Method for improving ion tolerance of self-electrophoretic driving micro-nanomotor and application thereof

Abstract

The application discloses a method for improving ion tolerance of self-electrophoretic driving micro-nanomotor and application thereof, and belongs to the technical field of micro-nanomotor.The method is characterized in that a metal organic framework (MOF) pore structure material is used to modify the surface of a self-electrophoretic driving micro-nanomotor, so that the ion tolerance of the self-electrophoretic driving micro-nanomotor in a high-salt environment is significantly improved.Compared with a self-electrophoretic driving micro-nanomotor without the surface modification of the MOF pore structure material, the ion tolerance of the self-electrophoretic driving micro-nanomotor with the surface modification of the MOF pore structure material can be improved by 266 times, so that the self-electrophoretic driving micro-nanomotor can keep stable movement under an electrolyte concentration of up to 150 mM.The ion quenching problem of the micro-nanomotor driven by the electrophoresis mechanism in a high-salt solution is solved, and the driving efficiency is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of micro-nano motor, and particularly relates to a method for improving ion tolerance of self-electrophoretic driving micro-nano motor and application thereof. BACKGROUND

[0002] Micro-nano motor can convert various types of energy (such as chemical energy, magnetic energy, acoustic energy and light energy) into mechanical movement, thereby performing complex tasks at the micro-nano level. With its precise controllability, high propulsion force and easy functionalization, micro-nano motor has become a promising candidate in biomedical applications, especially in the fields of drug delivery and precision medicine.

[0003] Among various types of micro-nano motor, self-electrophoretic driving micro-nano motor has attracted great interest. These self-electrophoretic driving micro-nano motors generate propulsion force through surface asymmetric chemical reactions, which is easy to adjust and provides great flexibility for design. Such self-electrophoretic driving micro-nano motor is expected to become an ideal artificial system for simulating biological chemotaxis phenomenon, i.e. cell migration guided by chemical gradient. They provide a promising platform for targeted drug delivery and precision medicine.

[0004] However, self-electrophoretic driving micro-nano motor faces ion quenching problem in high salt environment (such as blood and biological fluids). The classic Helmholtz-Smoluchowski theory shows that high ionic strength will cause the collapse of Debye layer, completely inhibiting the propulsion of self-electrophoretic driving. The salt concentration in biological medium is usually more than 150mM, for example, the osmotic pressure of blood is mainly maintained by Na + , Cl - and HCO3 - ions, and the concentration is usually between 290-310mM. Therefore, it is crucial to overcome the problem of high salt concentration (more than 150mM) in biological medium for biomedical applications. SUMMARY

[0005] To solve the above technical problems, the application provides a method for improving ion tolerance of self-electrophoretic driving micro-nano motor and application thereof.

[0006] To achieve the above purpose, the application provides the following technical solutions.

[0007] A method for improving ion tolerance of self-electrophoretic driving micro-nano motor, wherein the self-electrophoretic driving micro-nano motor is subjected to oxygen plasma treatment, and then a metal organic framework (MOF) pore structure material is modified on the surface of the self-electrophoretic driving micro-nano motor.

[0008] In a high salt environment, the traditional micro-nano motor often causes the collapse of the surface double electric layer (Debye layer) due to the ion shielding effect, which seriously weakens its self-electrophoretic driving performance. In view of this problem, the application innovatively modifies the metal organic framework (MOF) pore structure material on the surface of the micro-nano motor, which significantly improves the system ion tolerance through its unique pore structure. Specifically, the highly ordered nanoscale pores inside the MOF pore structure material form a three-dimensional ion transport network, which promotes the migration of electrolyte ions along the pores. By modifying the MOF porous material on the micro-nano motor, the application promotes the flow of ions around the particles and in the pores. The MOF pore structure material acts as an ion conductive channel, which can effectively maintain the "Debye layer" of the micro-nano motor in the electric field in a high salt environment, thereby maintaining the stability of the self-electrophoretic driving mechanism of the micro-nano motor. The highly ordered pore structure of the MOF porous material can act as an ion transport layer to effectively support fluid pumping in a high salt environment, which indicates that the metal organic framework material provides an ion conductive channel and effectively enhances the propulsion of the micro-nano motor, which is a key factor for improving ion tolerance.

[0009] The MOF pore structure material includes one of ZIF-8, UiO-66 and MIL-53 (Al).

[0010] Further, when the MOF pore structure material is ZIF-8, the method for improving the ion tolerance of the self-electrophoretic driving micro-nano motor includes the following steps:

[0011] The self-electrophoretic driving micro-nano motor is subjected to oxygen plasma treatment to obtain a pretreated self-electrophoretic driving micro-nano motor, and the surface of the self-electrophoretic driving micro-nano motor is modified by hydroxyl after the pretreatment;

[0012] The pretreated self-electrophoretic driving micro-nano motor is first added to a dimethyl imidazole aqueous solution, and then a soluble zinc salt aqueous solution is added, and the reaction is carried out for 30-60 min (such as 30 min, 40 min, 50 min or 60 min). After the reaction is completed, it is naturally cooled to room temperature, and the self-electrophoretic driving micro-nano motor is washed and dried.

[0013] The molar ratio of the dimethyl imidazole to the soluble zinc salt is 500:8.

[0014] The preparation method of the dimethyl imidazole aqueous solution is to dissolve dimethyl imidazole in water to obtain the dimethyl imidazole aqueous solution; and the preparation method of the soluble zinc salt aqueous solution is to dissolve the soluble zinc salt in water to obtain the soluble zinc salt aqueous solution.

[0015] Illustratively, the soluble zinc salt is zinc acetate dihydrate.

[0016] Further, when the MOF pore structure material is ZIF-8, the method for improving the ion tolerance of the self-electrophoretic driving micro / nanomotor comprises the following steps:

[0017] The self-electrophoretic driving micro / nanomotor is subjected to oxygen plasma treatment to obtain a pretreated self-electrophoretic driving micro / nanomotor;

[0018] 4.105 g (0.05 mol) of dimethylimidazole is dissolved in 50 mL of deionized water to obtain a dimethylimidazole aqueous solution; 0.183 g (0.0008 mol) of zinc acetate dihydrate is dissolved in 10 mL of deionized water to obtain a soluble zinc salt aqueous solution; the pretreated self-electrophoretic driving micro / nanomotor is immersed in the dimethylimidazole aqueous solution for 3 minutes, then the soluble zinc salt aqueous solution is added, and the reaction is carried out at room temperature and normal pressure for 40 min; after the reaction is completed, the self-electrophoretic driving micro / nanomotor is naturally cooled to room temperature, washed with deionized water and methanol, and dried to obtain a silicon nanowire micro / nanomotor with ZIF-8 pore structure material on the surface, which is an ion-tolerant self-electrophoretic driving micro / nanomotor and can be used in an environment with an ion concentration of 150 mM.

