A method for constructing chiral nanochannels of polyazobenzene nanomembrane and its application

Abstract

The present invention provides a method for constructing a chiral nanochannel of a polyazobenzene nanofilm and an application thereof. The method comprises the following steps: placing a cleaned and dried silicon nitride chip in a piranha solution for heating and cleaning for standby use; dissolving a chiral azobenzene polymer in a cyclopentanone solvent, spin-coating the cleaned silicon nitride chip to obtain a polyazobenzene nanofilm, and vacuum drying the film for standby use; then assembling the coated silicon nitride chip with a flowcell, injecting a buffer solution at both ends of the flowcell, connecting a patch clamp to measure an I-V curve, fitting the I-V curve to obtain a conductance G2, and when G2 drops below 1 and R 2m When the current rises significantly and there is no leakage current when voltage is applied, the polyazobenzene nanofilm is successfully coated on the silicon nitride chip; the polyazobenzene nanofilm is further placed in an electric field with a strength equivalent to the dielectric strength of the nanofilm, and the nanofilm is broken down to form nanopores, thereby obtaining a chiral nanochannel of the polyazobenzene nanofilm. The nanochannel preparation process of the present invention is simple, the nanopore size is easier to control, the film thickness is small, and the detection spatial resolution is better.

Description

Technical Field

[0001] The invention belongs to the technical field of nanochannel construction, and specifically relates to a construction method and application of a polyazobenzene nanomembrane chiral nanochannel. Background Art

[0002] Solid-state nanopores have made great progress in recent years due to their good mechanical stability, thermal stability, chemical stability, and easy modification. At present, with the vigorous development of solid-state nanopore preparation technology and new materials, solid-state nanopore devices with different material types, structural designs and functions have been derived. Conventional solid-state nanopores are divided into silicon-based nanopores, single-atom-layer two-dimensional material nanopores, and polymer pores according to different carrier materials. Compared with the first two nanopores, polymer nanopores have good biocompatibility and a large surface area inside the pore, so that active organic groups can serve as binding sites for a variety of molecules, which greatly promotes the research on functional modification of nanopores. Commonly used polymer materials for polymer nanopores include polyethylene terephthalate membrane (PET), polycarbonate (PC), polyimide (PI) and block copolymers (BCPs).

[0003] Traditional polymer nanopores have problems such as complex preparation process, difficult to control nanopore size, and low spatial resolution. Summary of the invention

[0004] In order to solve the problems in the prior art, the present invention spin-coats a polyazobenzene solution on a silicon nitride film chip to obtain a polyazobenzene nanomembrane, and then uses dielectric breakdown to form nanopores to form a new multifunctional chiral nanopore analysis platform, thereby providing a method for constructing a chiral nanochannel of a polyazobenzene nanomembrane and its application.

[0005] The present invention solves the technical problem by adopting the following technical solutions:

[0006] The first object of the present invention is to provide a method for constructing a chiral nanochannel of a polyazobenzene nanomembrane, characterized in that:

[0007] The cleaned and dried silicon nitride chip was placed in a piranha solution for heating and cleaning, and the chiral azobenzene polymer was dissolved in a cyclopentanone solvent and spin-coated on the cleaned silicon nitride chip to obtain a polyazobenzene nanofilm, which was then vacuum dried and used. The coated silicon nitride chip was then assembled with a flow cell, and a buffer solution was injected at both ends of the flow cell. The patch clamp was connected to measure the IV curve, and the IV curve was fitted to obtain the conductance G2. When G2 dropped below 1 and R 2mWhen the current rises significantly and there is no leakage current when voltage is applied, the polyazobenzene nanofilm is successfully coated on the silicon nitride chip; the polyazobenzene nanofilm is then placed in an electric field with an intensity equivalent to the dielectric strength of the nanofilm, and the nanofilm breaks down to form nanopores, thereby obtaining a chiral nanochannel of the polyazobenzene nanofilm.

[0008] Furthermore, the thickness of the polyazobenzene nanofilm is 10 to 50 nm.

[0009] Furthermore, the diameter of the nanopore is 3-6 nm.

[0010] Furthermore, the steps of cleaning the silicon nitride chip are: immersing the silicon nitride chip in acetone, water, and ethanol in sequence, and after drying, placing the silicon nitride chip in a piranha solution and heating it for 1 hour to complete the cleaning of the silicon nitride chip.

