Mb-COF nano-channel loaded filter membrane and preparation method thereof

Abstract

The invention relates to the technical field of nano-channel filter membranes, in particular to a filter membrane loaded with an Mb-COF nano-channel and a preparation method thereof.The preparation method comprises the steps that 2D COF is introduced into a cylindrical nano-channel through an in-situ growth technology, then the COF nano-channel loaded on the filter membrane is modified with Mb based on the aperture matching effect, and the filter membrane loaded with the Mb-COF nano-channel is obtained. The Mb-COF nano-channel loaded filter membrane with chiral selectivity is obtained through the method, the Mb-COF nano-channel loaded filter membrane is expected to be used for separating and / or detecting selective transport of chiral drug molecules through the membrane, and the preparation method is mild in reaction condition, simple and convenient to operate and easy to popularize and use.

Description

Technical Field

[0001] The invention relates to the technical field of nanochannel filter membranes, and in particular to a filter membrane loaded with Mb-COF nanochannels and a preparation method thereof. Background Art

[0002] Covalent organic framework (COF) is a new type of organic material, which is composed of organic units with controllable structure connected by covalent bonds. COF materials have advantages such as high crystallinity, large specific surface area, high conductivity, high porosity, low skeleton density and high thermochemical stability, so they are widely used in many fields. Myohemoglobin (Mb) is a small molecule pigment protein, which consists of a polypeptide chain and a cofactor heme. The hydrophobic side chains on the amino acid residues in the polypeptide chain are mostly located inside the molecule, while the hydrophilic side chains are mostly on the surface of the molecule, so it has good water solubility.

[0003] How to load Mb onto the COF covalent skeleton to mimic the cellular transport mechanism for drug separation and detection is a new challenge in the current application of COF nanochannels. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the first object of the present invention is to provide a method for preparing a filter membrane loaded with Mb-COF nanochannels; the second object of the present invention is to provide a filter membrane loaded with Mb-COF nanochannels.

[0005] In order to achieve the first purpose, the technical solution adopted by the present invention is: A method for preparing a filter membrane loaded with Mb-COF nanochannels comprises the following steps: S100, preparing cylindrical nanochannels on a polyethylene terephthalate (PET) membrane by a track etching method to obtain a filter membrane without nanochannel loading; S200, placing the etched PET membrane in a mixed solution of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDC) and N-hydroxysuccinimide (NHS) for activation, and then placing it in a R1-NH2 solution for reaction for 12 to 24 hours to covalently anchor R1-NH2 to the carboxyl group in the nanochannel, thereby obtaining a nanochannel filter membrane modified with R1-NH2; Wherein, R1 is selected from one or more of alkyl, alkenyl, alkynyl and aromatic groups; S300, placing the R1-NH2 modified nanochannel filter membrane in a polytetrafluoroethylene mold, applying voltage to the polytetrafluoroethylene mold, placing the R2CHO solution in the positive terminal of the polytetrafluoroethylene mold, placing the R1-NH2 solution containing the catalyst in the negative terminal of the polytetrafluoroethylene mold, reacting at 50-70° C. for 36-48 hours, and obtaining a filter membrane loaded with COF nanochannels; Wherein, R2 is selected from one or more of alkyl, alkenyl, alkynyl and aromatic groups; S400, preparing a Mb solution, immersing the filter membrane loaded with COF nanochannels in the Mb solution, reacting for 12 to 24 hours, and obtaining a filter membrane loaded with Mb-COF nanochannels.

[0006] Furthermore, in step S100, the etching solution used in the track etching is a NaOH solution or a KOH solution, and the stop solution is a mixed solution of HCOOH and KCl.

[0007] Further, R1-NH2 is tert-butylamine (TB-NH2).

[0008] Further, R2CHO is 4.4'-(1,4-phenylenebis(acetylene-2,1-diyl))benzaldehyde.

[0009] Further, in step 300, the molar ratio of the added amounts of R2CHO and R1-NH2 is 1:3 to 4:1.

[0010] Furthermore, in step S300, the solvent of the R2CHO solution is a methylpyrrolidone (NMP) solution.

[0011] Furthermore, in step S300, the solvent of the R1-NH2 solution is a dimethylformamide (DMF) solution.

[0012] Furthermore, in step S300, the catalyst contained in the R1-NH2 solution is p-Toluenesulfonic acid (PTSA), and the molar ratio of R1-NH2 to PTSA added in the R1-NH2 solution is 1:20 to 3:1.

[0013] In order to achieve the second purpose, the technical solution adopted by the present invention is: A filter membrane loaded with Mb-COF nanochannels is prepared by any of the above methods for preparing a filter membrane loaded with Mb-COF nanochannels.