[0019] Further, when the MOF pore structure material is UiO-66, the method for improving the ion tolerance of the self-electrophoretic driving micro / nanomotor comprises the following steps:

[0020] The self-electrophoretic driving micro / nanomotor is subjected to oxygen plasma treatment to obtain a pretreated self-electrophoretic driving micro / nanomotor;

[0021] 0.25 mmol of zirconium tetrachloride, 0.25 mmol of terephthalic acid, and 30 mL of N,N-dimethylformamide are stirred uniformly, then poured into a reaction kettle, and the pretreated self-electrophoretic driving micro / nanomotor is placed in the solution and heated at a temperature of 145℃ for 48 hours; after the reaction is completed, the self-electrophoretic driving micro / nanomotor is naturally cooled to room temperature, washed, and dried.

[0022] When the MOF pore structure material is UiO-66, in the method for improving the ion tolerance of the self-electrophoretic driving micro / nanomotor, the step of washing and drying the self-electrophoretic driving micro / nanomotor is as follows: the self-electrophoretic driving micro / nanomotor is washed with DMF (N,N-dimethylformamide) and ethanol for 3 times to remove unreacted precursors, and then vacuum dried at 60℃ for 12 hours.

[0023] Further, when the MOF pore structure material is MIL-53 (Al), the method for improving the ion tolerance of the self-electrophoretic driving micro / nanomotor comprises the following steps:

[0024] The self-electrophoretic driving micro / nanomotor is subjected to oxygen plasma treatment to obtain a pretreated self-electrophoretic driving micro / nanomotor;

[0025] Aluminum nitrate nine water and terephthalic acid are dissolved in deionized water in a molar ratio of 1:1, stirred until dissolved, the obtained solution is transferred to a high-pressure reaction kettle, the pretreated self-electrophoretic driving micro-nano motor is placed in the solution, after reaction at 150 DEG C for 24 hours, washed with deionized water and methanol, vacuum drying at 80 DEG C.

[0026] The self-electrophoretic driving micro-nano motor comprises a silicon-based self-electrophoretic driving micro-nano motor or a titanium-based self-electrophoretic driving micro-nano motor.

[0027] Illustratively, the silicon-based self-electrophoretic driving micro-nano motor comprises a silicon nanowire micro-nano motor or a SiO2-Pt micro-nano motor.

[0028] And / or, the titanium-based self-electrophoretic driving micro-nano motor is selected from a TiO2-Pt micro-nano motor.

[0029] The application also provides a high-ionic-resistance self-electrophoretic driving micro-nano motor obtained by the above method, wherein the salt concentration of the high-ionic-resistance self-electrophoretic driving micro-nano motor is 150 mM, that is, the self-electrophoretic driving micro-nano motor treated by the method of the application can be applied under a salt concentration of 150 mM.

[0030] The application also provides application of the high-ionic-resistance self-electrophoretic driving micro-nano motor in micro-region object transport materials, targeted drug delivery materials or optical nerve regulation materials.

[0031] The high-ionic-resistance self-electrophoretic driving micro-nano motor of the application is a near-infrared driving micro-nano motor, wherein the near-infrared driving micro-nano motor can be guided in the direction of movement under the driving of near-infrared light and the control of an external magnetic field, the intensity of the near-infrared light is 10-1200 mW / cm 2 ; and the external magnetic field is a gradient magnetic field, the direction of which is adjustable.

[0032] Compared with the prior art, the application has the following advantages and technical effects:

[0033] 1. The application provides ion conduction channels by modifying the surface of the self-electrophoretic driving micro-nano motor with porous structure materials (such as ZIF-8, UiO-66 or MIL-53), so that the self-electrophoretic driving micro-nano motor maintains good propulsion performance in a high-salt solution.

[0034] 2. The self-electrophoretic driving micro-nano motor modified with MOF pore structure materials can be propelled by 980 nm near-infrared light, and can still move stably and controllably even through an artificial blood vessel covered with biological tissues, which provides a reliable power source for targeted drug delivery.

[0035] 3. The surface-modified MOF pore structure material is universal and expandable, for example, it can be expanded to other types of self-electrophoretic driving micro-nanomotor, significantly enhances the ion tolerance thereof, and unlocks new possibilities for biomedical applications;

[0036] 4. The surface-modified MOF pore structure material not only enhances the ion tolerance of the self-electrophoretic driving micro-nanomotor, but also endows the micro-nanomotor with a drug loading and pH-responsive release function, and has good biocompatibility, and is suitable for a drug delivery system. BRIEF DESCRIPTION OF DRAWINGS

[0037] The accompanying drawings, which form a part of the present application, are intended to provide further understanding of the present application, and the illustrative embodiments thereof and their descriptions serve to explain the present application, and do not constitute an improper limitation of the present application. In the drawings:

[0038] Figure 1 A synthesis path diagram of the silicon nanowire micro-nanomotor (MIS-Au@ZIF-8) based on the ZIF-8 pore structure material in Example 1 of the present application;

[0039] Figure 2 A SEM image of the silicon nanowire micro-nanomotor based on the ZIF-8 pore structure material in Example 1;

[0040] Figure 3 An EDX element distribution diagram of the silicon nanowire micro-nanomotor based on the ZIF-8 pore structure material in Example 1;

[0041] Figure 4 A salt tolerance curve diagram of the silicon nanowire micro-nanomotor based on the ZIF-8 pore structure material in Example 1 of the present application and the silicon nanowire micro-nanomotor in Comparative Example 1;

[0042] Figure 5 A schematic diagram of the movement process of the silicon nanowire micro-nanomotor based on the ZIF-8 pore structure material in Example 1 under the driving of 980 nm near-infrared light in an artificial blood vessel;

[0043] Figure 6 SEM images of the Janus-structured TiO2-Pt@ZIF-8 micro-nanomotor in Example 2 and the Janus-structured SiO2-Pt@ZIF-8 micro-nanomotor in Example 3, wherein a is the TiO2-Pt@ZIF-8 micro-nanomotor, and b is the SiO2-Pt@ZIF-8 micro-nanomotor;

