Molecularly imprinted electrochemical sensor for rapidly detecting aconitine as well as preparation and application of molecularly imprinted electrochemical sensor

Abstract

The invention discloses a molecularly imprinted electrochemical sensor for rapidly detecting aconitine as well as preparation and application of the molecularly imprinted electrochemical sensor, and relates to the field of quality safety monitoring of medicinal plants. The preparation method of the molecularly imprinted electrochemical sensor comprises the following steps: preparing an N-Gr suspension, preparing an N-Gr / GCE modified electrode, and preparing the MIP-N-Gr / GCE molecularly imprinted electrochemical sensor. According to the preparation method, aconitine is taken as a template molecule, pyrrole is taken as a functional monomer, and a layer of molecularly imprinted polypyrrole film which is used for high-sensitivity and high-selectivity detection of an index component in monkshood and an easily toxic substance aconitine is prepared on the surface of an N-Gr modified glassy carbon electrode through an electropolymerization method. When the molecularly imprinted electrochemical sensor is used for detecting an actual monkshood sample, high selectivity and sensitivity are shown, good stability and reproducibility are kept, and high-sensitivity and rapid detection of trace AC in the actual sample can be achieved.

Description

Technical Field

[0001] The invention relates to the field of environmental monitoring and medicinal plant quality and safety monitoring, and in particular to an aconitine rapid detection molecular imprinting electrochemical sensor and a preparation method and application thereof. Background Art

[0002] Aconite is a processed product of the root of the Ranunculaceae plant Aconitum carmichaeli debx. As the first traditional Chinese medicine for restoring yang and rescuing adverse conditions, it has the effects of replenishing fire and yang, and expelling wind, cold and dampness. At present, the evaluation and detection methods of Aconite in the "Chinese Pharmacopoeia (2020 Edition)" mainly include property identification, microscopic identification, physical and chemical identification, and content determination (high performance liquid chromatography). Factors such as origin, cultivation method, harvesting time and processing will affect the quality of Aconite, which in turn affects its clinical efficacy and drug safety. Therefore, although the evaluation and detection methods in the "Chinese Pharmacopoeia (2020 Edition)" provide a basis for the quality control and safety of Aconite, there are still certain deficiencies and limitations in the evaluation of cultivation, planting, harvesting and origin processing of Aconite. For example, the detection sensitivity is low, it takes a long time, the cost is high, and it is impossible to achieve instant and convenient detection. The traditional sensory evaluation method is easily affected by human factors, and the objectivity and reliability of the results are not high. Therefore, based on the construction of a standardized system for the entire production process of aconite slices and their preparations, it is extremely important to screen out an indicator component that represents the overall quality of aconite, which will provide guidance for the quality control of the traditional Chinese medicine aconite and its preparations and the standardization and standardization of the cultivation, planting, harvesting, and processing of medicinal materials at the place of origin.

[0003] In recent years, the research on aconite has been continuously deepened, and many scholars have conducted research on the chemical composition, quality control, and dose-effect relationship of aconite. Aconitine (AC), as the most representative alkaloid in aconite, is the main toxic component and active ingredient of the genus Aconitum. It has good anti-inflammatory, analgesic, and cardiotonic effects and is widely used in the treatment of various diseases. However, the cardiotoxicity and neurotoxicity of aconitine have attracted widespread attention, making it the most popular plant poison in history. Therefore, the level of aconitine not only directly affects the efficacy of aconite, but also determines its safety. Aconitine is the key to the cardiotonic, anti-arrhythmic, anti-myocardial ischemia and hypoxia, analgesic, immune enhancement and anti-cancer effects of aconite. It can be used as one of the indicator components for the quality evaluation of aconite, and has the reliability of dose-effect relationship. In addition, the therapeutic dose of aconitine (0.1-0.2 mg / kg) and the toxic dose (about 1.8 mg / kg) are relatively close, that is, the narrow therapeutic window of aconitine limits the clinical application of Chinese medicine containing aconitine; excessive use of aconitine can cause ventricular tachyarrhythmia and cardiac arrest, both of which are potentially fatal. Therefore, safety assessment and monitoring are often required during the use of aconitine.

