A method for detecting a transgenic element and an electrochemical sensor used thereby

Abstract

A method for detecting transgenic components includes the following steps: sDNA / AuNPs@Cu-MOF@Fe3O4 is added to a centrifuge tube containing an equal volume of tDNA hybridization buffer and incubated at 35-38°C for 70-100 min. The resulting tDNA / sDNA / AuNPs@Cu-MOF@Fe3O4 is then dispersed in 1 mL of hybridization buffer to obtain a buffer system. BSA / cDNA / rGO / Au / GCE is immersed in the buffer system to hybridize using a capture probe previously immobilized on the surface of BSA / cDNA / rGO / Au / GCE. After incubation for 70-100 min, Fe3O4@Cu-MOF@AuNPs / sDNA / tDNA / BSA / cDNA / rGO / Au / GCE is washed with Tris-HCl buffer. Finally, measurements are performed using an electrochemical workstation with a three-electrode system in 0.1 M acetate buffer. The background signal of the electrochemical DNA biosensor constructed in this invention is only 49% of that of AuNPs@Cu-MOF.

Description

Technical Field

[0001] This invention relates to the field of detection technology, and in particular to a method for detecting genetically modified components and the electrochemical sensor used therein. Background Technology

[0002] Currently, the detection of genetically modified (GM) components mainly falls into two categories: detection of specific protein components and specific DNA sequences in GM crops. While protein test strips using exogenous target gene expression are low-cost and portable, they only target a single exogenous protein, requiring a cumbersome process of eliminating various exogenous proteins one by one. Furthermore, protein-based detection may lose activity during processing, affecting the results. Polymerase chain reaction (PCR), the most common nucleic acid detection method, offers good sensitivity, but its complex process requires high-precision instruments, long operating times, and advanced techniques, making it unsuitable for field applications. Additionally, false positives may occur when detecting low concentrations of gene fragments.

[0003] Biosensors, including capillary biosensors, colorimetric biosensors, fluorescence biosensors, and electrochemical biosensors, have become the newest and most attractive alternative platform for detecting genetically modified organisms (GMOs) in food. Electrochemical sensors, as a mature detection technology, directly generate electrical signals through electrochemical reactions, eliminating the need for expensive and complex signal transduction equipment. Among them, electrochemical DNA biosensors offer advantages such as ease of operation, high selectivity, portability, and efficient detection of small sample sizes of DNA sequences, providing a promising method for the detection of GMOs. Summary of the Invention

[0004] The purpose of this invention is to provide a method for detecting genetically modified components and the electrochemical sensor used therein.

[0005] To achieve the above and other related objectives, the technical solution provided by this invention is: an electrochemical sensor, the fabrication method of which includes: (1) Preparation of Cu-MOF@Fe3O4: Magnetite nanoparticles were added to an ethanol solution of mercaptoacetic acid and shaken for 20-30 h to prepare MAA-functionalized Fe3O4NPs (MAA-Fe3O4NPs). Then, the MAA-Fe3O4NPs were washed with ethanol in the presence of an external magnet and dried. The MAA-Fe3O4NPs were then dispersed in an ethanol solution of Cu(OAc)2·H2O and shaken for 10-30 min. The mixture was then shaken in an ethanol solution of H3BTC for 20-40 min, and this process was repeated 3-8 times. Finally, the material was washed with water and ethanol respectively and dried to obtain Cu-MOF@Fe3O4. (2) Preparation of AuNPs@Cu-MOF@Fe3O4 Cu-MOF@Fe3O4 was placed in a centrifuge tube, gold nanoparticle solution was added, and the mixture was shaken in the dark at 1-6℃ for 10-15 h. After the reaction was completed, it was separated by an external magnetic field and dried with ultrapure water to obtain AuNPs@Cu-MOF@Fe3O4. (3) Preparation of sDNA functionalized AuNPs@Cu-MOF@Fe3O4 signal probe AuNPs@Cu-MOF@Fe3O4 was dispersed in a previously prepared DNA fixation buffer solution, sDNA was added, and the mixture was shaken overnight at 1-6°C. After the reaction was completed, excess sDNA was removed by centrifugation, and the mixture was washed with DNA storage buffer. Finally, the mixture was dispersed in DNA storage buffer and stored at 1-6°C to obtain sDNA / AuNPs@Cu-MOF@Fe3O4.