[0014] Furthermore, it has adsorption properties for S-configuration compounds.

[0015] The above one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: The present invention provides a filter membrane loaded with Mb-COF nanochannels and a preparation method thereof. A 2D COF is introduced into the columnar nanochannel of the filter membrane by an in-situ growth technique, and then Mb is modified into the COF-loaded nanochannel of the filter membrane based on the pore size matching effect, thereby obtaining a filter membrane loaded with Mb-COF nanochannels having chiral selectivity. The filter membrane is expected to be used for separation and / or detection of selective transport of chiral drug molecules through the membrane.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a SEM scan of a filter membrane without nanochannels provided in an embodiment of the present invention.

[0018] Figure 2 This is a LSMC scan of a filter membrane loaded with COF nanochannels provided in an embodiment of the present invention.

[0019] Figure 3 This is a LSMC scan of a filter membrane loaded with Mb-COF nanochannels provided in an embodiment of the present invention.

[0020] Figure 4 The XPS spectra of the filter membrane without nanochannel loading, the filter membrane loaded with COF nanochannel loading and the filter membrane loaded with Mb-COF nanochannel provided in the embodiments of the present invention are shown.

[0021] Figure 5 It is a curve diagram of the surface wettability change of the filter membrane loaded with Mb-COF nanochannels to S-PRF / R-PRF provided by an embodiment of the present invention.

[0022] Figure 6 It is a gating curve diagram of the filter membrane loaded with COF nanochannel and the filter membrane loaded with Mb-COF nanochannel provided in the embodiments of the present invention.

[0023] Figure 7 This is a diagram of the selective transport of S-PRF by a filter membrane loaded with Mb-COF nanochannels detected by HPLC provided in an embodiment of the present invention.

[0024] Figure 8 1 is a graph showing the separation efficiency of S-PRF by a filter membrane without nanochannels, a filter membrane loaded with COF nanochannels, and a filter membrane loaded with Mb-COF nanochannels provided in an embodiment of the present invention.

[0025] Fig. 9It is a numerical simulation diagram of the transport of proteins in the filter membrane loaded with COF nanochannels and the filter membrane loaded with Mb-COF nanochannels provided in the embodiments of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0027] In the following examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all available from commercial sources unless otherwise specified.

[0028] A method for preparing a filter membrane loaded with Mb-COF nanochannels comprises the following steps: S100, preparing cylindrical nanochannels on a PET membrane by a track etching method to obtain a filter membrane without nanochannel loading; S200, placing the filter membrane without nanochannel loading in a mixed solution of EDC and NHS for activation, and then placing it in a dimethylformamide solution of R1-NH2 for reaction for 12 to 24 hours, covalently anchoring R1-NH2 to the carboxyl group in the nanochannel, and obtaining a nanochannel filter membrane modified with R1-NH2; Among them, the molar ratio of EDC and NHS added was 3:1; S300, placing the R1-NH2 modified nanochannel filter membrane in a polytetrafluoroethylene mold, applying voltage to the polytetrafluoroethylene mold, placing the R2CHO solution in the positive terminal of the polytetrafluoroethylene mold, placing the R1-NH2 solution containing the catalyst in the negative terminal of the polytetrafluoroethylene mold, 50-70° C., in-situ growth for 36-48 hours, to obtain a filter membrane loaded with COF nanochannels; The concentration of the R2CHO solution is 1-4 μmol / ml, and the solvent of the R2CHO solution is NMP; the concentration of the R1-NH2 solution is 1-3 μmol / ml, and the solvent of the R1-NH2 solution is DMF; the catalyst in the R1-NH2 solution is PTSA, and the concentration is 1-2 μmol / ml; S400, preparing a Mb solution, immersing the filter membrane loaded with COF nanochannels in the Mb solution, reacting for 12 to 24 hours, and obtaining a filter membrane loaded with Mb-COF nanochannels.

[0029] Example 1 Preparation of a filter membrane loaded with Mb-COF nanochannels.

[0030] 1. Prepare cylindrical nanochannels on PET membrane to obtain a filter membrane without nanochannels. The process is as follows: Irradiate the front and back of the PET film with a 365nm wavelength ultraviolet lamp for 2 hours each.

[0031] Prepare 6M NaOH (40 ml) as etching solution and 1M HCOOH+1M KCl (40 ml) as blocking solution.

[0032] The irradiated PET film was clamped in a polytetrafluoroethylene mold, deionized water was added to both ends of the polytetrafluoroethylene mold, and it was placed on a magnetic stirrer and heated at 60°C for 2 hours. Subsequently, the blocking solution and the etching solution were placed on a magnetic stirrer and heated at 60°C for 2 hours.

