Preparation method and application of chiral serine-modified graphyne

Abstract

The application discloses a preparation method and application of a chiral serine modified graphyne. The method comprises the following steps: adding a hexaethynylbenzene solution into a reactor provided with pyridine and copper foil to obtain graphyne powder; then, adding concentrated sulfuric acid, nitric acid and potassium permanganate in sequence to obtain the graphyne subjected to oxidation treatment; subsequently, dispersing the graphyne subjected to the oxidation treatment in deionized water through ultrasonic dispersion, adding serine and stirring at normal temperature for 20-30 hours, standing, suction filtration, water washing and drying to obtain a chiral serine modified graphyne material; after the L-serine-graphyne or D-serine-graphyne is modified on a glassy carbon electrode, the chiralities of amino acid molecules can be recognized according to differential pulse voltammetry peak current; and the application can also semi-quantitatively estimate the concentration of the amino acid according to the peak current.

Description

Technical Field

[0001] This invention relates to the preparation of serine-modified graphyne materials, which can be used for electrochemical chiral recognition of various amino acid enantiomers, and belongs to the fields of carbon materials, biotechnology and electrochemical research. Background Technology

[0002] Amino acids are the basic building blocks of proteins. Except for glycine, all natural amino acids are chiral. In various life activities, amino acids participate in protein synthesis, biological metabolism, and nerve signal transduction. Therefore, the chiral identification of small molecules such as amino acids plays an important role in biochemical and pharmaceutical research. Accurate identification of the chirality of amino acids is essential for disease diagnosis and treatment, as well as the research and development of new drugs. Compared with chromatography, spectroscopy, and nuclear magnetic resonance spectroscopy, electrochemical methods have advantages such as high sensitivity, low cost, and ease of operation, and are widely used in the field of chiral identification.

[0003] Graphdiyne, as a novel carbon nanomaterial, possesses unique physicochemical properties and structural tunability, attracting considerable attention from researchers. Its high specific surface area and abundant surface activity allow for the introduction of chiral molecules or functional groups through covalent or non-covalent modification, thereby acquiring chiral characteristics. In the chiral recognition of amino acid molecules, Graphdiyne can provide a chiral microenvironment, forming composite structures through interactions such as hydrogen bonding. Because different enantiomers of chiral molecules interact with it to varying degrees, resulting in differences in electrochemical signals, chiral recognition can be achieved. Graphdiyne exhibits good electrical conductivity and excellent chemical stability, laying a solid foundation for realizing efficient, sensitive, and practical chiral recognition technology, and holds promise for applications in biomedical, chemical sensing, and drug analysis research.

[0004] There are almost no functional graphyne materials in the chiral domain in the existing technology. Research on graphyne in the direction of electrochemical recognition is mainly focused on the non-chiral domain. For example, Zhang Ruilin et al. prepared a graphyne composite material modified with columnar aromatics. The host-guest recognition behavior is achieved through the specific interaction between the electron-rich rigid cavity of the columnar aromatics and methamphetamine. However, since the material does not contain chirality, it does not have a recognition effect on the left- or right-handed isomers of chiral guest molecules (CN 115015348A, 2022.09.06). Summary of the Invention

[0005] The purpose of this invention is to address the limitations of current technologies by providing a method for preparing chiral serine-modified graphyne and its application. This method involves synthesizing a graphyne film using a copper foil method, oxidizing it, and then linking it with chiral serine via an amidation reaction to achieve modification of the graphyne. After modifying a glassy carbon electrode with L-serine-graphyne or D-serine-graphyne, the chirality of amino acid molecules can be identified based on the differential pulse voltammetry peak current. Furthermore, the concentration of amino acids can be semi-quantitatively estimated based on the peak current magnitude. Compared to other chiral identification methods such as chromatography and optics, this invention detects lower concentrations (0~2.0 mg / L), has lower equipment costs, faster response, and shows promising application prospects.