[0006] The preferred technical solution is as follows: the ratio of Fe3O4NPs to ethanol solution of mercaptoacetic acid is 0.04-0.06 g: 10 mL, and the concentration of ethanol solution of mercaptoacetic acid is 0.29 mM; the ratio of MAA-Fe3O4NPs to ethanol solution of Cu(OAc)2·H2O is 0.04-0.06 g: 4 mL, and the concentration of ethanol solution of mercaptoacetic acid is 10 mM; the concentration of ethanol solution of H3BTC is 10 mM, and the amount is 3-6 mL.

[0007] The preferred technical solution is as follows: the ratio of Cu-MOF@Fe3O4NPs to AuNPs solution is 0.04-0.06 g: 5 mL; the preparation method of AuNPs solution includes: heating HAuCl4 solution to boiling, then adding sodium citrate, and continuing to heat to obtain a wine-red solution; after the reaction is completed, the obtained wine-red solution is placed in air to cool to room temperature, and then stored in the dark to obtain AuNPs solution.

[0008] The preferred technical solution is as follows: the ratio of AuNPs@Cu-MOF@Fe3O4 to DNA fixation buffer is 8-12 mg: 1 mL; the concentration of sDNA is 10 μM and the volume is 80-120 µL; the centrifugation speed is 8000-10000 rpm and the time is 3-8 min.

[0009] To achieve the above and other related objectives, the technical solution provided by this invention is: a method for detecting transgenic components, comprising the following steps: adding the sDNA / AuNPs@Cu-MOF@Fe3O4 to a centrifuge tube containing an equal amount of tDNA hybridization buffer, and incubating at 35-38℃ for 70-100 min; then dispersing the obtained tDNA / sDNA / AuNPs@Cu-MOF@Fe3O4 in 1 mL of hybridization buffer to obtain a buffer system; immersing BSA / cDNA / rGO / Au / GCE into the buffer system to hybridize using the capture probe previously immobilized on the surface of BSA / cDNA / rGO / Au / GCE; after incubation for 70-100 min; washing Fe3O4@Cu-MOF@AuNPs / sDNA / tDNA / BSA / cDNA / rGO / Au / GCE with Tris-HCl buffer; and finally measuring using an electrochemical workstation in a three-electrode system with 0.1 M acetate buffer.

[0010] The preferred technical solution is as follows: The preparation method of BSA / cDNA / rGO / Au / GCE includes: firstly, a well-dispersed reduced graphene oxide solution is dropped onto the surface of a glassy carbon electrode, and after drying, rGO / GCE is obtained; then, in HAuCl4 solution, at a constant potential of -0.2V, rGO / Au / GCE is electrodeposited on the rGO / GCE by amperometric method to form rGO / Au / GCE; then, cDNA is immobilized on the surface of rGO / Au / GCE, and treated in an environment of 1-6 ℃ for 8-20 h, and the unimmobilized cDNA is washed away to obtain cDNA / rGO / Au / GCE; bovine serum albumin solution is dropped onto cDNA / rGO / Au / GCE to treat non-specific sites, and after rinsing, BSA / cDNA / rGO / Au / GCE is obtained.

[0011] The preferred technical solution is as follows: the glassy carbon electrode is polished with 0.3 μm and 0.05 μm alumina powder respectively, then ultrasonicated in ultrapure water and ethanol, and finally dried with nitrogen.

[0012] The preferred technical solution is as follows: When performing electrochemical measurements, a 0.1M acetate buffer solution is used as the detection base solution; the electrochemical biosensor is used, and then differential pulse voltammetry is used as the electrochemical detection method; the measurement potential range of differential pulse voltammetry is -0.6 to 0.5V, and the scan rate is 100 mV s-1.

[0013] Due to the application of the above technical solution, the advantages of this invention compared with the prior art are: In one aspect, after synthesizing Fe3O4, comparing Cu-MOF@Fe3O4 and AuNPs@Cu-MOF@Fe3O4, AuNPs@Cu-MOF@Fe3O4 showed that AuNPs@Cu-MOF@Fe3O4 had higher conductivity and better stability. In another aspect, an electrochemical DNA biosensor was constructed, and a novel core-shell magnetic MOF material (AuNPs@Cu-MOF@Fe3O4) was prepared as a signal tag. The background signal of the constructed sensor was only 49% of that of AuNPs@Cu-MOF. Attached Figure Description

[0014] Appendix Figure 1 This is an electron microscope image of the nanomaterial.

