Rapid detection method for early warning marker DON of lily bulb rot

Abstract

The invention discloses a rapid detection method for a lily bulb rot early warning marker DON, and relates to the field of electrochemical sensors. The method comprises the following steps: preparing a lily bulb test solution; detecting and analyzing the lily bulb test solution by adopting a BSA / Ab-DON / AuNPs / MXene coated GO / GCE electrochemical immunosensor, and determining the concentration of DON; the preparation method of the BSA / Ab-DON / AuNPs / MXene coated GO / GCE electrochemical immunosensor comprises the following steps: preparing an MXene coated GO composite material, preparing an AuNPs / MXene coated GO / GCE modified electrode, and preparing the BSA / Ab-DON / AuNPs / MXene coated GO / GCE electrochemical immunosensor. The BSA / Ab-DON / AuNPs / MXene coated GO / GCE electrochemical immunosensor constructed by the invention is an immunosensor based on antigen-antibody recognition, realizes high-sensitivity rapid detection of a lily bulb rot early-warning marker deoxynivalenol (DON), does not need to additionally add a substrate or coenzyme, has higher specificity and sensitivity, wider detection range and stronger stability, and can be applied to the detection of lily bulb rot. The detection process is simplified, and the interference of substrate consumption, side reaction or impurities on the result is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochemical sensors, and particularly relates to a rapid detection method for DON, a warning marker for lily bulb rot disease. Background Art

[0002] Lanzhou Lily (Lily) is a perennial herb belonging to the genus Lilium of the family Liliaceae. Because of its extremely sweet taste, few fibers, no bitterness at all, and the content of lily polysaccharide being as high as more than 20%, it has various biological activities of plant polysaccharides, especially outstanding in immunomodulation, anti-aging, and anti-radiation, making it very popular. However, with the expansion of the cultivation area and the increase of continuous cropping years, the occurrence of lily diseases has been increasing year by year, especially diseases such as bulb rot, anthracnose, and phytophthora blight in the bulb part, resulting in a reduction in lily yield and quality, and even a complete crop failure in severe cases. Among them, the incidence of lily bulb rot disease is as high as 30% - 50%, which is one of the most serious diseases in lily planting production, seriously affecting the yield and quality of lilies, and has become one of the important factors restricting the high-quality development of the lily industry. Researchers found that lily bulb rot disease often occurs during lily planting, bulb storage, and transportation, mainly caused by the infection of lilies by fungi of the genus Fusarium. And deoxynivalenol (DON), as one of the most representative secondary metabolites produced by Fusarium graminearum, is also a highly sensitive biomarker for the early expression of induced bulb rot. It can inhibit the initiation or elongation of polypeptide chains by binding to the 60S ribosome, thereby preventing protein synthesis, inhibiting cell growth, accelerating cell apoptosis, and ultimately causing lily wilting and decay. Some studies have shown that the obvious apoptosis-promoting effect of DON is related to the DON dosage, action frequency, and action time. Taking the early trace expression of DON in Lanzhou lily plants as a warning "signal" for lily bulb rot disease and realizing its trace detection is of extremely important significance for the early warning of rot diseases in lilies and other plants and the precise implementation of prevention and control strategies.

[0003] Currently, methods for detecting biomolecules such as DON, such as high-performance liquid chromatography (HPLC), gas chromatography (GC), enzyme-linked immunosorbent assay, and their combined detection methods, although these methods have advantages such as high sensitivity and high accuracy, due to the complex sample pretreatment and time-consuming detection, it is difficult to achieve timely warning and rapid evaluation of diseases in various links such as lily and other crop planting, harvesting, processing, and transportation, which is not conducive to the early discovery of the warning "signal" DON of lily bulb rot disease, and is even less conducive to the field warning and prevention and control of high-quality lily production. Therefore, there is an urgent need for a warning technology that is simple, easy to implement, low-cost, and can achieve on-site instant detection and evaluation.

