Polygonatum polysaccharide rapid detection electrochemical sensor and preparation method and application thereof

Abstract

The invention discloses a rhizoma polygonati polysaccharide rapid detection electrochemical sensor as well as a preparation method and application thereof, and relates to the field of electrochemical sensors. The method comprises the following steps: (1) preparing an AC-COOH-PANI composite material; (2) preparing an AC-COOH-PANI (at) GCE modified electrode; and (3) preparing the MIP-AC-COOH-PANI (at) GCE. According to the present invention, Glu is adopted as a template molecule, MAA is adopted as a functional monomer, a molecularly imprinted polymer film is constructed on the surface of an AC-COOH-PANI composite material modified GCE electrode through a self-assembly polymerization technology, and the molecularly imprinted electrochemical sensor MIP-AC-COOH-PANI (at) GCE for rapid detection of polygonatum sibiricum polysaccharide is developed, the sensor shows relatively low detection limit, relatively wide linear range, relatively high sensitivity and good selectivity and stability, and has a good application prospect.

Description

Technical Field

[0001] The present invention relates to the field of electrochemical sensors, and in particular to a polygonatum polysaccharide rapid detection electrochemical sensor and a preparation method and application thereof. Background Art

[0002] Polygonatum sibiricum ( Polygonatum sibiricum ) is a traditional Chinese medicinal material widely distributed in the temperate regions of the Northern Hemisphere, particularly in Asia. First recorded in the "Famous Doctors' Records," according to Traditional Chinese Medicine theory, processed Polygonatum has excellent tonic and nourishing effects, making it particularly suitable for people with kidney deficiency, spleen deficiency, and dry lungs. Polygonatum must be correctly processed and rationally formulated to achieve optimal results. However, due to gaps in traditional processing methods, the quality of Polygonatum obtained using modern, emerging processing techniques varies greatly, making it difficult to ensure its full efficacy. Polygonatum polysaccharide, a characteristic component of processed Polygonatum, is also an indicator component for quality control of Polygonatum in the Chinese Pharmacopoeia. It has multiple biological effects, such as immunomodulation, antioxidant effects, hypoglycemic and hypolipidemic effects, and anti-inflammatory effects. Rapid, real-time, and accurate analysis of Polygonatum polysaccharide content in medicinal materials and preparations is crucial for quality assurance of bulk Polygonatum and the sustainable development of the Polygonatum-related industry.

[0003] Due to the complex structure and diverse connection modes of Polygonatum sibiricum polysaccharides, it is difficult to detect them directly. Currently reported methods mostly use the relatively easy-to-measure glucose content as a surrogate indicator of Polygonatum sibiricum polysaccharides to control the overall quality of Polygonatum sibiricum and achieve its rapid qualitative detection, such as redox method, infrared spectroscopy, fluorescence spectroscopy, enzymatic method and high performance liquid chromatography. Although these detection methods have been widely used and generally accepted, most of them require complicated sample pretreatment and professional technicians to operate, and even require the purchase of expensive instruments and equipment, which is not conducive to the popularization and expansion of analytical technology. Molecular imprinting electrochemical sensing technology is a new analytical method that has attracted much attention in recent years. It has been applied in the fields of drug analysis, environmental testing, food safety, and clinical drug monitoring because of its characteristics such as no need for complicated sample pretreatment, simple operation, strong selectivity, high sensitivity, and fast analysis speed. Summary of the Invention