[0015] Appendix Figure 2 Feasibility analysis for electrochemical sensors.

[0016] Appendix Figure 3 To optimize experimental conditions.

[0017] Appendix Figure 4 To assess the analytical performance of the electrochemical sensor.

[0018] Appendix Figure 5 To improve the selectivity, stability, and repeatability of electrochemical sensors.

[0019] Appendix Figure 6 For the detection of actual samples for electrochemical sensors.

[0020] Appendix Figure 7 This is a flowchart illustrating the fabrication process of the electrochemical sensor of this invention. Detailed Implementation

[0021] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0022] Please see Figure 1-7 It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding and reading. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0023] Unless otherwise specified, all reagents or materials described in the following examples are commercially available.

[0024] Reagents and materials: Copper acetate monohydrate (Cu(OAc)2·H2O), chloroauric acid (HAuCl4), sodium citrate (C6H7NaO7), sodium acetate (C2H3NaO2), magnesium chloride (MgCl2), sodium chloride (NaCl), ethylenediaminetetraacetic acid (EDTA), potassium ferrocyanide (K4[Fe[Fe(CN)6]), potassium ferricyanide (K3[Fe(CN)6]), potassium chloride (KCl), potassium nitrate (KNO3), ethanol, acetic acid, and hydrochloric acid were purchased from Sinopharm Shanghai Chemical Reagent Co., Ltd. (Shanghai, China). Iron(III) oxide (Fe3O4) was purchased from Shanghai Chaowei Nanotechnology Co., Ltd. Tris(hydroxymethyl)aminomethane (Tris) was purchased from Beijing Solarbio Technology Co., Ltd. (Beijing, China). Tris(II) phenyltricarboxylic acid (TMA), bovine serum albumin (BSA), tris(2-carboxyethyl)phosphine (TCEP), and mercaptoacetic acid were purchased from Aladdin Reagent Co., Ltd. (Shanghai, China). Graphene (GO) was purchased from Sinopharm Nanomaterials Technology Co., Ltd. (Jiangsu, China).

[0025] The DNA sequences used in the experiment were all synthesized and purified by Sangon Biotech (Shanghai) Co., Ltd., and the sequences (5'-3') are as follows: cDNA: HS-CTG AAG GCG GG.

[0026] tDNA:ATT GTC GTT TCC CGC CTT CAG.

[0027] sDNA: AAA CGA CAA T-SH.

[0028] 1MT:ATT GTC GTT TCA CGC CTT CAG.

[0029] 2MT: ATC GTC GTT TCA CGC CTT CAG.

[0030] 3MT: ATC GTC GTT TCA CGC CTT AAG.

[0031] NC: GCT TCA TCC CAA TAT ACC TGA.

[0032] Primer F: TCC CGC TCT AGC GCT TCA AT.

[0033] Primer R: TCG AGC AGG ACC TGC AGA A.

[0034] Example 1: A method for simultaneously determining the content of four B components and related substances in polymyxin B raw material and its preparations. I. The synthetic material consists of the following four parts: (1) Preparation of AuNPs 100 mL of 0.01% HAuCl4 solution was heated to a complete boil, and then 3.5 mL of sodium citrate (1%) was quickly added. The mixture was heated for 20 min to obtain a wine-red solution. After the reaction was complete, the wine-red solution was cooled to room temperature in air and stored in the dark.

[0035] (2) Preparation of Cu-MOF@Fe3O4 To prepare MAA-functionalized Fe3O4NPs, 0.05 g of purchased Fe3O4NPs were added to 10 mL of 0.29 mM thioglycolic acid (MAA) ethanol solution and shaken for 24 h. The Fe3O4NPs were then washed three times with ethanol under an external magnetic field and dried at 60 °C. Next, 0.05 g of MAA-Fe3O4NPs were dispersed in 4 mL of 10 mM Cu(OAc)2·H2O ethanol solution and shaken thoroughly for 15 min; then, they were shaken thoroughly in 4 mL of 10 mM H3BTC ethanol solution for 30 min. This process was repeated five times, with washing with ethanol under a magnetic field between each step. Finally, the obtained material was washed three times with water and three times with ethanol, and dried at 60 °C.