[0044] Figure 7a is the salt tolerance curve of SiO2-Pt micro / nanomotors modified with ZIF-8 porous materials (SiO2-Pt@ZIF-8) in Example 3 and SiO2-Pt micro / nanomotors without ZIF-8 porous materials (SiO2-Pt) in Comparative Example 3 in ferrocene methanol solution at different salt concentrations, b is the salt tolerance curve of TiO2-Pt micro / nanomotors modified with ZIF-8 porous materials (TiO2-Pt@ZIF-8) in Example 2 and TiO2-Pt micro / nanomotors without ZIF-8 porous materials (TiO2-Pt) in Comparative Example 2 in ferrocene methanol solution at different salt concentrations;

[0045] Figure 8 pH-responsive drug release profile of the micro / nanomotors based on ZIF-8 porous material silicon nanowires in Example 1 after drug loading (DOX);

[0046] Figure 9 Morphology of the micro / nanomotors with different types of MOF porous materials grown on silicon nanowires in Example 4 and Example 5, wherein a is Example 4, b is Example 5. DETAILED DESCRIPTION

[0047] Various exemplary embodiments of the present application will now be described in detail, which should be considered to be merely illustrative in nature and are not to be considered as limiting the scope of the present application, and are understood to be within the scope of the present application.

[0048] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. In addition, where particular ranges of values are given, understand that each intervening value, to the upper or lower limit, is encompassed, unless the context clearly dictates otherwise. Each smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in that stated range is also encompassed. The upper and lower limits of these smaller ranges can independently be included or excluded in the range, and are also encompassed, subject to any specifically excluded limit in the stated range. Unless defined otherwise, all technical and scientific terms and any acronyms used herein have the same meanings as commonly understood by one of ordinary skill in the art in the field of the application. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, the preferred methods and materials are described. All publications mentioned herein are incorporated by reference to disclose and describe the methods and / or materials in connection with which the publications are cited. The citation of any reference is not an admission that it is prior art with respect to the present application. All documents mentioned herein are incorporated herein by reference.

[0049] Unless defined otherwise, all technical and scientific terms and any acronyms used herein have the same meanings as commonly understood by one of ordinary skill in the art in the field of the application. Although preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application. All documents mentioned herein are incorporated by reference to disclose and describe the methods and / or materials in connection with which the documents are cited. In the case of conflict between the present specification and any document incorporated by reference, the present specification will control.

[0050] Many modifications and variations of the present application described in the specification are possible without departing from the scope or spirit of the application. Other implementations of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. The specification and examples given are exemplary only.

[0051] As used herein, the terms "comprise", "comprising", "include", "including", "have", "having" and the like are open-ended terms that are intended to mean including, but not limited to.

[0052] The present application provides a method for improving ion tolerance of self-electrophoretic driving micro-nanomotor, wherein the self-electrophoretic driving micro-nanomotor is subjected to oxygen plasma treatment, and then a metal organic framework (MOF) porous material is modified on the surface of the self-electrophoretic driving micro-nanomotor, and the MOF porous material includes one of ZIF-8, UiO-66 and MIL-53 (Al) for example.

[0053] In some embodiments of the present application, when the MOF porous material is ZIF-8, the method for improving ion tolerance of self-electrophoretic driving micro-nanomotor includes the following steps:

[0054] The self-electrophoretic driving micro-nanomotor is subjected to oxygen plasma treatment to obtain a pretreated self-electrophoretic driving micro-nanomotor;

[0055] The pretreated self-electrophoretic driving micro-nanomotor is first added into a dimethylimidazole aqueous solution, and then a soluble zinc salt aqueous solution is added, and the reaction is carried out for 30-60 min (such as 30 min, 40 min, 50 min or 60 min), and after the reaction is completed, the self-electrophoretic driving micro-nanomotor is naturally cooled to room temperature, and then washed and dried, wherein the molar ratio of dimethylimidazole to soluble zinc salt is 500:8; the dimethylimidazole aqueous solution is prepared by dissolving dimethylimidazole in water; the soluble zinc salt aqueous solution is prepared by dissolving a soluble zinc salt in water; and the soluble zinc salt is preferably zinc acetate dihydrate.

[0056] In some preferred embodiments of the present application, when the MOF porous material is ZIF-8, the method for improving ion tolerance of self-electrophoretic driving micro-nanomotor includes the following steps:

[0057] The self-electrophoretic driving micro-nanomotor is subjected to oxygen plasma treatment to obtain a pretreated self-electrophoretic driving micro-nanomotor;

[0058] The 4.105 g (0.05 mol) dimethylimidazole is dissolved in 50 mL of deionized water to obtain a dimethylimidazole aqueous solution; 0.183 g (0.0008 mol) of zinc acetate dihydrate is dissolved in 10 mL of deionized water to obtain a soluble zinc salt aqueous solution; the pretreated self-electrophoretic driving micro-nano motor is immersed in the dimethylimidazole aqueous solution for 3 minutes, then the soluble zinc salt aqueous solution is added, and the reaction is carried out at room temperature and normal pressure for 40 min; after the reaction is completed, it is naturally cooled to room temperature, and the self-electrophoretic driving micro-nano motor is washed with deionized water and methanol, and dried to obtain a silicon nanowire micro-nano motor modified with a ZIF-8 porous material, which is an ion-tolerant self-electrophoretic driving micro-nano motor and can be used in an environment with an ion concentration of up to 150 mM.

[0059] In some preferred embodiments of the present application, when the MOF porous material is UiO-66, the method for improving the ion tolerance of the self-electrophoretic driving micro-nano motor comprises the following steps:

[0060] The self-electrophoretic driving micro-nano motor is subjected to oxygen plasma treatment to obtain a pretreated self-electrophoretic driving micro-nano motor;

[0061] After 0.25 mmol of zirconium tetrachloride, 0.25 mmol of terephthalic acid and 30 mL of N,N-dimethylformamide are stirred uniformly, they are poured into a reaction kettle, the pretreated self-electrophoretic driving micro-nano motor is placed in the solution, heated at a temperature of 145°C for 48 hours, after the reaction is completed, it is naturally cooled to room temperature, the self-electrophoretic driving micro-nano motor is washed with DMF (N,N-dimethylformamide) and ethanol for 3 times to remove unreacted precursors, and then vacuum dried at 60°C for 12 hours.