[0006] The technical solution of this invention is as follows: A method for preparing chiral serine-modified graphyne, the method comprising the following steps: A hexaethynylbenzene solution was added to a reactor containing solvent and copper foil, and reacted at 50-70°C under an argon atmosphere for 3-5 days. The mixture was then washed with dilute hydrochloric acid, filtered, and dried to obtain graphyne powder. Concentrated sulfuric acid, nitric acid, and potassium permanganate were then added sequentially, and the mixture was reacted at 55-65°C for 15-20 hours to obtain oxidized graphyne. The oxidized graphyne was then ultrasonically dispersed in deionized water, EDC was added, and the mixture was stirred. NHS was then added and stirred for 0.3-0.7 hours. Finally, serine was added and stirred at room temperature for 20-30 hours. The mixture was allowed to stand, filtered, washed with water, and dried to obtain chiral serine-modified graphyne material. Among them, every 50~100cm 2 Add 50-100 mg of hexaethynylbenzene to copper foil; Add 20-30 mg of graphene to 5-10 mL of concentrated sulfuric acid, 20-30 mg of potassium permanganate, and 2-3 mL of concentrated nitric acid. 10-30 mg of oxidized graphylene was ultrasonically dispersed in 10-100 mL of deionized water, 5-15 μL of EDC, 5-10 mg of NHS, and 5-15 mg of serine. The serine mentioned is L-serine or D-serine; The solvent is pyridine; the solvent for the hexaethynylbenzene solution is pyridine, with a concentration of 0.5~2 mg / mL; The method for preparing chiral serine-modified graphyne is characterized in that the concentrated sulfuric acid has a mass fraction of 98.3% and the concentrated nitric acid has a mass fraction of 68%. The chiral serine-modified graphyne prepared by the method is used for the electrochemical chiral recognition of amino acid molecules. Specifically, the steps include the following: a three-electrode system is adopted, with a glassy carbon electrode modified with L-serine-graphyne or D-serine-graphyne as the working electrode, a platinum sheet electrode as the counter electrode, and a silver / silver chloride electrode as the reference electrode. Using the test solution as the electrolyte, differential pulse scanning was performed within a voltage range of 0.5~1.1V. Then, based on the different oxidation peak current values ​​of different chiral amino acids, the chirality (D-type or L-type) of the amino acid was determined. Alternatively, the concentration of amino acids in the solution can be determined based on the linear relationship between the oxidation peak current and concentration. The preparation method of the chiral serine graphdiyne-modified electrode includes the following steps: A chiral serine graphyne dispersion was coated onto the surface of a glassy carbon electrode and allowed to dry naturally to obtain the prepared working electrode. The chiral serine graphyne dispersion was prepared by adding 0.5-1.5 mg of chiral serine graphyne, 0.2-0.8 μL of Nafion solution, and 0.1-0.5 mL of ethanol to every 0.75 mL of water, followed by ultrasonic dispersion. A standard 3mm diameter glassy carbon electrode is coated with 0.3~0.7μL of chiral serine graphyne dispersion; The chiral amino acid to be identified is tryptophan, valine, proline, or tyrosine; The determination of the chirality of the amino acid can be done using one of the following two methods; Method 1 for determining the chirality of tryptophan: When testing the chirality of tryptophan in the test solution using an L-serine-graphyne modified electrode as the working electrode, an oxidation peak current of 0.0035 mA indicates that the test solution contains D-tryptophan; when testing the solution with the L-serine-graphyne modified electrode, an oxidation peak current of 0.0023 mA indicates that the test solution contains L-tryptophan. The peak current corresponding to D-tryptophan was 0.0035 mA, which is greater than that of L-tryptophan (0.0023 mA). Alternatively, Method 2: When testing the chirality of tryptophan in the test solution using a D-serine-graphyne modified electrode as the working electrode, an oxidation peak current of 0.0035 mA indicates that the test solution contains L-tryptophan; when testing the solution with a D-serine-graphyne modified electrode, an oxidation peak current of 0.0027 mA indicates that the test solution contains D-tryptophan. The peak current corresponding to L-tryptophan was 0.0035 mA, which is greater than that of D-tryptophan (0.0027 mA). In either Method 1 or Method 2, the test concentration of tryptophan in the test solution is 1.5~2.5 mg / L; In Method 1, when testing the chirality of valine in the test solution using an L-serine-graphyne modified electrode as the working electrode, an oxidation peak current of 0.0021 mA indicates that the test solution contains D-valine; when the L-serine-graphyne modified electrode is used to test the solution, an oxidation peak current of 0.0015 mA indicates that the test solution contains L-valine. In Method 2, when testing the chirality of valine in the test solution using a D-serine-graphyne modified electrode as the working electrode, an oxidation peak current of 0.0030 mA indicates that the test solution contains L-valine; when testing the solution with the D-serine-graphyne modified electrode, an oxidation peak current of 0.0017 mA indicates that the test solution contains D-valine. In either Method 1 or Method 2, the test concentration of valine in the test solution is 0.7~1.5 mg / L; In Method 1, when testing the chirality of proline in the test solution using an L-serine-graphyne modified electrode as the working electrode, an oxidation peak current of 0.0018 mA indicates that the test solution contains D-proline; when the L-serine-graphyne modified electrode is used to test the solution, an oxidation peak current of 0.0013 mA indicates that the test solution contains L-proline. In Method 2, when testing the chirality of proline in the test solution using a D-serine-graphyne modified electrode as the working electrode, an oxidation peak current of 0.0020 mA indicates that the test solution contains L-proline; when testing the solution with the D-serine-graphyne modified electrode, an oxidation peak current of 0.0015 mA indicates that the test solution contains D-proline. In either Method 1 or Method 2, the test concentration of proline in the test solution is 0.7~1.5 mg / L; In Method 1, when testing the chirality of tyrosine in the test solution using an L-serine-graphyne modified electrode as the working electrode, an oxidation peak current of 0.0040 mA indicates that the test solution contains D-tyrosine; when the L-serine-graphyne modified electrode is used to test the solution, an oxidation peak current of 0.0025 mA indicates that the test solution contains L-tyrosine. In Method 2, when testing the chirality of tyrosine in the test solution using a D-serine-graphyne modified electrode as the working electrode, an oxidation peak current of 0.0040 mA indicates that the test solution contains L-tyrosine; when testing the solution with the D-serine-graphyne modified electrode, an oxidation peak current of 0.0025 mA indicates that the test solution contains D-tyrosine. In either Method 1 or Method 2, the test concentration of tyrosine in the test solution is 1.5~2.0 mg / L; Determination of amino acid concentration in solution: When the L-serine-graphyne-modified electrode was used to test D-tryptophan solution, the oxidation peak current showed a clear linear relationship with concentration. (mA) =0.00131C (mg / L) +0.00126; When the L-serine-graphyne modified electrode was used to test L-tryptophan solution, I (mA) =0.00059C (mg / L) +0.00074, where I represents peak current and C represents amino acid concentration; The concentration range for solution determination is 0~2.0 mg / L.

