Chiral molecular imprinted modified graphene material and preparation method thereof

Abstract

The present invention discloses a chiral molecularly imprinted graphene material, which is graphene or reduced graphene oxide modified with chiral molecular imprinting, wherein chiral recognition sites are located on the surface of the graphene or reduced graphene oxide. In the graphene material of the present invention, the chiral molecular imprinting is modified on the single-atom-thick graphene plane, which can maximize the advantages of graphene's large specific surface area and increase the number of active sites. Furthermore, the chiral recognition sites are located on the graphene plane, which can effectively improve the efficiency of material transport and charge transfer, and enhance the utilization efficiency of the chiral sites in chiral applications of the graphene material. The present invention also discloses a method for preparing the graphene material.

Description

Technical Field

[0001] The present invention relates to the technical field of functionalization and modification of graphene materials, and more specifically to a chiral molecular imprinted modified graphene material and a preparation method thereof. Background Art

[0002] Graphene has excellent electrical conductivity, mechanical properties, optical properties and a large specific surface area (theoretical specific surface area is as high as 2630m 2 ·g -1 ) and is widely used in research fields such as nanotechnology, energy storage, biomedicine, and electrochemical sensing. Although graphene holds considerable promise in many fields, its π-π stacking, which easily leads to irreversible aggregation, hinders its dispersibility and processability in most solvents, creating significant challenges for its practical application. Functionalizing graphene sheets—that is, modifying the graphene surface with covalent or non-covalent modifications—can not only improve its dispersibility but also impart new functionalities, thereby expanding its application areas.

[0003] Graphene is composed of sp 2 The monoatomic layer carbon film composed of hybridized carbon does not have chirality. The chiral center can be grafted onto graphene by covalent bond grafting to obtain a graphene composite material with chiral function. The chiral reagents used to modify graphene include chitosan, cyclodextrin, protein and amino acid (Anal.Methods, 2015, 7, 1387, Anal.Chem., 2019, 91, 11864, Anal.Chem., 2019, 91, 2908). In the preparation of the above-mentioned chiral functionalized graphene material, the graphene sheet only plays the role of "substrate", and the chiral center is away from the sheet of graphene. The chiral functionality of the graphene composite depends on the properties of the chiral center, and the chiral center is generally away from the substrate and has poor stability.

[0004] Molecular imprinting technology can modify chiral information onto substrates of various materials (such as polymers, transition metals, and metal oxides, etc.) (Nature, 1993, 361, 645, ACS Nano, 2020, 14, 4682, Nat. Chem., 2020, 12, 551, Nat. Chem., 2017, 9, 531), among which molecularly imprinted polymers are the most commonly used method for preparing molecularly imprinted materials. This method generally involves mixing the target molecule, monomer, and initiator, and removing the target molecule after polymerization, thereby leaving a cavity for the target molecule in the polymer to impart the chiral information of the target molecule to the substrate. The disadvantage of this method is that the conductivity of the polymer is poor, the stability of the chiral molecule cavity is poor, and there are relatively few chiral recognition sites. Therefore, this method is limited in the application of molecularly imprinted materials. Summary of the Invention

[0005] Based on the above shortcomings, the purpose of the present invention is to provide a chiral molecular imprinted modified graphene material and its preparation method to solve the problems of poor stability of chiral molecular cavity and relatively few chiral recognition sites in the application of molecular imprinting technology in polymers.

[0006] In a first aspect, the present invention provides a chiral molecular imprinted modified graphene material, which is chiral molecular imprinted modified graphene or reduced graphene oxide, wherein the chiral recognition site is located on the surface of the graphene or reduced graphene oxide.

[0007] In this technical solution, the obtained chiral molecular imprinted modified graphene material introduces chiral molecular imprinting on the skeleton surface of single-atom-thick graphene, which can maximize the advantage of graphene's large specific surface area and increase the number of chiral sites; moreover, the chiral sites are located on the graphene sheets, which can effectively improve the efficiency of material transmission and charge transfer, and improve the utilization efficiency of the chiral sites of the above-mentioned graphene material in applications.

[0008] Furthermore, in the graphene material, the skeleton of the chiral molecule is compounded with graphene or reduced graphene oxide through π-π interaction.

[0009] Furthermore, the chiral molecule has a conjugated structure and is selected from D-tryptophan, L-tryptophan, D-phenylalanine, L-phenylalanine, D-tyrosine, L-tyrosine, D-histidine, L-histidine, R-dibenzo(C,G)phenanthrene, S-dibenzo(C,G)phenanthrene and their derivatives.

[0010] Furthermore, the graphene material is a porous or non-porous film, porous foam or porous powder.

[0011] Furthermore, the reduced graphene oxide is prepared by reducing graphene oxide (GO), which can be expressed as RGO; the graphene is prepared by chemical vapor deposition.

[0012] In a second aspect, the present invention provides a method for preparing a chiral molecularly imprinted graphene material, comprising the following steps:

[0013] uniformly mixing the chiral molecule with the graphene oxide (GO) aqueous dispersion to obtain a mixed dispersion;

[0014] And, further,

[0015] i) freeze-drying and heat-treating the mixed dispersion to obtain a chiral molecularly imprinted reduced graphene oxide (RGO) porous foam material; or

[0016] ii) freeze-drying and heat-treating the mixed dispersion to obtain a chiral molecularly imprinted reduced graphene oxide (RGO) porous foam material, and grinding the porous foam material to obtain a chiral molecularly imprinted reduced graphene oxide (RGO) porous powder material; or

[0017] iii) spin-coating the mixed dispersion on a substrate, drying, and heat-treating to obtain a chiral molecularly imprinted modified (RGO) thin film material.

[0018] The present invention provides another method for preparing a chiral molecularly imprinted graphene material, comprising the following steps:

[0019] Dissolving the chiral molecule in a solvent to obtain a chiral molecule solution;

[0020] And, further,

[0021] iv) coating the chiral molecule solution on the graphene surface, spin coating, drying, and heat treating to obtain a chiral imprinted modified graphene film material; or

[0022] v) soaking the graphene powder or graphene foam in a chiral molecule solution, removing the graphene powder or graphene foam, drying the graphene powder or graphene foam, and heat treating the chiral imprinted modified graphene powder or graphene foam.