[0004] The purpose of the present invention is to provide a rapid detection electrochemical sensor for polygonatum polysaccharide, as well as a preparation method and application thereof. The method develops a molecular imprinting electrochemical sensor with high selectivity, high sensitivity and rapid detection of polygonatum polysaccharide, an indicator component for polygonatum quality evaluation, which facilitates the rapid monitoring of polygonatum polysaccharide, an intrinsic microscopic component of polygonatum in the formula, simplifies its detection steps, reduces detection costs, and shortens the detection cycle. It plays a vital role in ensuring the high quality and efficacy of compound preparations containing polygonatum and the controllable overall quality. It also provides a forward-looking exploration of electrochemical analysis technology in the quality evaluation and drug safety of traditional Chinese medicine.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a method for preparing a rapid detection electrochemical sensor for Polygonatum sibiricum polysaccharide, comprising the following steps: (1) Preparation of AC-COOH-PANI composite materials Carboxylated activated carbon (AC-COOH) and spherical polyaniline (PANI) were mixed in a mass ratio of 3:8, and then dispersed in an appropriate amount of 0.05wt% chitosan (CS) solution. The mixture was ultrasonically treated for 30 minutes, dried at 40°C for 12 hours, and ground in an agate mortar to obtain a powder with uniform particle size, which is the polyaniline-doped carboxylated activated carbon (AC-COOH-PANI) composite material. (2) Preparation of AC-COOH-PANI@GCE modified electrode The glassy carbon electrode (GCE) was mechanically polished with 800-grit metallographic sandpaper to remove the surface oxide layer. The suede surface was then mirror-polished using 0.3 μm and 0.05 μm alumina polishing slurries, respectively. The GCE was ultrasonically cleaned with methanol and ultrapure water for 5 min each and then air-dried at room temperature to obtain the pretreated GCE. A suspension of 1 mg of AC-COOH-PANI composite material was dispersed in 1 mL of 0.05 wt% CS solution to form a suspension. 6.00 μL of the suspension was evenly drop-coated on the pretreated GCE surface and cured by vacuum drying at 40°C for 2 h to obtain the AC-COOH-PANI@GCE modified electrode. (3) Preparation of MIP-AC-COOH-PANI@GCE 5 mg of glucose (Glu) was dissolved in a mixed solution containing 110 μL of methacrylic acid (MAA) and 0.5 mL of dimethyl sulfoxide (DMSO), and ultrasonicated at room temperature for 10 min to form a pre-assembled system. 1.2 mL of ethylene glycol dimethacrylate (EGDMA) and 0.34 mg of azobisisobutyronitrile (AIBN) were added and ultrasonicated for another 10 min to prepare a MIP prepolymerization solution. 2 mL of the MIP prepolymerization solution was evenly coated on the surface of the AC-COOH-PANI@GCE modified electrode and thermally polymerized at 40°C for 2 h to form a polymer film. The template molecules were eluted by soaking in a methanol / acetic acid mixture with a volume ratio of 1:4 for 15 min. The MIP-AC-COOH-PANI@GCE was obtained after washing with ultrapure water and drying.

[0006] Furthermore, in step (1), the preparation method of the spherical polyaniline (PANI) is as follows: 0.75 g of aniline monomer is dissolved in 10 mL of ethylene glycol, 1 mL of hydrochloric acid is added, and the mixture is stirred at room temperature for 2 h until the solution becomes clear, followed by adding 0.91 g of hydrogen peroxide solution, and stirring is continued at room temperature overnight. The product is naturally dried to obtain the product.

[0007] In a second aspect, the present invention provides a rapid detection electrochemical sensor for polygonatum polysaccharide, which is prepared by the above-mentioned preparation method.

[0008] In the third aspect, the present invention proposes an electrochemical sensor for rapid detection of polygonatum polysaccharide in the detection of polygonatum polysaccharide content in processed polygonatum. The specific method is as follows: MIP-AC-COOH-PANI@GCE is used as a working electrode, a platinum wire electrode is used as an auxiliary electrode, and a saturated calomel electrode is used as a reference electrode. The electrolytic cell is filled with a concentration of 4.24×10 -1 mg / mL of ferrocyanide ion ([Fe(CN)6] 4- ) and potassium chloride (KCl) with a concentration of 7.46 mg / mL, the polygonatum sample extract was tested by differential pulse voltammetry to determine the content of polygonatum polysaccharide; wherein, the potential range of differential pulse voltammetry was 0.1-0.7 V, and the concentration of polygonatum polysaccharide was 1×10 -2 ~1×10 6 ng / mL, the oxidation peak current showed a good linear relationship with the concentration, and the linear equation was expressed as Ip=-0.89×10 -2 C+5.69×10 1 , correlation coefficient R 2 =9.95×10 -1 The detection limit was 4.75×10 -4 ng / mL, signal-to-noise ratio S / N=3, Ip is the oxidation peak current, unit is μA, C is the concentration, unit is ng / mL.