[0033] After heating, pour out the deionized water in the polytetrafluoroethylene mold, and then insert the platinum electrodes on the picoammeter into both ends of the polytetrafluoroethylene mold.

[0034] The picoammeter instrument was set to direct current (DC) mode, 1V voltage, and etching solution was added to both ends of the polytetrafluoroethylene for 4 minutes. After etching, the etching solution was sucked out with a pipette, and the PET membrane was rinsed and then added with blocking solution for scanning for 40 minutes. After scanning, the blocking solution was sucked out with a pipette, rinsed, and then added with deionized water for scanning for 40 minutes. The PET membrane was placed in deionized water overnight to obtain a filter membrane without nanochannel loading. The scanning electron microscope (SEM) scanning results of the filter membrane without nanochannel loading are shown as follows: Figure 1 shown.

[0035] Second, the loaded nanochannels were modified with -NH2. The process was as follows: the filter membrane loaded with cylindrical nanochannels was placed in a mixed solution of 150 mM EDC (20 mL) and 50 mM NHS (20 mL) for activation for 2.5 h, and then the activated filter membrane was placed in a 1 mM 20 mL TB-NH2 DMF solution for overnight reaction to obtain a nanochannel filter membrane modified with TB-NH2; 3. In situ growth of COF in the TB-NH2 modified nanochannel to obtain a filter membrane loaded with COF nanochannels, the process is as follows: Prepare 10 ml of 3 μmol / ml 4.4'-(1,4-phenylenebis(acetylene-2,1-diyl))benzaldehyde NMP solution and 10 ml of 2 μmol / ml tert-butylamine DMF solution, and add 0.1 mmol PTSA to the tert-butylamine DMF solution; The picoammeter was set to direct current (DC) mode with a voltage of 1 V. The TB-NH2-modified nanochannel filter membrane was clamped at both ends of the polytetrafluoroethylene mold. The 4.4'-(1,4-phenylenebis(acetylene-2,1-diyl))dibenzaldehyde NMP solution was placed at the positive terminal, and the tert-butylamine DMF solution was placed at the negative terminal. The membrane was grown in situ at 60°C for two days to obtain a filter membrane loaded with COF nanochannels. The laser scanning confocal microscope (LSMC) scanning results of the COF nanochannels were shown in Figure 2. Figure 2 shown.

[0036] 4. Preparation of COF nanochannel filter membrane, the process is as follows: The concentration was 6.6×10 -5 The Mb solution was prepared by dipping the filter membrane loaded with COF nanochannels into the Mb solution and reacting overnight to obtain the filter membrane loaded with Mb-COF nanochannels. The LSMC scanning results of the Mb-COF nanochannels are shown in FIG. Figure 3 shown.

[0037] X-ray photoelectron spectroscopy (XPS) of filter membranes without nanochannels, filter membranes loaded with COF nanochannels, and filter membranes loaded with Mb-COF nanochannels Figure 4 As shown, the spectrum of the filter membrane loaded with COF nanochannels showed an N1s element peak at 400.84 eV, which indicated that COF was successfully grown in situ into the nanochannels; in addition, the presence of the Fe2p element peak at 707.16 eV in the filter membrane loaded with Mb-COF nanochannels and the change in the ratio of C and O elements indicated that Mb was successfully incorporated into the COF nanochannels.

[0038] The surface wettability of the filter membrane loaded with Mb-COF nanochannels to S-PRF / R-PRF was measured by contact angle method. Figure 5 As shown, it has relatively excellent wettability to S-PRF within 2.5 min, and the contact angle (CA) value decreases sharply from 62.5±2.7° at the beginning to 15.3±1.6° at the end, while for R-PRF, the CA value only decreases from 70.8±3.1° to 59.2±2.5°. The dynamic contact angle experiment shows that the filter membrane loaded with Mb-COF nanochannels is more receptive to S-PRF, so S-PRF is more likely to pass through the loaded Mb-COF nanochannels; Among them, PRF is platelet-rich fibrin.

[0039] The gating curves of the filter membrane loaded with COF nanochannels and the filter membrane loaded with Mb-COF nanochannels are shown in Figure 2. Figure 6 As shown, the results show that the enantioselectivity of the filter membrane loaded with Mb-COF nanochannels is significantly better than that of the filter membrane loaded with COF nanochannels.