[0062] In some preferred embodiments of the present application, when the MOF porous material is MIL-53 (Al), the method for improving the ion tolerance of the self-electrophoretic driving micro-nano motor comprises the following steps:

[0063] The self-electrophoretic driving micro-nano motor is subjected to oxygen plasma treatment to obtain a pretreated self-electrophoretic driving micro-nano motor;

[0064] The aluminum nitrate nonahydrate and terephthalic acid are dissolved in deionized water at a molar ratio of 1:1, stirred until dissolved, and then the obtained solution is transferred to a high-pressure reaction kettle; the pretreated self-electrophoretic driving micro-nano motor is placed in the solution, and after reaction at 150°C for 24 hours, it is washed with deionized water and methanol, and vacuum dried at 80°C.

[0065] In the embodiments of the present application, the self-electrophoretic driving micro-nanomotor includes a silicon-based self-electrophoretic driving micro-nanomotor or a titanium-based self-electrophoretic driving micro-nanomotor. Exemplarily, the silicon-based self-electrophoretic driving micro-nanomotor includes a silicon nanowire micro-nanomotor or a SiO2-Pt micro-nanomotor; and / or, the titanium-based self-electrophoretic driving micro-nanomotor is selected from a TiO2-Pt micro-nanomotor.

[0066] The embodiments of the present application also provide a high-ion-tolerant self-electrophoretic driving micro-nanomotor obtained by the above method, and the salt concentration tolerance of the high-ion-tolerant self-electrophoretic driving micro-nanomotor reaches 150 mM, that is, the self-electrophoretic driving micro-nanomotor treated by the method of the present application can be applied under a salt concentration of 150 mM.

[0067] The high-ion-tolerant self-electrophoretic driving micro-nanomotor provided by the embodiments of the present application can be used in micro-region object transport materials, targeted drug delivery materials or optical neuromodulation materials, for example, the high-ion-tolerant self-electrophoretic driving micro-nanomotor of the present application can be used for drug delivery, neuromodulation, dynamic detection and / or cancer treatment.

[0068] The high-ion-tolerant self-electrophoretic driving micro-nanomotor of the present application is a near-infrared driving micro-nanomotor, which means that the micro-nanomotor can be guided in the direction of movement under the driving of near-infrared light and the control of an external magnetic field, and the intensity of the near-infrared light is 10-1200 mW / cm 2 ; the external magnetic field is a gradient magnetic field, and the direction is adjustable.

[0069] The present application significantly improves the ion tolerance of the self-electrophoretic driving micro-nanomotor in a high-salt environment by modifying the metal organic framework (MOF) pore structure material on the surface of the self-electrophoretic driving micro-nanomotor. Compared with the self-electrophoretic driving micro-nanomotor without surface modification of the MOF pore structure material, the ion tolerance of the self-electrophoretic driving micro-nanomotor with surface modification of the MOF pore structure material can be increased by 266 times, so that the self-electrophoretic driving micro-nanomotor can maintain stable movement under an electrolyte concentration as high as 150 mM, solving the ion quenching problem of the micro-nanomotor driven by the electrophoresis mechanism and improving the driving efficiency. The micro-nanomotor with surface modification of the MOF pore structure material of the present application exhibits excellent performance in a high-salt environment, and the method is widely applicable to the micro-nanomotor driven by the electrophoresis mechanism. The porous nature of the MOF material can make the self-electrophoretic driving micro-nanomotor with surface modification of the MOF pore structure material used for drug delivery, dynamic monitoring, targeted neuromodulation, precision medicine and other biomedical fields.

[0070] In the present application, in order to quantify the ion tolerance, the concept of "median effective ion intensity" (EI 50 ) is introduced. EI 50It refers to the salt concentration when the speed of the micro-nanomotor is reduced to half of the initial speed. Compared with the self-electrophoretic driving micro-nanomotor of the un-surface modified MOF pore structure material, the ion tolerance of the self-electrophoretic driving micro-nanomotor of the surface modified MOF pore structure material can be increased by 266 times, which makes the self-electrophoretic driving micro-nanomotor able to keep stable movement under an electrolyte concentration of up to 150 mM.

[0071] Unless otherwise specified, the room temperature in the present application is 25±2℃, and the normal pressure refers to one atmosphere (101.325 kPa).

[0072] The raw materials used in the examples and comparative examples of the present application are all commercially available.

[0073] It should be noted that the details not described in the present application are all conventional operating means in the art, and are not the focus of the present application.

[0074] The technical solutions of the present application are further illustrated by the following examples.

[0075] Comparative Example 1

[0076] The present comparative example provides a preparation method of a silicon nanowire micro-nanomotor, and the specific steps are as follows:

[0077] (1) Cleaning the silicon wafer: according to the volume ratio of 1:7, the mixture of 30% mass fraction hydrogen peroxide and 98% mass fraction concentrated sulfuric acid is used as the cleaning solution, the <100> type n-type silicon wafer is placed in the cleaning solution, and the silicon wafer is cleaned by heating to 180℃, and then cleaned with water, isopropyl alcohol and acetone alternately;

[0078] (2) Preparing the dot array pattern by photolithography: the selected photoresist is AZ 5214 photoresist, the spin coating conditions are rotation speed of 4000 rpm for 30 s, 110℃ drying for 2 min, then covering the mask with a pattern size of 4.5×4.5cm, dot diameter of 2μm and dot spacing of 2μm, exposing for 20 s, developing with developer ZX-238 to obtain the dot array pattern; the diameter of the dot array can be controlled to control the diameter of the subsequent silicon nanowire;

[0079] (3) Wet etching of silicon nanowire: the silicon wafer with dot array pattern is placed in the etching solution, and the etching solution is a mixed aqueous solution of HF and AgNO3, in the etching solution, the concentration of HF is 5mol / L, and the concentration of AgNO3 is 0.02mol / L, the volume of the etching solution used is related to the area of the silicon wafer, and the ratio is 3mL / cm 2, the etching rate is 142 nm / min; after taking out, the remaining photoresist is removed by acetone, and after washing with water, it is soaked in concentrated nitric acid to remove the remaining Ag, and after taking out, it is washed with water and isopropyl alcohol in turn, and dried on a 80°C heating table; by controlling the etching time, the length of the silicon nanowire can be controlled, in this comparative example, the wet etching time is 70 minutes, and the length of the obtained silicon nanowire is 10 μm; the subsequent thermal oxidation etching can control the diameter of the silicon nanowire;

[0080] (4) Control of the diameter of the silicon nanowire: After that, the fine silicon nanowires outside the array are removed by thermal oxidation and etching, and the diameter of the array is adjusted. The specific steps are as follows: the sample obtained in step (3) is thermally oxidized at 1000°C in an oxygen atmosphere, the oxidation rate is 100 nm / h, and the time is 90 min; then the silicon oxide is etched by a buffer solution of hydrofluoric acid (BHF, 49wt% HF and 40wt% NH4F aqueous solution are prepared according to the volume ratio of 1:5), the rate is 100 nm / min, and the time is 5 min, and the etching is repeated twice, and the diameter of the obtained silicon nanowire is 1 μm;