[0007] The essential features of this invention are: Chiral serine graphyne interacts with amino acid molecules through various hydrogen bonds in solution, easily forming intermediate complexes. The interaction between serine graphyne and amino acid molecules with opposite chirality is stronger than that with molecules of the same chirality, and the resulting complex structure yields a higher redox peak current after a certain potential is applied. The chirality of molecules can be determined based on the level of the oxidation peak current in the differential pulse voltammogram.

[0008] The beneficial effects of this invention are: This invention presents a method for modifying graphyne materials with chiral serine, filling a gap in the field of chiral modification of graphyne. Due to the abundance of alkyne groups on the surface of graphyne, oxidation treatment readily yields numerous oxygen-containing functional groups, providing ample active sites for the loading of chiral serine. The amino acid loading is significantly higher than that of other amino acid-modified carbon materials. Strong interactions, such as hydrogen bonds, exist between chiral serine-modified graphyne and amino acid molecules, and the interactions differ depending on the chirality of the amino acid, resulting in variations in current signal intensity. When modified onto a glassy carbon electrode, this material exhibits excellent recognition of the chirality of various amino acid molecules, with an L / D-tryptophan peak current ratio reaching 1.5 times. Furthermore, the current signal intensity increases linearly with increasing amino acid concentration, enabling semi-quantitative estimation of amino acid concentration. Compared to other chiral recognition methods such as chromatography and optics, this method detects lower concentrations (0–2.0 mg / L), has lower equipment costs, and offers faster response times, demonstrating promising application prospects. Attached Figure Description

