic, and then dried at room temperature to obtain a pretreated glassy carbon electrode; 4 μL of 1 mg / mL MoS2 DMF dispersion was moved to the surface of a clean glassy carbon electrode with a diameter of 3 mm using a microsyringe, and dried under an infrared lamp to obtain MoS2 / GCE; 4 μL of 1 mg / mL ZnPTC DMF dispersion was moved to the electrode using a microsyringe to obtain ZnPTC / MoS2 / GCE; the prepared electrochemiluminescence sensor was named ZnPTC / MoS2 / GCE;

[0097] Application method of an electrochemiluminescence sensor for detecting trilobatin:

[0098] ZnPTC / MoS2 / GCE was used as the working electrode, platinum wire electrode as the auxiliary electrode, and Ag / AgCl as the reference electrode, and the electrochemiluminescence intensity of the modified electrode before and after detecting trilobatin was tested by cyclic voltammetry scanning (electrochemical window: -1.6V-0V; photomultiplier high voltage: 700V; scan rate: 0.1V / s) in a three-electrode system;

[0099] The specific application method is the same as that of Example 1, and the results of the sensor detecting trilobatin in actual samples are shown in Table 1.

[0100] Preparation method and application method of an electrochemiluminescence sensor for detecting trilobatin.

[0101] Preparation method of an electrochemiluminescence sensor for detecting trilobatin:

[0102] (1) Preparation method of ZnPTC:

[0103] Preparation method of K4PTC is same as S1 of step (1) of Example 1;

[0104] The preparation method of ZnPTC is the same as step (1) of S2 of Comparative Example 3;

[0105] (2) The preparation method of MoS2 / ZnPTC / GCE is:

[0106] The glassy carbon electrode was polished and ultrasonically cleaned with anhydrous ethanol solution and deionized water for 15 min, and then dried at room temperature to obtain a pretreated glassy carbon electrode; 4 μL of a 1 mg / mL DMF dispersion of ZnPTC was transferred to the surface of a clean glassy carbon electrode with a diameter of 3 mm using a microsyringe, and dried under an infrared lamp to obtain a ZnPTC / GCE; 4 μL of a 1 mg / mL DMF dispersion of MoS2 was then transferred to the electrode using a microsyringe to obtain a MoS2 / ZnPTC / GCE; and the prepared electrochemiluminescence sensor was named MoS2 / ZnPTC / GCE;

[0107] An application method of an electrochemiluminescence sensor for detecting trilobatin;

[0108] MoS2 / ZnPTC / GCE was used as the working electrode, a platinum wire electrode was used as the auxiliary electrode, and Ag / AgCl was used as the reference electrode, and the electrochemiluminescence intensity of the modified electrode before and after detecting trilobatin was tested by cyclic voltammetry scanning (electrochemical window: -1.6 V to 0 V; photomultiplier high voltage: 700 V; scan rate: 0.1 V / s) in a three-electrode system;

[0109] The specific application method was the same as in Example 1, and the results of the sensor detecting trilobatin in actual samples are shown in Table 1.

[0110] Comparative Example 6: A preparation method and application method of an electrochemiluminescence sensor for detecting trilobatin.

[0111] A preparation method of an electrochemiluminescence sensor for detecting trilobatin:

[0112] (1) The preparation method of ZrMOF@MoS2 is:

[0113] The preparation method of K4PTC was the same as step (1) of S1 of Example 1;

[0114] The preparation method of ZrMOF@MoS2 was as follows: K4PTC and MoS2 were added to 15 mL of a zirconium acetate tetrahydrate solution, which was stirred uniformly at room temperature, and then the solution was transferred to a reaction kettle for hydrothermal reaction, and after cooling to room temperature, centrifugation and washing with deionized water were performed, and the obtained precipitate was vacuum dried to obtain ZrPTC@MoS2 powder;

[0115] The molar ratio of K4PTC, zirconium acetate tetrahydrate and MoS2 is 1:2:2, the molar mass of K4PTC is 0.05mmol, the temperature of the hydrothermal reaction is 100℃, and the time of the hydrothermal reaction is 12h.