[0009] Compared with the prior art, the present invention has the following beneficial technical effects: the present invention utilizes the synergistic effect of the rod-shaped skeleton in AC-COOH and the PANI nanospheres to form an AC-COOH-PANI composite material with a three-dimensional conductive network. The open pores of AC-COOH promote electrolyte penetration, while the high specific surface area of ​​the PANI nanospheres provides abundant electrochemical active sites, which together significantly improve the interfacial charge transfer efficiency. The rod-shaped PANI composite material prepared by in situ polymerization on the AC surface overcomes the problem of single PANI material affecting the material's cyclic stability due to volume expansion, greatly reduces the electrochemical impedance, and thus significantly improves the sensor's response performance. Using Glu as the template molecule and MAA as the functional monomer, a molecularly imprinted polymer film was constructed on the surface of the GCE electrode modified with the AC-COOH-PANI composite material through self-assembly polymerization technology, and a molecularly imprinted electrochemical sensor MIP-AC-COOH-PANI@GCE for rapid detection of Polygonatum sibiricum polysaccharide was developed. The sensor exhibits a low detection limit, a wide linear range, high sensitivity, good selectivity and stability, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a schematic diagram of the construction of a rapid detection electrochemical sensor for polygonatum polysaccharide in an embodiment of the present invention.

[0011] Figure 2 Figure 1 is a structural representation diagram of the AC-COOH-PANI composite material, AC-COOH-PANI@GCE modified electrode, and MIP-AC-COOH-PANI@GCE sensor in the embodiments of the present invention, where AD represents the carboxylated activated carbon (AC-COOH), the AC-COOH-PANI composite material, the MIP-AC-COOH-PANI modified on the glassy carbon electrode (GCE) before removal, and the MIP-AC-COOH-PANI modified on the glassy carbon electrode (GCE) after removal. Scanning electron microscope (SEM) images of: EF are Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) patterns of AC-COOH and AC-COOH-PANI, respectively; G is the cyclic voltammetry (CV) spectra of (a) bare glassy carbon electrode (GCE), (b) glassy carbon electrode modified with AC-COOH (AC-COOH@GCE), and (c) glassy carbon electrode modified with AC-COOH-PANI composite material (AC-COOH-PANI@GCE); H is the cyclic voltammetry (CV) spectra of (a) bare glassy carbon electrode (GCE), (b) Nyquist plots of the glassy carbon electrode modified with AC-COOH (AC-COOH@GCE) and (c) the glassy carbon electrode modified with AC-COOH-PANI composite material (AC-COOH-PANI@GCE); I represents the state of (a) the glassy carbon electrode modified with MIP-AC-COOH-PANI before template removal, (b) the glassy carbon electrode modified with MIP-AC-COOH-PANI after template removal, and (c) the glassy carbon electrode modified with MIP-AC-COOH-PANI after the template is re-bound. J is (a) the state of the glassy carbon electrode modified with MIP-AC-COOH-PANI before the template is removed, (b) the state of the glassy carbon electrode modified with MIP-AC-COOH-PANI after the template is removed, (c) the state of the glassy carbon electrode modified with MIP-AC-COOH-PANI after rebinding with the template molecules, and (d) the Nyquist spectrum of the glassy carbon electrode modified with NIP-AC-COOH-PANI.

[0012] Figure 3These are the test results of the single-factor experiment and response surface experiment of AC-COOH-PANI@GCE in the embodiment of the present invention, wherein A is the single-factor test result of AC-COOH-PANI@GCE, B is the contour map of drop coating amount and chitosan concentration, C is the contour map of drop coating amount and material ratio, D is the contour map of chitosan concentration and material ratio, E is the response surface map of drop coating amount and chitosan concentration, F is the response surface map of drop coating amount and material ratio, G is the response surface map of chitosan concentration and material ratio, and HM are the single-factor test results of MAA amount, drop coating amount, self-assembly time, eluent ratio, elution time, and enrichment time of AC-COOH-PANI@GCE sensor, respectively.

