A filter membrane loaded with mb-cof nanochannels and a preparation method thereof

Abstract

The application relates to the technical field of nanochannel filter membrane, in particular to a filter membrane loaded with Mb-COF nanochannels and a preparation method thereof. The preparation method introduces 2D COF into the cylindrical nanochannel through in-situ growth technology, then based on the pore size matching effect, Mb is modified into the COF nanochannel loaded on the filter membrane, a filter membrane loaded with Mb-COF nanochannels with chiral selectivity is obtained, the filter membrane loaded with Mb-COF nanochannels is expected to be used for separating and / or detecting the selective transport of chiral drug molecules through the membrane, the preparation method has mild reaction conditions, simple operation, and is easy to popularize and use.

Description

Technical Field

[0001] The present 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 frameworks (COFs) are a new type of organic material composed of organic units with controllable structures connected by covalent bonds. COF materials exhibit advantageous properties such as high crystallinity, large specific surface area, high electrical conductivity, high porosity, low backbone density, and high thermochemical stability, leading to their widespread application in various fields. Myohemoglobin (Mb) is a small molecule pigment protein composed of a polypeptide chain and a prosthetic group, heme. The hydrophobic side chains on the amino acid residues in the polypeptide chain are mostly located internally, while the hydrophilic side chains are mostly on the surface, resulting in 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 address 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:

[0006] A method for preparing a filter membrane loaded with Mb-COF nanochannels comprises the following steps:

[0007] S100, preparing cylindrical nanochannels on a polyethylene terephthalate (PET) membrane using a track etching method to obtain a filter membrane without nanochannel loading;

[0008] 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 groups in the nanochannel, thereby obtaining a nanochannel filter membrane modified with R1-NH2;

[0009] R1 is selected from one or more of alkyl, alkenyl, alkynyl and aryl;

[0010] S300, placing the R1-NH2 modified nanochannel filter membrane in a polytetrafluoroethylene mold, applying a voltage to the polytetrafluoroethylene mold, placing the R2CHO solution in the positive electrode end of the polytetrafluoroethylene mold, and placing the R1-NH2 solution containing a catalyst in the negative electrode end of the polytetrafluoroethylene mold, 50-70℃, reacting for 36-48h, to obtain a filter membrane loaded with COF nanochannels;

[0011] R2 is selected from one or more of alkyl, alkenyl, alkynyl and aryl;

[0012] S400, preparing an Mb solution, and soaking the filter membrane loaded with COF nanochannels in the Mb solution, reacting for 12-24h, to obtain a filter membrane loaded with Mb-COF nanochannels.

[0013] Further, 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.

[0014] Further, R1-NH2 is tert-butylamine (TB-NH2).

[0015] Further, R2CHO is 4.4'-(1,4-phenylenebis(ethyn-2,1-diyl))benzaldehyde.

[0016] Further, in step 300, the molar ratio of the addition amount of R2CHO to R1-NH2 is 1:3-4:1.

[0017] Further, in step S300, the solvent of the R2CHO solution is methylpyrrolidone (NMP) solution.

[0018] Further, in step S300, the solvent of the R1-NH2 solution is dimethyl formamide (DMF) solution.

[0019] Further, in step S300, the catalyst contained in the R1-NH2 solution is p-toluenesulfonic acid (PTSA), and the molar ratio of the addition amount of R1-NH2 to PTSA in the R1-NH2 solution is 1:20-3:1.

[0020] To achieve the second object, the technical scheme adopted by the present application is:

[0021] A filter membrane loaded with Mb-COF nanochannels is prepared by the preparation method of the filter membrane loaded with Mb-COF nanochannels described in any of the above.

[0022] Further, the compound with the S configuration has adsorption.