[0009] The invention is further illustrated below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the chemical structure of chiral serine-modified graphyne in Example 1; Figure 2This is a scanning electron microscope image of chiral serine-modified graphyne in Example 1; Figure 3 The image shows the Raman spectrum of chiral serine-modified graphynylene in Example 1. Figure 4 The image shows the X-ray photoelectron spectrum of chiral serine-modified graphyne in Example 1. Figure 5 The circular dichroism spectra of L-serine-graphyne and D-serine-graphyne in Example 1 are shown. Figure 6 This is a diagram showing the recognition effect of the L-serine-graphyne modified electrode on tryptophan enantiomers in Example 1. Figure 7 This is a diagram showing the recognition effect of the D-serine-graphyne modified electrode on tryptophan enantiomers in Example 1; Figure 8 This is a graph showing the linear recognition effect of the L-serine-graphyne modified electrode on D-tryptophan in Example 1. Figure 9 This is a graph showing the linear recognition effect of the L-serine-graphyne modified electrode on L-tryptophan in Example 1. Figure 10 This is a diagram showing the recognition effect of the oxidized graphdiyne-modified electrode on tryptophan enantiomers in Comparative Example 2. Figure 11 The image shows the recognition effect of L-serine-graphyne and D-serine-graphyne modified electrodes on valine, proline and tyrosine in Example 3. Detailed Implementation

[0010] Example 1: Preparation of chiral serine-modified graphyne materials and a method for electrochemical chiral recognition of tryptophan molecules: Deprotection of hexa(trimethylsilylethynyl)benzene: 100 mg of hexa(trimethylsilylethynyl)benzene was dissolved in 100 mL of anhydrous tetrahydrofuran under ice-water bath protection, and bubbled for about 10 minutes in the dark. 2 mL of tetrabutylammonium fluoride solution was added and the reaction was carried out for 0.5 hours. After the reaction, the product was extracted, washed and dried to obtain the hexaethynylbenzene monomer.

[0011] Preparation of graphdiyne films: First, cut approximately 20 pieces of 2×2cm film. 2 The copper foil was ultrasonically washed with hydrochloric acid, water, and acetone for about 5 minutes in sequence, dried with argon, and 100 mL of pyridine was added to a three-necked flask. 50 mg of hexaethynylbenzene was dissolved in 50 mL of pyridine solution and added dropwise to the three-necked flask at a rate of about one drop every 10 seconds. The mixture was then heated to 60 °C under argon atmosphere and reacted for 3 days. After the reaction, the mixture was washed with N,N-dimethylformamide, acetone, and 1 mol / L hydrochloric acid in sequence and the black film was peeled off. After washing again, the graphyne film was obtained.

[0012] In the reaction, copper foil is in a pyridine solution. Under alkaline conditions, copper ions are generated on the surface of the copper foil, which complex with pyridine and act as a catalyst. At the same time, the monomer is catalyzed and polymerized on the surface of the copper foil, and thin film-shaped graphyne is grown on the copper foil as a substrate.

[0013] Oxidation treatment of graphdiene: Under ice bath conditions, 24 mg of graphdiene was added to 7.2 mL of 98.3% concentrated sulfuric acid, followed by the slow addition of 24 mg of potassium permanganate and 2.4 mL of 15.2 mol / L concentrated nitric acid. The mixture was heated to 60 °C and reacted for 20 hours. After the reaction, 1 mol / L NaOH solution was added to adjust the pH to 10. The mixture was then filtered, washed with distilled water, and dried to obtain oxidized graphdiene powder.