[0023] Furthermore, the concentration of the GO aqueous dispersion is 0.5 to 100 mg mL -1 , the mass ratio of the chiral molecule to GO is 0.01-10.

[0024] Furthermore, in steps i)-v), the heat treatment conditions are independently: a heat treatment temperature of 200-1000°C and a heat treatment time of 0.01-4 hours. These optimized conditions enable effective recombination of the conjugated chiral molecular skeleton with the graphene sheets, forming a three-dimensional porous structure, increasing the specific surface area, and enhancing the number of chiral imprinting active sites, thereby obtaining a chiral molecularly imprinted modified graphene material.

[0025] Furthermore, in step iii) and step iv), during spin coating, the rotation speed is 100 to 1500 rpm and the coating time is 5 to 120 seconds.

[0026] Furthermore, the uniform mixing can be achieved by ultrasonication for 0.5 to 60 minutes. More preferably, the ultrasonication time is 10 minutes. The selection of such optimized conditions enables the conjugated chiral molecules to be fully mixed and composited with GO.

[0027] Furthermore, in step ii), the grinding time is 0.1 to 100 minutes.

[0028] Furthermore, in step iii), the substrate is any substrate that can be wetted by the surface of the chiral molecule / GO aqueous dispersion, for example, the substrate includes but is not limited to ITO glass.

[0029] Furthermore, in step a), the spin coating speed is 100 to 1500 rpm, and the coating time is 5 to 120 seconds.

[0030] Furthermore, the graphene may be chemical vapor deposition graphene, which is commercially available or may be prepared according to the literature Nano Lett., 2009, 9, 4362.

[0031] Furthermore, the preparation process of the graphene powder and foam material can be found in references Carbon, 2015, 92, 84, Nat. Mater., 2011, 10, 424.

[0032] Furthermore, in step iii), the drying method is freeze drying or natural drying;

[0033] When the drying method is freeze-drying, a chiral molecular imprinted modified RGO porous film material is prepared;

[0034] When the drying method is natural drying, the prepared chiral molecular imprinted modified RGO film material is free of pores.

[0035] In the above technical solution, freeze-drying is to maximize the specific surface area of ​​RGO modified with chiral molecular imprinting to expose more chiral sites.

[0036] In the preparation method of the present invention, a chiral molecule with a conjugated structure is compounded with graphene through π-π interaction, and the conformational information of the chiral molecule is imprinted on the skeleton of the graphene through heat treatment, thereby obtaining a chiral graphene surface.

[0037] The beneficial effects of the present invention are as follows:

[0038] This patent proposes a new preparation method for loading chiral molecular imprints on a graphene skeleton. This method realizes the composite of conjugated chiral molecules and graphene through π-π interaction, and then imprints the conformational information of the chiral molecules onto the graphene skeleton through heat treatment, thereby obtaining a chiral graphene surface.

[0039] Compared with other methods for chiral modification of graphene, the chiral molecular imprinted graphene material modified by the present invention has the following advantages: modifying the chiral molecular imprint on the single-atom-thick graphene plane can maximize the advantage of the large specific surface area of ​​graphene and increase the number of chiral sites; moreover, the chiral sites are located on the graphene skeleton, which can effectively improve the efficiency of material transport and charge transfer in chirality-related applications, thereby improving the utilization efficiency of the chiral sites of the above-mentioned graphene material. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0041] Figure 1 The scanning electron micrograph of the D-tryptophan molecularly imprinted modified RGO porous foam in Example 1 of the present invention is shown.

[0042] Figure 2 The scanning electron micrograph of the D-tryptophan molecularly imprinted modified RGO porous powder in Example 1 of the present invention is shown.

[0043] Figure 3 The XRD patterns of GO and D-tryptophan composite GO in Example 11 of the present invention are shown.

[0044] Figure 4 The scanning electron micrograph of the D-tryptophan molecularly imprinted modified RGO porous film in Example 11 of the present invention is shown.

[0045] Figure 5 The differential pulse voltammetry (DPV) curve of Example 11 of the present invention is shown, which is obtained by electrochemically detecting D- and L-tryptophan chiral solutions using a D-tryptophan molecularly imprinted RGO porous film electrode.

[0046] Figure 6 The scanning electron micrograph of the D-tryptophan molecularly imprinted modified RGO film in Example 21 of the present invention is shown.

[0047] Figure 7 A spherical aberration corrected transmission electron microscopy image of the D-tryptophan molecularly imprinted modified graphene film in Example 23 of the present invention is shown. DETAILED DESCRIPTION

[0048] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the following detailed description is illustrative rather than restrictive and should not be used to limit the scope of protection of the present invention.

[0049] Example 1

[0050] A method for preparing a chiral molecularly imprinted modified RGO porous foam or porous powder material comprises the following steps:

[0051] Step 1: Preparation of GO

[0052] GO was prepared using the Hummers method or the improved Hummers method. The specific preparation process is as follows:

[0053] (1) Prepare 50 mL of concentrated sulfuric acid (98%) in an 80°C oil bath, add 10 g of potassium thiosulfate (K2S2O8) and 10 g of phosphorus pentoxide (P2O5) successively, stir and dissolve evenly, add natural graphite powder or expanded graphite (which has been subjected to a high-temperature treatment at 1000°C) to the above reaction system, stir magnetically at 80°C for 4.5 hours, cool to room temperature after the reaction is completed, dilute with 2 L of deionized water, let it stand for 12 hours, pour off the supernatant, vacuum filter the remaining product and wash with 1 L of deionized water, and dry the filter cake naturally for 12 hours;

[0054] (2) Gently rub the solid powder off the filter paper and add it to 460 mL of concentrated sulfuric acid (98%). Then slowly add 60 g of potassium permanganate while keeping the reaction system below 10°C. Then heat it to 35°C and stir magnetically for 2 hours.

[0055] (3) The reaction system was cooled and diluted with 1 L of deionized water, while maintaining the temperature below 10°C. 2–3 L of deionized water and 50 mL of 30% hydrogen peroxide were added, stirred for 2 hours, and allowed to stand for 12 hours.