[0011] Furthermore, the buffer solution is a mixed solution of 1M KCl, 10mM Tris, 1mM EDTA, pH=8.

[0012] Furthermore, the silicon nitride chips are screened before spin coating, and silicon nitride nanopore chips with a pore size of 10 to 50 nm are selected as the supporting substrate of the polymer film.

[0013] Furthermore, after the silicon nitride chip is cleaned and dried, it is first assembled with the flowcell, buffer solution is injected at both ends of the flowcell, the patch clamp is connected to measure the IV curve, the IV curve is fitted to obtain the conductance G1, the pore size of the silicon nitride film is recorded, and the silicon nitride film chips are screened, and silicon nitride chips with a pore size of 10-50nm are selected as the membrane support substrate.

[0014] Furthermore, the synthesis process of the chiral azobenzene polymer is as follows: an azobenzene monomer, an initiator 5% azobisisobutyronitrile (AIBN), and dry NN dimethylformamide (DMF) are added to a dry Schlenk tube, and after three cycles of freezing, vacuuming, and nitrogen filling, a polymerization reaction is carried out; then the Schlenk tube is quickly placed in an ice-water mixture to cool to terminate the reaction, and finally the reaction solution is slowly added to a methanol solution to precipitate a yellow solid, which is vacuum dried to obtain an azobenzene polymer.

[0015] Furthermore, the amount of azobenzene monomer and NN dimethylformamide added is 0.1-0.5 g: 0.7-1 ml.

[0016] Furthermore, the amount of the added initiator azobisisobutyronitrile is 5% of the mass of the azobenzene monomer.

[0017] Furthermore, the ratio of the methanol solution to the azobenzene monomer is 50-200 ml: 0.1-0.5 g.

[0018] Furthermore, the polymerization reaction conditions are 70° C. and 65 to 80 hours.

[0019] Furthermore, the preparation method of the azobenzene monomer is: 4'-hydroxyazobenzene-4-carboxylic acid hydrate and sodium bicarbonate are mixed in N,N-dimethylacetamide (DMAC), and then (S)-2-methylbutyl p-toluenesulfonate is added for reaction, and Azo-3 is obtained by recrystallization; N,N'-dicyclohexylcarbodiimide (DCC) is dissolved in dichloromethane to obtain a mixed solution 1, and the mixed solution 1 is added dropwise to a mixed solution 2 containing methacrylic acid, 4-dimethylaminopyridine (DMAP), Azo-3, and dry CH2Cl2 to react, and the azobenzene monomer is obtained by filtering, washing, and silica gel column chromatography.

[0020] The reaction formula is as follows:

[0021]

[0022] Furthermore, during silica gel column chromatography, dichloromethane and hexane in a volume ratio of 1:4 were first used for separation, and then dichloromethane and hexane in a volume ratio of 1:1 were used for purification.

[0023] The second object of the present invention is to provide an application of a polyazobenzene nanomembrane chiral nanochannel in the detection of chiral biomacromolecule conformation.

[0024] Furthermore, the method for detecting the conformation of chiral biomacromolecules is as follows: assemble the polyazobenzene nanomembrane chiral nanochannel with the flowcell, add 10nM chiral biomacromolecules at the cis end of the flowcell, inject buffer at the trans end, connect the patch clamp, apply 50-100mV bias, obtain the electrical signal difference caused by the differential interaction between different chiral biomacromolecules and chiral membrane channels, and thus identify the conformational differences of chiral molecules.

[0025] Furthermore, the chiral biomacromolecule is a nucleic acid, a protein or an oligosaccharide.

[0026] Furthermore, the nucleic acid is a nucleic acid G-quadruplex.

[0027] Furthermore, the 10 nM chiral biomacromolecule is prepared by preparing a 10 nM chiral biomacromolecule solution in a buffer solution of 1 M KCl, 10 mM Tris, 1 mM EDTA, pH 7.4, annealing the solution at 95° C. for 5 min, and then cooling the solution at room temperature for 1 h.

[0028] Compared with the prior art, the beneficial technical effects of the present invention are:

[0029] The polyazobenzene nanofilm chiral nanochannel of the present invention is different from the traditional organic polymer nanochannel with micron-level thickness. The polymer membrane channel length provided is in the sub-ten nanometer range, and can provide a spatial resolution significantly higher than that of the traditional polymer channel. The polyazobenzene chiral nanochannel of the present invention has a simple preparation process, the nanopore size is easier to control, and the film thickness is small, and the detection spatial resolution is better.