[0004] At present, the detection methods of aconitine (AC) mainly include ultraviolet spectrophotometry (UV), high performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC-MS), gas chromatography-mass spectrometry (GC-MS), capillary electrophoresis, etc. Although spectrophotometry is simple to operate, its detection sensitivity is low; although other methods have accurate measurement results, they are cumbersome to operate and have a long cycle, which is difficult to meet the on-site, immediate and rapid evaluation of the quality of traditional Chinese medicines.

[0005] As a device that converts the interaction between the target analyte and the electrode surface receptor into a useful analytical signal, electrochemical sensors have shown great application potential in the detection of the content of traditional Chinese medicines due to their unique advantages such as low cost, convenient operation, rapid response, and easy miniaturization. In view of this, we have developed a molecular imprinting electrochemical sensor for rapid detection of aconitine, which can achieve high sensitivity, high selectivity, and accurate rapid detection of aconitine. On the one hand, it provides a means for the quality evaluation of aconite and ensures the quality and efficacy of aconite and its related products; on the other hand, it provides a monitoring technology for the safe use of aconite and its aconitine. Summary of the invention

[0006] The purpose of the present invention is to provide a molecular imprinting electrochemical sensor for rapid detection of aconitine and its preparation and application in view of the defects of the prior art in the above-mentioned background technology.

[0007] In order to achieve the above object, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing aconitine rapid detection molecular imprinting electrochemical sensor, comprising the following steps: (1) Preparation of N-Gr suspension Graphene oxide (GO) was dispersed in water and then treated with 30 wt% NH 3 ·H 2 O to adjust the pH of the solution to 10, stir for 10 minutes, then add 2.0 mL of hydrazine, heat to 80 ° C, react for 12 to 48 hours, filter, collect the black precipitate, wash with double distilled water until neutral, and dry to obtain N-Gr nanomaterials; add 2 to 4 mg of N-Gr nanomaterials to 1 to 2 mg of DMF to obtain N-Gr suspension; (2) Preparation of N-Gr / GCE modified electrode First, the glassy carbon electrode (GCE) was polished on suede with 0.30μm and 0.05μm alumina polishing powder to obtain a smooth surface of the glassy carbon electrode (GCE), and then the glassy carbon electrode (GCE) was ultrasonically cleaned with water and methanol for 3-5 min, and then dried under an infrared lamp; secondly, N-Gr suspension was added dropwise on the surface of the glassy carbon electrode (GCE), and then dried in air for 30-60 min to obtain the N-Gr / GCE modified electrode; (3) Preparation of MIP-N-Gr / GCE molecular imprinting electrochemical sensor The N-Gr / GCE modified electrode was immersed in acetic acid buffer (ABS) with pH value of 4.0 and concentration of 0.10 mol / L containing pyrrole (Py) and aconitine (AC). The CV cycle scanning polymerization was carried out for 20 cycles at a scan rate of 100 mV / s and a potential range of -1.0 to 1.0 V to prepare the MIP-N-Gr / GCE composite electrode with imprinted polymer film embedded with aconitine molecules. Then, the MIP-N-Gr / GCE composite electrode was subjected to 10 cycles of CV cycle scanning in a 0.10 mol / L NaOH solution at a scan rate of 50 mV / s in the potential range of 0 to 1.0 V to obtain the MIP-N-Gr / GCE composite electrode with imprinted cavity. Finally, it was washed with deionized water and dried at 37 ℃ to obtain the MIP-N-Gr / GCE molecularly imprinted electrochemical sensor.

[0008] Furthermore, in step (1), the graphene oxide is prepared and synthesized using graphite powder as raw material by adopting an improved Hummers method.

[0009] Furthermore, in step (1), the concentration of the N-Gr suspension is 2.00 mg / mL.

[0010] Furthermore, in step (2), the amount of N-Gr suspension added is 15 μL.

[0011] Furthermore, in step (3), the amount of pyrrole used is 10 mg / mL; the amount of aconitine used is 5 mg / mL.

[0012] In a second aspect, the present invention further provides an aconitine rapid detection molecular imprinting electrochemical sensor, which is prepared by the above-mentioned preparation method.