[0013] Figure 4 is the electrode kinetic characteristic analysis result in the embodiment of the present invention, Figure 4 AD are the CV curves, peak current vs. scan rate, peak current vs. square root of scan rate, and peak current vs. logarithm of scan rate of AC-COOH-PANI@GCE at scan rates of 0.02 to 0.36 V / s; EI are the CV curves, peak current vs. scan rate, and peak current vs. square root of scan rate of MIP-AC-COOH-PANI@GCE at scan rates of 0.02 to 0.28 V / s; H is the relationship between peak current and logarithm of scan rate; I is the relationship between peak potential and logarithm of scan rate; J is the chrono-Coulomb curve, and K is Qt 1 / 2 curve.

[0014] Figure 5 The AC-COOH-PANI@GCE performance analysis and actual sample test results in the embodiment of the present invention are shown in Figure 1. A is 1.00×10 -2 pg / mL~1.00×10 6 Figure 3 shows the differential pulse voltammetry curve for the 100 mg / mL range; B is the linear regression equation of the peak current and the logarithm of the glucose concentration; C is the linear regression equation of the peak current and the glucose concentration in the concentration range of 200 to 1000 ng / mL; DG are the specificity, repeatability, reproducibility, and stability test results of AC-COOH-PANI@GCE, respectively; H is the linear regression equation of the phenol-sulfuric acid method; I is the differential pulse voltammetry current of the actual Polygonatum odoratum sample before and after hydrolysis. DETAILED DESCRIPTION

[0015] The following is a clear and complete description of the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0016] In the present invention, unless otherwise specified, all raw materials involved are commercially available products well known in the art.

[0017] Example like Figure 1 As shown, the preparation method of a Polygonatum sibiricum rapid detection electrochemical sensor provided in this embodiment has the following specific steps: (1) Preparation of PANI Dissolve 0.75 g of aniline monomer in 10 mL of ethylene glycol, add 1 mL of hydrochloric acid, and stir at room temperature for 2 h until the solution becomes clear. Then add 0.91 g of hydrogen peroxide solution and continue stirring at room temperature overnight. The product is naturally dried to obtain; (2) Preparation of AC-COOH-PANI composite materials Carboxylated activated carbon (AC-COOH) and spherical polyaniline (PANI) were mixed in a mass ratio of 3:8, and then dispersed in an appropriate amount of 0.05wt% chitosan (CS) solution. The mixture was ultrasonically treated for 30 minutes, dried at 40°C for 12 hours, and ground in an agate mortar to obtain a powder with uniform particle size, which is the polyaniline-doped carboxylated activated carbon (AC-COOH-PANI) composite material. (3) Preparation of AC-COOH-PANI@GCE modified electrode The glassy carbon electrode (GCE) was mechanically polished with 800-grit metallographic sandpaper to remove the surface oxide layer. The suede surface was then mirror-polished using 0.3 μm and 0.05 μm alumina polishing slurries, respectively. The GCE was ultrasonically cleaned with methanol and ultrapure water for 5 min each and then air-dried at room temperature to obtain the pretreated GCE. A suspension of 1 mg of AC-COOH-PANI composite material was dispersed in 1 mL of 0.05 wt% CS solution to form a suspension. 6.00 μL of the suspension was evenly drop-coated on the pretreated GCE surface and cured by vacuum drying at 40°C for 2 h to obtain the AC-COOH-PANI@GCE modified electrode. (4) Preparation of MIP-AC-COOH-PANI@GCE 5 mg of glucose (Glu) was dissolved in a mixed solution containing 110 μL of methacrylic acid (MAA) and 0.5 mL of dimethyl sulfoxide (DMSO), and ultrasonicated at room temperature for 10 min to form a pre-assembled system. 1.2 mL of ethylene glycol dimethacrylate (EGDMA) and 0.34 mg of azobisisobutyronitrile (AIBN) were added and ultrasonicated for another 10 min to prepare a MIP prepolymerization solution. 2 mL of the MIP prepolymerization solution was evenly coated on the surface of the AC-COOH-PANI@GCE modified electrode and thermally polymerized at 40°C for 2 h to form a polymer film. The template molecules were eluted by soaking in a methanol / acetic acid mixture with a volume ratio of 1:4 for 15 min. The MIP-AC-COOH-PANI@GCE was obtained after washing with ultrapure water and drying.