[0014] Preparation of chiral serine-modified graphyne: 25 mg of oxidized graphyne was ultrasonically dispersed in 25 mL of deionized water, 10 μL of EDC was added and stirred for 10 minutes, then 6.3 mg of NHS was added and stirred for 0.5 hours, followed by the addition of 10.5 mg of L-serine or D-serine and stirring at room temperature for 24 hours. After filtration, washing and drying, chiral serine-modified graphyne material was obtained.

[0015] like Figure 2 As shown, the lattice structure of graphdiene can be seen in the scanning electron microscopy image, and the relatively rough surface is due to the damage to the surface during the oxidation and modification process. Figure 3 The partial overlap between the D and G peaks in the Raman spectrum indicates that the modification process generated a large number of defects, thereby promoting the linkage of serine. Figure 4 The nitrogen peak in the mid-X-ray photoelectron spectroscopy confirmed the successful introduction of serine; in Figure 5 The signal peaks of L-serine-graphyne and D-serine-graphyne in the circular dichroism chromatogram are symmetrical, confirming that the modified graphyne has a chiral structure.

[0016] Preparation of chiral serine graphyne-modified electrode: First, the glassy carbon electrode was polished in 0.05 μm alumina polishing powder for 3 minutes, washed with deionized water and dried with nitrogen gas; then, 1 mg L-serine or D-serine graphyne, 0.5 μL Nafion solution, 0.25 mL ethanol and 0.75 mL water were prepared into a solution, ultrasonically dispersed for 10 minutes, and 0.5 μL was dropped onto the surface of the glassy carbon electrode and allowed to dry naturally to obtain the prepared working electrode.

[0017] Electrochemical chiral recognition of tryptophan by chiral serine graphyne: The experiment was conducted using a CHI760E electrochemical workstation. The peak oxidation current of graphyne was analyzed by differential pulse voltammetry, and the chiral recognition was determined by comparing the peak currents in L- and D-amino acid solutions. All experiments were performed at room temperature to ensure consistency of experimental conditions and comparability of results. A three-electrode system was used: a glassy carbon electrode modified with L-serine-graphyne or D-serine-graphyne as the working electrode, a platinum sheet electrode as the counter electrode, and a silver / silver chloride electrode as the reference electrode. First, the electrode was immersed in a 7.5 g / L potassium chloride solution, and a voltage scan range of -0.5 V to 1.2 V was set for 20 cycles. Then, the three-electrode system was placed in a 2.0 mg / L L- / D-tryptophan solution and allowed to stand for 5 minutes. A differential pulse voltammetry scan was then performed with a voltage range of 0.5 to 1.1 V and a scan rate of 50 mV / s.

[0018] According to the appendix Figure 6 The data was processed using an L-serine-graphyne modified electrode as the working electrode to test the chirality of tryptophan in the test solution. When an oxidation peak current of 0.0035 mA was obtained, it indicated that the test solution contained D-tryptophan; when an oxidation peak current of 0.0023 mA was obtained, it indicated that the test solution contained L-tryptophan. The peak current corresponding to D-tryptophan (0.0035 mA) was greater than that of L-tryptophan (0.0023 mA).

[0019] According to the appendix Figure 7 When testing the chirality of tryptophan in the test solution using a D-serine-graphyne modified electrode as the working electrode, an oxidation peak current of 0.0035 mA indicates the presence of L-tryptophan in the test solution; an oxidation peak current of 0.0027 mA indicates the presence of D-tryptophan. The peak current corresponding to L-tryptophan (0.0035 mA) is greater than that of D-tryptophan (0.0027 mA).

[0020] In conclusion, tryptophan, which has the opposite chirality to graphynylene, corresponds to a larger peak current.

[0021] The peak current ratio corresponding to D / L-amino acids was used as the criterion for judging the chiral recognition effect; the larger the ratio difference, the better the recognition effect. The recognition effect (I) of the L-serine-graphyne modified electrode was thus determined. D-色氨酸 / I L-色氨酸 The recognition effect of the D-serine-graphyne modified electrode was 1.5. L-色氨酸 / I D-色氨酸 The value is 1.3.