[0056] (4) Repeatedly washing with 10% HCl solution for more than 20 times, and then washing with a large amount of deionized water until the pH is close to 7, and finally obtaining a GO aqueous dispersion.

[0057] Step 2: Composite of conjugated chiral molecules and GO

[0058] (1) Add 0.5 mg mL D-tryptophan -1 , in 10 mL of GO aqueous dispersion, the mass ratio of D-tryptophan to GO was 0.01, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0059] (2) Freeze the above samples in liquid nitrogen for 5 minutes, place the frozen samples in a vacuum desiccator, and dry them at -10°C and 2 Pa vacuum for 5 hours;

[0060] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0061] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min-1 The heating rate was increased from 50°C to 200°C, kept constant for 0.01 hour, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous foam material. The RGO porous foam material was ground for 0.1 minute to obtain a chiral molecular imprinted modified RGO porous powder material.

[0062] Figure 1 This is a scanning electron microscope photograph of D-tryptophan chiral molecular imprinted modified RGO porous foam. It can be seen that there is a three-dimensional pore structure that penetrates each other. This structure can effectively increase the specific surface area of ​​the material and expose more chiral center active sites.

[0063] Figure 2 A scanning electron micrograph of RGO porous powder imprinted with D-tryptophan chiral molecules. The powder is obtained by grinding porous foam. The grinding process does not destroy the three-dimensional pore structure, effectively retaining its high porosity. It also possesses a large specific surface area and abundant chiral active sites.

[0064] Example 2

[0065] A method for preparing a chiral molecularly imprinted modified RGO porous foam or porous powder material comprises the following steps:

[0066] Step 1: Preparation of GO

[0067] Same as step 1 in Example 1.

[0068] Step 2: Composite of conjugated chiral molecules and GO

[0069] (1) Add 0.5 mg mL of L-tryptophan -1 , in 10 mL of GO aqueous dispersion, the mass ratio of L-tryptophan to GO was 0.01, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0070] (2) Freeze the above samples in liquid nitrogen for 5 minutes, place the frozen samples in a vacuum desiccator, and dry them at -10°C and 2 Pa vacuum for 5 hours;

[0071] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0072] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 200°C, kept constant for 0.01 hour, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous foam material. The RGO porous foam material was ground for 0.1 minute to obtain a chiral molecular imprinted modified RGO porous powder material.

[0073] Example 3

[0074] A method for preparing a chiral molecularly imprinted modified RGO porous foam or porous powder material comprises the following steps:

[0075] Step 1: Preparation of GO

[0076] Same as step 1 in Example 1.

[0077] Step 2: Composite of conjugated chiral molecules and GO

[0078] (1) Add 5 mg·mL of D-phenylalanine -1 , in 10 mL of GO aqueous dispersion, the mass ratio of D-phenylalanine to GO was 0.5, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0079] (2) Freeze the above samples in liquid nitrogen for 5 minutes, place the frozen samples in a vacuum desiccator, and dry them at -10°C and 2 Pa vacuum for 5 hours;

[0080] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0081] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 300°C, kept constant for 1 hour, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous foam material. The RGO porous foam material was ground for 1 minute to obtain a chiral molecular imprinted modified RGO porous powder material.

[0082] Example 4

[0083] A method for preparing a chiral molecularly imprinted modified RGO porous foam or porous powder material comprises the following steps:

[0084] Step 1: Preparation of GO

[0085] Same as step 1 in Example 1.

[0086] Step 2: Composite of conjugated chiral molecules and GO

[0087] (1) Add 5 mg mL of L-phenylalanine -1 , in 10 mL of GO aqueous dispersion, the mass ratio of L-phenylalanine to GO was 0.5, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0088] (2) Freeze the above samples in liquid nitrogen for 5 minutes, place the frozen samples in a vacuum desiccator, and dry them at -10°C and 2 Pa vacuum for 5 hours;

[0089] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0090] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 300°C, kept constant for 1 hour, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous foam material. The RGO porous foam material was ground for 1 minute to obtain a chiral molecular imprinted modified RGO porous powder material.

[0091] Example 5

[0092] A method for preparing a chiral molecularly imprinted modified RGO porous foam or porous powder material comprises the following steps:

[0093] Step 1: Preparation of GO

[0094] Same as step 1 in Example 1.

[0095] Step 2: Composite of conjugated chiral molecules and GO

[0096] (1) Add 10 mg mL of D-tyrosine -1 , in 10 mL of GO aqueous dispersion, the mass ratio of D-tyrosine to GO was 1, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0097] (2) Freeze the above samples in liquid nitrogen for 5 minutes, place the frozen samples in a vacuum desiccator, and dry them at -10°C and 2 Pa vacuum for 5 hours;

[0098] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0099] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 400°C, kept constant for 2 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous foam material. The RGO porous foam material was ground for 4 minutes to obtain a chiral molecular imprinted modified RGO porous powder material.

[0100] Example 6

[0101] A method for preparing a chiral molecularly imprinted modified RGO porous foam or porous powder material comprises the following steps:

[0102] Step 1: Preparation of GO

[0103] Same as step 1 in Example 1.

[0104] Step 2: Composite of conjugated chiral molecules and GO

[0105] (1) Add 10 mg mL of L-tyrosine -1 , in 10 mL of GO aqueous dispersion, the mass ratio of L-tyrosine to GO was 1, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0106] (2) Freeze the above samples in liquid nitrogen for 5 minutes, place the frozen samples in a vacuum desiccator, and dry them at -10°C and 2 Pa vacuum for 5 hours;

[0107] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0108] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 400°C, kept constant for 2 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous foam material. The RGO porous foam material was ground for 4 minutes to obtain a chiral molecular imprinted modified RGO porous powder material.

[0109] Example 7

[0110] A method for preparing a chiral molecularly imprinted modified RGO porous foam or porous powder material comprises the following steps:

[0111] Step 1: Preparation of GO

[0112] Same as step 1 in Example 1.