[0004] Due to its characteristics such as simple operation, rapid detection, low cost, and high sensitivity, electrochemical sensing technology has developed vigorously in the field of life analysis in recent years, especially in the research and application of trace detection of microbial molecules, environmental food safety, disease early warning diagnosis and other fields. Summary of the Invention

[0005] The purpose of the present invention is to provide a rapid detection method for DON, a warning marker for lily bulb rot disease. The present invention not only provides an accurate and effective means for the early objective warning of lily bulb rot disease, but also provides an instant and sensitive detection method for the detection of DON in food, and will effectively solve the problems of insufficient early accurate warning technology for rot diseases of crops such as Lanzhou lily and high-sensitivity rapid detection technology for harmful substance DON in food.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions: A rapid detection method for DON, a warning marker for lily bulb rot disease, proposed by the present invention includes the following steps: S1: Prepare a test solution of lily bulbs; S2: Use a BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor to detect and analyze the test solution of lily bulbs to determine the concentration of DON.

[0007] As a preferred implementation method of the present invention, in step S1, the preparation method of the test solution of lily bulbs is as follows: Take 50 g of lily samples, crush, juice, and filter them with a blender. Take 10 mL of the filtrate and dilute it to 10 times the original volume with deionized water. Divide the diluted sample into 10 equal parts, and use the standard addition method to add DON-Ag solutions with standard concentrations of 31.25 pg·mL -1 、62.50 pg·mL -1 、125.00 pg·mL -1 、250.00 pg·mL -1 、500.00 pg·mL -1 、1000.00 pg·mL -1 、2000.00 pg·mL -1 、4000.00 pg·mL -1 、8000.00 pg·mL -1 、16000.00 pg·mL -1 solution to obtain an actual sample test solution.

[0008] As a preferred implementation method of the present invention, in step S2, the preparation steps of the BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor are as follows: (1) Preparation of MXene@GO composite material Mix 2 mg·mL -1 of MXene dispersion with 2 mg·mL -1 of graphene oxide dispersion at 25 °C, and ultrasonically self-assemble for 1 h to obtain MXene@GO suspension; (2) Preparation of AuNPs / MXene@GO / GCE modified electrode Polish the bare glassy carbon electrode (GCE) with 0.3 μm and 0.05 μm Al2O3 powder on suede until smooth, then ultrasonically clean it in methanol and distilled water for 10 minutes each. Rinse the surface of the GCE electrode with distilled water, dry it with filter paper. Take 10 μL of the prepared MXene@GO suspension and drop-coat it on the surface of the treated GCE, and dry it under an infrared lamp at 30 °C to form a thin film on the surface, obtaining the MXene@GO / GCE modified electrode. Place the MXene@GO / GCE modified electrode in 10 mL of 0.1 mol / L H2SO4 solution containing 1 mM HAuCl4, and scan it 30 cycles at a rate of 100 mv·s -1 in the potential range of -0.8~0.4 V to deposit AuNPs, namely obtaining the AuNPs / MXene@GO / GCE modified electrode; (3) Preparation of BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor Incubate the AuNPs / MXene@GO / GCE modified electrode with 50 μL of 2 μg·mL -1 of deoxynivalenol antibody solution (Ab-DON) at 4 °C for 5 h. Then, wash away the physically adsorbed DON antibody on the electrode surface with the pre-prepared 0.1 mmol / L PBST solution. Then, place it in the blocking solution at room temperature for 50 min to block the active sites. After blocking, wash it again with the PBST solution and dry it naturally to obtain the BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor, which is stored in a 4 °C refrigerator for later use.