[0013] In a third aspect, the present invention also provides an application of aconitine rapid detection molecular imprinting electrochemical sensor in the quality detection of Aconitum carmichaelii.

[0014] Compared with the prior art, the beneficial technical effects of the present invention are: 1. The present invention uses aconitine (AC) as a template molecule and pyrrole (Py) as a functional monomer, and prepares a molecular imprinting polypyrrole film on the surface of an N-Gr modified glassy carbon electrode by electropolymerization for the highly sensitive and selective detection of aconitine, an indicator component in aconite and a toxic substance; wherein the PPy film formed by electropolymerization of pyrrole not only has stable chemical properties and good electrical conductivity, but also a large number of amino groups can combine with AC through hydrogen bonds to form a molecular imprinting film for specific recognition and detection of AC; meanwhile, the excellent electrical conductivity and chemical stability of N-Gr also provide a prerequisite for the sensitive detection of AC.

[0015] 2. When the AC concentration is in the range of 0.5 to 1500 μg / mL, the AC concentration and the DPV peak current value detected by the MIP-N-Gr / GCE molecular imprinting electrochemical sensor constructed by the present invention show a good linear relationship, and the detection limit is 0.05 μg / mL. When the molecular imprinting electrochemical sensor is used for actual sample detection, it shows high selectivity and sensitivity, and maintains good stability and reproducibility, which can achieve high sensitivity and rapid detection of trace AC in actual samples. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the preparation principle of a rapid detection molecular imprinting electrochemical sensor for aconitine of the present invention; Figure 2 FTIR spectra of N-Gr and py-N-Gr in a test example of the present invention; Figure 3 is a SEM image of N-Gr in a test example of the present invention; Figure 4 This is a SEM image of MIP-N-Gr / GCE before elution in a test example of the present invention; Figure 5 This is a SEM image of MIP-N-Gr / GCE after elution in a test example of the present invention; Figure 6 In a test example of the present invention, 2.0 mM KCl containing 0.10 mM K 3 [Fe(CN) 6 ] / K 4 [Fe(CN) 6 ] CV curves of GCE, N-Gr / GCE, NIP-N-Gr / GCE, MIP-N-Gr / GCE before elution, MIP-N-Gr / GCE after elution and re-adsorbed MIP-N-Gr / GCE detected by cyclic voltammetry (CV) in the solution; Figure 7 In a test example of the present invention, 2.0 mM KCl containing 0.10 mM K 3 [Fe(CN)6 ] / K 4 [Fe(CN) 6 ] Partially enlarged diagram of CV curves of GCE, N-Gr / GCE, NIP-N-Gr / GCE, MIP-N-Gr / GCE before elution, MIP-N-Gr / GCE after elution and re-adsorbed MIP-N-Gr / GCE detected by cyclic voltammetry (CV) in solution; Figure 8 In a test example of the present invention, 2.0 mM KCl containing 0.10 mM K 3 [Fe(CN) 6 ] / K 4 [Fe(CN) 6 ]EIS curves of GCE, N-Gr / GCE, NIP-N-Gr / GCE, MIP-N-Gr / GCE before elution, MIP-N-Gr / GCE after elution and re-adsorbed MIP-N-Gr / GCE detected by electrochemical impedance spectroscopy (EIS) in the solution; Fig. 9 In a test example of the present invention, 0.1 mM KCl and 2.0 mM Fe(CN) 6 3- / 4- Chronocoulometry (CC) curves of GCE, N-Gr / GCE, MIP-N-Gr / GCE before elution, and MIP-N-Gr / GCE after elution in the probe solution; Fig.10 In a test example of the present invention, 0.1 mM KCl and 2.0 mM Fe(CN) 6 3- / 4- The Qt values ​​of GCE, N-Gr / GCE, MIP-N-Gr / GCE before elution, and MIP-N-Gr / GCE after elution were detected by chronocoulometry (CC) in the probe solution. 1 / 2 curve; Fig.11 In a test example of the present invention, 0.10 mM KCl and 2.0 mM [Fe(CN) 6 ] 3− / 4− CV curves at a scan rate of 10 to 200 mV / s in a probe solution; Fig.12 is a graph showing the relationship between the peak current and the square root of the scan rate in a test example of the present invention; Fig.13 DPV curves of AC with different concentrations on MIP-N-Gr / GCE in a test example of the present invention; Fig.14is a graph showing the relationship between the peak current and AC concentration of MIP-N-Gr / GCE in a test example of the present invention; Fig.15 This is a diagram showing the repeatability test results of the MIP-N-Gr / GCE molecular imprinting electrochemical sensor in a test example of the present invention; Fig.16 This is a diagram showing the stability test results of the MIP-N-Gr / GCE molecular imprinting electrochemical sensor in a test example of the present invention; Fig.17 This is a diagram showing the specific detection results of the MIP-N-Gr / GCE molecular imprinting electrochemical sensor in a test example of the present invention. DETAILED DESCRIPTION