[0022] According to the appendix Figure 8 and attached Figure 9The data showed that L-serine-graphyne was detected in D-tryptophan solutions with concentration gradients ranging from 0.4 to 2.0 mg / L. The results exhibited good linear correlation. When the L-serine-graphyne modified electrode tested D-tryptophan solutions, the oxidation peak current showed a significant linear relationship with concentration. (mA) =0.00131C (mg / L) +0.00126; When the L-serine-graphyne modified electrode was used to test L-tryptophan solution, I (mA) =0.00059C (mg / L) +0.00074, where I represents the peak current and C represents the amino acid concentration; this means that based on chiral recognition, the concentration of amino acid molecules can be semi-quantitatively estimated according to the magnitude of the peak current.

[0023] Comparative Example 2: A method for electrochemical chiral recognition of tryptophan molecules using oxidized graphyne materials. The experiment employed a three-electrode system, with an oxidized graphyne-modified glassy carbon electrode as the working electrode, a platinum sheet electrode as the counter electrode, and a silver / silver chloride electrode as the reference electrode. The electrode was immersed in a 7.5 g / L potassium chloride solution and circulated several times before being placed in a 2.0 mg / L L- / D-tryptophan solution for differential pulse voltammetry scanning. The oxidation peak currents of both L-tryptophan and D-tryptophan were around 0.0022 mA, showing no significant recognition effect. This indicates that the recognition effect mainly originates from the chiral serine molecules loaded on the graphyne surface.

[0024] Example 3: A method for electrochemical chiral recognition of valine, proline, and tyrosine molecules by modifying graphyne with chiral serine: The experiment employed a three-electrode system, with a chiral serine-graphyne-modified glassy carbon electrode as the working electrode, a platinum sheet electrode as the counter electrode, and a silver / silver chloride electrode as the reference electrode. The electrode was immersed in a 7.5 g / L potassium chloride solution and cyclically scanned several times. Using PBS buffer, solutions of 1.1 mg / L L- / D-valine, 1.1 mg / L L- / D-proline, and 1.8 mg / L L- / D-tyrosine were prepared. Differential pulse voltammetry scans were performed on the three-electrode system in these solutions, all of which demonstrated good chiral recognition capabilities.

[0025] According to the appendix Figure 11According to the data, in determining the chirality of valine, when using an L-serine-graphyne-modified electrode as the working electrode, an oxidation peak current of 0.0021 mA indicates that the test solution contains D-valine; an oxidation peak current of 0.0015 mA indicates that the test solution contains L-valine; when using a D-serine-graphyne-modified electrode as the working electrode, an oxidation peak current of 0.0030 mA indicates that the test solution contains L-valine; and an oxidation peak current of 0.0017 mA indicates that the test solution contains D-valine.

[0026] In determining the chirality of proline, when using an L-serine-graphyne-modified electrode as the working electrode, an oxidation peak current of 0.0018 mA indicates the presence of D-proline in the test solution; an oxidation peak current of 0.0013 mA indicates the presence of L-proline; when using a D-serine-graphyne-modified electrode as the working electrode, an oxidation peak current of 0.0020 mA indicates the presence of L-proline; and an oxidation peak current of 0.0015 mA indicates the presence of D-proline.

[0027] In determining the chirality of tyrosine, when using an L-serine-graphyne-modified electrode as the working electrode, an oxidation peak current of 0.0040 mA indicates the presence of D-tyrosine in the test solution; an oxidation peak current of 0.0025 mA indicates the presence of L-tyrosine. Similarly, when using a D-serine-graphyne-modified electrode as the working electrode, an oxidation peak current of 0.0040 mA indicates the presence of L-tyrosine in the test solution; and an oxidation peak current of 0.0025 mA indicates the presence of D-tyrosine.