[0009] Furthermore, in step (1), the preparation method of the MXene powder is: Mix 8 mL of 6 mol·L -1The hydrogen chloride solution was added to a polytetrafluoroethylene beaker and stirred magnetically. Then, 200 mg of lithium fluoride powder was added. After the powder was completely dissolved, 200 mg of Ti3AlC2 powder was slowly added. The mixture was stirred at 40 °C for 48 h, and then repeatedly rinsed with distilled water and centrifuged. The centrifugation process was repeated several times until the pH value of the supernatant after centrifugation was 7. The obtained solid was washed with ethanol and freeze-dried to form MXene powder, which was stored in a refrigerator at 4 °C. Using 0.2% chitosan as a solvent, 4 mg of MXene powder was weighed and added to 2 mL of 0.2% chitosan solution, and ultrasonic dispersion was carried out for 30 min to obtain an MXene dispersion.

[0010] Further, in step (1), the preparation method of the graphene oxide dispersion is as follows: Using DMF as a solvent, 4 mg of GO was weighed and added to 2 mL of DMF solution, and ultrasonic dispersion was carried out for 30 min.

[0011] Further, in step (1), the MXene dispersion and the graphene oxide dispersion were mixed in a volume ratio of 1:2 to a total of 10 mL.

[0012] Further, in step (3), the blocking solution is a phosphate buffer solution of 0.05 wt% Tween and 2 wt% BSA with pH = 7.0.

[0013] As a preferred embodiment of the present invention, in step S2, the detection and analysis are carried out by ELISA method. The OD values corresponding to DON in the concentration range of 500~16000 pg·mL -1 were detected, and the fitted linear regression equation is: OD = 8.4275×10 -5 C DON + 0.1272, R 2 =0.9968, and the detection limit is 35.48 ng·mL -1 .

[0014] As another preferred embodiment of the present invention, in step S2, the detection and analysis are carried out by DPV method. The current response values corresponding to the logarithm of DON concentration were detected by DPV method, and the fitted linear regression equation is: I p =154.85-29.52Lg[C DON , R 2 = 0.99166; the detection limit is 1.92×10 -2 pg·mL -1 , S / N=3.

[0015] Compared with the prior art, the beneficial technical effects of the present invention: 1. The rapid detection method of DON, a warning marker for lily bulb rot disease provided by the present invention, is an electrochemical sensing technology for highly sensitive and rapid detection of DON, a warning marker for lily bulb rot disease, and has the advantages of simple operation, short detection time, good stability, and can be applied to on-site rapid detection.

[0016] 2. The BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor constructed by the present invention realizes the highly sensitive and rapid detection of deoxynivalenol (DON), a warning marker for lily bulb rot disease. By using MXene@GO as the electrode modification material, the performance of the electrochemical sensor can be significantly improved. In order to further improve the conductivity of the electrochemical sensor, gold nanoparticles (AuNPs) with good biocompatibility and high conductivity are modified on the MXene@GO electrode by electrodeposition method; at the same time, immunosensors based on antigen-antibody recognition have higher specificity, sensitivity, wider detection range and stronger stability, because immunosensors directly trigger signals through antigen-antibody binding, without the need to add additional substrates or coenzymes, which simplifies the detection process, avoids the interference of substrate consumption, side reactions or impurities on the results, and usually can give detection results in a shorter time, which is crucial for application scenarios that require rapid response; finally, the design of the immunosensor is based on the strong specific recognition of antigen-antibody, which enables the sensor to distinguish the target substance from other interfering substances, and this selectivity ensures the accuracy of the detection results and reduces errors. Brief Description of the Drawings

[0017] Figure 1 It is the material physical and chemical structure characterization diagram in the embodiment of the present invention. Among them, A is the SEM diagram of GO, B is the SEM diagram of MXene, C is the SEM diagram of MXene@GO, D is the SEM diagram of the AuNPs / MXene@GO composite material, E is the Fourier transform infrared spectrum diagram of GO, MXene, and the MXene@GO composite material, and F is the Raman spectrum diagram of GO, MXene, and the MXene@GO composite material.