[0116] (2) The preparation method of the ZrMOF@MoS2 / GCE is as follows:

[0117] The preparation method of the ZrMOF@MoS2 / GCE is the same as step (2) of the embodiment 1, wherein the dispersion solution taken by the microsyringe is a 1mg / mL ZrMOF@MoS2 DMF dispersion solution;

[0118] An application method of the electrochemiluminescence sensor for detecting triflavin.

[0119] The ZrMOF@MoS2 / GCE is used as a working electrode, the platinum wire electrode is used as an auxiliary electrode, the Ag / AgCl is used as a reference electrode, and the electrochemiluminescence intensity of the modified electrode before and after detecting triflavin is tested in a three-electrode system through cyclic voltammetry scanning (electrochemical window: -1.6V-0V; photomultiplier high voltage: 700V; scanning speed: 0.1V / s).

[0120] The specific application method is the same as that of the embodiment 1, and the results of the sensor detecting triflavin in the actual sample are shown in Table 1.

[0121] Table 1: Detection results of the leaf samples of Lithocarpus polystachyus

[0122]

[0123]

[0124] As shown in Table 1, the standard addition recovery rate of the electrochemiluminescence sensor based on the ZnPTC@MoS2 / GCE for detecting triflavin in the leaf samples of Lithocarpus polystachyus is 98.98%-103.66%, and the relative standard deviation is less than 2.5%, which indicates that the performance of the sensor for detecting triflavin is better. According to the above experimental results, it can be obviously observed that the triflavin in the leaf samples of Lithocarpus polystachyus cannot be detected by using the ZnPTC@MoS2 composite material prepared in the molar ratio range of K4PTC and MoS2, by using the one-pot hydrothermal method to directly synthesize the ZnPTC@MoS2 composite material, and by using other MOFs materials and MoS2 composite materials to assemble the electrochemiluminescence sensor element, and therefore the electrochemiluminescence sensor constructed by the application can be used for sensitively and selectively detecting triflavin in the leaf samples of Lithocarpus polystachyus.

[0125] A selective application method of the electrochemiluminescence sensor for detecting triflavin.

[0126] An application method for detecting the selectivity of a trifolin electrochemiluminescence sensor:

[0127] Using ZnPTC@MoS2 / GCE prepared in Example 1 as the working electrode, a platinum wire electrode as the auxiliary electrode, and Ag / AgCl as the reference electrode, with a 1×10 -4 M-trifolin was used as a control, and 50 times the amount of glucose (Glu), sucralose (Suc), and ascorbic acid (AA) and 100 times the amount of sodium were selected. + K + Cl - As an interfering agent, the electrochemiluminescence intensity of the modified electrode in an electrolyte containing trifolin and the interfering agent was measured using cyclic voltammetry in a three-electrode system (electrochemical window: -1.6V to 0V; photomultiplier tube high voltage: 700V; scan rate: 0.1V / s). The results are as follows: Figure 5 As shown, compared with the electrochemiluminescence change measured without interfering substances, the change measured by the sensor with interfering substances showed no significant difference, with a relative standard deviation (RSD) of 2.97%. This indicates that the introduced interfering substances have a significant impact on the detection...

[0128] There is no significant impact, and the sensor has strong anti-interference ability, meaning that the ZnPTC@MoS2 / GCE electrochemiluminescence sensor has good selectivity for detecting trifolin.

[0129] An electrochemiluminescence sensor was constructed based on a ZnPTC@MoS2-modified glassy carbon electrode. When trace amounts of trifolin were present in the detection solution, the electrochemiluminescence signal of the ZnMOF@MoS2 / GCE sensor was significantly quenched. Studies revealed that the change in electrochemiluminescence intensity of the ZnPTC@MoS2 / GCE electrochemiluminescence sensor for detecting trifolin exhibited a good linear relationship with the logarithm of the trifolin concentration. The electrochemiluminescence method used in this invention not only possesses advantages such as simple operation, fast response, high sensitivity, wide linear range, low detection limit, and good selectivity, but also lays a solid foundation for the subsequent design and development of electrochemiluminescence sensors for the sensitive and selective quantitative detection of trifolin.