[0030] The polyazobenzene nanomembrane chiral nanochannel of the present invention realizes high capture detection of nucleic acid G-quadruplexes and is a new multifunctional chiral nanopore analysis platform, which provides a direction for subsequent detection and analysis of other single molecules using the multifunctional chiral nanopore analysis platform.

[0031] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The present invention is a schematic diagram of a method for constructing a chiral nanochannel of a polyazobenzene nanomembrane and a process for detecting electrical signals of a nucleic acid G-quadruplex.

[0033] Figure 2 This is a data characteristic distribution diagram of a polyazobenzene nanomembrane chiral nanochannel in the present invention in the detection of nucleic acid G-quadruplex electrical signals.

[0034] in, Figure 2 (A) is the original translocation trajectory of nucleic acid G-quadruplex through the chiral nanochannel of polyazobenzene nanomembrane driven by a voltage of 50 mV to 100 mV in a buffer solution of 1 M KCl, 10 mM Tris, 1 mM EDTA, pH 7.4; Figure 2 (B) is the distribution diagram of the blocking amplitude of nucleic acid G-quadruplex ion current under different transmembrane potentials; Figure 2 (C) is a scatter plot of the ion current blockade amplitude distribution and translocation time; Figure 2 (D) is a line graph of translocation time and voltage. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following embodiments are only exemplary illustrations and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope of protection that the present invention is intended to protect.

[0036] In addition, unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0037] The flowcell used in the present invention is a liquid pool made of PDMS and PEEK.

[0038] Embodiment 1:

[0039] A method for constructing a chiral nanochannel of a polyazobenzene nanofilm comprises the following steps: Figure 1 , which is the construction of chiral nanochannels in polyazobenzene nanomembranes and the electrical signal detection process of nucleic acid G-quadruplexes.

[0040] 1) Synthesis of azobenzene polymers

[0041] A mixture of 2 g of 4'-hydroxyazobenzene-4-carboxylic acid hydrate and 0.672 g of sodium bicarbonate in 6.856 ml of N,N-dimethylacetamide (DMAC) was stirred at 90°C for 4 h. 1.72 ml of (S)-2-methylbutyl p-toluenesulfonate was added to the mixed solution after the reaction. The mixture was stirred at 90°C for 8 hours to react, cooled to room temperature, and poured into water. The yellow precipitate was filtered out, recrystallized in ethanol-water with a volume ratio of 1:1 overnight, and finally the solvent was removed on a rotary evaporator and dried to obtain Azo-3.

[0042] At room temperature, 0.82 g of N,N'-dicyclohexylcarbodiimide (DCC) was dissolved in 3.85 ml of dry dichloromethane (CH2Cl2) to obtain a mixed solution 1. Then, the mixed solution 1 was added dropwise to a mixed solution of 0.5 g of methacrylic acid, 0.024 g of 4-dimethylaminopyridine (DMAP), 0.6 g of Azo-3, and 7.69 ml of dry CH2Cl2 at room temperature, and the mixed solution after the addition was stirred at 30°C for 72 h. Then, the solution after the reaction was filtered to obtain a mixture, and washed with water, 1.2 M HCl, 5% sodium bicarbonate aqueous solution and water in sequence, and a yellow solid was obtained after removing the solvent. Finally, the pure monomer is separated from the impurities by silica gel column chromatography using dichloromethane (CH2Cl2) and hexane (Hexane) in a volume ratio of 1:4 as eluent, and then purified by silica gel column chromatography using CH2Cl2 and Hexane in a volume ratio of 1:1 as eluent to obtain a yellow solid, i.e., azobenzene monomer.

[0043] Add 0.1g of azobenzene monomer obtained above, 5% initiator azobisisobutyronitrile (AIBN) of azobenzene monomer mass fraction, and 0.7ml dry NN dimethylformamide (DMF) into a dry Schlenk tube. After three cycles of freezing, vacuuming and nitrogen filling, the polymerization reaction was carried out at 70°C for 72h. After the reaction was completed, the Schlenk tube was quickly placed in an ice-water mixture to cool to terminate the reaction. Finally, the reaction solution was slowly added to 100ml of methanol solution to precipitate a yellow solid. Finally, the obtained precipitate was placed on a rotary evaporator to drain the solvent to obtain an azobenzene polymer.