[0023] The one or more technical solutions described above in the embodiments of the present application have at least one of the following technical effects:

[0024] The present application provides a filter membrane loaded with Mb-COF nanochannels and a preparation method thereof, 2D COF is introduced into the cylindrical nanochannel of the filter membrane by in-situ growth technology, then Mb is modified into the COF nanochannel loaded on the filter membrane based on the pore size matching effect, and a filter membrane loaded with Mb-COF nanochannels with chiral selectivity is obtained, which is expected to be used for separating and / or detecting the selective transport of chiral drug molecules through the membrane.

[0025] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is the SEM scanning diagram of the filter membrane without loaded nanochannels provided by the embodiments of the present application.

[0027] Figure 2 is the LSMC scanning diagram of the filter membrane loaded with COF nanochannels provided by the embodiments of the present application.

[0028] Figure 3 is the LSMC scanning diagram of the filter membrane loaded with Mb-COF nanochannels provided by the embodiments of the present application.

[0029] Figure 4 is the XPS spectrum diagram of the filter membrane without loaded nanochannels, the filter membrane loaded with COF nanochannels and the filter membrane loaded with Mb-COF nanochannels provided by the embodiments of the present application.

[0030] Figure 5 is the surface wettability change curve diagram of the filter membrane loaded with Mb-COF nanochannels provided by the embodiments of the present application to S-PRF / R-PRF.

[0031] Figure 6 is the gating curve diagram of the filter membrane loaded with COF nanochannels and the filter membrane loaded with Mb-COF nanochannels provided by the embodiments of the present application.

[0032] Figure 7 is the HPLC detection graph of the selective transport of the filter membrane loaded with Mb-COF nanochannels to S-PRF provided by the embodiments of the present application.

[0033] 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.

[0034] Figure 9 This is a numerical simulation diagram of protein transport in a filter membrane loaded with COF nanochannels and a filter membrane loaded with Mb-COF nanochannels provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] To make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0036] In the following examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0037] A method for preparing a filter membrane loaded with Mb-COF nanochannels comprises the following steps:

[0038] S100, preparing cylindrical nanochannels on a PET membrane by a track etching method to obtain a filter membrane without nanochannel loading;

[0039] S200, placing the filter membrane without nanochannels 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 to covalently anchor R1-NH2 to the carboxyl groups in the nanochannels, thereby obtaining a nanochannel filter membrane modified with R1-NH2;

[0040] Among them, the molar ratio of EDC and NHS added was 3:1;

[0041] S300, placing the R1-NH2 modified nanochannel filter membrane in a polytetrafluoroethylene mold, applying voltage to the polytetrafluoroethylene mold, placing the R2CHO solution into the positive terminal of the polytetrafluoroethylene mold, placing the catalyst-containing R1-NH2 solution into the negative terminal of the polytetrafluoroethylene mold, and in situ growing at 50-70° C. for 36-48 hours to obtain a filter membrane loaded with COF nanochannels;

[0042] The concentration of the R2CHO solution is 1 to 4 μmol / ml, and the solvent of the R2CHO solution is NMP; the concentration of the R1-NH2 solution is 1 to 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 to 2 μmol / ml;

[0043] S400, preparing an Mb solution, soaking the filter membrane loaded with COF nanochannels in the Mb solution, and reacting for 12 to 24 hours to obtain a filter membrane loaded with Mb-COF nanochannels.

[0044] Example 1 Preparation of a filter membrane loaded with Mb-COF nanochannels.

[0045] 1. Prepare cylindrical nanochannels on a PET membrane to obtain a filter membrane without nanochannels. The process is as follows:

[0046] Irradiate the front and back of the PET film with a 365nm wavelength ultraviolet lamp for 2 hours each.

[0047] Prepare 6M NaOH (40 ml) as etching solution and 1M HCOOH+1M KCl (40 ml) as blocking solution.

[0048] The irradiated PET film was clamped into a polytetrafluoroethylene mold, deionized water was added to both ends of the polytetrafluoroethylene mold, and the mold was placed on a magnetic stirrer and heated at 60°C for 2 hours. Subsequently, the blocking solution and etching solution were placed on a magnetic stirrer and heated at 60°C for 2 hours.

[0049] 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.

