Micro-nano motor based on liquid metal and preparation method and application thereof
By constructing a liquid metal-based asymmetric reactor and preparing catalase-like active materials in situ on its surface, the problems of complexity and material uniformity in the preparation of micro-nano motors have been solved, realizing a simple and efficient multifunctional micro-nano motor suitable for applications such as biofilm removal and surface sterilization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WUHAN UNIV
- Filing Date
- 2026-01-12
- Publication Date
- 2026-05-01
AI Technical Summary
In existing technologies, the fabrication process of micro-nano motors is complex, the materials are limited, and it is difficult to achieve multifunctional applications. In particular, when constructing asymmetric structures, there are problems such as high technical sensitivity and reliance on expensive and complex equipment.
Using liquid metal as a base, metals and/or metal oxides with catalase-like activity are prepared in situ on the surface of an asymmetric reactor to form micro-nano motors with an asymmetric core-shell structure. The plasticity and reactivity of liquid metal are utilized to simplify the preparation process and achieve multifunctionality.
A simple and efficient fabrication of micro-nano motors has been achieved, which can be driven by generating bubbles in response to hydrogen peroxide. They are suitable for a variety of applications, especially showing good practical application prospects in biofilm removal and surface sterilization.
Smart Images
Figure CN121966346A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of micro-nano motor technology, specifically to a micro-nano motor based on liquid metal, its fabrication method, and its applications. Background Technology
[0002] Micromotors are advanced devices that achieve energy conversion at the micro and nanoscale. They can convert various forms of energy in the environment into mechanical motion and perform diverse tasks. Thanks to their unique autonomous movement capabilities and compact size, micromotors exhibit extremely high accessibility in confined spaces, enabling the efficient loading, transport, and release of various micro- and nano-scale cargoes. This characteristic makes micromotors demonstrate enormous application potential and broad development prospects in fields such as biosensing technology, precision drug delivery, and environmental remediation.
[0003] As a typical type of micro / nano motor, chemically driven micro / nano motors are usually designed with asymmetric morphologies to generate bubble-driving force, that is, to construct a highly asymmetric field around asymmetric particles to achieve bubble actuation. Therefore, more and more researchers are dedicated to developing asymmetric structures to fabricate micro / nano motors. To date, many complex micro / nano motors with asymmetric structures have been synthesized based on building blocks such as nanocrystals, metal-organic framework nanoparticles, mesoporous nanoparticles, and polymer nanoparticles. However, the construction methods for these asymmetric structures all suffer from problems such as high technical sensitivity, reliance on expensive and complex equipment and templates, and limited synthetic products.
[0004] Liquid metals, with their exceptional fluidity and plasticity at the micro- and nanoscale, are ideal materials for constructing asymmetric micro- and nano-motors. Based on this, this invention presents an innovative liquid metal-based micro- and nano-motor. First, an asymmetric reactor is constructed. Then, metals and / or metal oxides with catalase-like activity are prepared on the surface of the liquid metal within the asymmetric reactor. This allows for the construction of a series of small-sized bubbles capable of driving micro- and nano-motors in response to hydrogen peroxide. By controlling the type of metal or metal oxide, different application scenarios can be addressed. This technological breakthrough significantly improves the versatility of micro- and nano-motor fabrication methods and lays a solid technical foundation for the wide expansion of their application fields. Summary of the Invention
[0005] To address the shortcomings of existing technologies, this invention, based on the plasticity of liquid metal at the micro- and nanoscale, provides a liquid metal-based micro / nano motor, its fabrication method, and its applications. This invention first constructs a liquid metal-based asymmetric reactor with a simple process, wide applicability, and integrated functions, and verifies the universality of the liquid metal-based asymmetric reactor in a series of hydrogen peroxide-responsive metal and metal oxide systems. The liquid metal-based asymmetric reactor is then applied to the fabrication of a series of hydrogen peroxide-responsive small-sized bubble-driven micro / nano motors, effectively overcoming the problems of complex fabrication processes, limited motor materials, and difficulty in achieving multifunctional applications in existing micro / nano motor technologies.
[0006] To achieve the above objectives, the specific technical solution of the present invention is as follows:
[0007] In a first aspect, the present invention provides a method for fabricating a liquid metal-based micro / nano motor, comprising: asymmetrically anchoring liquid metal nanoparticles within an empty shell to form an asymmetric core-shell structure as the basic framework of the micro / nano motor; and then preparing in situ metal and / or metal oxides with catalase-like activity on the surface of the liquid metal nanoparticles to obtain a liquid metal-based micro / nano motor.