[0017] The technical solution of the present invention will be described clearly and completely in conjunction with the embodiments below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Example 1 Please refer to the attached Figure 1 As shown, the preparation method of a quick detection molecular imprinting electrochemical sensor for aconitine provided in this embodiment comprises the following steps: (1) Preparation of N-Gr suspension Graphene oxide (GO) was dispersed in water and then treated with 30 wt% NH 3 ·H 2 O to adjust the pH of the solution to 10, stir for 10 minutes, then add 2.0 mL of hydrazine, heat to 80 ° C, react for 12 hours, filter, collect the black precipitate, wash with double distilled water until neutral, and dry to obtain N-Gr nanomaterials; add 2 mg of N-Gr nanomaterials to 1 mL of DMF and mix well to obtain a N-Gr suspension with a concentration of 2.00 mg / mL; (2) Preparation of N-Gr / GCE modified electrode First, the glassy carbon electrode (GCE) was polished on suede with 0.30μm and 0.05μm alumina polishing powder to obtain a smooth surface of the glassy carbon electrode (GCE), and then the glassy carbon electrode (GCE) was ultrasonically cleaned with water and methanol for 3-5 min, and then dried under an infrared lamp; secondly, 15μL of N-Gr suspension was added to the surface of the glassy carbon electrode (GCE), and then dried in air for 30 minutes to obtain the N-Gr / GCE modified electrode; (3) Preparation of MIP-N-Gr / GCE molecular imprinting electrochemical sensor The N-Gr / GCE modified electrode was immersed in acetic acid buffer (ABS) with pH 4.0 and concentration of 0.10 mol / L containing 6 mg / mL pyrrole (Py) and 3 mg / mL aconitine (AC). The CV cycle scanning polymerization was carried out for 20 cycles at a scan rate of 100 mV / s and a potential range of -1.0 to 1.0 V to prepare the MIP-N-Gr / GCE composite electrode with imprinted polymer film embedded with aconitine molecules. Then, the MIP-N-Gr / GCE composite electrode was subjected to 10 cycles of CV cycle scanning in 0.10 mol / L NaOH solution at a scan rate of 50 mV / s in the potential range of 0 to 1.0 V to obtain the MIP-N-Gr / GCE composite electrode with imprinted cavity. Finally, it was washed with deionized water and dried at 37 ℃ to obtain the MIP-N-Gr / GCE molecularly imprinted electrochemical sensor.