[0081] (5) Insulating layer obtained by thermal oxidation method: the sample obtained in step (4) is thermally oxidized at 900°C in an oxygen atmosphere, and the thickness of the insulating layer SiO2 is adjusted by controlling the treatment time; in this comparative example, the treatment time is 2 minutes, and the thickness of the insulating layer SiO2 is 5 nm;

[0082] (6) Thermal evaporation of magnetic metal Ni: using a high vacuum resistance thermal evaporation coating equipment, the magnetic metal Ni is evaporated on the surface of the silicon nanowire to form a MIS solar cell structure, and the thickness of the metal layer is controlled by the evaporation rate and time; in this embodiment, the evaporation rate is the evaporation time is 400 s, and the thickness of the obtained metal layer is 20 nm;

[0083] (7) Control of the catalyst layer: first, using a plasma cleaning machine, the sample obtained in step (6) is treated in an oxygen atmosphere for 300 s, so that the metal Ni is partially oxidized to obtain NiO x When the thickness of the metal Ni layer is 10-30 nm, the treatment time in the oxygen atmosphere is controlled to be 200-400 s, and the metal Ni can be partially oxidized, and the performance of the final micro-nano motor is equivalent); then, using an ion sputtering instrument, Au nanoparticles are deposited and controlled to form a discontinuous film (equivalent thickness of 2-5 nm), as a co-catalyst, to obtain a micro-nano motor based on a MIS solar cell structure, which is a silicon nanowire micro-nano motor.

[0084] Example 1

[0085] The embodiment provides a method for improving ion tolerance of a silicon nanowire micro-nanomotor by surface modification of a ZIF-8 pore structure material, and the obtained high-ion-tolerance micro-nanomotor is denoted as MIS-Au@ZIF-8, and the synthesis path is shown in Figure 1 (A regular array of n-type silicon nanowires is obtained by a method of micro-nano processing; an insulating layer SiO2 is obtained by a thermal oxidation method, a magnetic metal is evaporated to the surface of the silicon nanowire array to form a MIS junction, NiO x is obtained by a thermal oxidation method, Au nanoparticles are deposited on the surface by magnetron sputtering to obtain a MIS@Au silicon nanowire micro-nanomotor; and a ZIF-8 pore structure material is modified in situ on the surface of the MIS@Au silicon nanowire micro-nanomotor), and the specific steps are as follows:

[0086] (1) cleaning the silicon wafer: according to a volume ratio of 1:7, a cleaning solution is obtained by mixing hydrogen peroxide with a mass fraction of 30% and concentrated sulfuric acid with a mass fraction of 98%, a <100> type n-type silicon wafer is placed in the cleaning solution, and the silicon wafer is cleaned by heating to 180 DEG C; after the end, the silicon wafer is cleaned by water, isopropyl alcohol and acetone alternately;

[0087] (2) preparing a dot array pattern by photolithography: the selected photoresist is AZ 5214 photoresist, the spin coating conditions are as follows: the rotating speed is 4000 rpm, the rotating time is 30 s, the drying temperature is 110 DEG C, the drying time is 2 min, then a mask plate with a pattern size of 4.5*4.5 cm, a dot diameter of 2 μm and a dot spacing of 2 μm is covered, the exposure time is 20 s, the developing liquid is ZX-238, and a dot array pattern is obtained; the diameter of the dot array can be controlled to control the diameter of the subsequent silicon nanowire;

[0088] (3) wet etching of the silicon nanowire: the silicon wafer with the dot array pattern is placed in an etching solution, the etching solution is a mixed aqueous solution of HF and AgNO3, in the etching solution, the concentration of HF is 5 mol / L, the concentration of AgNO3 is 0.02 mol / L, the volume of the etching solution is related to the area of the silicon wafer, the ratio is 3 mL / cm 2 , and the etching rate is 142 nm / min; after taking out, the remaining photoresist is removed by acetone, after water washing, the remaining Ag is removed by soaking in concentrated nitric acid, and after taking out, the silicon wafer is washed by water, isopropyl alcohol and acetone successively, and is dried on a heating table at 80 DEG C; the length of the silicon nanowire can be controlled by controlling the etching time, in the embodiment, the wet etching time is 70 minutes, and the length of the obtained silicon nanowire is 10 μm; the diameter of the silicon nanowire can be controlled by subsequent thermal oxidation etching;

[0089] (4) Control of the diameter of the silicon nanowires: The sample obtained in step (3) is then heat-oxidized at 1000 °C in an oxygen atmosphere at a rate of 100 nm / h for 90 min, and the silicon nanowires outside the array are removed by etching the oxidized silicon with a buffered hydrofluoric acid (BHF, 49 wt% HF and 40 wt% NH4F aqueous solution at a volume ratio of 1:5) at a rate of 100 nm / min for 5 min, repeated twice, to obtain silicon nanowires with a diameter of 1 μm;

[0090] (5) Obtaining an insulating layer by heat oxidation: The sample obtained in step (4) is heat-oxidized at 900 °C in an oxygen atmosphere, and the thickness of the insulating layer of SiO2 is adjusted by controlling the treatment time; in this embodiment, the treatment time is 2 min, and the thickness of the insulating layer of SiO2 is 5 nm;

[0091] (6) Thermal evaporation of a magnetic metal Ni: A high-vacuum resistance thermal evaporation coating device is used to evaporate the magnetic metal Ni onto the surface of the silicon nanowires to form a MIS solar cell structure, and the thickness of the metal layer is controlled by the evaporation rate and time; in this embodiment, the evaporation rate is 0.2 A / s, the evaporation time is 400 s, and the thickness of the obtained metal layer is 20 nm;

[0092] (7) Control of the catalyst layer: First, the sample obtained in step (6) is treated in an oxygen atmosphere for 300 s using a plasma cleaning machine to partially oxidize the metal Ni to obtain NiO x (the thickness of the metal Ni layer is 10-30 nm, and the treatment time in an oxygen atmosphere is controlled to be 200-400 s, both of which can achieve partial oxidation of the metal Ni, and the performance of the final micro / nano motor is equivalent); then, Au nanoparticles are deposited using an ion sputtering instrument to form a discontinuous film (equivalent thickness of 2-5 nm) as a co-catalyst, to obtain a micro / nano motor based on a MIS solar cell structure, which is a silicon nanowire micro / nano motor;