[0008] Furthermore, the liquid metal includes at least one of gallium and its alloys.
[0009] Furthermore, the material of the hollow shell is silicon dioxide (SiO2).
[0010] Furthermore, the particle size of the liquid metal-based micro / nano motor is 100-1500 nm.
[0011] Furthermore, the fabrication method of the liquid metal-based micro / nano motor includes the following steps:
[0012] S1. Liquid metal nanoparticles are dispersed in an alcohol solvent, and an isotropic silica shell is formed on the surface of the liquid metal nanoparticles by in-situ hydrolysis to obtain core-shell structured liquid metal particles.
[0013] S2. Disperse the core-shell structured liquid metal particles uniformly in an acid solution and perform acid etching to partially etch the liquid metal core, forming an asymmetric core-shell structure with gaps between the core and shell, which is a liquid metal-based asymmetric reactor.
[0014] S3. Add the liquid metal-based asymmetric reactor to the metal salt solution to carry out the metal salt galvanic displacement reaction. In situ, grow metals and / or metal oxides with catalase-like activity on the surface of the liquid metal core to obtain a liquid metal-based micro / nano motor with hydrogen peroxide response.
[0015] Furthermore, in step S1, the particle size of the liquid metal nanoparticles is 100-1500 nm.
[0016] Further, in step S1, the liquid metal nanoparticles are prepared by the following method: mixing liquid metal with an alcohol solvent and ultrasonically treating the mixture to reduce the particle size of the liquid metal particles to the micro-nano scale, and then collecting the liquid metal nanoparticles.
[0017] Furthermore, the ultrasonic treatment is performed at a temperature of 15-37°C for a duration of 0.5-6 h.
[0018] Furthermore, the alcohol solvent includes, but is not limited to, at least one of ethanol, ethylene glycol, and isopropanol.
[0019] Further, the specific operation of step S1 is as follows: the liquid metal nanoparticles are uniformly dispersed in 85% isopropanol solvent, then alkali and silicate are added, and ultrasonic treatment is performed to allow the silicate to hydrolyze in situ under alkaline conditions, forming an isotropic silica shell on the surface of the liquid metal nanoparticles, thus obtaining core-shell structured liquid metal particles.
[0020] Further, the alkali includes ammonia, and the silicate ester includes tetraethyl silicate; the volume ratio of ammonia to tetraethyl silicate is 7.5-5:1.
[0021] Further, in step S2, the acid solution includes at least one of hydrochloric acid, nitric acid, or sulfuric acid solution, with a concentration range of 0.1-2 M.
[0022] Further, in step S2, the acid etching treatment is performed at a temperature of 30-100°C for a time of 5-30 minutes. During the acid etching stage, temperature and time significantly affect the structure and morphology of the liquid metal-based asymmetric reactor. If the temperature is too high or the time is too long, all the liquid metal may be etched away. If the temperature is too low or the time is too short, it is difficult to form effective voids between the core and shell, thus preventing the effective growth of metals and / or metal oxides with catalase-like activity, resulting in an inability to respond effectively to hydrogen peroxide.
[0023] Further, in step S3, the metal salt includes at least one of chloroauric acid, chloroplatinic acid, silver nitrate, copper chloride, and potassium permanganate.
[0024] Furthermore, in step S3, the temperature of the galvanic displacement reaction is 25-35°C, and the time is 5-15 min. In the galvanic displacement reaction, temperature and time significantly affect the structure and morphology of the liquid metal-based asymmetric reactor. If the temperature is too high or the time is too long, the liquid metal is easily completely converted. If the temperature is too low or the time is too short, the displacement reaction is difficult to occur, resulting in a smaller deposition of metals and / or metal oxides with catalase-like activity, leading to an inability to effectively respond to hydrogen peroxide.
[0025] Further, in step S3, the metal and / or metal oxide includes at least one of gold, platinum, silver, copper, or manganese dioxide.
[0026] A second aspect of the present invention provides a liquid metal-based micro / nano motor prepared by the aforementioned preparation method, the liquid metal-based micro / nano motor comprising: a silica shell, liquid metal nanoparticles asymmetrically anchored within the shell, and a metal and / or metal oxide having catalase-like activity grown on the liquid metal nanoparticles.