[0018] Without adding the template molecule Glu, the non-imprinted composite electrode NIP-AC-COOH-PANI@GCE was prepared according to the above steps in the example.

[0019] After constructing the AC-COOH-PANI@GCE modified electrode, it was characterized by infrared spectroscopy, X-ray diffraction spectroscopy, scanning electron microscopy and electrochemical characterization. The test results are as follows Figure 2 Electrochemical characterization aims to characterize the preparation and performance of electrodes through electrochemical testing methods.

[0020] Electrochemical characterization of the basic electrode: In the presence of 5.00 mmol [Fe(CN)6] 3- / 4- The modified electrodes were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in 0.10 mol KCl and 0.2 mol KCl solutions. The CV measurement conditions were: potential range -0.2 V to 0.8 V, scan rate 100 mV / s. The EIS measurement conditions were: amplitude 0.05×10 -1 V, voltage is 0.2V, frequency range is 0.1~1.05×10 2 Hz.

[0021] Then, in the electrolytic cell, the concentration of 4.24×10 -1 mg / mL [Fe(CN)6] 4- The electrolyte system consisted of 7.46 mg / mL KCl. Cyclic voltammetry was performed using MIP-AC-COOH-PANI@GCE as the working electrode, a platinum wire electrode as the auxiliary electrode, and a saturated calomel electrode as the reference electrode. The potential range was -0.2 to 0.8 V at a scan rate of 100 mV / s until the curve stabilized. Glu standard solutions of varying concentrations were then added to the system, maintaining a uniform state. Cyclic voltammograms were recorded after accumulation at open circuit potential for 300 s. The potential range for differential pulse voltammetry was 0.1 to 0.7 V.

[0022] Before the electrochemical experiment, the solution was purged with N2 for 10 minutes. Electrochemical experiments were performed in an N2 atmosphere at room temperature (~20°C). To maintain reproducibility and stability of the modified electrode, the electrode was re-modified after each scan. Standard solutions containing different Glu concentrations were analyzed, and their cyclic voltammograms and Nyquist plots were recorded.

[0023] In the electrochemical experiment, the preparation method of the crude polysaccharide extract of polygonatum sibiricum was as follows: 6.00 g of the sample powder of polygonatum sibiricum (Hunan Boshikang Chinese Medicine Co., Ltd., wine-distilled) dried to constant weight at 60°C was accurately weighed and placed in a round-bottom flask; 150 mL of 80% ethanol was added, and the mixture was refluxed in a 90°C water bath for 1 h. After filtering while hot, the residue was washed with 80% hot ethanol (3×10 mL); the residue was transferred to a flask, 150 mL of ultrapure water was added, and the mixture was refluxed in a boiling water bath for a second time for 1 h; after filtering while hot, the flask and the residue were washed with hot water (4×10 mL), and the filtrate and washing liquid were combined; after cooling to room temperature, the volume was adjusted to a 250 mL volumetric flask and mixed to obtain the product.

[0024] Figure 2 The test results show that AC-COOH, AC-COOH-PANI, AC-COOH-PANI@GCE and MIP-AC-COOH-PANI@GCE were all successfully prepared.

[0025] The construction process of the MIP-AC-COOH-PANI@GCE sensor was optimized by combining single factor experiments with response surface experiments. The experimental results are shown in Figure 2. Figure 3 As shown in Figure 3, the optimal conditions for the preparation of the MIP-AC-COOH-PANI@GCE sensor were obtained through single factor and response surface analysis. Under the optimal conditions, the peak current of the MIP-AC-COOH-PANI@GCE sensor was 245 μA.