[0036] (3) Preparation of AuNPs@Cu-MOF@Fe3O4 0.05 g of Cu-MOF@Fe3O4NPs was placed in a centrifuge tube, and 5 mL of gold nanoparticle (AuNPs) solution was added. The mixture was then shaken in a refrigerator at 4 ℃ in the dark for 12 h. After the reaction was completed, the mixture was separated using an external magnetic field and washed three times with ultrapure water. Finally, it was dried at 60 ℃ to obtain AuNPs@Cu-MOF@Fe3O4.

[0037] (4) Preparation of sDNA functionalized AuNPs@Cu-MOF@Fe3O4 signal probe sDNA-functionalized AuNPs@Cu-MOF@Fe3O4 (sDNA / AuNPs@Cu-MOF@Fe3O4) was prepared via Au and −SH reaction. 10 mg of AuNPs@Cu-MOF@Fe3O4 was dispersed in 1 mL of DNA fixation buffer, and 100 µL of sDNA (10 μM) was added. The mixture was then incubated overnight at 4 °C with shaking. After the reaction, excess sDNA was removed by centrifugation at 9000 rpm for 5 min, followed by washing three times with DNA storage buffer. Finally, the mixture was dispersed in DNA storage buffer and stored at 4 °C.

[0038] II. Fabrication of Biosensors (1) Electrode pretreatment Before electrode modification, GCE was polished with 0.3 and 0.05 μm alumina powder, then sonicated in ultrapure water and ethanol, and finally dried with nitrogen to obtain a smooth, mirror-like electrode surface. Next, the electrode was assembled. First, 5 μL of well-dispersed rGO solution was dropped onto the electrode surface and dried at room temperature for 120 min, denoted as rGO / GCE. Then, in a solution containing 3.0 mM HAuCl4 (containing 0.1 mM KNO3), rGO / Au / GCE was formed by amperometric electrodeposition at a constant potential of -0.2 V for 70 s. Next, cDNA (10 μL, 1 μM) was immobilized onto the electrode surface and treated at 4 ℃ for 12 h. Unimmobilized cDNA was washed away with Tris-HCl (10 mM, pH 7.4) to obtain cDNA / rGO / Au / GCE. A 1% BSA solution was added dropwise to the modified electrode to treat non-specific sites, and the BSA / cDNA / rGO / Au / GCE was obtained by rinsing with Tris-HCl.

[0039] (2) Electrochemical detection First, two DNA hybridization processes were performed. In the first step, sDNA / AuNPs@Cu-MOF@Fe3O4 was added to a hybridization buffer containing an equal volume of the target, and incubated at 37 °C with gentle shaking for 90 min. The resulting tDNA / sDNA / Fe3O4NPs@Cu-MOF@Au was then dispersed in 1 mL of hybridization buffer. Finally, BSA / cDNA / rGO / Au / GCE was immersed in the buffer to perform a second hybridization step using the capture probe previously immobilized on the electrode surface. After incubation for 90 min, the electrode was washed with Tris-HCl buffer, and finally, measurements were taken in 0.1 M acetate buffer.

[0040] 1. Morphological characterization of materials: The morphology and size of the prepared nanocomposite materials were characterized using scanning electron microscopy (SEM). Figure 1 As shown in Figure A, pure Fe3O4 has a spherical structure. When Cu-MOF is loaded on the outer layer of Fe3O4, it becomes a tetrahedral structure with a larger diameter. Figure 1 (B). When AuNPs are combined with Cu-MOF@Fe3O4, it can be clearly observed that there is no significant change in shape, while the surface of Cu-MOF@Fe3O4 is covered with some tiny particles (B). Figure 1 The C indicates that AuNPs were successfully deposited on the Cu-MOF@Fe3O4 surface.