[0027] A third aspect of the invention provides applications of the liquid metal-based micro / nano motor, including but not limited to biofilm removal or surface sterilization. The biofilm removal includes in-situ removal of biofilms from medical devices with complex surface microstructures using the liquid metal-based micro / nano motor.
[0028] Compared with the prior art, the advantages of the present invention are:
[0029] (1) The liquid metal-based micro-nano motor provided by the present invention can generate bubbles in response to hydrogen peroxide to achieve drive. It is an excellent micro-environment response self-driven micro-nano motor with good practical application prospects.
[0030] (2) The present invention first constructs a universal asymmetric reactor based on liquid metal, and then prepares metal and / or metal oxide with catalase-like activity on the surface of liquid metal in the asymmetric reactor through metal salt galvanic displacement reaction, thereby constructing a series of small-sized bubbles that can respond to hydrogen peroxide to drive micro-nano motors; the method is simple, has low technical sensitivity, and is highly versatile.
[0031] (3) The preparation method of liquid metal-based micro-nano motors provided by the present invention is applicable to the synthesis of a series of hydrogen peroxide-responsive bubble-driven micro-nano motors, effectively solving the problems of material uniformity and multifunctional application limitations in the existing micro-nano motor preparation process. Attached Figure Description
[0032] Figure 1 A schematic cross-sectional view of the micro / nano motor based on liquid metal provided by the present invention;
[0033] Figure 2 This is a transmission electron microscope image of the liquid gallium nanoparticles in Example 1;
[0034] Figure 3 This is a transmission electron microscope (TEM) image of the liquid gallium metal particles encapsulated in silica in Example 1.
[0035] Figure 4 This is a transmission electron microscope image of the liquid metal-based asymmetric reactor in Example 1;
[0036] Figure 5 Transmission electron microscopy images and elemental distribution diagrams of the (Ga-Au)-motor, (Ga-Pt)-motor, (Ga-Ag)-motor, (Ga-Cu)-motor, and (Ga-Mn)-motor prepared in Examples 1-5;
[0037] Figure 6 The photothermal conversion performance (A) and self-oxygen supply capacity (B) of the (Ga-Au)-motor, (Ga-Pt)-motor, (Ga-Ag)-motor, and (Ga-Cu)-motor prepared in Examples 1-4 are evaluated.
[0038] Figure 7 The photothermal conversion performance (A) and self-oxygen supply capacity (B) of the (Ga-Mn)-motor prepared in Example 5 are compared with those of Ga@vSiO2 and MnO2.
[0039] Figure 8 The motion trajectories of the (Ga-Mn)-motor prepared in Example 5 in hydrogen peroxide solutions of different concentrations;
[0040] Figure 9 The graphs show the relationship between MSD (mean squared displacement) and Δt (time interval) of the (Ga-Mn)-motor prepared in Example 5 in hydrogen peroxide solutions of different concentrations, and the graphs showing the change in motion speed with hydrogen peroxide concentration.
[0041] Figure 10 The results of the evaluation of the antibacterial activity of the (Ga-Mn)-motor on various biofilms in Example 1 are shown; among them, Figure 10 A shows the results of crystal violet staining; Figure 10 B shows the results of live / dead staining and 3D reconstruction. Figure 10 C represents the SEM image;
[0042] Figure 11 The results of the (Ga-Mn)-motor performance evaluation for removing mixed biofilm from dental implants are shown in Example 2; where, Figure 11 A represents the statistical results of crystal violet staining; Figure 11B is a photograph of the actual results of crystal violet staining; Figure 11 CF is the SEM image; Figure 11 G represents the AFM analysis result. Detailed Implementation
[0043] To enable those skilled in the art to clearly and completely understand the technical solution of the present invention, the present invention will be further described in detail below with reference to embodiments. Obviously, the embodiments described herein are only for explaining the present invention and are not intended to limit the scope of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0044] This invention provides a method for fabricating a liquid metal-based micro / nano motor, comprising: asymmetrically anchoring liquid metal nanoparticles within an empty shell to form an asymmetric core-shell structure as the basic framework of the micro / nano motor; and then in-situ fabricating a metal and / or metal oxide with catalase-like activity on the surface of the liquid metal nanoparticles to obtain the liquid metal-based micro / nano motor; a cross-sectional schematic diagram of the liquid metal-based micro / nano motor is shown below. Figure 1 As shown, it includes: a silica shell, liquid metal nanoparticles asymmetrically anchored within the shell, and metals and / or metal oxides with catalase-like activity grown on the liquid metal nanoparticles.