[0018] Figure 2It is the electrochemical characterization diagram of each basic electrode in the embodiments of the present invention. Among them, A is the CV curves of (a) GCE, (b) GO / GCE, (c) MXene / GCE, (d) MXene@GO / GCE, (e) AuNPs / MXene@GO / GCE; B is the EIS curves of (a) GCE, (b) GO / GCE, (c) MXene / GCE, (d) MXene@GO / GCE, (e) AuNPs / MXene@GO / GCE; C is the chronocoulometric curves of (a) GCE, (b) GO / GCE, (c) MXene / GCE, (d) MXene@GO / GCE, (e) AuNPs / MXene@GO / GCE; D is the Q-t1 / 2 curves of GCE, (b) GO / GCE, (c) MXene / GCE, (d) MXene@GO / GCE, (e) AuNPs / MXene@GO / GCE.

[0019] Figure 3 It is the electrochemical characterization diagram of the AuNPs / MXene@GO / GCE modified electrode in the embodiments of the present invention. Among them, A is the CV curves detected by AuNPs / Mxene@GO / GCE at different scan rates; B is the relationship between the peak current of the AuNPs / MXene@GO / GCE modified electrode and the square root of the scan rate.

[0020] Figure 4 It is the practicality test results of the BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor in the embodiments of the present invention. Among them, A is the specific test results of the BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor for fumonisin, zearalenone, aflatoxin, and fusaric acid; B is the reproducibility determination results of the BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor; C is the stability determination results of the BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor.

[0021] Figure 5This is the test result of using the BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor for rapid detection of DON in the embodiments of the present invention. Among them, A is the absorbance value corresponding to different concentrations of DON analyzed by the ELISA method, B is the DPV response signal value of the BSA / DON-Ab / AuNPs / MXene@GO / GCE electrochemical immunosensor for detecting different concentrations of DON, C is the curve relationship between the BSA / DON-Ab / AuNPs / MXene@GO / GCE electrochemical immunosensor for detecting different concentrations of DON and the current response value, and D is the linear relationship between the DPV response value of the BSA / DON-Ab / AuNPs / MXene@GO / GCE electrochemical immunosensor and the logarithm of the DON concentration. Detailed implementation mode

[0022] The technical solutions in the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0023] In the present invention, unless otherwise specified, the raw materials involved are well-known commercially available products in the art.

[0024] Embodiment Preparation of MXene dispersion: Add 8 mL of 6 mol·L -1 hydrochloric acid solution to a polytetrafluoroethylene beaker and stir magnetically. Then add 200 mg of lithium fluoride powder. After the powder is completely dissolved, slowly add 200 mg of Ti3AlC2 powder and stir at 40 °C for 48 h. Then rinse repeatedly with distilled water and centrifuge. The centrifugation process is repeated multiple times until the pH value of the supernatant after centrifugation is 7. Wash the obtained solid with ethanol and freeze-dry to form MXene powder, and store it in a refrigerator at 4 °C; Weigh 4 mg of MXene powder and add it to 2 mL of 0.2% chitosan solution, and ultrasonically disperse for 30 min to obtain MXene dispersion.

[0025] Preparation of graphene oxide dispersion: Using DMF as a solvent, weigh 4 mg of GO and add it to 2 mL of DMF solution, and ultrasonically disperse for 30 min.

[0026] Preparation of MXene@GO composite: The 2 mg·mL -1 MXene dispersion and 2 mg·mL -1Take a total of 10 mL of the graphene oxide dispersion at 25 °C in a volume ratio of 1:2, and ultrasonically self-assemble for 1 h to obtain an MXene@GO suspension.