[0050] The picoammeter was set to direct current (DC) mode with a voltage of 1V. Etching solution was added to both ends of the polytetrafluoroethylene and etched for 4 minutes. After etching, the etching solution was aspirated with a pipette, and the PET membrane was rinsed and then scanning was performed with blocking solution for 40 minutes. After scanning, the blocking solution was aspirated with a pipette, rinsed, and then scanning was performed with deionized water for 40 minutes. The PET membrane was placed in deionized water overnight to obtain a filter membrane without nanochannels. The scanning electron microscopy (SEM) scanning results of the membrane without nanochannels are shown as follows: Figure 1 shown.

[0051] 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. Subsequently, the activated filter membrane was placed in a 1 mM TB-NH2 solution (20 mL) in DMF for overnight reaction to obtain a nanochannel filter membrane modified with TB-NH2.

[0052] 3. In situ growth of COF within the TB-NH2 modified nanochannels to obtain a filter membrane loaded with COF nanochannels. The process is as follows:

[0053] Prepare 10 ml of a 3 μmol / ml solution of 4,4'-(1,4-phenylenebis(acetylene-2,1-diyl))benzaldehyde in NMP and 10 ml of a 2 μmol / ml solution of tert-butylamine in DMF. Add 0.1 mmol of PTSA to the DMF solution of tert-butylamine.

[0054] The picoammeter was set to direct current (DC) mode with a voltage of 1 V. The TB-NH2-modified nanochannel filter membrane was clamped between the two 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 as follows: Figure 2 shown.

[0055] 4. Preparation of COF nanochannel filter membrane, the process is as follows:

[0056] The concentration was 6.6×10 -5 The Mb solution was prepared by immersing the filter membrane loaded with COF nanochannels in PBS buffer with a concentration of 0.1 M and a pH of 8. The filter membrane loaded with Mb-COF nanochannels was reacted overnight to obtain the filter membrane loaded with Mb-COF nanochannels. The LSMC scanning results of the filter membrane loaded with Mb-COF nanochannels are shown in FIG. Figure 3 shown.

[0057] 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 4As shown in the figure, 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.

[0058] 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 in the figure, 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. 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. Therefore, S-PRF is more likely to pass through the loaded Mb-COF nanochannels.

[0059] Among them, PRF is platelet-rich fibrin.

[0060] 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.

[0061] The selective transport of S-PRF by the filter membrane loaded with Mb-COF nanochannels was detected by HPLC. Figure 7 As shown in Figure 2, the separation efficiency of the filter membrane without nanochannels, the filter membrane loaded with COF nanochannels and the filter membrane loaded with Mb-COF nanochannels for S-PRF is as follows: 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 was as high as 96.4%; in comparison, 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.

[0062] Possible mechanisms of protein transport in the filter membrane loaded with COF nanochannels and the filter membrane loaded with Mb-COF nanochannels and numerical simulation of PRF concentration distribution, as shown in Figure 9 The results show that, compared with the filter membrane loaded with COF nanochannels and the filter membrane without loaded nanochannels, the concentration of S-PRF into 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 only slight enrichment of S-PRF in the filter membrane loaded with COF nanochannels and the filter membrane without loaded nanochannels.

[0063] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, and not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

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 the R1-NH2 to the carboxyl groups 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 into the positive terminal of the polytetrafluoroethylene mold, placing the catalyst-containing R1-NH2 solution into the negative terminal of the polytetrafluoroethylene mold, and in situ growing at 50-70° C. 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, wherein: In step S100 , the etching solution used in the track etching is a NaOH solution or a KOH solution, and the stopper 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, wherein: R1-NH2 is tert-butylamine.

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

5. The method for preparing a filter membrane loaded with Mb-COF nanochannels according to claim 1, wherein: 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, wherein: 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, wherein: 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, wherein: In step S300, the catalyst contained in the R1-NH2 solution is p-toluenesulfonic acid, and the molar ratio of R1-NH2 to p-toluenesulfonic acid added to 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 according to 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 properties for S-configuration compounds.

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