[0045] In some examples, the liquid metal includes at least one of gallium and its alloys.
[0046] In some examples, the particle size of the liquid metal-based micro / nano motor is 100-1500 nm.
[0047] In the following specific embodiments, the fabrication method of the liquid metal-based micro / nano motor includes the following steps:
[0048] (1) Liquid metal is mixed with an alcohol solvent and ultrasonically treated to reduce the particle size of the liquid metal particles to the micro-nano scale, and liquid metal nanoparticles are collected; the particle size of the liquid metal nanoparticles is 100-1500 nm; the ultrasonic treatment temperature is 15-37℃ and the time is 0.5-6 h; the alcohol solvent includes, but is not limited to, at least one of ethanol and ethylene glycol.
[0049] (2) Liquid metal nanoparticles are uniformly dispersed in an alcohol solvent, then an alkali and a silicate ester are added, and ultrasonic treatment is performed to allow the silicate ester to hydrolyze in situ under alkaline conditions, forming an isotropic silica shell on the surface of the liquid metal nanoparticles, thus obtaining core-shell structured liquid metal particles; the alcohol solvent includes, but is not limited to, at least one of ethanol and isopropanol; the alkali includes ammonia, and the silicate ester includes tetraethyl silicate; the volume ratio of ammonia to tetraethyl silicate is 7.5-5:1;
[0050] (3) The liquid metal particles with core-shell structure are uniformly dispersed in an acid solution and acid etched at 30-100℃ for 5-30 min to partially etch the liquid metal core, forming an asymmetric core-shell structure with gaps between the core and shell, which is a liquid metal-based asymmetric reactor; the acid solution includes at least one of hydrochloric acid, nitric acid or sulfuric acid solution, with a concentration range of 0.1-2 M;
[0051] (4) A liquid metal-based asymmetric reactor is added to a metal salt solution to carry out a metal salt galvanic displacement reaction. Metals and / or metal oxides with catalase-like activity are grown in situ on the surface of the liquid metal core to obtain a liquid metal-based micro / nano motor with hydrogen peroxide response. The temperature of the galvanic displacement reaction is 25-35℃ and the time is 5-15 min. The metal salt includes at least one of chloroauric acid, chloroplatinic acid, silver nitrate, copper chloride, and potassium permanganate. The metal and / or metal oxide includes at least one of gold, platinum, silver, copper, or manganese dioxide.
[0052] Example 1
[0053] A micro / nano motor based on liquid metal was obtained by in-situ growth of gold with catalase-like activity on the surface of liquid metal in a liquid metal-based asymmetric reactor. The preparation steps are as follows:
[0054] (1) 300 mg of liquid gallium metal was mixed with 8 mL of ethylene glycol and sonicated for 4 h to reduce the particle size of the liquid metal particles to the nanoscale, resulting in a dispersion of liquid gallium metal nanoparticles. After sonication, the dispersion was centrifuged at gradient speeds (3000, 5000, and 9000 rpm, 5 min each time) to remove large particles, and then centrifuged at 9500 rpm to collect the liquid gallium metal nanoparticles (GaNPs). The transmission electron microscope image of the liquid gallium metal nanoparticles is shown below. Figure 2 As shown, it has high sphericity.
[0055] (2) 100 mg of liquid gallium nanoparticles were added to 26.8 mL of 85% isopropanol solution and sonicated for 30 min to disperse them evenly, resulting in a suspension. 0.6 mL of ammonia and 0.08 mL of tetraethyl silicate were slowly added to the suspension and sonicated for 2 h to allow the tetraethyl silicate to hydrolyze in situ under alkaline conditions, forming an isotropic silica shell on the surface of the liquid gallium nanoparticles. The silica-coated liquid gallium nanoparticles (Ga@SiO2) were then collected by centrifugation at 9500 rpm for 5 min. The transmission electron microscope image of the silica-coated liquid gallium nanoparticles is shown below. Figure 3 As shown.