[0044] The organic synthesis process of azobenzene polymer is as follows:

[0045]

[0046] 2) Composite of polyazobenzene nanofilm and silicon nitride

[0047] First, the silicon nitride chip was placed in acetone, water and ethanol for 20 minutes to remove organic and inorganic pollutants on the surface. Then, the cleaned and dried silicon nitride chip was placed in piranha solution and heated at 90°C for 1 hour to further remove surface pollutants and increase surface hydrophilicity. Then, the silicon nitride chip was assembled with the flow cell, 1M KCl, TE, pH = 8 buffer was injected into both ends of the flow cell, and the patch clamp was connected to measure the IV curve. The IV curve was fitted to obtain the conductance G1, and the pore size and membrane capacitance (C 1m ) and membrane resistance (R 1m ). Select a silicon nitride chip with a pore size range of 10-50nm.

[0048] The cleaned silicon nitride chip was placed on a spin coater, and the organically synthesized azobenzene polymer was dissolved in a cyclopentanone solvent, and 5-10 μl was dropped on the silicon nitride chip. Next, the spin coater firstly rotated at a speed of 500 rpm and an acceleration of 100 rpm for 10 seconds to evenly spin coat the azobenzene polymer solution on the silicon nitride chip; then, the spin coater rotated at a speed of 4000 rpm and an acceleration of 3000 rpm for 40 seconds to obtain an azobenzene nanofilm. Finally, the spin-coated silicon nitride chip was placed in a vacuum drying oven and vacuum dried at 120°C overnight to remove the solvent.

[0049] The coated silicon nitride chip was assembled with the flow cell, 1M KCl, 10mM Tris, 1mM EDTA, pH=8 buffer was injected into both ends of the flow cell, and the patch clamp was connected to measure the IV curve. The IV curve was fitted to obtain the conductance G2, and the pore size and membrane capacitance (C 2m ) and membrane resistance (R 2m). If G2 drops below 1 and R 2m If the voltage rises significantly and no leakage current is generated when voltage is applied, it means that the polyazobenzene nanofilm is successfully coated on the silicon nitride chip.

[0050] 3) Preparation of chiral nanochannels in polyazobenzene nanomembranes

[0051] By providing current pulses through a power meter, the polyazobenzene nanofilm is exposed to an electric field with a strength comparable to the dielectric strength of the film. The charge accumulation and thermal effect of the strong electric field will generate leakage current at the structural defects of the film, resulting in dielectric breakdown of the film and the formation of nanopores, resulting in chiral nanochannels in the polyazobenzene nanofilm.

[0052] Embodiment 2:

[0053] A method for constructing a chiral nanochannel of a polyazobenzene nanomembrane comprises the following steps:

[0054] 1) Synthesis of azobenzene polymers

[0055] 0.5 g of the azobenzene monomer obtained in Example 1, 5% initiator azobisisobutyronitrile (AIBN) by mass fraction of azobenzene monomer, and 1 ml of dry NN dimethylformamide (DMF) were added to a dry Schlenk tube. After three cycles of freezing, vacuuming and nitrogen filling, the polymerization reaction was carried out at 70°C for 80 hours. After the reaction was completed, the Schlenk tube was quickly placed in an ice-water mixture to cool to terminate the reaction. Finally, the reaction solution was slowly added to 150 ml of methanol solution to precipitate a yellow solid. Finally, the obtained precipitate was placed on a rotary evaporator to drain the solvent to obtain an azobenzene polymer.

[0056] 2) Composite of polyazobenzene nanofilm and silicon nitride

[0057] First, the silicon nitride chip was placed in acetone, water and ethanol for 20 minutes to remove organic and inorganic pollutants on the surface. Then, the cleaned and dried silicon nitride chip was placed in piranha solution and heated at 90°C for 1 hour to further remove surface pollutants and increase surface hydrophilicity. Then, the silicon nitride chip was assembled with the flow cell, 1M KCl, TE, pH = 8 buffer was injected into both ends of the flow cell, and the patch clamp was connected to measure the IV curve. The IV curve was fitted to obtain the conductance G1, and the pore size and membrane capacitance (C 1m ) and membrane resistance (R 1m ). A silicon nitride chip with a pore size range of 10-50 nm was selected as the membrane support substrate.