[0027] Preparation of the AuNPs / MXene@GO / GCE modified electrode: Polish the bare glassy carbon electrode (GCE) with 0.3 μm and 0.05 μm Al2O3 powder on suede until smooth, then ultrasonically treat it in methanol and distilled water for 10 minutes respectively. Rinse the surface of the GCE electrode with distilled water, wipe it dry with filter paper, take 10 μL of the prepared MXene@GO suspension and drop-coat it on the treated GCE surface, and dry it under an infrared lamp at 30 °C to form a thin film on the surface, obtaining the MXene@GO / GCE modified electrode. Place the MXene@GO / GCE modified electrode in 10 mL of 0.1 mol / L H2SO4 solution containing 1 mM HAuCl4, and use cyclic voltammetry to scan at a rate of 100 mv·s -1 in the potential range of -0.8 to 0.4 V for 30 cycles to deposit AuNPs, that is, the AuNPs / MXene@GO / GCE modified electrode is obtained.

[0028] Preparation of the BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor: Incubate the AuNPs / MXene@GO / GCE modified electrode with 50 μL of 2 μg·mL -1 of the deoxynivalenol antibody solution (Ab-DON) at 4 °C for 5 h. Then, wash away the physically adsorbed DON antibody on the electrode surface with the pre-prepared 0.1 mmol / L PBST solution, and then place it in the blocking solution at room temperature for 50 min. The blocking solution is a phosphate buffer solution of 0.05 wt% Tween and 2 wt% BSA with pH = 7.0 to block the active sites. After blocking, wash it again with the PBST solution and dry it naturally to obtain the BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor, which is stored in a 4 °C refrigerator for later use.

[0029] In this example, after constructing the AuNPs / MXene@GO / GCE modified electrode, infrared spectroscopy, Raman spectroscopy, and SEM characterization were performed on it, and the characterization results are as Figure 1 shown.

[0030] Figure 1 The test results show that the AuNPs / MXene@GO composite material has been successfully prepared and modified on the GCE electrode.

[0031] Subsequent electrochemical characterization was carried out to characterize the preparation and performance of the electrodes through electrochemical testing methods.

[0032] In this example, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronocoulometry (CC) were used to characterize the electrochemical behaviors of GCE, GO / GCE, MXene / GCE, MXene@GO / GCE, and AuNPs / MXene@GO / GCE. A 4.0 mM K3[Fe(CN)6] / K4[Fe(CN)6] solution containing 0.01 M KCl was used as the electrolyte. The characterization measurement conditions for the basic electrode by the CV method were: voltage range -0.4 V to 0.8 V, scan rate 100 mV s -1 , and the testing conditions for the EIS method were: frequency range 1 Hz to 106 Hz, sine wave signal amplitude 5 mV, voltage 0.22 V. The characterization results are as Figure 2 shown.

[0033] In this example, the CV characterization of the AuNPs / MXene@GO / GCE modified electrode was carried out by the CV method. Specifically, in the voltage range of -0.4 V to 0.8 V, in a 4.0 mM K3[Fe(CN)6] / K4[Fe(CN)6] solution containing 0.01 M KCl, cyclic voltammetry scans were performed in the range of 30 to 160 mV·s -1 range, and the characterization results are as Figure 3 shown.

[0034] Figure 2 and 3 The test results show that the AuNPs / MXene@GO composite material and the AuNPs / MXene@GO / GCE modified electrode were successfully prepared, and the effective surface area values of the GCE, GO / GCE, MXene / GCE, MXene@GO / GCE, and AuNPs / MXene@GO / GCE electrodes were 0.0749 cm 2 , 0.7761 cm 2 , 0.8957 cm 2 , 1.2161 cm 2 , 1.6785 cm 2 .

[0035] In this embodiment, to verify the practicability of the BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor, the constructed BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor was tested for specificity, repeatability, and stability. Among them, the interferents used in the specificity detection were fumonisin (FUM), zearalenone (ZEN), aflatoxin (AFT), and fusaric acid (FA), the DON concentration was 125 pg·mL -1 , and the interferent concentration was 1.0 mg·m L -1 . The test results are as Figure 4 shown.