[0093] ​(8) Modification of metal-organic framework pore structure material: first, the micro-nano motor based on MIS solar cell structure is treated by oxygen plasma to be hydroxyl functionalized to obtain pretreated micro-nano motor; then, 4.105 g (0.05 mol) of dimethylimidazole is dissolved in 50 mL of deionized water to obtain a dimethylimidazole aqueous solution; 0.183 g (0.0008 mol) of zinc acetate dihydrate is dissolved in 10 mL of deionized water to obtain a soluble zinc salt aqueous solution; the pretreated micro-nano motor is immersed in the dimethylimidazole aqueous solution for 3 minutes, then the soluble zinc salt aqueous solution is poured into the dimethylimidazole solution, and the reaction is carried out at room temperature and normal pressure for 40 min; after the reaction is completed, it is naturally cooled to room temperature, and the micro-nano motor is washed thoroughly with deionized water and methanol, and dried to obtain a silicon nanowire micro-nano motor based on ZIF-8 pore structure material (MIS-Au@ZIF-8).

[0094] The scanning electron microscope (SEM) image of the silicon nanowire micro-nano motor based on ZIF-8 pore structure material in the present embodiment is shown in Figure 2 It can be seen that the micro-nano motor is arranged regularly, the length is about 15 μm, and the diameter is 1.5 μm; ZIF-8 can be clearly seen to grow uniformly on the MIS@Au silicon nanowire to form a layer of dense and uniform ZIF-8 pore structure material; the successful formation of the pore structure material provides stronger ion conductivity and stability for the micro-nano motor, and creates favorable conditions for improving its salt tolerance.

[0095] The EDX element distribution map of the silicon nanowire micro-nano motor based on ZIF-8 pore structure material in the present embodiment is shown in Figure 3 It can be seen that Si, Ni, Au and Zn elements are uniformly distributed on the surface of the silicon nanowire.

[0096] The salt tolerance of the ZIF-8 porous material-based silicon nanowire micro / nanomotor of the present example and the silicon nanowire micro / nanomotor without any MOF material modification in Comparative Example 1 was tested according to the following method: The material to be tested was placed on an electrical conductivity table with a glass slide for testing the real-time conductivity of the ZIF-8 porous material-based silicon nanowire micro / nanomotor prepared in Example 1 in the salt tolerance experiment. The glass slide has a rectangular liquid pool (16 mm x 25 mm x 1 mm) with a number mark made of a 20 nm thick titanium layer. In addition, there are two pairs of gold electrodes (15 mm x 4 mm) in the liquid pool, and the distance between the electrodes is 100 μm for testing the conductivity of the medium. Before the experiment, the glass slide was thoroughly cleaned with a solution of NH3·H2O:H2O2:H2O = 1:1:5 (v:v:v), and each slide was calibrated by a series of NaCl solutions with known concentrations (concentration range of 0 to 200 mM). The ZIF-8 porous material-based silicon nanowire micro / nanomotor / silicon nanowire micro / nanomotor was carefully scraped off the substrate with a blade and dispersed into a ferrocene methanol solution to measure its migration behavior. The conductivity of the solution was adjusted by adding high-concentration NaCl to the ferrocene methanol solution, and the measurement was carried out once the reading of the conductivity meter was stable.

[0097] The salt tolerance curve of the ZIF-8 porous material-based silicon nanowire micro / nanomotor of the present example and the silicon nanowire micro / nanomotor of Comparative Example 1 is shown in FIG. 6. Figure 4 The propulsion of the silicon nanowire micro / nanomotor depends on the self-electrophoresis, and in a high-salt environment, the silicon nanowire micro / nanomotor driven by self-electrophoresis usually loses its motility. According to the prediction of the Helmholtz-Smoluchowski theory, this phenomenon is due to the electric field shielding effect, which causes the Debye layer to be compressed from about 100 nm to about 1 nm. This compression inhibits the electrophoretic movement, thereby reducing the propulsion efficiency of the silicon nanowire micro / nanomotor. In contrast, the ZIF-8 porous material as a porous scaffold provides ion-conductive channels, preventing the collapse of the Debye layer and thus maintaining the self-electrophoresis mechanism. Therefore, the ZIF-8 porous material significantly improves the ion tolerance of the silicon nanowire micro / nanomotor by enhancing the electroosmotic flow of the silicon nanowire micro / nanomotor. From the salt tolerance curve, the EI 50 value of the silicon nanowire micro / nanomotor in Comparative Example 1 was 0.020 ± 0.001 mM, while the EI 50 value of the ZIF-8 porous material-based silicon nanowire micro / nanomotor of the present example was 5.322 ± 0.271 mM, which was increased by nearly 266 times. This trend indicates that reducing the size of the micro / nanomotor and then modifying the MOF pore structure material can help to enhance its stability and propulsion ability in a high-salt environment.

[0098] To further evaluate its adaptability in complex biological environment, the ZIF-8 porous material-based micro-nano motor was placed in PBS solution and its movement performance under near-infrared light driving was tested in the artificial blood vessels covered with 3 mm thick muscle tissue. The movement process diagram of the ZIF-8 porous material-based silicon nanowire micro-nano motor in the artificial blood vessels under 980 nm near-infrared light driving in this embodiment is shown in FIG. 8A, and the results show that the ZIF-8 porous material-based micro-nano motor can effectively advance under 980 nm near-infrared light irradiation and can accurately pass through these artificial blood vessels under the guidance of a magnetic field. This indicates that the micro-nano motor modified with MOF porous material has the ability to stably move in a simulated biological environment. Figure 5

[0099] Comparative Example 2

[0100] This comparative example provides a preparation method of TiO2-Pt micro-nano motor (TiO2-Pt), and the specific steps are as follows:

[0101] 5 mL of TTIP was dissolved in 20 mL of ethanol solution, and in another beaker, a mixed solution of 50 mL of anhydrous ethanol + 2 mL of deionized water + 1 mL of glacial acetic acid was prepared. The TTIP solution was slowly added to the mixed solution, and stirred for 2 h to fully hydrolyze and condense, forming a stable TiO2 sol. Then, the sol was transferred to a reaction kettle and reacted at 150°C for 12 h. After the reaction was completed, the precipitate was taken out, washed with ethanol and deionized water three times, and vacuum dried at 80°C for 12 h, and finally calcined for 2 h to obtain crystalline TiO2 beads. The film fishing method was used to uniformly disperse the TiO2 beads on the surface of the silicon wafer. First, the beads were dispersed in ethanol, and ultrasonic treatment was used to ensure uniform distribution of the beads. Then, a clean silicon wafer was immersed in an ethanol solution, and the dispersed TiO2 beads were adsorbed onto the surface of the silicon wafer by surface tension and volatilization. Subsequently, platinum nanoparticles were sputtered on the surface of the silicon wafer by magnetron sputtering method, and finally TiO2-Pt micro-nano motor was obtained.