[0113] Step 2: Composite of conjugated chiral molecules and GO

[0114] (1) Add 40 mg mL of D-histidine -1 , in 10 mL of GO aqueous dispersion, the mass ratio of D-histidine to GO was 5, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0115] (2) Freeze the above samples in liquid nitrogen for 5 minutes, place the frozen samples in a vacuum desiccator, and dry them at -10°C and 2 Pa vacuum for 5 hours;

[0116] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0117] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 500°C, kept constant for 3 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous foam material. The RGO porous foam material was ground for 8 minutes to obtain a chiral molecular imprinted modified RGO porous powder material.

[0118] Example 8

[0119] A method for preparing a chiral molecularly imprinted modified RGO porous foam or porous powder material comprises the following steps:

[0120] Step 1: Preparation of GO

[0121] Same as step 1 in Example 1.

[0122] Step 2: Composite of conjugated chiral molecules and GO

[0123] (1) Add 40 mg mL of L-histidine -1 , in 10 mL of GO aqueous dispersion, the mass ratio of L-histidine to GO was 5, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0124] (2) Freeze the above samples in liquid nitrogen for 5 minutes, place the frozen samples in a vacuum desiccator, and dry them at -10°C and 2 Pa vacuum for 5 hours;

[0125] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0126] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 500°C, kept constant for 3 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous foam material. The RGO porous foam material was ground for 8 minutes to obtain a chiral molecular imprinted modified RGO porous powder material.

[0127] Example 9

[0128] A method for preparing a chiral molecularly imprinted modified RGO porous foam or porous powder material comprises the following steps:

[0129] Step 1: Preparation of GO

[0130] Same as step 1 in Example 1.

[0131] Step 2: Composite of conjugated chiral molecules and GO

[0132] (1) Add 100 mg·mL of R-dibenzo(C,G)phenanthrene -1 , in 10 mL of GO aqueous dispersion, the mass ratio of R-dibenzo(C,G)phenanthrene to GO was 10, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0133] (2) Freeze the above samples in liquid nitrogen for 5 minutes, place the frozen samples in a vacuum desiccator, and dry them at -10°C and 2 Pa vacuum for 5 hours;

[0134] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0135] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 1000°C, kept constant for 4 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous foam material. The RGO porous foam material was ground for 10 minutes to obtain a chiral molecular imprinted modified RGO porous powder material.

[0136] Example 10

[0137] A method for preparing a chiral molecularly imprinted modified RGO porous foam or porous powder material comprises the following steps:

[0138] Step 1: Preparation of GO

[0139] Same as step 1 in Example 1.

[0140] Step 2: Composite of conjugated chiral molecules and GO

[0141] (1) Add 100 mg·mL of S-dibenzo(C,G)phenanthrene -1 , in 10 mL of GO aqueous dispersion, the mass ratio of S-dibenzo(C,G)phenanthrene to GO was 10, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0142] (2) Freeze the above samples in liquid nitrogen for 5 minutes, place the frozen samples in a vacuum desiccator, and dry them at -10°C and 2 Pa vacuum for 5 hours;

[0143] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0144] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min-1 The heating rate was increased from 50°C to 1000°C, kept constant for 4 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous foam material. The RGO porous foam material was ground for 10 minutes to obtain a chiral molecular imprinted modified RGO porous powder material.

[0145] Example 11

[0146] A method for preparing a chiral molecular imprinted modified RGO porous film comprises the following steps:

[0147] Step 1: Preparation of GO

[0148] Same as step 1 in Example 1.

[0149] Step 2: Composite of conjugated chiral molecules and GO

[0150] (1) Add 5 mg mL of D-tryptophan -1 , in 10 mL of GO aqueous dispersion, the mass ratio of D-tryptophan to GO was 0.01, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0151] (2) Spin-coat the mixed dispersion onto the ITO glass at 900 rpm for 9 s.

[0152] (3) Freeze the spin-coated sample in liquid nitrogen for 5 minutes, place the frozen sample in a vacuum desiccator, and dry it at -10°C and 2 Pa vacuum for 5 hours;

[0153] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0154] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The temperature was raised from 50°C to 400°C, held constant for 2 hours, and then cooled to room temperature to obtain a chiral molecularly imprinted RGO porous film. The preparation of the chiral molecularly imprinted RGO compact film did not require freeze-drying; the remaining steps were identical to those for the preparation of the chiral molecularly imprinted RGO porous film. The chiral molecularly imprinted RGO porous film and the compact film were each fabricated into electrodes for electrochemical chiral detection of D- and L-tryptophan chiral solutions.

[0155] Figure 3 The XRD spectra of GO and D-tryptophan composite GO (D-Trp / GO) are shown in Figure 3. The interlayer spacing of GO and D-tryptophan composite GO is calculated to be 0.82nm and 0.88nm respectively by the Bragg diffraction equation. The increase in the interlayer spacing proves that D-tryptophan is successfully attached to the GO surface through the π-π interaction between GO. Figure 4 This is a scanning electron microscope photo of the RGO porous film modified with D-tryptophan chiral molecular imprinting. It can be seen that the porous film has a highly cross-linked three-dimensional pore structure and an ultra-thin pore wall. This structure can effectively increase the specific surface area of ​​the material and expose more chiral center active sites. The test results show that the specific surface area of ​​the porous film is as high as 805m 2 ·g -1 , the sheet resistance is less than Electrodes prepared by modifying RGO porous films with D-tryptophan molecules were used to perform electrochemical chiral detection of D- and L-tryptophan chiral solutions, respectively. Both showed obvious current responses, proving that the porous film has excellent conductivity. In addition, the detection current of D-tryptophan is significantly higher than that of L-tryptophan, indicating a higher recognition efficiency, with a peak current ratio of about 1.3 times ( Figure 5 ), proving that the porous film has abundant chiral sites.

[0156] Example 12

[0157] A method for preparing a chiral molecular imprinted modified RGO porous film comprises the following steps:

[0158] Step 1: Preparation of GO

[0159] Same as step 1 in Example 1.

[0160] Step 2: Composite of conjugated chiral molecules and GO

[0161] (1) Add 0.5 mg mL of L-tryptophan -1 , in 10 mL of GO aqueous dispersion, the mass ratio of L-tryptophan to GO was 0.01, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0162] (2) Spin-coat the mixed dispersion onto the ITO glass at a speed of 100 rpm for 5 s.