[0058] The cleaned silicon nitride chip was placed on a spin coater, and the organically synthesized azobenzene polymer was dissolved in a cyclopentanone solvent, and 5-10 μl was dropped on the silicon nitride chip. Next, the spin coater firstly rotated at a speed of 500 rpm and an acceleration of 100 rpm for 10 seconds to evenly spin coat the azobenzene polymer solution on the silicon nitride chip; then, the spin coater rotated at a speed of 4000 rpm and an acceleration of 3000 rpm for 40 seconds to obtain an azobenzene nanofilm. Finally, the spin-coated silicon nitride chip was placed in a vacuum drying oven and vacuum dried at 120°C overnight to remove the solvent.

[0059] The coated silicon nitride chip was assembled with the flow cell, 1M KCl, 10mM Tris, 1mM EDTA, pH=8 buffer was injected into both ends of the flow cell, and the patch clamp was connected to measure the IV curve. The IV curve was fitted to obtain the conductance G2, and the pore size and membrane capacitance (C 2m ) and membrane resistance (R 2m ). If G2 drops below 1 and R 2m If the voltage rises significantly and no leakage current is generated when voltage is applied, it means that the polyazobenzene nanofilm is successfully coated on the silicon nitride chip.

[0060] 3) Preparation of chiral nanochannels in polyazobenzene nanomembranes

[0061] By providing current pulses through a power meter, the polyazobenzene nanofilm is exposed to an electric field with a strength comparable to the dielectric strength of the film. The charge accumulation and thermal effect of the strong electric field will generate leakage current at the structural defects of the film, resulting in dielectric breakdown of the film and the formation of nanopores, resulting in chiral nanochannels in the polyazobenzene nanofilm.

[0062] Embodiment 3:

[0063] Detection process of nucleic acid G-quadruplex electrical signal:

[0064] 10 nM nucleic acid G-quadruplex was prepared in a buffer solution of 1 M KCl, 10 mM Tris, 1 mM EDTA, pH 7.4, annealed at 95° C. for 5 min, and then cooled at room temperature for 1 h to form a G4 structure.

[0065] Using the polyazobenzene nanomembrane chiral nanochannel obtained in Example 1, 10 nM nucleic acid G-quadruplex was added to the cis end of the flowcell, and 1 M KCl, 10 mM Tris, 1 mM EDTA, pH 7.4 buffer solution was added to the trans end. Then, the flowcell was connected to the patch clamp, and a bias of 50-100 mV was applied to obtain the electrical signal of the nucleic acid G-quadruplex passing through the polyazobenzene nanomembrane chiral nanochannel. The collected nucleic acid G-quadruplex electrical signal was analyzed on the Clampfit software, and the analysis data is attached. Figure 2 shown.

[0066] Figure 2 (A) is the original translocation trajectory of nucleic acid G-quadruplex through the chiral nanochannel of polyazobenzene nanomembrane driven by a voltage of 50 mV to 100 mV in a buffer solution of 1 M KCl, 10 mM Tris, 1 mM EDTA, pH 7.4. It can be seen from the figure that as the voltage gradually increases, the frequency of the electrical signal of nucleic acid G-quadruplex per unit time gradually increases. Figure 2 (B) is the distribution diagram of the ion current blockade amplitude of nucleic acid G-quadruplex under different transmembrane potentials. It can be seen from the figure that as the transmembrane potential gradually increases, the ion current blockade amplitude tends to increase. Figure 2 (C) is the scatter plot of the ion current blockade amplitude distribution and translocation time. Figure 2 (D) is a line graph of translocation time and voltage. It can be seen from the figure that at a voltage of 50-100 mV, there are two current amplitude distributions, and the translocation time increases with the increase of the transmembrane voltage. It can be concluded that when the nucleic acid G-quadruplex passes through this nanochannel, the small molecules of the nucleic acid G-quadruplex will also interact with the nanopore channel wall, thereby extending the translocation time. From the preliminary test results, it can be seen that this azobenzene nanomembrane nanopore can detect nucleic acid G-quadruplexes, proving that the constructed new polymer nanopore analysis platform is successful, and provides a new direction for the subsequent use of this platform to detect and analyze other single molecules.