[0019] Example 2 Please refer to the attached Figure 1 As shown, the preparation method of a quick detection molecular imprinting electrochemical sensor for aconitine provided in this embodiment comprises the following steps: (1) Preparation of N-Gr suspension Graphene oxide (GO) was dispersed in water and then treated with 30 wt% NH 3 ·H 2 O to adjust the pH of the solution to 10, stir for 10 minutes, then add 2.0 mL of hydrazine, heat to 80 ° C, react for 36 hours, filter, collect the black precipitate, wash with double distilled water until neutral, and dry to obtain N-Gr nanomaterials; add 3 mg of N-Gr nanomaterials to 1.5 mL of DMF, mix well, and obtain a N-Gr suspension with a concentration of 2.00 mg / mL; (2) Preparation of N-Gr / GCE modified electrode First, the glassy carbon electrode (GCE) was polished on suede with 0.30μm and 0.05μm alumina polishing powder to obtain a smooth surface of the glassy carbon electrode (GCE), and then the glassy carbon electrode (GCE) was ultrasonically cleaned with water and methanol for 3-5 min, and then dried under an infrared lamp; secondly, 15μL of N-Gr suspension was added to the surface of the glassy carbon electrode (GCE), and then dried in air for 30 minutes to obtain the N-Gr / GCE modified electrode; (3) Preparation of MIP-N-Gr / GCE molecular imprinting electrochemical sensor The N-Gr / GCE modified electrode was immersed in 0.10 mol / L acetate buffer (ABS) with pH 4.0 and concentration of 8 mg / mL pyrrole (Py) and 4 mg / mL aconitine (AC). The CV cycle scanning polymerization was carried out for 20 cycles at a scan rate of 100 mV / s and a potential range of -1.0 to 1.0 V to prepare the MIP-N-Gr / GCE composite electrode with imprinted polymer film embedded with aconitine molecules. Then, the MIP-N-Gr / GCE composite electrode was subjected to 10 cycles of CV cycle scanning in 0.10 mol / L NaOH solution at a scan rate of 50 mV / s in the potential range of 0 to 1.0 V to obtain the MIP-N-Gr / GCE composite electrode with imprinted cavity. Finally, it was washed with deionized water and dried at 37 ℃ to obtain the MIP-N-Gr / GCE molecularly imprinted electrochemical sensor.

[0020] Example 3 Please refer to the attached Figure 1 As shown, the preparation method of a quick detection molecular imprinting electrochemical sensor for aconitine provided in this embodiment comprises the following steps: (1) Preparation of N-Gr suspension Graphene oxide (GO) was dispersed in water and then treated with 30 wt% NH 3 ·H 2 O to adjust the pH of the solution to 10, stir for 10 minutes, then add 2.0 mL of hydrazine, heat to 80 ° C, react for 48 hours, filter, collect the black precipitate, wash with double distilled water until neutral, and dry to obtain N-Gr nanomaterials; add 4 mg of N-Gr nanomaterials to 2 mL of DMF, mix well, and obtain a N-Gr suspension with a concentration of 2.00 mg / mL; (2) Preparation of N-Gr / GCE modified electrode First, the glassy carbon electrode (GCE) was polished on suede with 0.30μm and 0.05μm alumina polishing powder to obtain a smooth surface of the glassy carbon electrode (GCE), and then the glassy carbon electrode (GCE) was ultrasonically cleaned with water and methanol for 3-5 min, and then dried under an infrared lamp; secondly, 15μL of N-Gr suspension was added to the surface of the glassy carbon electrode (GCE), and then dried in air for 30 minutes to obtain the N-Gr / GCE modified electrode; (3) Preparation of MIP-N-Gr / GCE molecular imprinting electrochemical sensor The N-Gr / GCE modified electrode was immersed in acetic acid buffer (ABS) with pH 4.0 and concentration of 0.10 mol / L containing 10 mg / mL pyrrole (Py) and 5 mg / mL aconitine (AC). The CV cycle scanning polymerization was carried out for 20 cycles at a scan rate of 100 mV / s and a potential range of -1.0 to 1.0 V to prepare the MIP-N-Gr / GCE composite electrode with imprinted polymer film embedded with aconitine molecules. Then, the MIP-N-Gr / GCE composite electrode was subjected to 10 cycles of CV cycle scanning in 0.10 mol / L NaOH solution at a scan rate of 50 mV / s in the potential range of 0 to 1.0 V to obtain the MIP-N-Gr / GCE composite electrode with imprinted cavity. Finally, it was washed with deionized water and dried at 37 ℃ to obtain the MIP-N-Gr / GCE molecularly imprinted electrochemical sensor.

[0021] Test Example 1 Electrochemical Characterization of Basic Electrodes In the process of preparing the MIP-N-Gr / GCE molecular imprinting electrochemical sensor in Example 1, infrared spectroscopy and SEM electron microscopy characterization were performed. The characterization results are as follows Figure 2-5 shown.