[0056] (3) The silica-encapsulated liquid gallium particles prepared in step (2) using 100 mg of liquid gallium nanoparticles were uniformly dispersed in 20 mL of 1M hydrochloric acid solution. The solution was then subjected to acid etching at a constant temperature of 50°C for 5 min, resulting in partial etching of the liquid metal core and the formation of an asymmetric core-shell structure with voids between the core and shell. The resulting nanoparticles were collected by centrifugation at 9500 rpm for 5 min, thus forming the liquid metal-based asymmetric reactor (Ga@vSiO2). The transmission electron microscope image of the liquid metal-based asymmetric reactor is shown below. Figure 4 As shown, after etching a portion of the liquid metal core with hydrochloric acid, the liquid metal nanoparticles are asymmetrically anchored within the silica shell.
[0057] (4) The liquid metal-based asymmetric reactor prepared in step (3) is added to 20 mL of 3.76 mM chloroauric acid solution and subjected to a metal salt galvanic displacement reaction at 30 °C for 10 min. Metallic gold with catalase-like activity is grown in situ on the surface of the liquid metal core, and a small bubble-driven micro-nano motor with hydrogen peroxide response is obtained, denoted as (Ga-Au)-motor.
[0058] Example 2
[0059] A micro / nano motor based on liquid metal was obtained by in-situ growth of platinum with catalase-like activity on the surface of liquid metal in a liquid metal-based asymmetric reactor. The preparation steps are as follows:
[0060] Steps (1)-(3) of this embodiment are the same as in embodiment 1; step (4) is as follows: the liquid metal-based asymmetric reactor prepared in step (3) is added to 20 mL of 3.76 mM chloroplatinic acid solution and a metal salt galvanic coupling reaction is carried out at 30 °C for 10 min. Platinum metal with catalase-like activity is grown in situ on the surface of the liquid metal core, and a small bubble-driven micro-nano motor with hydrogen peroxide response is obtained, denoted as (Ga-Pt)-motor.
[0061] Example 3
[0062] A micro / nano motor based on liquid metal was prepared by in-situ growth of silver with catalase-like activity on the surface of liquid metal in a liquid metal-based asymmetric reactor. The preparation steps are as follows:
[0063] Steps (1)-(3) of this embodiment are the same as in embodiment 1; step (4) is as follows: the liquid metal-based asymmetric reactor prepared in step (3) is added to 20 mL of 18.8 mM silver nitrate solution and a metal salt galvanic coupling reaction is carried out at 30 °C for 10 min. Metal silver with catalase-like activity is grown in situ on the surface of the liquid metal core, and a small bubble-driven micro-nano motor with hydrogen peroxide response is obtained, denoted as (Ga-Ag)-motor.
[0064] Example 4
[0065] A micro / nano motor based on liquid metal was obtained by in-situ growth of copper with catalase-like activity on the surface of liquid metal in a liquid metal-based asymmetric reactor. The preparation steps are as follows:
[0066] Steps (1)-(3) of this embodiment are the same as in embodiment 1; step (4) is as follows: the liquid metal-based asymmetric reactor prepared in step (3) is added to 20 mL of 18.8 mM copper chloride solution and a metal salt galvanic coupling reaction is carried out at 30°C for 10 min. Metal copper with catalase-like activity is grown in situ on the surface of the liquid metal core, and a small bubble-driven micro-nano motor with hydrogen peroxide response is obtained, denoted as (Ga-Cu)-motor.
[0067] Example 5
[0068] A micro / nano motor based on liquid metal was obtained by in-situ growth of manganese dioxide with catalase-like activity on the surface of liquid metal in a liquid metal-based asymmetric reactor. The preparation steps are as follows:
[0069] Steps (1)-(3) of this embodiment are the same as in embodiment 1; step (4) is as follows: the liquid metal-based asymmetric reactor prepared in step (3) is added to 20 mL of 18.8 mM potassium permanganate solution and a metal salt galvanic coupling reaction is carried out at 30°C for 10 min. A metal oxide manganese dioxide with catalase-like activity is grown in situ on the surface of the liquid metal core, and a small bubble-driven micro-nano motor with hydrogen peroxide response is obtained, denoted as (Ga-Mn)-motor.
[0070] Transmission electron microscopy (TEM) images and elemental distribution maps of the micro / nano motors (Ga-Au)-motor, (Ga-Pt)-motor, (Ga-Ag)-motor, (Ga-Cu)-motor, and (Ga-Mn)-motor prepared in Examples 1-5 are shown below. Figure 5 As shown, this invention successfully loads a hydrogen peroxide-responsive metal or metal oxide onto an asymmetric core-shell framework by utilizing the unique chemical reactivity difference between an inert target material and liquid metal. In this process, liquid gallium loses electrons to generate gallium ions, while the inert metal ions gain electrons in the solution and are reduced in situ, depositing on the surface of the liquid gallium, ultimately forming a small-sized bubble-driven micro / nano motor responsive to hydrogen peroxide. The liquid metal-based asymmetric reactor can serve as a general-purpose reactor for synthesizing a series of small-sized bubble-driven micro / nano motors responsive to hydrogen peroxide under appropriate reaction conditions.