[0067] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A method for constructing a chiral nanochannel of a polyazobenzene nanomembrane, characterized in that: The cleaned and dried silicon nitride chip was placed in a piranha solution for heating and cleaning, and the chiral azobenzene polymer was dissolved in a cyclopentanone solvent and spin-coated on the cleaned silicon nitride chip to obtain a polyazobenzene nanofilm, which was then vacuum dried and used. The coated silicon nitride chip was then assembled with a flow cell, and a buffer solution was injected at both ends of the flow cell. The patch clamp was connected to measure the IV curve, and the IV curve was fitted to obtain the conductance G2. When G2 dropped below 1 and R 2m When the current rises significantly and there is no leakage current when voltage is applied, the polyazobenzene nanofilm is successfully coated on the silicon nitride chip; the polyazobenzene nanofilm is then placed in an electric field with an intensity equivalent to the dielectric strength of the nanofilm, and the nanofilm breaks down to form nanopores, thereby obtaining a chiral nanochannel of the polyazobenzene nanofilm.

2. A method for constructing a chiral nanochannel of a polyazobenzene nanofilm as claimed in claim 1, characterized in that: The thickness of the polyazobenzene nanofilm is 10 to 50 nm.

3. A method for constructing a chiral nanochannel of a polyazobenzene nanofilm as claimed in claim 1, characterized in that: The steps of cleaning the silicon nitride chip are as follows: soak the silicon nitride chip in acetone, water, and ethanol in turn, and after drying, place the silicon nitride chip in a piranha solution and heat it for 1 hour to complete the cleaning of the silicon nitride chip.

4. A method for constructing a chiral nanochannel of a polyazobenzene nanofilm as claimed in claim 1, characterized in that: The buffer solution is a mixed solution of 1M KCl, 10mM Tris, 1mM EDTA, pH=8.

5. A method for constructing a chiral nanochannel of a polyazobenzene nanofilm as claimed in claim 3, characterized in that: After the silicon nitride chip is cleaned and dried, it is first assembled with the flowcell, buffer solution is injected at both ends of the flowcell, and the patch clamp is connected to measure the IV curve. The IV curve is fitted to obtain the conductance G1, the pore size of the silicon nitride film is recorded, and the silicon nitride film chips are screened. Silicon nitride chips with a pore size of 10-50nm are selected as the membrane support substrate.

6. A method for constructing a chiral nanochannel of a polyazobenzene nanofilm as claimed in claim 1, characterized in that: The synthesis process of the chiral azobenzene polymer is as follows: an azobenzene monomer, an initiator azobisisobutyronitrile, and dry NN dimethylformamide are added to a dry Schlenk tube, and a polymerization reaction is carried out after three cycles of freezing, vacuuming, and nitrogen filling; then the Schlenk tube is quickly placed in an ice-water mixture to cool to terminate the reaction, and finally the reaction solution is slowly added to a methanol solution to precipitate a yellow solid, which is then vacuum dried to obtain an azobenzene polymer.

7. A method for constructing a chiral nanochannel of a polyazobenzene nanofilm as claimed in claim 6, characterized in that: The amount of the added initiator azobisisobutyronitrile is 5% of the mass of the azobenzene monomer.

8. A method for constructing a chiral nanochannel of a polyazobenzene nanofilm as claimed in claim 6, characterized in that: The preparation method of the azobenzene monomer comprises the following steps: mixing 4'-hydroxyazobenzene-4-carboxylic acid hydrate and sodium bicarbonate in N,N-dimethylacetamide (DMAC), then adding (S)-2-methylbutyl p-toluenesulfonate for reaction, and recrystallizing to obtain Azo-3; dissolving N,N'-dicyclohexylcarbodiimide (DCC) in dichloromethane to obtain a mixed solution 1, and dropping the mixed solution 1 into a mixed solution 2 containing methacrylic acid, 4-dimethylaminopyridine (DMAP), Azo-3, and dry CH2Cl2 for reaction, filtering, washing, and performing silica gel column chromatography to obtain the azobenzene monomer.

9. Use of the polyazobenzene nanomembrane chiral nanochannel according to any one of claims 1 to 8 in the detection of chiral biomacromolecule conformation.

10. The use according to claim 9, characterized in that The method for detecting the conformation of chiral biomacromolecules is as follows: assembling a polyazobenzene nanomembrane chiral nanochannel with a flowcell, adding 10 nM chiral biomacromolecules to the cis end of the flowcell, injecting a buffer solution to the trans end, connecting a patch clamp, applying a bias voltage of 50 to 100 mV, and obtaining an electrical signal of the chiral biomacromolecules passing through the polyazobenzene nanomembrane chiral nanochannel.

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