[0028] When the peak current ratio corresponding to D / L-amino acids is used as the criterion for judging the chiral recognition effect, it can be concluded that when the L-serine-graphyne modified electrode is used for testing, I D-缬氨酸 / I L-缬氨酸 It is 1.4, I D-脯氨酸 / I L-脯氨酸 It is 1.4, I D-酪氨酸 / I L-酪氨酸 The value is 1.6; when tested with the D-serine-graphyne modified electrode, I... L-缬氨酸 / I D-缬氨酸 It is 1.7, I L-脯氨酸 / I D-脯氨酸 It is 1.3, I L-酪氨酸 / I D-酪氨酸 It is 1.6.

[0029] This invention explores a method for modifying graphyne with chiral serine and fully utilizes the chiral microenvironment provided by serine to prepare a chiral serine-graphyne modified electrode, which has good chiral recognition ability for a variety of amino acid molecules.

[0030] Matters not covered in this invention are common knowledge.

Claims

1. A method for preparing chiral serine-modified graphyne, characterized in that the method includes the following steps: A hexaethynylbenzene solution was added to a reactor containing solvent and copper foil, and reacted at 50-70 °C for 3-5 days under an argon atmosphere. The mixture was then washed with dilute hydrochloric acid, filtered, and dried to obtain graphyne powder. Concentrated sulfuric acid, nitric acid, and potassium permanganate were then added sequentially, and the mixture was reacted at 55-65 °C for 15-20 hours to obtain oxidized graphyne. The oxidized graphyne was then ultrasonically dispersed in deionized water, EDC was added, and the mixture was stirred. NHS was then added and stirred for 0.3-0.7 hours. Finally, serine was added and stirred at room temperature for 20-30 hours. The mixture was then filtered, washed with water, and dried to obtain chiral serine-modified graphyne material. Among them, every 50~100 cm 2 Add 50-100 mg of hexaethynylbenzene to copper foil; Add 20-30 mg of graphene to 5-10 mL of concentrated sulfuric acid, 20-30 mg of potassium permanganate, and 2-3 mL of concentrated nitric acid. 10-30 mg of oxidized graphene was ultrasonically dispersed in 10-100 mL of deionized water, 5-15 μL of EDC, 5-10 mg of NHS, and 5-15 mg of serine. The serine mentioned is L-serine or D-serine; The solvent is pyridine; the solvent for the hexaethynylbenzene solution is pyridine, with a concentration of 0.5~2 mg / mL; The concentrated sulfuric acid has a mass fraction of 98.3%; the concentrated nitric acid has a mass fraction of 68%.

2. The application of chiral serine-modified graphyne prepared by the method of claim 1, characterized in that it is used for electrochemical chiral recognition of amino acid molecules.

3. The application as described in claim 2, characterized by comprising the following steps: using a three-electrode system, with an L-serine-graphyne or D-serine-graphyne modified glassy carbon electrode as the working electrode, a platinum sheet electrode as the counter electrode, and a silver / silver chloride electrode as the reference electrode. Using the test solution as the electrolyte, differential pulse scanning was performed within a voltage range of 0.5~1.1 V. Then, the chirality of amino acids was determined based on the different oxidation peak current values ​​of different chiral amino acids. Alternatively, the concentration of amino acids in the solution can be determined based on the linear relationship between the oxidation peak current and concentration. The preparation method of the chiral serine graphdiyne-modified electrode includes the following steps: A chiral serine graphyne dispersion was coated onto the surface of a glassy carbon electrode and allowed to dry naturally to obtain the prepared working electrode. in, The chiral serine graphyne dispersion was prepared by adding 0.5-1.5 mg of chiral serine graphyne, 0.2-0.8 μL of Nafion solution, and 0.1-0.5 mL of ethanol to every 0.75 mL of water, followed by ultrasonic dispersion. A standard 3 mm diameter glassy carbon electrode surface is coated with 0.3~0.7 μL of chiral serine graphyne dispersion.

4. The application as described in claim 2, characterized in that the amino acid to be identified as chiral is tryptophan, valine, proline, or tyrosine.