[0071] The performance of the (Ga-Au)-motor, (Ga-Pt)-motor, (Ga-Ag)-motor, (Ga-Cu)-motor, and (Ga-Mn)-motor prepared in Examples 1-5 is evaluated below:
[0072] First, the (Ga-Au)-motor, (Ga-Pt)-motor, (Ga-Ag)-motor, and (Ga-Cu)-motor prepared in Examples 1-4 (250 μg mL) were tested. -1 The photothermal conversion performance and self-oxygen supply capacity of the sample were evaluated, and the results are shown in [the table below]. Figure 6 .like Figure 6 As shown in Figure A, under laser irradiation at 808 nm (1.5 W cm⁻¹), -2 Under these conditions, the aforementioned micro- and nano-motors all exhibit significant photothermal effects, with temperatures reaching 52.6 ± 0.634 °C ((Ga-Ag)-motor) to 63.3 ± 0.818 °C ((Ga-Pt)-motor). For example... Figure 6As shown in Figure B, in a 0.25 mM hydrogen peroxide solution, all micro / nanomotors effectively generated oxygen, with dissolved oxygen concentration increases ranging from 1.23 ± 0.00817 to 2.18 ± 0.00245 mg / L. These results demonstrate that the liquid metal-based micro / nanomotors provided by this invention possess self-oxygenation and photothermal properties. Furthermore, by changing the type of metal or metal oxide with catalase-like activity, the oxygen production and heating intensity can be adjusted, laying a solid foundation for their application in biofilm removal, surface sterilization, and other fields. These results verify the universality and functional tunability of the liquid metal-based asymmetric core-shell reactor. This invention utilizes the unique low-temperature fluidity of liquid metal to construct a multi-level self-asymmetric core-shell framework from macroscopic to nanoscale. The liquid metal within the framework serves as an interfacial electrochemical reactor, enabling customized design of modular nanomotors through high-throughput synthesis and component control.
[0073] Furthermore, using the (Ga-Mn)-motor prepared in Example 5 as the research object, the synergistic effect between photothermal therapy, spontaneous movement, and oxygen supply was studied. The (Ga-Mn)-motor (250 μg mL) was evaluated and compared. -1 ) and Ga@vSiO2 (245.3 μg / mL) -1 MnO2 (4.7 μg mL) -1 The photothermal conversion and decomposition performance of hydrogen peroxide to produce oxygen (Ga@vSiO2 and MnO2 were normalized to the same amount as liquid gallium or manganese in the (Ga-Mn)-motor) are shown in the results. Figure 7 .like Figure 7 As shown in Figure A, under near-infrared laser irradiation (808 nm, 1.5 W cm⁻¹), -2 At this temperature, the (Ga-Mn)-motor exhibits significantly better photothermal performance than single MnO2 or Ga@vSiO2, with the temperature increasing from the initial 22.2±0.141°C to 67.3±0.141°C, indicating that the liquid metal-based micro / nano motor system of this invention can significantly improve photothermal efficiency. Furthermore, Figure 7 Figure B shows that the dissolved oxygen measurement results in 0.25 mM hydrogen peroxide solution further confirm the excellent catalytic efficiency of the liquid metal-based micro / nano motor, with an oxygen concentration increment as high as 1.94 ± 0.00817 mg L. -1 It is significantly superior to MnO2 alone (0.197 ± 0.00471 mg L / L). -1 Ga@vSiO2 showed no significant change. These results fully demonstrate that (Ga-Mn)-motor possesses excellent catalase-like activity, and also suggest that self-driven catalyst diffusion enhancement may improve catalytic activity and substrate affinity.