[0163] (3) Freeze the spin-coated sample in liquid nitrogen for 5 minutes, place the frozen sample in a vacuum desiccator, and dry it at -10°C and 2 Pa vacuum for 5 hours;

[0164] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0165] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 200°C, kept constant for 0.01 hour, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous film.

[0166] Example 13

[0167] A method for preparing a chiral molecular imprinted modified RGO porous film comprises the following steps:

[0168] Step 1: Preparation of GO

[0169] Same as step 1 in Example 1.

[0170] Step 2: Composite of conjugated chiral molecules and GO

[0171] (1) Add 5 mg·mL of D-phenylalanine -1 , in 10 mL of GO aqueous dispersion, the mass ratio of D-phenylalanine to GO was 0.5, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0172] (2) Spin-coat the mixed dispersion onto the ITO glass at a spin-coating speed of 1000 rpm for 7 s.

[0173] (3) Freeze the spin-coated sample in liquid nitrogen for 5 minutes, place the frozen sample in a vacuum desiccator, and dry it at -10°C and 2 Pa vacuum for 5 hours;

[0174] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0175] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50 °C to 300 °C, kept constant for 1 hour, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous film.

[0176] Example 14

[0177] A method for preparing a chiral molecular imprinted modified RGO porous film comprises the following steps:

[0178] Step 1: Preparation of GO

[0179] Same as step 1 in Example 1.

[0180] Step 2: Composite of conjugated chiral molecules and GO

[0181] (1) Add 5 mg mL of L-phenylalanine -1 , in 10 mL of GO aqueous dispersion, the mass ratio of L-phenylalanine to GO was 0.5, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0182] (2) Spin-coat the mixed dispersion onto the ITO glass at a spin-coating speed of 100 rpm for 7 s.

[0183] (3) Freeze the spin-coated sample in liquid nitrogen for 5 minutes, place the frozen sample in a vacuum desiccator, and dry it at -10°C and 2 Pa vacuum for 5 hours;

[0184] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0185] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50 °C to 300 °C, kept constant for 1 hour, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous film.

[0186] Example 15

[0187] A method for preparing a chiral molecular imprinted modified RGO porous film comprises the following steps:

[0188] Step 1: Preparation of GO

[0189] Same as step 1 in Example 1.

[0190] Step 2: Composite of conjugated chiral molecules and GO

[0191] (1) Add 10 mg mL of D-tyrosine -1 , in 10 mL of GO aqueous dispersion, the mass ratio of D-tyrosine to GO was 1, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0192] (2) Spin-coat the mixed dispersion onto the ITO glass at 900 rpm for 9 s.

[0193] (3) Freeze the spin-coated sample in liquid nitrogen for 5 minutes, place the frozen sample in a vacuum desiccator, and dry it at -10°C and 2 Pa vacuum for 5 hours;

[0194] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0195] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50 °C to 400 °C, kept constant for 2 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous film.

[0196] Example 16

[0197] A method for preparing a chiral molecular imprinted modified RGO porous film comprises the following steps:

[0198] Step 1: Preparation of GO

[0199] Same as step 1 in Example 1.

[0200] Step 2: Composite of conjugated chiral molecules and GO

[0201] (1) Add 10 mg mL of L-tyrosine -1 , in 10 mL of GO aqueous dispersion, the mass ratio of L-tyrosine to GO was 1, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0202] (2) Spin-coat the mixed dispersion onto the ITO glass at 900 rpm for 9 s.

[0203] (3) Freeze the spin-coated sample in liquid nitrogen for 5 minutes, place the frozen sample in a vacuum desiccator, and dry it at -10°C and 2 Pa vacuum for 5 hours;

[0204] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0205] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50 °C to 400 °C, kept constant for 2 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous film.

[0206] Example 17

[0207] A method for preparing a chiral molecular imprinted modified RGO porous film comprises the following steps:

[0208] Step 1: Preparation of GO

[0209] Same as step 1 in Example 1.

[0210] Step 2: Composite of conjugated chiral molecules and GO

[0211] (1) Add 40 mg mL of D-histidine -1 , in 10 mL of GO aqueous dispersion, the mass ratio of D-histidine to GO was 5, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0212] (2) Spin-coat the mixed dispersion onto the ITO glass at a spin-coating speed of 1200 rpm for 60 s.

[0213] (3) Freeze the spin-coated sample in liquid nitrogen for 5 minutes, place the frozen sample in a vacuum desiccator, and dry it at -10°C and 2 Pa vacuum for 5 hours;

[0214] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0215] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 500°C, kept constant for 3 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous film.

[0216] Example 18

[0217] A method for preparing a chiral molecular imprinted modified RGO porous film comprises the following steps:

[0218] Step 1: Preparation of GO

[0219] Same as step 1 in Example 1.

[0220] Step 2: Composite of conjugated chiral molecules and GO

[0221] (1) Add 40 mg mL of L-histidine -1 , in 10 mL of GO aqueous dispersion, the mass ratio of L-histidine to GO was 5, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0222] (2) Spin-coat the mixed dispersion onto the ITO glass at a spin-coating speed of 1200 rpm for 60 s.

[0223] (3) Freeze the spin-coated sample in liquid nitrogen for 5 minutes, place the frozen sample in a vacuum desiccator, and dry it at -10°C and 2 Pa vacuum for 5 hours;

[0224] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0225] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 500°C, kept constant for 3 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous film.

[0226] Example 19

[0227] A method for preparing a chiral molecular imprinted modified RGO porous film comprises the following steps:

[0228] Step 1: Preparation of GO

[0229] Same as step 1 in Example 1.

[0230] Step 2: Composite of conjugated chiral molecules and GO

[0231] (1) Add 80 mg mL of R-dibenzo(C,G)phenanthrene -1 , in 10 mL of GO aqueous dispersion, the mass ratio of R-dibenzo(C,G)phenanthrene to GO was 10, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0232] (2) Spin-coat the mixed dispersion onto the ITO glass at a spin-coating speed of 1500 rpm for 120 s.