5. The application as described in claim 4, Its characteristic is that the chirality of the amino acid is determined by one of the following two methods; Method 1 for determining the chirality of tryptophan: When testing the chirality of tryptophan in the test solution using an L-serine-graphyne modified electrode as the working electrode, an oxidation peak current of 0.0035 mA indicates that the test solution contains D-tryptophan; when testing the solution with the L-serine-graphyne modified electrode, an oxidation peak current of 0.0023 mA indicates that the test solution contains L-tryptophan. The peak current corresponding to D-tryptophan was 0.0035 mA, which is greater than that of L-tryptophan (0.0023 mA). Alternatively, Method 2: When testing the chirality of tryptophan in the test solution using a D-serine-graphyne modified electrode as the working electrode, an oxidation peak current of 0.0035 mA indicates that the test solution contains L-tryptophan; when testing the solution with a D-serine-graphyne modified electrode, an oxidation peak current of 0.0027 mA indicates that the test solution contains D-tryptophan. The peak current corresponding to L-tryptophan was 0.0035 mA, which is greater than that of D-tryptophan (0.0027 mA). In either Method 1 or Method 2, the test concentration of tryptophan in the test solution is 1.5~2.5 mg / L; In Method 1, when testing the chirality of valine in the test solution using an L-serine-graphyne modified electrode as the working electrode, an oxidation peak current of 0.0021 mA indicates that the test solution contains D-valine; when the L-serine-graphyne modified electrode is used to test the solution, an oxidation peak current of 0.0015 mA indicates that the test solution contains L-valine. In Method 2, when testing the chirality of valine in the test solution using a D-serine-graphyne modified electrode as the working electrode, an oxidation peak current of 0.0030 mA indicates that the test solution contains L-valine; when testing the solution using the D-serine-graphyne modified electrode, an oxidation peak current of 0.0017 mA indicates that the test solution contains D-valine. In either Method 1 or Method 2, the test concentration of valine in the test solution is 0.7~1.5 mg / L; In Method 1, when testing the chirality of proline in the test solution using an L-serine-graphyne modified electrode as the working electrode, an oxidation peak current of 0.0018 mA indicates that the test solution contains D-proline; when the L-serine-graphyne modified electrode is used to test the solution, an oxidation peak current of 0.0013 mA indicates that the test solution contains L-proline. In Method 2, when testing the chirality of proline in the test solution using a D-serine-graphyne modified electrode as the working electrode, an oxidation peak current of 0.0020 mA indicates that the test solution contains L-proline; when testing the solution with the D-serine-graphyne modified electrode, an oxidation peak current of 0.0015 mA indicates that the test solution contains D-proline. In either Method 1 or Method 2, the test concentration of proline in the test solution is 0.7~1.5 mg / L; In Method 1, when testing the chirality of tyrosine in the test solution using an L-serine-graphyne modified electrode as the working electrode, an oxidation peak current of 0.0040 mA indicates that the test solution contains D-tyrosine; when the L-serine-graphyne modified electrode is used to test the solution, an oxidation peak current of 0.0025 mA indicates that the test solution contains L-tyrosine. In Method 2, when testing the chirality of tyrosine in the test solution using a D-serine-graphyne modified electrode as the working electrode, an oxidation peak current of 0.0040 mA indicates that the test solution contains L-tyrosine; when testing the solution with the D-serine-graphyne modified electrode, an oxidation peak current of 0.0025 mA indicates that the test solution contains D-tyrosine. In either Method 1 or Method 2, the test concentration of tyrosine in the test solution is 1.5~2.0 mg / L.

6. The application as described in claim 3, characterized in that the determination of the amino acid concentration in the solution includes the following steps: When the L-serine-graphyne-modified electrode was used to test D-tryptophan solution, the oxidation peak current showed a clear linear relationship with concentration. (mA) =0.00131C (mg / L) +0.00126; When the L-serine-graphyne modified electrode was used to test L-tryptophan solution, I (mA) =0.00059C (mg / L) +0.00074, where I represents peak current and C represents amino acid concentration; The concentration range for solution determination is 0~2.0 mg / L.

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