[0041] 2. Feasibility Analysis: To verify the enhancement effect of AuNPs@Cu-MOF@Fe3O4 on electrochemical signals, the DPV signals of the two materials in 0.1M acetate buffer solution were compared. Figure 2 As shown in Figure A, compared to the Cu-MOF@Fe3O4-loaded electrode, the AuNPs@Cu-MOF@Fe3O4-modified electrode exhibits the highest peak current due to the excellent conductivity of AuNPs. Experimental results demonstrate that the electrochemical signal amplification strategy using AuNPs@Cu-MOF@Fe3O4 can improve the analytical performance of the electrochemical sensor.

[0042] To explore the role of Fe3O4NPs in reducing background signal, the current values ​​of AuNPs@Cu-MOF@Fe3O4 and AuNPs@Cu-MOF were compared in 0.1 M acetate buffer solution when the background signal was reduced. Figure 2 B. After adding Fe3O4NPs, the background signal current value of the constructed sensor is much lower than that without Fe3O4NPs, about 49% of that of AuNPs@Cu-MOF.

[0043] 3. Condition optimization: To achieve the most sensitive analytical performance of the sensor, several key variables were optimized, including the pH of the acetate buffer solution, the hybridization time of tDNA and sDNA, the hybridization time of cDNA and tDNA, and the concentration of the signal tag. Figure 3 As shown, the optimal pH of the acetate buffer solution was ultimately selected as 5.5, the optimal hybridization time for tDNA and sDNA was 90 min, the optimal hybridization time for cDNA and tDNA was 90 min, and the optimal concentration of the signal tag was 3 mg / mL.

[0044] 4. Analytical performance like Figure 4 As shown in A, Cu 2+The DPV signal increases with increasing tDNA concentration, eventually reaching a plateau. Figure 4 B shows that tDNA at 1.0 × 10 -14 M to 1.0×10 -8 Within the range of M, there is a good linear relationship between the current value and the logarithm of the tDNA concentration, and the calculated detection limit is 1.09 × 10⁻⁶. -15 M (S / N = 3).

[0045] 6. Selectivity, stability, and repeatability The DPV signal was measured for target DNA (tDNA), single-base mismatched DNA (Mis-1), double-base mismatched DNA (Mis-2), triple-base mismatched DNA (Mis-3), and non-complementary DNA (NC). Figure 5 (A) The selectivity of the developed electrochemical biosensor was investigated. It was found that only the target DNA exhibited a high current response, indicating that the sensor has good selectivity. Furthermore, as... Figure 5 As shown in Figure B, the electrode was stored at 4°C for 0, 3, 7, and 14 days to further determine its stability. After 14 days, the peak current remained at 83.6% of the initial response, indicating good stability. Furthermore, the reproducibility of this biosensor was investigated. Five different batches of the biosensor were constructed and measured five times under the same experimental conditions to detect genetically modified soybeans. Figure 5 The C-values ​​show that the RSD of the peak current values ​​among the five biosensors is approximately 4.29%, indicating good reproducibility.

[0046] 7. Testing of actual samples Purchased genetically modified soybean powder was used as a real sample to verify the sensor's performance in actual samples. Agarose gel electrophoresis of the PCR product of the MON89788 gene in genetically modified soybean is shown in Figure 6A. A fragment of approximately 142 bp appeared in the genetically modified soybean sample (lane 2), while no band was observed in the non-genetically modified sample (lane 3) and the blank control (lane 4), indicating that the PCR amplified the 142 bp fragment. This was then applied to the constructed biosensor to analyze the initial total DNA and PCR product (…). Figure 6(B) It can be seen that the DPV response of the negative (non-GMO) sample (curve b) is almost unchanged compared with the blank control (curve a). This indicates that there are no PCR products of the MON89788 gene fragment in the non-GMO soybean sample. However, the DPV response for detecting the initial total DNA (curve c) is higher than the blank signal, and the DPV response to the PCR products of GMO soybean is significantly increased (curve d). These DPV responses are in excellent agreement with the results obtained by gel electrophoresis, indicating that the prepared GMO soybean MON89788 biosensor has potential practical applications in the detection of GMO foods and crops.

[0047] The above description is merely a preferred embodiment for explaining the present invention and is not intended to limit the present invention in any way. Therefore, any modifications or changes made to the present invention under the same inventive spirit should still be included within the scope of protection intended by the present invention.