[0074] The (Ga-Mn)-motor prepared in Example 5 was placed in hydrogen peroxide solutions of different concentrations, and its motion behavior was observed. The results are as follows: Figure 8 As shown, under conditions without hydrogen peroxide (0 mM), the (Ga-Mn)-motor exhibits typical Brownian motion, while in hydrogen peroxide solution, the (Ga-Mn)-motor displays a concentration-dependent, enhanced self-driven motion in response to hydrogen peroxide. The graphs showing the variation of the (Ga-Mn)-motor's velocity with hydrogen peroxide concentration and the relationship between MSD (mean squared displacement) and Δt (time interval) in hydrogen peroxide solutions of different concentrations are shown below. Figure 9 As shown. Clearly, the (Ga-Mn)-motor prepared in this invention can use hydrogen peroxide as "fuel." Driven by hydrogen peroxide, the MSD and speed of the (Ga-Mn)-motor gradually increase with increasing hydrogen peroxide concentration. This movement behavior greatly improves the diffusion efficiency of the generated oxygen in a hydrogen peroxide-rich microenvironment. For example, in a biofilm microenvironment containing endogenous hydrogen peroxide, it can alleviate hypoxic conditions inside the biofilm and enhance the anti-biofilm effect. Its related clinical applications include, but are not limited to, infection control, biofilm removal, surface sterilization, and in-situ removal of biofilms from medical devices with complex surface microstructures (such as dental implants).
[0075] Application Example 1
[0076] Given that dental plaque involves a variety of oral bacteria, this application example evaluates (Ga-Mn)-motor (250 μg / mL) dispersed in PBS. -1 Antibacterial activity against various biofilms, including *Porphyromonas gingivalis*, *Fusobacterium nucleatum*, and *Streptococcus gordonii*. The activity was assessed using Ga@vSiO2 (245.3 μg / mL), which has no oxygen-producing capacity. -1 ) and Ga@vSiO2 (245.3 μg mL) which has oxygen-producing capabilities but exhibits passive diffusion. -1 ) and MnO2 (4.7 μg mL -1 A mixture of Ga@vSiO2+MnO2 served as the experimental control group. The above nanomaterials were applied to the biofilm, and the results were compared with and without near-infrared laser irradiation (808 nm, 1.5 W cm⁻¹). –2 The anti-biofilm ability under the condition of 5 min. The evaluation results are as follows. Figure 10 As shown, crystal violet staining ( Figure 10A) shows that Ga@vSiO2 only caused partial damage; in contrast, Ga@vSiO2+MnO2 and (Ga-Mn)-motor more effectively disrupted the integrity of the biofilm. Notably, the (Ga-Mn)-motor of this invention, utilizing endogenous hydrogen peroxide-driven motion activation, achieved an antibacterial membrane efficacy of 89.1±0.542%, significantly superior to the passive treatment group (P<0.0001). SEM images ( Figure 10 C) shows that under near-infrared laser irradiation, biofilms treated with culture medium or Ga@vSiO2 remained densely packed with only slight shrinkage. Conversely, thanks to enhanced photothermal efficiency, Ga@vSiO2+MnO2 and (Ga-Mn)-motor caused structural damage and extracellular polymeric substance (EPS) degradation under laser irradiation, leading to membrane rupture and protein denaturation. Among these, (Ga-Mn)-motor caused the most extensive damage, leaving only distorted and broken bacterial debris in the field of view. This autonomous movement capability enabled deeper penetration, and its anti-biofilm effect was significantly better than that of passive nanoparticles. Live / dead staining and three-dimensional reconstruction ( Figure 10 B) This further confirms the above results. The figure shows that the (Ga-Mn)-motor group has the least amount of biofilm residue and is mainly stained red (i.e., mainly dead bacteria). The above results fully highlight the significant advantages of the liquid metal-based micro-nano motor of the present invention in overcoming the biofilm barrier.
[0077] Application Example 2
[0078] This application example systematically evaluated the removal performance of a near-infrared photothermal efficiency-enhanced (Ga-Mn)-motor on dental implants with mixed biofilms. Dental implants with attached biofilms were either subjected to clinical mechanical curretage or immersed in a (Ga-Mn)-motor PBS solution (250 μg / mL). -1 In the process, it was irradiated with near-infrared laser (808 nm, 1.5 Wcm). -2 (5 min). Evaluation results are as follows: Figure 11 As shown, crystal violet staining ( Figure 11 A and B indicate that although mechanical scraping can reduce biomass by 69.1 ± 0.741%, it is difficult to completely remove residual contaminants in microscopic crevices; while (Ga-Mn)-motor, by responding to hydrogen peroxide and leveraging the synergistic effect of bubble-driven and autonomous swimming, increases the contact area and penetration depth, improving the biofilm removal rate to 84.1 ± 0.477%, which is significantly better than the mechanical scraping group (P < 0.0001).