[0233] (3) Freeze the spin-coated sample in liquid nitrogen for 5 minutes, place the frozen sample in a vacuum desiccator, and dry it at -10°C and 2 Pa vacuum for 5 hours;

[0234] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0235] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 1000°C, kept constant for 4 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous film.

[0236] Implementation 20

[0237] A method for preparing a chiral molecular imprinted modified RGO porous film comprises the following steps:

[0238] Step 1: Preparation of GO

[0239] Same as step 1 in Example 1.

[0240] Step 2: Composite of conjugated chiral molecules and GO

[0241] (1) Add 80 mg mL of S-dibenzo(C,G)phenanthrene -1 , in 10 mL of GO aqueous dispersion, the mass ratio of S-dibenzo(C,G)phenanthrene to GO was 10, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0242] (2) Spin-coat the mixed dispersion onto the ITO glass at a spin-coating speed of 1200 rpm for 120 s.

[0243] (3) Freeze the spin-coated sample in liquid nitrogen for 5 minutes, place the frozen sample in a vacuum desiccator, and dry it at -10°C and 2 Pa vacuum for 5 hours;

[0244] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0245] The freeze-dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 1000°C, kept constant for 4 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO porous film.

[0246] Implementation 21

[0247] A method for preparing a chiral molecular imprinted modified RGO film comprises the following steps:

[0248] Step 1: Preparation of GO

[0249] Same as step 1 in Example 1.

[0250] Step 2: Composite of conjugated chiral molecules and GO

[0251] (1) Add 0.5 mg mL D-tryptophan -1 , in 10 mL of GO aqueous dispersion, the mass ratio of D-tryptophan to GO was 0.01, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0252] (2) Spin-coat the mixed dispersion onto the ITO glass at a speed of 100 rpm for 5 s.

[0253] (3) Allow the spin-coated sample to dry naturally overnight;

[0254] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0255] The dried sample was placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50 °C to 200 °C, kept constant for 0.01 h, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO film.

[0256] Figure 6 This is a scanning electron microscope photograph of the RGO film modified with D-tryptophan chiral molecular imprinting. A dense and flat film surface can be seen. The specific surface area of ​​this film is much lower than that of porous RGO and graphene. Therefore, the number of chiral center active sites will also be reduced accordingly.

[0257] Implementation 22

[0258] A method for preparing a chiral molecular imprinted modified RGO film comprises the following steps:

[0259] Step 1: Preparation of GO

[0260] Same as step 1 in Example 1.

[0261] Step 2: Composite of conjugated chiral molecules and GO

[0262] (1) Add 100 mg mL of L-tryptophan -1 , in 10 mL of GO aqueous dispersion, the mass ratio of L-tryptophan to GO was 10, and the mixture was uniformly mixed by ultrasonication for 10 min;

[0263] (2) Spin-coat the mixed dispersion onto the ITO glass at a spin-coating speed of 1500 rpm for 120 s.

[0264] (3) Allow the spin-coated sample to dry naturally overnight;

[0265] Step 3: Conjugated chiral molecular imprinting modification of RGO

[0266] The dried sample was placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 1000°C, kept constant for 4 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified RGO film.

[0267] Example 23

[0268] A method for preparing a chiral molecularly imprinted modified graphene film comprises the following steps:

[0269] Step 1: Preparation and transfer of graphene film. The preparation process of graphene film is described in reference NanoLett., 2009, 9, 4362. Since it is not protected by this patent, it is omitted here. The steps for transferring the graphene film are as follows:

[0270] (1) Graphene was grown on copper foil. A chlorobenzene solution of PMMA (4 wt%) was spin-coated on the graphene. The spin-coating parameters were: 500 rpm for 5 s and 3000 rpm for 60 s.

[0271] (2) Etching the copper substrate. Float the PMMA / graphene / copper sample on the surface of a 0.3M ammonium persulfate solution. Wait 2-3 hours for the copper substrate to be completely etched, yielding the PMMA / graphene sample. Rinse the sample with water twice, 10 minutes each time.

[0272] (3) Ultrasonic cleaning of the target substrate ITO glass. Place the target substrate in acetone, ethanol, and distilled water for 2 minutes.

[0273] (4) Use the target substrate to remove the PMMA / graphene sample from the distilled water, dry it naturally overnight, and then heat it at 150°C for 10 minutes.

[0274] (5) Removal of PMMA: Soak the PMMA / graphene / target substrate in acetone for two rounds, each lasting 15 minutes.

[0275] (6) Finally, the sample surface is blown dry with N2 to obtain a graphene / target substrate sample.

[0276] Step 2: Composite of conjugated chiral molecules and graphene

[0277] (1) Dissolve D-tryptophan in a solution (volume ratio of water to ethanol is 1:1) and sonicate for 2 minutes;

[0278] (2) Drop the D-tryptophan solution onto the surface of the graphene film and let it stand for 2 minutes; spin coat the film at 600 rpm for 30 seconds and dry it at room temperature for 2 hours.

[0279] Step 3: Conjugated chiral molecular imprinting modification of graphene

[0280] The spin-coated and dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 400°C, kept constant for 2 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified graphene film.

[0281] Figure 7 Aberration-corrected transmission electron micrograph of graphene modified with D-tryptophan chiral molecular imprinting. The continuous honeycomb lattice of graphene is partially covered by a thin layer composed of five-membered rings, sometimes adjacent to six-membered rings. The observed structural features indicate that the pyrrole and indole layers covering the graphene are derived from D-tryptophan molecules, indicating that the molecular backbone of D-tryptophan is imprinted on the graphene basal plane.

[0282] Example 24

[0283] A method for preparing a chiral molecularly imprinted modified graphene film comprises the following steps:

[0284] Step 1: Preparation and transfer of graphene film.

[0285] Same as step 1 in Example 21.

[0286] Step 2: Composite of conjugated chiral molecules and graphene

[0287] (1) Dissolve L-tryptophan in a solution (volume ratio of water to ethanol is 1:1) and sonicate for 2 minutes;

[0288] (2) Drop L-tryptophan solution on graphene and let it stand for 0.01 minutes; spin coating with the spin coating parameters of 100 rpm for 5 seconds and drying at room temperature for 2 hours.