[0022] The test results show that N-Gr and MIP-N-Gr / GCE were successfully prepared, and the effective surface areas of GCE, N-Gr / GCE, MIP-N-Gr / GCE before elution, and MIP-N-Gr / GCE after elution were 0.584 cm 2 , 1.773 cm 2 , 0.796 cm 2 and 1.039 cm 2 .

[0023] Test Example 2 Cyclic voltammetry characterization of MIP-N-Gr / GCE molecular imprinted electrochemical sensor In the process of preparing the MIP-N-Gr / GCE molecular imprinting electrochemical sensor in Example 1, the electrochemical characterization of GCE, N-Gr / GCE, MIP-N-Gr / GCE before elution, and MIP-N-Gr / GCE after elution was performed by CV method, EIS method, and chronocoulometry; wherein the CV method was performed in 0.01 M KCl and 2.0 mM K 3 [Fe(CN) 6 ] / K 4 [Fe(CN) 6 ] in the base solution, the voltage range was -0.4 V to 0.8 V, and the scan rate was 100 mV / s; the EIS method test setting frequency range was: 1 Hz to 106 Hz, the sine wave signal amplitude was 5 mV, and the voltage was 0.22 V. The electrochemical characterization results are shown in Figure 6-12 shown.

[0024] The test results show that N-Gr, N-Gr / GCE and MIP-N-Gr / GCE were all successfully prepared.

[0025] Test Example 3 AC Measurement Performance Test The MIP-N-Gr / GCE molecular imprinting electrochemical sensor prepared in Example 1 was placed in AC standards of different concentrations for adsorption for 10 min, and then the response current Ip was recorded by differential pulse voltammetry (DPV) scanning. DPV measurement was performed in a 2.0 mM KCl solution containing 0.10 mM KCl. 3 [Fe(CN) 6 ] / K 4 [Fe(CN) 6 ] electrolyte solution, the measurement conditions are: voltage range 0 ~ 0.45 V; amplitude 0.05V; pulse width 0.05s; sampling width 0.0167s; pulse period 0.5s, and standing time 2s. Finally, the linear function relationship between AC concentration and electrochemical response value is determined by mathematical modeling. The test results are as follows Fig.13 and 14 shown.

[0026] Test results show that: at 0.5, 25, 50, 100, 300, 500, 700, 900, 1000, 1300, 1500μg mL -1 Within the concentration range, the concentration of AC and the current response show a good linear relationship, and the linear equation is Ipa (μA) = -0.012 C AC + 27.097 (R 2 = 0.9925) and the detection limit was 5×10-2 μg / mL (S / N=3).

[0027] Test Example 4 Practicality test of MIP-N-Gr / GCE molecular imprinting electrochemical sensor In order to verify the practicality of the MIP-N-Gr / GCE molecular imprinting electrochemical sensor of the present invention, the repeatability, stability and anti-interference performance of the MIP-N-Gr / GCE molecular imprinting electrochemical sensor prepared in Example 1 were tested. In the anti-interference performance test, the interfering substance selected was Ca 2+, K+, Na+, Matrine and Glucose. The ratio of interfering substances to AC was selected as 10:1, and the prepared IP-N-Gr / GCE molecular imprinting electrochemical sensor was tested and the data was recorded; in the repeatability test, 5 identical MIP-N-Gr / GCE molecular imprinting electrochemical sensors were prepared at the same time, and CV tests were performed and data were recorded respectively; in order to evaluate its stability, MIP-N-Gr / GCE was stored at room temperature for 4 weeks and the corresponding tests were performed every other week. The test results are shown in Figure 15-17 shown.

[0028] The test results show that the MIP-N-Gr / GCE molecular imprinting electrochemical sensor of the present invention has excellent repeatability, stability and anti-interference.

[0029] Application Examples In order to verify the feasibility of the MIP-N-Gr / GCE molecular imprinting electrochemical sensor of the present invention in actual sample detection, mass analysis was performed on actual samples of Aconitum carmichaelii.