[0102] Example 2

[0103] This example provides a method for improving the ion tolerance of TiO2-Pt micro-nano motor by surface modification of ZIF-8 porous material, and the obtained high ion tolerance micro-nano motor is denoted as TiO2-Pt@ZIF-8, and the specific steps are as follows:

[0104] ​The preparation method of the TiO2-Pt micro-nanomotor is the same as that in Comparative Example 2. First, the TiO2-Pt micro-nanomotor is subjected to oxygen plasma treatment to perform hydroxyl functionalization, to obtain a pretreated micro-nanomotor. Then, 4.105 g (0.05 mol) of dimethylimidazole is dissolved in 50 mL of deionized water to obtain a dimethylimidazole aqueous solution. 0.183 g (0.0008 mol) of zinc acetate dihydrate is dissolved in 10 mL of deionized water to obtain a soluble zinc salt aqueous solution. The pretreated micro-nanomotor is immersed in the dimethylimidazole aqueous solution for 3 minutes. Then, the soluble zinc salt aqueous solution is poured into the dimethylimidazole aqueous solution, and the reaction is performed at room temperature and normal pressure for 40 min. After the reaction is completed, the micro-nanomotor is naturally cooled to room temperature, and is thoroughly washed with deionized water and methanol. After drying, the TiO2-Pt@ZIF-8 micro-nanomotor is obtained.

[0105] Comparative Example 3

[0106] The present comparative example provides a preparation method of a SiO2-Pt micro-nanomotor (SiO2-Pt), and the specific steps are as follows:

[0107] In 80 mL of anhydrous ethanol, 20 mL of deionized water is added, and 6 mL of ammonia water is added dropwise as a catalyst. Under stirring, 4 mL of tetraethyl orthosilicate is slowly added, and the stirring is continued for 24 h. The SiO2 particles gradually grow and stabilize. The residual reactants are removed by centrifugation and washing, and the SiO2 beads are obtained after drying. The SiO2 beads are uniformly dispersed on the surface of a silicon wafer by the film fishing method. First, the beads are dispersed in ethanol, and ultrasonic treatment is performed to ensure uniform distribution of the beads. Then, a clean silicon wafer is immersed in the ethanol solution, and the dispersed SiO2 beads are adsorbed onto the surface of the silicon wafer by surface tension and volatilization. Then, platinum nanoparticles are sputtered on the surface of the silicon wafer by a magnetron sputtering method, and finally the SiO2-Pt micro-nanomotor is obtained.

[0108] Example 3

[0109] The present example provides a method for improving the ion tolerance of a SiO2-Pt micro-nanomotor by surface modification of a ZIF-8 pore structure material, and the obtained high ion tolerance micro-nanomotor is denoted as SiO2-Pt@ZIF-8. The specific steps are as follows:

[0110] The preparation method of the SiO2-Pt micro-nanomotor is the same as that of the comparative example 3. First, the SiO2-Pt micro-nanomotor is subjected to oxygen plasma treatment to be hydroxyl functionalized to obtain a pretreated micro-nanomotor. Then, 4.105 g (0.05 mol) of dimethylimidazole is dissolved in 50 mL of deionized water to obtain a dimethylimidazole aqueous solution. 0.183 g (0.0008 mol) of zinc acetate dihydrate is dissolved in 10 mL of deionized water to obtain a soluble zinc salt aqueous solution. The pretreated micro-nanomotor is immersed in the dimethylimidazole aqueous solution for 3 minutes. Then, the soluble zinc salt aqueous solution is poured into the dimethylimidazole aqueous solution, and the reaction is carried out at room temperature and normal pressure for 40 min. After the reaction is completed, the micro-nanomotor is naturally cooled to room temperature, and then washed with deionized water and methanol. After drying, the SiO2-Pt@ZIF-8 micro-nanomotor is obtained.

[0111] To verify the universality of the surface porous material ZIF-8 in enhancing the ion tolerance of the micro-nanomotor, the ZIF-8 porous structure material is applied to two other widely studied electrolyte self-diffusiophoretic micro-nanomotors: TiO2-Pt micro-nanomotor and SiO2-Pt micro-nanomotor (see examples 2 and 3). The SEM images of the TiO2-Pt@ZIF-8 micro-nanomotor in example 2 and the SiO2-Pt@ZIF-8 micro-nanomotor in example 3 are shown in FIGS. 2 and 3, respectively. The results show the successful preparation of these micro-nanomotors, and both have a Janus structure. Then, the micro-nanomotors in examples 2-3 and comparative examples 2-3 are transferred to solutions with different salt concentrations (0-4 mM), and migration tests are carried out under a microscope to further evaluate their salt tolerance. Figure 6

[0112] The salt tolerance curves of the micro-nanomotors modified with the ZIF-8 porous structure material and the micro-nanomotors without the ZIF-8 porous structure material in the ferrocene methanol solution with different salt concentrations are shown in FIGS. 4 and 5, respectively. It can be seen that after the surface is modified with the ZIF-8 porous structure material, both the TiO2-Pt micro-nanomotor and the SiO2-Pt micro-nanomotor show significant improvement in ion tolerance, further verifying the effectiveness of the ZIF-8 porous structure material in improving the salt tolerance of various self-electrophoretic driving micro-nanomotors. Figure 7

[0113] The above experimental results not only prove the applicability of the ZIF-8 porous structure material in different self-electrophoretic driving micro-nanomotor systems, but also provide a strong basis for further research and optimization of the performance of the self-electrophoretic driving micro-nanomotor in complex biological environments.

[0114] ​​To further verify the drug-loading capacity of the self-electrophoretic driven micro / nano motor after surface modification of MOF porous materials, the following experiment was conducted using the doxorubicin (DOX)-loaded micro / nano motor based on ZIF-8 porous silicon nanowires (hereinafter referred to as "drug-loaded micro / nano motor") from Example 1 as an example: The micro / nano motor with surface modification of ZIF-8 porous material was immersed in a PBS solution with a DOX concentration of 75 μg / mL for 24 h, allowing DOX to diffuse into the pores of ZIF-8. The sample was then gently washed with deionized water to remove unadsorbed drug from the surface. The pH-responsive drug release diagram of the above-mentioned drug-loaded micro / nano motor is shown in the figure. Figure 8 As shown, the drug-loaded micro / nanomotor exhibits a significant pH-responsiveness in drug release from DOX in both simulated tumor environments (pH = 7.4) and slightly acidic environments (pH = 5.5). Specifically, drug release is slow at pH = 7.4, while it is significantly accelerated in the acidic environment of pH = 5.5. This pH-responsive release characteristic enables self-electrophoretic driven micro / nanomotors with MOF porous surface-modified materials to achieve more precise drug release in the tumor microenvironment.