[0289] Step 3: Conjugated chiral molecular imprinting modification of graphene

[0290] The spin-coated and dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 200°C, kept constant for 0.01 hour, and cooled to room temperature to obtain a chiral molecular imprinted modified graphene film.

[0291] Example 25

[0292] A method for preparing a chiral molecularly imprinted modified graphene film comprises the following steps:

[0293] Step 1: Preparation and transfer of graphene film

[0294] Same as step 1 in Example 21.

[0295] Step 2: Composite of conjugated chiral molecules and graphene

[0296] (1) Dissolve D-phenylalanine in a solution (volume ratio of water to ethanol is 1:1) and sonicate for 2 minutes;

[0297] (2) Drop D-phenylalanine solution on graphene and let it stand for 2 minutes; spin coating with the spin coating parameters of 600 rpm for 7 seconds and dry at room temperature for 2 hours.

[0298] Step 3: Conjugated chiral molecular imprinting modification of graphene

[0299] The spin-coated and dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 300°C, kept constant for 1 hour, and cooled to room temperature to obtain a chiral molecular imprinted modified graphene film.

[0300] Example 26

[0301] A method for preparing a chiral molecularly imprinted modified graphene film comprises the following steps:

[0302] Step 1: Preparation and transfer of graphene film

[0303] Same as step 1 in Example 21.

[0304] Step 2: Composite of conjugated chiral molecules and graphene

[0305] (1) Dissolve L-phenylalanine in a solution (the volume ratio of water to ethanol is 1:1) and sonicate for 2 minutes;

[0306] (2) Drop L-phenylalanine solution on graphene and let it stand for 6 minutes; spin coating with the spin coating parameters of 600 rpm for 7 seconds and drying at room temperature for 2 hours.

[0307] Step 3: Conjugated chiral molecular imprinting modification of graphene

[0308] The spin-coated and dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 300°C, kept constant for 1 hour, and cooled to room temperature to obtain a chiral molecular imprinted modified graphene film.

[0309] Example 27

[0310] A method for preparing a chiral molecularly imprinted modified graphene film comprises the following steps:

[0311] Step 1: Preparation and transfer of graphene film

[0312] Same as step 1 in Example 21.

[0313] Step 2: Composite of conjugated chiral molecules and graphene

[0314] (1) Dissolve D-tyrosine in a solution (volume ratio of water to ethanol is 1:1) and sonicate for 2 minutes;

[0315] (2) Drop the D-tyrosine solution on the graphene and let it stand for 10 minutes; spin coat the graphene with the spin coating parameters of 900 rpm for 9 seconds and dry it at room temperature for 2 hours.

[0316] Step 3: Conjugated chiral molecular imprinting modification of graphene

[0317] The spin-coated and dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 400°C, kept constant for 2 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified graphene film.

[0318] Example 28

[0319] A method for preparing a chiral molecularly imprinted modified graphene film comprises the following steps:

[0320] Step 1: Preparation and transfer of graphene film

[0321] Same as step 1 in Example 21.

[0322] Step 2: Composite of conjugated chiral molecules and graphene

[0323] (1) Dissolve L-tyrosine in a solution (the volume ratio of water to ethanol is 1:1) and sonicate for 2 minutes;

[0324] (2) Drop L-tyrosine solution on graphene and let it stand for 10 minutes; spin coating with the spin coating parameters of 900 rpm for 9 seconds and drying at room temperature for 2 hours.

[0325] Step 3: Conjugated chiral molecular imprinting modification of graphene

[0326] The spin-coated and dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 400°C, kept constant for 2 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified graphene film.

[0327] Example 29

[0328] A method for preparing a chiral molecularly imprinted modified graphene film comprises the following steps:

[0329] Step 1: Preparation and transfer of graphene film

[0330] Same as step 1 in Example 21.

[0331] Step 2: Composite of conjugated chiral molecules and graphene

[0332] (1) Dissolve D-histidine in a solution (volume ratio of water to ethanol is 1:1) and sonicate for 2 minutes;

[0333] (2) Drop D-histidine solution on graphene and let it stand for 30 minutes; spin coating with the spin coating parameters of 1200 rpm for 60 seconds and drying at room temperature for 2 hours.

[0334] Step 3: Conjugated chiral molecular imprinting modification of graphene

[0335] The spin-coated and dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1The heating rate was increased from 50°C to 500°C, kept constant for 3 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified graphene film.

[0336] Example 30

[0337] A method for preparing a chiral molecularly imprinted modified graphene film comprises the following steps:

[0338] Step 1: Preparation and transfer of graphene film

[0339] Same as step 1 in Example 21.

[0340] Step 2: Composite of conjugated chiral molecules and graphene

[0341] (1) Dissolve L-histidine in a solution (volume ratio of water to ethanol is 1:1) and sonicate for 2 minutes;

[0342] (2) Drop L-histidine solution on graphene and let it stand for 30 minutes; spin coating with the spin coating parameters of 1200 rpm for 60 seconds and drying at room temperature for 2 hours.

[0343] Step 3: Conjugated chiral molecular imprinting modification of graphene

[0344] The spin-coated and dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 500°C, kept constant for 3 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified graphene film.

[0345] Example 31

[0346] A method for preparing a chiral molecularly imprinted modified graphene film comprises the following steps:

[0347] Step 1: Preparation and transfer of graphene film

[0348] Same as step 1 in Example 21.

[0349] Step 2: Composite of conjugated chiral molecules and graphene

[0350] (1) Dissolve R-dibenzo(C,G)phenanthrene in a solution (volume ratio of water to ethanol is 1:1) and sonicate for 2 minutes;

[0351] (2) Drop the R-dibenzo(C,G)phenanthrene solution on the graphene and let it stand for 60 minutes; spin-coat it with the spin-coating parameters of 1500 rpm for 120 seconds and dry it at room temperature for 2 hours.

[0352] Step 3: Conjugated chiral molecular imprinting modification of graphene

[0353] The spin-coated and dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 1000°C, kept constant for 4 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified graphene film.