[0130] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An electrochemiluminescence sensor for selective detection of trilobatin, characterized in that, The electrochemiluminescence sensor is ZnPTC@MoS2 / GCE; wherein ZnPTC@MoS2 is MoS2 uniformly loaded on rhombic sheet-shaped ZnPTC; The preparation method of the ZnPTC@MoS2 comprises the following steps: S1. Disperse 3,4,9,10-perylenetetracarboxylic dianhydride and potassium hydroxide in deionized water, stir the reaction in a water bath, then add ethanol, stir to form a yellow solid substance, centrifuge, wash, dry, and obtain K4PTC powder; S2. Add K4PTC and MoS2 to a zinc acetate dihydrate solution, stir uniformly at room temperature, then move the solution to a reaction kettle to perform hydrothermal reaction, cool to room temperature, centrifuge, wash, dry, and obtain ZnPTC@MoS2 powder.

2. The electrochemiluminescence sensor for selective detection of trifolin according to claim 1, wherein, In S1, the molar ratio of 3,4,9,10-perylenetetracarboxylic dianhydride to potassium hydroxide is 1:1-1:10, the stirring reaction time is 6-24 h, and the stirring rate is 120-720 rpm.

3. The electrochemiluminescence sensor for selective detection of trifolin according to claim 1, wherein, In S2, the molar ratio of K4PTC, zinc acetate dihydrate and MoS2 is 1:1:1-1:5:5; the hydrothermal reaction temperature is 75-125 ℃, and the hydrothermal reaction time is 6-24 h.

4. The electrochemiluminescence sensor for selective detection of trifolin according to claim 1, wherein, Disperse ZnPTC@MoS2 on the surface of a pretreated glassy carbon electrode, dry, and obtain ZnPTC@MoS2 / GCE.

5. A method of using an electrochemiluminescent sensor for selective detection of trilobatin, characterized in that: Use the ZnPTC@MoS2 / GCE of any one of claims 1-4 as a working electrode, use a platinum wire electrode as an auxiliary electrode, use Ag / AgCl as a reference electrode, detect the electrochemiluminescence intensity of different concentrations of trilostane by electrochemiluminescence in a three-electrode system, so as to realize selective detection and quantitative analysis of trilostane.

6. The application method of the electrochemiluminescence sensor for selectively detecting trilostane according to claim 5, and the specific steps are as follows: A1. Preparation of standard solutions containing different concentrations of trilostane: A stock solution of 1 x 10 -3 M solution of M was prepared and a series of different concentrations of the standard solution of trilobatin was diluted, ranging from 5 x 10 -8 ~1 x 10 -3 M. A2. Drawing of a standard curve: Use ZnPTC@MoS2 / GCE as a working electrode, use a platinum wire electrode as an auxiliary electrode, use Ag / AgCl as a reference electrode, form a three-electrode system, detect the electrochemiluminescence intensity in a buffer solution containing potassium persulfate as a blank solution, then place it in a series of different concentrations of trilostane standard solutions prepared in step A1, perform cyclic voltammetry scanning, record the electrochemiluminescence intensity-time curve, establish the linear relationship between the difference in luminescence intensity before and after the sensor detects trilostane and the logarithmic value of the concentration of trilostane, and obtain the corresponding linear regression equation; A3. Actual sample detection: Dilute the solution containing the trilostane sample with a buffer solution containing potassium persulfate to obtain a sample to be tested, add standard samples of different concentrations and test the electrochemiluminescence performance, and calculate the concentration of trilostane in the sample to be tested according to the linear regression equation obtained in A2.

7. The method of using the electrochemiluminescent sensor for selective detection of trifolin according to claim 6, wherein, The buffer solution containing potassium persulfate was a 0.1 M PBS buffer solution containing 0.05 M K2S208 at pH 7.4; the minimum detection limit was 5.6 x 10 -9 M.

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