[0036] Figure 4 The test results in

[0037] show that the BSA / DON-Ab / AuNPs / Mxene@GO / GCE electrochemical immunosensor has excellent specificity, repeatability, and stability. Figure 5 As shown in A, in this embodiment, when the enzyme-linked immunosorbent assay (ELISA) method was used to detect different concentrations of DON, the absorbance (OD) values corresponding to DON in the concentration range of 500 - 16000 pg·mL -1 were detected by the ELISA method. The OD values of the ELISA detection method showed a good linear relationship with the DON concentration, and the linear regression equation was OD = 8.4275×10 -5 C DON +0.1272 (R 2 = 0.9968), and the detection limit was 35.48 ng·m L -1 .

[0038] The BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor was incubated in DON solutions with concentrations of 16000, 8000, 4000, 2000, 1000, 500, 250, 125, 62.5, and 31.25 pg·mL -1 for 120 minutes, and the effective recognition reaction of the modified electrode in antigen solutions with different concentrations was detected. The results are as Figure 5 shown in B.

[0039] As shown in C, in this embodiment, when the differential pulse voltammetry (DPV) method was used to detect different concentrations of DON, the DPV response value decreased with the increase in the DON antibody concentration; as Figure 5 shown in D, the DPV current response showed a good linear relationship with the logarithm of the DON antibody concentration, and the linear regression equation was I Figure 5 =154.85 - 29.52Lg[C p =154.85-29.52Lg[CDON (R 2 = 0.99166), and the detection limit was 1.92 × 10 -2 pg·mL -1 −1 (S / N = 3). It can be seen that the constructed method shows good analytical performance for the detection of DON and can be used as a platform for detecting DON in actual samples.

[0040] Finally, to verify the detection feasibility of the method of the present invention in actual samples, lily actual samples were analyzed and compared with the results of other detection methods. As shown in Table 1, the results indicate that the sensor has a wider detection range and a lower detection limit.

[0041] Table 1 Comparison of different analytical methods for the detection of DON

[0042] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the technical solutions and concepts of the present invention shall be included within the protection scope of the present invention.

Claims

1. A rapid detection method for the warning marker DON of lily bulb rot disease, characterized in that, It includes the following steps: S1: Prepare the lily bulb test solution; S2: Use the BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor to detect and analyze the lily bulb test solution to determine the concentration of DON.

2. The rapid detection method of DON, a warning marker for lily bulb rot disease according to claim 1, is characterized in that: In step S1, the preparation method of the lily bulb test solution is as follows: Take 50 g of lily samples, crush, juice, and filter them with a blender. Take 10 mL of the filtrate and dilute it to 10 times the original volume with deionized water. Divide the diluted sample into 10 equal parts. Using the standard addition method, add solutions of DON-Ag with standard concentrations of 31.25 pg·mL -1 , 62.50 pg·mL -1 , 125.00 pg·mL -1 , 250.00 pg·mL -1 , 500.00 pg·mL -1 , 1000.00 pg·mL -1 , 2000.00 pg·mL -1 , 4000.00 pg·mL -1 , 8000.00 pg·mL -1 , 16000.00 pg·mL -1 to obtain the actual sample test solution.