[0354] Example 32

[0355] A method for preparing a chiral molecularly imprinted modified graphene film comprises the following steps:

[0356] Step 1: Preparation and transfer of graphene film

[0357] Same as step 1 in Example 21.

[0358] Step 2: Composite of conjugated chiral molecules and graphene

[0359] (1) Dissolve S-dibenzo(C,G)phenanthrene in a solution (volume ratio of water to ethanol is 1:1) and sonicate for 2 minutes;

[0360] (2) Drop the S-dibenzo(C,G)phenanthrene solution on the graphene and let it stand for 60 minutes; spin-coat it with the spin-coating parameters of 1500 rpm for 120 seconds and dry it at room temperature for 2 hours.

[0361] Step 3: Conjugated chiral molecular imprinting modification of graphene

[0362] The spin-coated and dried samples were placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 1000°C, kept constant for 4 hours, and cooled to room temperature to obtain a chiral molecular imprinted modified graphene film.

[0363] Example 33

[0364] A method for preparing chiral molecularly imprinted modified graphene powder and foam material comprises the following steps:

[0365] Step 1: Preparation of graphene powder and foam material. The preparation process of graphene powder and foam material can be found in references Carbon, 2015, 92, 84, Nat. Mater., 2011, 10, 424, which are omitted here because they are not protected by this patent.

[0366] Step 2: Composite of conjugated chiral molecules and graphene

[0367] (1) Dissolve D-tryptophan in the solution and sonicate for 2 minutes;

[0368] (2) Graphene powder and foam material were immersed in D-tryptophan solution and allowed to stand for 0.01 minutes; after being taken out, they were dried naturally.

[0369] Step 3: Conjugated chiral molecular imprinting modification of graphene

[0370] The dried sample was placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 200°C, kept constant for 2 hours, and cooled to room temperature to obtain chiral molecular imprinted modified graphene powder and foam material.

[0371] Since the morphology of the chiral molecular imprinted modified graphene powder and foam material is highly consistent with the morphology of the chiral molecular imprinted modified RGO powder and foam material in the scanning electron microscope images with lower magnification, the scanning electron microscope images of the chiral molecular imprinted modified graphene powder and foam material are not shown here.

[0372] Example 34

[0373] A method for preparing chiral molecularly imprinted modified graphene powder and foam material comprises the following steps:

[0374] Step 1: Preparation of graphene powder and foam materials.

[0375] Same as step 1 in Example 31.

[0376] Step 2: Composite of conjugated chiral molecules and graphene

[0377] (1) Dissolve L-tryptophan in the solution and sonicate for 2 minutes;

[0378] (2) Graphene powder and foam material are immersed in L-tryptophan solution and allowed to stand for 60 minutes; then they are taken out and dried naturally.

[0379] Step 3: Conjugated chiral molecular imprinting modification of graphene

[0380] The dried sample was placed in a tube furnace for heat treatment. The parameters were set as follows: under argon atmosphere, at 0.5 °C·min -1 The heating rate was increased from 20℃ to 50℃ at 5℃·min -1 The heating rate was increased from 50°C to 1000°C, kept constant for 4 hours, and cooled to room temperature to obtain chiral molecular imprinted modified graphene powder and foam material.

[0381] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for preparing a chiral molecularly imprinted graphene material, characterized in that: The graphene material is graphene or reduced graphene oxide modified with chiral molecular imprinting, wherein the chiral recognition site is located on the surface of the graphene or reduced graphene oxide; The chiral molecule has a conjugated structure and is selected from D-tryptophan, D-phenylalanine, L-phenylalanine, D-tyrosine, L-tyrosine, D-histidine, L-histidine, R-dibenzo(C,G)phenanthrene, S-dibenzo(C,G)phenanthrene and their derivatives; The preparation method comprises the following steps: uniformly mixing the chiral molecule with the graphene oxide aqueous dispersion to obtain a mixed dispersion; And, further, i) freeze-drying and heat-treating the mixed dispersion to obtain a chiral molecularly imprinted reduced graphene oxide porous foam material; or ii) freeze-drying and heat-treating the mixed dispersion to obtain a chiral molecularly imprinted reduced graphene oxide porous foam material, and grinding the porous foam material to obtain a chiral molecularly imprinted reduced graphene oxide porous powder material; or iii) spin-coating the mixed dispersion on a substrate, drying, and heat-treating to obtain a chiral molecularly imprinted reduced graphene oxide thin film material; or The preparation method comprises the following steps: Dissolving the chiral molecule in a solvent to obtain a chiral molecule solution; And, further, iv) coating the chiral molecule solution on the graphene surface, spin coating, drying, and heat treating to obtain a chiral imprinted modified graphene film material; or v) soaking the graphene powder or graphene foam in a chiral molecule solution, removing the graphene powder or graphene foam, drying the graphene powder or graphene foam, and heat treating the chiral imprinted modified graphene powder or graphene foam.

2. The preparation method according to claim 1, characterized in that In the graphene material, the skeleton of the chiral molecule is compounded with graphene or reduced graphene oxide through π-π interaction.

3. The preparation method according to claim 1, characterized in that The graphene material is a porous or non-porous film, porous foam or porous powder.

4. The preparation method according to claim 1, characterized in that The concentration of the graphene oxide aqueous dispersion is 0.5 to 100 mg mL -1 , the mass ratio of the chiral molecule to graphene oxide is 0.01 to 10.

5. The preparation method according to claim 1, characterized in that The heat treatment conditions are independently: heat treatment temperature of 200 to 1000° C., and heat treatment time of 0.01 to 4 hours.

6. The preparation method according to claim 1, characterized in that In step iii) and step iv), during spin coating, the rotation speed is 100 to 1500 rpm and the coating time is 5 to 120 seconds.

7. The preparation method according to claim 1, characterized in that In step iii), the drying method is freeze drying or natural drying; When the drying method is freeze-drying, a chiral molecularly imprinted reduced graphene oxide porous film material is prepared; When the drying method is natural drying, the prepared chiral molecular imprinted modified reduced graphene oxide film material without pores is obtained.

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