[0079] Furthermore, the integrity of the microstructure of the dental implant surface is crucial for osseointegration. SEM images ( Figure 11CF) and AFM Figure 11 G) Analysis showed that mechanical scraping reduced the surface roughness of dental implants and produced significant scratches, damaging their original morphology. In contrast, the (Ga-Mn)-motor efficiently removed biofilm while perfectly preserving the surface microstructure and oxide layer of the dental implant, showing no significant difference from the blank control group. This result confirms the dual advantages of the micro-nano motor of this invention in thoroughly purifying the implant while ensuring the safety of the matrix material.
[0080] In summary, this invention utilizes an asymmetric core-shell structure, asymmetrically anchored liquid metal nanoparticles within an empty shell, as the basic framework of a micro / nano motor. Furthermore, metals and / or metal oxides with catalase-like activity are grown in situ on the surface of the liquid metal nanoparticles, thus fabricating a liquid metal-based micro / nano motor. This basic framework exhibits broad material compatibility, adapting to all inorganic materials responsive to hydrogen peroxide. It effectively overcomes the problems of process sensitivity, material limitations, and restricted functional applications inherent in existing bioresponsive self-driven micro / nano motor fabrication methods. This technological breakthrough not only significantly improves the universality of micro / nano motor fabrication methods but also lays a solid foundation for the widespread expansion of their application scenarios.
[0081] The above detailed embodiments describe the implementation of the present invention; however, the present invention is not limited to the specific details described in the above embodiments. Within the scope of the claims and technical concept of the present invention, various simple modifications and changes can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.
Claims
1. A method for fabricating micro / nano motors based on liquid metal, characterized in that, include: By asymmetrically anchoring liquid metal nanoparticles within an empty shell to form an asymmetric core-shell structure as the basic framework of a micro / nano motor, and then preparing metals and / or metal oxides with catalase-like activity in situ on the surface of the liquid metal nanoparticles, a liquid metal-based micro / nano motor is obtained.
2. The method for fabricating a micro / nano motor based on liquid metal according to claim 1, characterized in that, The liquid metal includes at least one of gallium and its alloys.
3. The method for fabricating a micro / nano motor based on liquid metal according to claim 1, characterized in that, The shell is made of silicon dioxide.
4. The method for fabricating a micro / nano motor based on liquid metal according to claim 1, characterized in that, Includes the following steps: S1. Liquid metal nanoparticles are dispersed in an alcohol solvent, and a silica shell is formed on the surface of the liquid metal nanoparticles by in-situ hydrolysis to obtain core-shell structured liquid metal particles. S2. Disperse the core-shell structured liquid metal particles uniformly in an acid solution and perform acid etching to partially etch the liquid metal core, forming an asymmetric core-shell structure with gaps between the core and shell, which is a liquid metal-based asymmetric reactor. S3. Add the liquid metal-based asymmetric reactor to the metal salt solution to carry out the reaction, and grow metals and / or metal oxides with catalase-like activity in situ on the surface of the liquid metal core to obtain a liquid metal-based micro / nano motor with hydrogen peroxide response.
5. The method for fabricating a micro / nano motor based on liquid metal according to claim 4, characterized in that, The operation of step S1 is as follows: liquid metal nanoparticles are uniformly dispersed in an alcohol solvent, then alkali and silicate are added, and ultrasonic treatment is performed to allow the silicate to hydrolyze in situ under alkaline conditions, forming a silica shell on the surface of the liquid metal nanoparticles, thus obtaining core-shell structured liquid metal particles.
6. The method for fabricating a micro / nano motor based on liquid metal according to claim 4, characterized in that, The acid etching process is performed at a temperature of 30-100℃ for 5-30 minutes.
7. The method for fabricating a micro / nano motor based on liquid metal according to claim 4, characterized in that, The metal and / or metal oxide includes at least one of gold, platinum, silver, copper, or manganese dioxide.
8. The method for fabricating a micro / nano motor based on liquid metal according to claim 7, characterized in that, The metal salt includes at least one of chloroauric acid, chloroplatinic acid, silver nitrate, copper chloride, and potassium permanganate.
9. A liquid metal-based micro / nano motor prepared by the preparation method according to any one of claims 1-8.
10. The application of the liquid metal-based micro / nano motor as described in claim 9, characterized in that, This includes, but is not limited to, biofilm removal or surface sterilization.