[0026] The electrode kinetic characteristics were analyzed by chronocoulometry. The analysis results are as follows: Figure 4 AK. The effective specific surface area of ​​the electrodes was quantitatively evaluated in a 1 mmol / L K3[Fe(CN)6] (containing 1.0 mol / L KCl) system. Experimental parameters included an initial potential of 0.5 V, a final potential of 0.25 V, a pulse width of 0.25 s, and a sampling interval of 0.1 s. The effective specific surface areas of GCE, AC-COOH@GCE, and AC-COOH-PANI@GCE were 1.06×10 -1 , 1.59×10 -1 and 2.58×10 -1 cm 2 The effective specific surface areas of the MIP-AC-COOH-PANI@GCE electrodes before and after elution were 0.19×10 -1 cm 2 and 1.14×10 -1 cm 2 The scanning rate analysis also verified that the construction process of the MIP-AC-COOH-PANI@GCE electrode surface is controlled by diffusion-adsorption mixing, which is an irreversible process. 3- / 4-The single electron transfer mechanism of the probe system is consistent, and the electron transfer rate is significantly accelerated.

[0027] like Figure 5 As shown in AC, the gradient concentration samples were tested under the optimized conditions. It can be seen that the concentration of Glu was 1.00×10 -2 ~1.00×10 6 ng / mL, the oxidation peak current showed a good linear relationship with the concentration, and the linear equation was expressed as Ip=-0.89×10 -2 C+5.69×10 1 , correlation coefficient R 2 =9.95×10 -1 The detection limit was 4.75×10 -4 ng / mL, signal-to-noise ratio S / N=3, Ip is the oxidation peak current, unit is μA, C is the concentration, unit is ng / mL.

[0028] In order to verify the practicality of the MIP-AC-COOH-PANI@GCE sensor of the embodiment, the repeatability, reproducibility, selectivity and stability of the MIP-AC-COOH-PANI@GCE sensor were tested. The test results are as follows: Figure 5 DG. Repeatability test was performed using a single electrode for 5 cycles to detect 0.3 mg / mL Glu (V 甲醇 / V 乙酸 =1:4, elution 10 min, enrichment 12 min), current response RSD% = 1.48%. Reproducibility was demonstrated using five independently prepared electrodes to detect the same concentration of Glu, with a response RSD% = 4.64%. This variation was attributed to batch-to-batch fluctuations in the micromorphology of the glassy carbon electrode surface. Selectivity was demonstrated by sequentially adding 10-fold (0.30 mg / mL) concentrations of structural analogs (Rha, Man, Gal, and Ara) to PBS buffer (pH 4.00) containing 0.03 mg / mL Glu. The RSD% of the Glu oxidation peak current in the presence of interfering agents was less than 5.00%, attributed to the size screening effect of the imprinted cavity and specific hydrogen bond recognition. After 20 days of storage at 25.00°C in the dark, the sensor retained 89.10% of its response to 0.30 mg / mL Glu. This stability advantage is attributed to the mechanical strength of the AC-COOH-PANI composite and the structural durability of the imprinted cavity, making it suitable for continuous monitoring scenarios.