3. The rapid detection method of DON, a warning marker for lily bulb rot disease according to claim 1, is characterized in that: In step S2, the preparation steps of the BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor are as follows: (1) Preparation of the MXene@GO composite material Disperse 2 mg·mL -1 of MXene in 2 mg·m L -1 of graphene oxide dispersion, mix them at 25 °C, and perform ultrasonic self-assembly for 1 h to obtain an MXene@GO suspension; (2) Preparation of the AuNPs / MXene@GO / GCE modified electrode The bare glassy carbon electrode was polished to smoothness on suede with 0.3 μm and 0.05 μm Al2O3 powder respectively, and then it was sonicated in methanol and distilled water for 10 minutes respectively. The surface of the GCE electrode was rinsed with distilled water and dried with filter paper. 10 μL of the prepared MXene@GO suspension was taken and drop-coated on the surface of the treated GCE, and dried under an infrared lamp at 30 °C to form a thin film on the surface, obtaining the MXene@GO / GCE modified electrode. The MXene@GO / GCE modified electrode was placed in 10 mL of 0.1 mol / L H2SO4 solution containing 1 mM HAuCl4, and cyclic voltammetry was used to scan 30 cycles at a rate of 100 mv·s -1 in the potential range of -0.8 to 0.4 V to deposit AuNPs, and the AuNPs / MXene@GO / GCE modified electrode was obtained; (3) Preparation of the BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor Incubate the AuNPs / MXene@GO / GCE modified electrode with 50 μL of 2 μg·mL-1 deoxynivalenol antibody solution at 4 °C for 5 h, then wash away the physically adsorbed DON antibody on the electrode surface with the pre-prepared 0.1 mmol / L PBST solution, and then place it in the blocking solution at 37 °C for 50 min to block the active sites. After the blocking is completed, wash it again with the PBST solution and dry it naturally to obtain the BSA / Ab-DON / AuNPs / MXene@GO / GCE electrochemical immunosensor, which is stored in a 4 °C refrigerator for later use.

4. The rapid detection method of DON, a warning marker for lily bulb rot disease according to claim 3, is characterized in that: In step (1), the preparation method of the MXene dispersion is as follows: Add 8 mL of 6 mol·L -1 hydrochloric acid solution into a polytetrafluoroethylene beaker and stir magnetically. Then add 200 mg of lithium fluoride powder. After the powder is completely dissolved, slowly add 200 mg of Ti3AlC2 powder, stir at 40 °C for 48 h, then rinse repeatedly with distilled water and centrifuge. The centrifugation process is repeated multiple times until the pH value of the supernatant after centrifugation is 7. Wash the obtained solid with ethanol and freeze-dry it to form MXene powder, and store it in a refrigerator at 4 °C. Weigh 4 mg of MXene powder, add it to 2 mL of 0.2% chitosan solution, and ultrasonically disperse it for 30 min to obtain the MXene dispersion.

5. The rapid detection method of DON, a warning marker for lily bulb rot disease according to claim 4, is characterized in that: In step (1), the preparation method of the graphene oxide dispersion is: weigh 4 mg of GO powder, add it to 2 mL of DMF solution, and ultrasonically disperse it for 30 minutes to obtain the GO dispersion.

6. The rapid detection method of DON, a warning marker for lily bulb rot disease according to claim 4, is characterized in that: In step (1), 10 mL of the MXene dispersion and the graphene oxide dispersion are taken in a volume ratio of 1:2 and mixed.

7. A method for rapid detection of DON, a warning marker for lily bulb rot disease according to claim 4, characterized in that: In step (3), the blocking solution is a phosphate buffer solution of 0.05 wt% Tween and 2 wt% BSA with pH = 7.

0.

8. The rapid detection method of DON, a warning marker for lily bulb rot disease according to claim 1, is characterized in that: In step S2, ELISA method is used for detection and analysis. ELISA method detects the OD values corresponding to DON within the concentration range of 500 - 16,000 pg·mL -1 , and the fitted linear regression equation is: OD = 8.4275×10 -5 C DON + 0.1272, R 2 = 0.9968, the detection limit is 35.48 ng·mL -1 .

9. The rapid detection method of DON, a warning marker for lily bulb rot disease according to claim 1, is characterized in that: In step S2, the differential pulse voltammetry (DPV) method is used for detection and analysis. The DPV method detects the current response value corresponding to the logarithm of the DON concentration, and the fitted linear regression equation is: I p = 154.85 - 29.52Lg[C DON , R 2 = 0.99166; The detection limit is 1.92×10 -2 pg·mL -1 , S / N = 3.

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