[0115] Example 4

[0116] This embodiment provides a method for improving the ion tolerance of silicon nanowire micro / nanomotors by surface modification with UiO-66 porous structure material. The resulting high ion tolerance micro / nanomotor is denoted as MIS-Au@UiO-66. The specific steps are as follows:

[0117] The self-electrophoretic driven micro-nano motor was pretreated with oxygen plasma to obtain a pretreated self-electrophoretic driven micro-nano motor.

[0118] The pretreated self-electrophoretic driven micro-nano motor was placed in solution and heated at 145℃ for 48 hours. After the reaction was completed, it was naturally cooled to room temperature. The self-electrophoretic driven micro-nano motor was washed three times with DMF (N,N-dimethylformamide) and ethanol to remove unreacted precursors. Then it was vacuum dried at 60℃ for 12 hours to obtain the high ion tolerance micro-nano motor MIS-Au@UiO-66.

[0119] Example 5

[0120] This embodiment provides a method for improving the ion tolerance of silicon nanowire micro / nano motors by surface-modifying a porous material called MIL-53(Al). The resulting high ion tolerance micro / nano motor is denoted as MIS-Au@MIL-53(Al). The specific steps are as follows:

[0121] The self-electrophoretic driven micro-nano motor was pretreated with oxygen plasma to obtain a pretreated self-electrophoretic driven micro-nano motor.

[0122] Aluminum nitrate nonahydrate and terephthalic acid were dissolved in deionized water at a molar ratio of 1:1. After stirring until dissolved, the resulting solution was transferred to a high-pressure reactor. The pretreated self-electrophoretic driven micro / nano motor was placed in the solution and reacted at 150°C for 24 hours. After washing with deionized water and methanol, it was vacuum dried at 80°C to obtain the high ion tolerance micro / nano motor MIS-Au@MIL-53(Al).

[0123] The morphology images of different types of MOF porous structure materials grown on silicon nanowire micro / nano motors in Examples 4 and 5 are shown below. Figure 9 As shown, compared to the ZIF-8 porous structure, the MOF layer formed on the surface of the UiO-66 porous structure is more loose and has larger grain spacing. The MIL-53(Al) porous structure forms a less loose, pointed structure, which is more conducive to enhancing drug loading and release performance compared to the ZIF-8 and UiO-66 porous structures. The unique structure of the MIL-53(Al) porous structure gives it excellent performance in applications such as dynamic detection and environmental monitoring.

[0124] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for improving ion tolerance of self-electrophoretic driven micro- nanomotor, characterized in that, After oxygen plasma treatment of the self-electrophoretic driving micro-nanomotor, a metal organic framework pore structure material is modified on the surface of the self-electrophoretic driving micro-nanomotor; The metal organic framework pore structure material is selected from one of ZIF-8, UiO-66 and MIL-53(Al); When the metal organic framework pore structure material is selected from ZIF-8, the method comprises the following steps: performing oxygen plasma treatment on the self-electrophoretic driving micro-nanomotor to obtain pretreated self-electrophoretic driving micro-nanomotor; first, the pretreated self-electrophoretic driving micro-nanomotor is soaked in a dimethyl imidazole aqueous solution for 3 minutes, then a soluble zinc salt aqueous solution is added, and the reaction is carried out for 30-60 min; after the reaction is completed, the self-electrophoretic driving micro-nanomotor is naturally cooled to room temperature, and then washed and dried. When the metal organic framework pore structure material is selected from UiO-66, the method comprises the following steps: performing oxygen plasma treatment on the self-electrophoretic driving micro-nanomotor to obtain pretreated self-electrophoretic driving micro-nanomotor; 0.25 mmol of zirconium tetrachloride, 0.25 mmol of terephthalic acid and 30 mL of N,N-dimethylformamide are stirred uniformly, then poured into a reaction kettle, and the pretreated self-electrophoretic driving micro-nanomotor is placed in the solution and heated at a temperature of 145 DEG C for 48 hours; after the reaction is completed, the self-electrophoretic driving micro-nanomotor is naturally cooled to room temperature, and then washed and dried. When the metal organic framework pore structure material is selected from MIL-53(Al), the method comprises the following steps: performing oxygen plasma treatment on the self-electrophoretic driving micro-nanomotor to obtain pretreated self-electrophoretic driving micro-nanomotor; aluminum nitrate nonahydrate and terephthalic acid are dissolved in deionized water at a molar ratio of 1:1, stirred until dissolved, and then the obtained solution is transferred to a high-pressure reaction kettle; the pretreated self-electrophoretic driving micro-nanomotor is placed in the solution and reacted at 150 DEG C for 24 hours; then the self-electrophoretic driving micro-nanomotor is washed with deionized water and methanol, and vacuum dried at 80 DEG C.

2. The method of claim 1, wherein the ion tolerance of the self-electrophoretically driven micro / nanomotor is improved by, The molar ratio of the dimethyl imidazole and the soluble zinc salt is 500:

8.

3. The method of claim 1, wherein the ion tolerance of the self-electrophoretically driven micro / nanomotor is improved by, The self-electrophoretic driving micro-nanomotor comprises a silicon-based self-electrophoretic driving micro-nanomotor or a titanium-based self-electrophoretic driving micro-nanomotor.

4. The method of claim 3, wherein the method is characterized by, The silicon-based self-electrophoretic driving micro-nanomotor comprises a silicon nanowire micro-nanomotor or a SiO2-Pt micro-nanomotor; And / or, the titanium-based self-electrophoretic driving micro-nanomotor is selected from a TiO2-Pt micro-nanomotor.

5. A high ion-tolerant self-electrophoretic driven micro / nanomotor, characterized in that, The high-ionic-tolerance self-electrophoretic driving micro-nanomotor prepared by the method of any one of claims 1-4 has a salt tolerance of up to 150 mM.

6. Use of the high-ionic-tolerance self-electrophoretic driving micro-nanomotor of claim 5 in micro-region object transport materials, targeted drug loading materials or optical neuromodulation materials.

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