[0030] The standard addition method was used to determine AC in the samples of Aconite (Heishun Tablets) and serum. 2.5-12.5 μg / ml AC standard solution was added to the Aconite extract and serum samples, and then the determination was performed. A three-electrode system was used during the determination, with the MIP-N-Gr / GCE molecular imprinting electrochemical sensor as the working electrode, the saturated calomel electrode (SCE) as the reference electrode, and the platinum wire electrode as the counter electrode. DPV was used for detection, and the test results are shown in Table 1.

[0031] Table 1 Determination of AC in actual samples

[0032] Note: a is the average of three measurements, b is not detected.

[0033] The detection results show that the MIP-N-Gr / GCE molecular imprinting electrochemical sensor of the present invention can realize the high-sensitivity and rapid detection of trace amounts of Aconitum carmichaelii (Heishunpian) and the microscopic component AC in serum.

Claims

1. A method for preparing aconitine rapid detection molecular imprinting electrochemical sensor, characterized in that: The steps include: (1) Preparation of N-Gr suspension Graphene oxide was dispersed in water, and then the pH of the solution was adjusted to 10.0 with 30wt% NH3·H2O. After stirring for 10min, 2.0mL hydrazine was added, and the mixture was heated to 80℃ for 12-48h. The mixture was filtered, and the black precipitate was collected and washed with double distilled water until it was neutral and dried to obtain N-Gr nanomaterials. 2-4mg N-Gr nanomaterials were added to 1-2mL DMF solution and mixed to obtain N-Gr suspension. (2) Preparation of N-Gr / GCE modified electrode First, the glassy carbon electrode was polished on suede with 0.30μm and 0.05μm alumina polishing powder to obtain a smooth glassy carbon electrode. Then, the glassy carbon electrode GCE was ultrasonically cleaned with water and methanol for 3-5 min, and then dried under an infrared lamp. Secondly, 15μL of N-Gr suspension was added to the surface of the glassy carbon electrode, and then dried in air for 30-60min to obtain a N-Gr / GCE modified electrode. (3) Preparation of MIP-N-Gr / GCE molecular imprinting electrochemical sensor The N-Gr / GCE modified electrode was immersed in an acetate buffer solution with a pH of 4.0 and a concentration of 0.10 mol / L containing 6-10 mg / mL pyrrole and 3-5 mg / mL aconitine. The CV cycle scanning polymerization was performed for 20 cycles at a scan rate of 100 mV / s and a potential range of -1.0 to 1.0 V to obtain a MIP-N-Gr / GCE composite electrode with an imprinted polymer film embedded with aconitine molecules. The MIP-N-Gr / GCE composite electrode was then subjected to 10 CV cycle scannings in a 0.10 mol / L NaOH solution at a scan rate of 50 mV / s in the potential range of 0 to 1.0 V to obtain a MIP-N-Gr / GCE composite electrode with an imprinted cavity. Finally, the electrode was washed with deionized water and dried at 37 ℃ to obtain a MIP-N-Gr / GCE molecularly imprinted electrochemical sensor.

2. The method for preparing a rapid detection molecular imprinted electrochemical sensor for aconitine according to claim 1, characterized in that: In step (1), the graphene oxide is prepared and synthesized using graphite powder as raw material by adopting an improved Hummers method.

3. The method for preparing a rapid detection molecular imprinted electrochemical sensor for aconitine according to claim 1, characterized in that: In step (1), the concentration of the N-Gr suspension is 2.00 mg / mL.

4. The method for preparing a rapid detection molecular imprinted electrochemical sensor for aconitine according to claim 1, characterized in that: In step (2), the amount of N-Gr suspension added is 15 μL.

5. The method for preparing a rapid detection molecular imprinted electrochemical sensor for aconitine according to claim 1, characterized in that: In step (3), the amount of pyrrole used is 10 mg / mL; the amount of aconitine used is 5 mg / mL.

6. A molecular imprinting electrochemical sensor for rapid detection of aconitine, prepared by the preparation method described in any one of claims 1 to 5.

7. Use of the aconitine rapid detection molecular imprinting electrochemical sensor as claimed in claim 6 in the quality detection of Aconitum carmichaelii.

Images