Claims

1. A method for detecting genetically modified components, characterized in that: The steps include: adding sDNA / AuNPs@Cu-MOF@Fe3O4 to a centrifuge tube containing hybridization buffer for target tDNA, incubating at 35-38℃ for 70-100 min, and then dispersing the obtained tDNA / sDNA / AuNPs@Cu-MOF@Fe3O4 in 1 mL of hybridization buffer to obtain the buffer system; BSA / cDNA / rGO / Au / GCE was immersed in the buffer system to hybridize using the capture probe previously immobilized on the surface of BSA / cDNA / rGO / Au / GCE. After incubation for 70-100 min, Fe3O4@Cu-MOF@AuNPs / sDNA / tDNA / BSA / cDNA / rGO / Au / GCE was obtained. Fe3O4@Cu-MOF@AuNPs / sDNA / tDNA / BSA / cDNA / rGO / Au / GCE was washed with Tris-HCl buffer. Finally, the measurements were performed using an electrochemical workstation in a three-electrode system with 0.1 M acetate buffer. The preparation method of BSA / cDNA / rGO / Au / GCE includes: firstly, a well-dispersed reduced graphene oxide solution is dropped onto the surface of a glassy carbon electrode, and after drying, rGO / GCE is obtained; then, in HAuCl4 solution, under constant potential, rGO / Au / GCE is electrodeposited on the rGO / GCE by amperometry to form rGO / Au / GCE; then, cDNA is immobilized on the surface of rGO / Au / GCE, and treated at 1-6 ℃ for 8-20 h, and the unimmobilized cDNA is washed away to obtain cDNA / rGO / Au / GCE; bovine serum albumin solution is dropped onto cDNA / rGO / Au / GCE to treat non-specific sites, and after rinsing, BSA / cDNA / rGO / Au / GCE is obtained. The method for preparing sDNA / AuNPs@Cu-MOF@Fe3O4 includes: (1) Preparation of Cu-MOF@Fe3O4: Ferric oxide magnetic nanoparticles were added to an ethanol solution of mercaptoacetic acid and shaken for 20-30 h to prepare mercaptoacetic acid-functionalized Fe3O4NPs, which are called MAA-Fe3O4NPs. Then, the MAA-Fe3O4NPs were washed with ethanol in the presence of an external magnet and dried. The MAA-Fe3O4NPs were then dispersed in an ethanol solution of Cu(OAc)2·H2O and shaken for 10-30 min. Then, the mixture was shaken in an ethanol solution of H3BTC for 20-40 min. This process was repeated 3-8 times. Finally, the material was washed with water and ethanol respectively and dried to obtain Cu-MOF@Fe3O4. (2) Preparation of AuNPs@Cu-MOF@Fe3O4 Cu-MOF@Fe3O4 was placed in a centrifuge tube, gold nanoparticle solution was added, and the mixture was shaken in the dark at 1-6℃ for 10-15 h. After the reaction was completed, the mixture was separated by an external magnetic field and washed with ultrapure water. After drying, AuNPs@Cu-MOF@Fe3O4 was obtained. (3) Preparation of sDNA functionalized AuNPs@Cu-MOF@Fe3O4 signal probe AuNPs@Cu-MOF@Fe3O4 was dispersed in a previously prepared DNA fixation buffer solution, sDNA was added, and the mixture was shaken overnight at 1-6°C. After the reaction was completed, excess sDNA was removed by centrifugation, and the mixture was washed with DNA storage buffer. Finally, the mixture was dispersed in DNA storage buffer and stored at 1-6°C to obtain sDNA / AuNPs@Cu-MOF@Fe3O4.

2. The method for detecting genetically modified components according to claim 1, characterized in that: The glassy carbon electrode was polished with 0.3 μm and 0.05 μm alumina powder, respectively, then sonicated in ultrapure water and ethanol, and finally dried with nitrogen.

3. The method for detecting genetically modified components according to claim 1, characterized in that: For electrochemical measurements: a 0.1M acetate buffer solution was used as the detection base solution, and differential pulse voltammetry was employed as the electrochemical detection method. The measurement potential range of differential pulse voltammetry was -0.6 to 0.5 V, and the scan rate was 100 mV·s. -1 .

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