[0029] like Figure 5 As shown in H, the absorbance of the crude polysaccharide extract of Polygonatum sibiricum was measured by the phenol-sulfuric acid method to be 8.88×10 -1 , based on the standard curve (A = 41.96 × 10 -1 C+1.38×10 -1 , R 2 =9.98×10-1 ) Calculated apparent polysaccharide content 1.79×10 -1 mg / mL, the actual content after calibration is 1.61×10 -1 mg / mL. At the same time, the glucose content in the crude polysaccharide solution was measured by the sensor and was 6.29×10 -3 mg / mL, and the total glucose content of the hydrolyzate obtained by acid hydrolysis was 1.47×10 -1 mg / mL, the glucose content of polysaccharide cleavage calculated by difference was 1.41×10 -1 mg / mL, proving that the sensor of the present invention can analyze the polysaccharide content. Figure 5 The test results of I also verified this.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the technical solution and conceptual invention of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a rapid detection electrochemical sensor for polygonatum polysaccharide, characterized in that: The following steps are involved: (1) Preparation of AC-COOH-PANI composite materials AC-COOH and PANI were mixed in a mass ratio of 3:8, and then dispersed in a 0.05 wt% CS solution. The mixture was ultrasonically treated for 30 min, dried at 40°C for 12 h, and ground in an agate mortar to obtain a powder with uniform particle size, which was the AC-COOH-PANI composite material. (2) Preparation of AC-COOH-PANI@GCE modified electrode The GCE was mechanically polished with 800-grit metallographic sandpaper to remove the surface oxide layer. The suede surface was then mirror-polished using 0.3 μm and 0.05 μm alumina polishing slurries, respectively. The surface was ultrasonically cleaned with methanol and ultrapure water for 5 min each and then air-dried at room temperature to obtain a pretreated GCE for later use. A suspension of 1 mg of AC-COOH-PANI composite material was dispersed in 1 mL of 0.05 wt% CS solution to form a suspension. 6.00 μL of the suspension was evenly drop-coated on the pretreated GCE surface and cured by vacuum drying at 40°C for 2 h to obtain an AC-COOH-PANI@GCE modified electrode. (3) Preparation of MIP-AC-COOH-PANI@GCE 5 mg of Glu was dissolved in a mixed solution containing 110 μL of MAA and 0.5 mL of DMSO, and the solution was sonicated at room temperature for 10 min to form a pre-assembled system. After adding 1.2 mL of EGDMA and 0.34 mg of AIBN, the solution was sonicated for another 10 min to prepare a MIP prepolymer solution. 2 mL of the MIP prepolymer solution was evenly coated on the surface of the AC-COOH-PANI@GCE modified electrode and thermally polymerized at 40 °C for 2 h to form a polymer film. The template molecules were eluted by soaking in a methanol / acetic acid mixture with a volume ratio of 1:4 for 15 min. The MIP-AC-COOH-PANI@GCE was obtained after washing with ultrapure water and drying.

2. The method for preparing a rapid detection electrochemical sensor for polygonatum polysaccharide according to claim 1, characterized in that: In step (1), the preparation method of PANI is as follows: 0.75 g of aniline monomer is dissolved in 10 mL of ethylene glycol, 1 mL of hydrochloric acid is added, and the mixture is stirred at room temperature for 2 h until the solution becomes clear, followed by adding 0.91 g of hydrogen peroxide solution, and the mixture is stirred at room temperature overnight. The product is then naturally dried to obtain the product.

3. A rapid detection electrochemical sensor for polygonatum polysaccharide, characterized in that: Prepared by the preparation method according to any one of claims 1 to 2.

4. An application of the polygonatum sibiricum polysaccharide rapid detection electrochemical sensor according to claim 3 in detecting the polygonatum sibiricum polysaccharide content in processed polygonatum sibiricum, the specific method comprising: MIP-AC-COOH-PANI@GCE was used as the working electrode, platinum wire electrode as the auxiliary electrode, and saturated calomel electrode as the reference electrode. -1 The content of polysaccharide in the extract of polygonatum was determined by differential pulse voltammetry in an electrolyte system consisting of ferrocyanide ions with a concentration of 100 mg / mL and potassium chloride with a concentration of 7.46 mg / mL. The potential range of differential pulse voltammetry was 0.1-0.7 V, and the concentration of polysaccharide in the range of 1×10 -2 ~1×10 6 ng / mL, the oxidation peak current showed a good linear relationship with the concentration, and the linear equation was expressed as Ip=-0.89×10 -2 C+5.69×10 1 , correlation coefficient R 2 =9.95×10 -1 The detection limit was 4.75×10 -4 ng / mL, signal-to-noise ratio S / N=3, Ip is the oxidation peak current, unit is μA, C is the concentration, unit is ng / mL.

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