[0040] The selective transport of S-PRF by the filter membrane loaded with Mb-COF nanochannels was detected by HPLC. Figure 7 As shown in FIG. 1 , the separation efficiency of the filter membrane without nanochannel loading, the filter membrane loaded with COF nanochannel loading, and the filter membrane loaded with Mb-COF nanochannel for S-PRF is shown in FIG. Figure 8 As shown, Figure 7 , Figure 8 The results showed that the membrane loaded with Mb-COF nanochannels exhibited obvious chiral selectivity, and the transport rate of S-PRF through the membrane loaded with Mb-COF nanochannels was 0.36 mmol▪m -2 ▪h -1 , the ee value is as high as 96.4%; in contrast, under the same conditions, the filter membrane loaded with COF nanochannels and the filter membrane without nanochannels could not control the transport of S / R-PRF and did not show chiral selectivity.

[0041] The possible mechanism of protein transport in the filter membrane loaded with COF nanochannels and the filter membrane loaded with Mb-COF nanochannels and the numerical simulation of the PRF concentration distribution, such as Fig. 9 As shown, the results indicate that compared with the filter membrane loaded with COF nanochannels and the filter membrane not loaded with nanochannels, the concentration of S-PRF entering the filter membrane loaded with Mb-COF nanochannels is higher, resulting in a larger concentration gradient of S-PRF through the filter membrane loaded with Mb-COF nanochannels, and S-PRF is only slightly enriched in the filter membrane loaded with COF nanochannels and the filter membrane not loaded with nanochannels.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a filter membrane loaded with Mb-COF nanochannels, characterized in that: The steps include: S100, preparing cylindrical nanochannels on a PET membrane by a track etching method to obtain a filter membrane without nanochannel loading; Wherein, PET film is polyethylene terephthalate film; S200, placing the etched PET membrane in a mixed solution of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and N-hydroxysuccinimide for activation, and then placing it in a R1-NH2 solution for reaction for 12 to 24 hours to covalently anchor R1-NH2 to the carboxyl group in the nanochannel to obtain a nanochannel filter membrane modified with R1-NH2; Wherein, R1 is selected from one or more of alkyl, alkenyl, alkynyl and aromatic groups; S300, placing the R1-NH2 modified nanochannel filter membrane in a polytetrafluoroethylene mold, applying voltage to the polytetrafluoroethylene mold, placing the R2CHO solution in the positive terminal of the polytetrafluoroethylene mold, placing the R1-NH2 solution containing the catalyst in the negative terminal of the polytetrafluoroethylene mold, 50-70° C., in-situ growth for 36-48 hours, to obtain a filter membrane loaded with COF nanochannels; Wherein, R2 is selected from one or more of alkyl, alkenyl, alkynyl and aromatic groups; S400, preparing a myoglobin solution, immersing the filter membrane loaded with COF nanochannels in the myoglobin solution, and reacting for 12 to 24 hours to obtain a filter membrane loaded with Mb-COF nanochannels.

2. The method for preparing a filter membrane loaded with Mb-COF nanochannels according to claim 1, characterized in that: In step S100, the etching solution used for track etching is NaOH solution or KOH solution, and the blocking solution is a mixed solution of HCOOH and KCl.

3. The method for preparing a filter membrane loaded with Mb-COF nanochannels according to claim 1, characterized in that: R1-NH2 is tert-butylamine.

4. The method for preparing a filter membrane loaded with Mb-COF nanochannels according to claim 1, characterized in that: R2CHO is 4.4'-(1,4-phenylenebis(ethynyl-2,1-diyl))benzaldehyde.

5. The method for preparing a filter membrane loaded with Mb-COF nanochannels according to claim 1, characterized in that: In step S300, the molar ratio of the added amounts of R2CHO and R1-NH2 is 1:3 to 4:

1.

6. The method for preparing a filter membrane loaded with Mb-COF nanochannels according to claim 1, characterized in that: In step S300, the solvent of the R2CHO solution is methyl pyrrolidone.

7. The method for preparing a filter membrane loaded with Mb-COF nanochannels according to claim 1, characterized in that: In steps S200 and S300, the solvent of the R1-NH2 solution is dimethylformamide.

8. The method for preparing a filter membrane loaded with Mb-COF nanochannels according to claim 1, characterized in that: In step S300, the catalyst contained in the R1-NH2 solution is p-toluenesulfonic acid, and the molar ratio of the amount of R1-NH2 added to the p-toluenesulfonic acid in the R1-NH2 solution is 1:20 to 3:

1.

9. A filter membrane loaded with Mb-COF nanochannels, characterized in that: The method is prepared by the method for preparing a filter membrane loaded with Mb-COF nanochannels as claimed in any one of claims 1 to 8.

10. The filter membrane loaded with Mb-COF nanochannels according to claim 9, characterized in that: It has adsorption capacity for S-configuration compounds.

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