CN110465920A - It is a kind of novel using pollen as the magnetic pollen of template travelling Micro-Robot preparation method - Google Patents

Abstract

The invention provides a novel preparation method of a magnetic pollen swimming micro-robot using pollen as a template, and belongs to the technical field of preparation and driving of a magnetic swimming micro-robot. In the present invention, the outer pollen sheath coating is removed by pollen pretreatment: the pollen is dipped in chloroform/methanol mixed solution, and then the solution is removed by vacuum filtration; the second dipping treatment is performed in hydrochloric acid after vacuum drying; rinsed with deionized water Then in situ synthesis of magnetic particles on pollen: the product is placed in FeCl ₂ solution and then placed in FeCl ₃ solution, both are shaken, centrifuged, the supernatant is removed, and deionized water is added to the flask, heated under nitrogen, Then add the pollen treated by the above steps, adjust the pH value, stir and heat; use a magnet to hold the pollen particles, and pour off the supernatant to obtain a magnetic pollen swimming micromachine. The invention uses pollen as a template, and the prepared swimming micro-robots have various shapes and high biocompatibility.

Description

A novel preparation method of a magnetic pollen-swimming microrobot using pollen as a template

technical field

The invention relates to a novel preparation method of a magnetic pollen swimming micro-robot using pollen as a template, and belongs to the technical field of preparation and driving of a magnetic swimming micro-robot.

Background technique

Due to the application prospects of micro-robots in biomedicine and other fields, the synthesis of various special structures and micro-robots using special materials has become one of the current research hotspots. Pollen in nature has various shapes. We use pollen as a natural template to synthesize magnetic particles on the pollen in situ, so that we can get magnetic pollen swimming micromachines with various shapes, which can control the magnetic properties under the control of a magnetic field. Movement direction and movement speed of the pollen-swimming microrobot. The present invention solves the problems of complex method for synthesizing magnetic swimming microrobots, troublesome post-processing, low biocompatibility and low experiment repeatability. The magnetic pollen swimming microrobot prepared by the invention is small in size, strong in magnetism and good in biocompatibility, and has wide application prospects in the fields of biomedicine, bionic design and the like.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the problem that the existing swimming robots existing in the above-mentioned prior art have a single shape and are complicated to prepare; the solvothermal method is difficult to accurately determine the chemical composition and geometric shape of the swimming robot; the electrochemical deposition method is difficult to process waste liquid, and the cost The problem of low surface energy of common constituent substances of the layer-by-layer assembly method is provided, and the preparation of a new type of magnetic pollen-swimming microrobot using pollen as a template is provided.

The purpose of this invention is to realize through the following technical solutions:

The preparation of a new type of magnetic pollen-swimming micro-robot using pollen as a template includes the following steps:

1. Removal of the outer pollen sheath coating by pollen pretreatment

Step 1: immerse 0.01g-0.1g of pollen in 5-20ml of chloroform/methanol mixture for 12-36 hours, and then remove the solution by vacuum filtration;

Step 2: vacuum drying the product obtained in step 1 at 20-60° C. for 6-24 hours;

Step 3: The product obtained in Step 2 is subjected to a second immersion treatment in 5-30ml of hydrochloric acid solution for 0.5-2 hours, centrifugation to remove the supernatant, and vacuum drying;

Step 4: rinse the product obtained in step 3 with deionized water for 2 to 5 times;

2. In situ synthesis of magnetic particles on pollen

Step 5: put the product obtained in step 4 into 0.01g/mL～0.5g/mL FeCl2 solution, shake for 0.5～3h, centrifuge, and remove the supernatant;

Step 6: put the product obtained in step 5 into 0.01g/mL～0.5g/mL FeCl3 solution, shake for 0.5～3h, centrifuge, and remove the supernatant;

Step 7: Add 5-50 mL of deionized water to the three-necked flask, heat it to 50-100°C under nitrogen, then add the pollen treated in the above steps, adjust the pH value, make the whole solution in an alkaline environment, and vigorously stir the mixture , heated at 50～100℃ for 0.2～2h;

Step 8: use a magnet to hold the pollen particles in the reaction flask, and quickly pour off the supernatant to obtain an in-situ synthetic magnetic pollen swimming micromachine.

The water used in the experiment was deionized water, and deoxygenated deionized water was passed through high-purity nitrogen gas into the deionized water for a period of time.

In the first step, the pollen includes sunflower pollen, rape pollen, camellia pollen, buckwheat pollen, etc., all of which are unbroken pollen with a single pollen particle size of 5-50 μm.

In the step 1, the volume ratio in the chloroform/methanol mixed solution is chloroform/methanol=3/1.

The rotational speed of the centrifugal treatment in the third step is 2000-8000 rpm.

The concentration of the hydrochloric acid solution used in the step 3 is 0.5-2 mol/L.

The rotational speed of the centrifugation used in the step 5 is 2000-8000 rpm.

In the seventh step, an alkaline solution is used to adjust the pH value between 9 and 14.

The beneficial effects of the present invention are:

The invention solves the problem that the shape of the swimming robot existing in the prior art is single and the preparation is complicated. Solvothermal method is difficult to accurately determine the chemical composition and geometric shape of the swimming robot; electrochemical deposition method is difficult to treat waste liquid, and the cost is high; the surface energy of common constituent substances of layer-by-layer assembly method is low. It has the characteristics of various shapes. Using pollen as a template, the prepared swimming microrobots have various shapes and high biocompatibility.

The shape of the swimming robot obtained by the template method of the traditional swimming robot is single, and most of them are spherical, rod-shaped and peanut-shaped. The present invention turns the template into pollen, because the pollen in nature has various forms, so the swimming robots of various shapes can be prepared, and the preparation process of the method is simple, and can be applied to industry and mass production; The product used is non-toxic in vivo and has good biocompatibility.

At present, the maximum countercurrent speed of the robot that performs countercurrent motion in the quartz glass capillary can only reach 2mm/s, and the robot cannot turn during the motion. Taking the magnetic sea urchin-like swimming robot made from sunflower pollen as a template as an example, in the quartz glass capillary, the magnetic sea urchin-like swimming robot can perform countercurrent motion at a water flow rate of 8 mm/s, because the sea urchin-like spiny structure , which increases the friction between the swimming robot and the substrate, so it can always move against the wall and can rotate in any direction.

During the application process, by adjusting the frequency of the magnetic field, the movement speed of the magnetic pollen swimming robot will change accordingly; by adjusting the angle of the magnetic field, the moving direction of the magnetic pollen swimming robot will change accordingly; by adjusting the magnetic induction intensity of the magnetic field, the magnetic pollen swimming robot can The countercurrent speed of the countercurrent motion changes accordingly to precisely control the magnetic pollen swimming robot.

Description of drawings

Figure 1 is a microscope image of a sea urchin-shaped magnetic pollen swimming robot with a diameter of 15-35 microns.

Figure 2 is a scanning electron microscope image of a sea urchin-shaped magnetic pollen swimming robot with a diameter of 15-35 microns.

Figure 3 shows the EDS spectrum of the sea urchin-shaped magnetic pollen swimming robot.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings: the present embodiment is implemented on the premise of the technical solution of the present invention, and provides a detailed implementation manner, but the protection scope of the present invention is not limited to the following embodiments.

As shown in Figure 1, Figure 2 and Figure 3, a novel preparation method of a magnetic pollen swimming micro-robot using pollen as a template involved in this embodiment includes the following steps:

1. Removal of the outer pollen sheath coating by pollen pretreatment

Step 1: immerse 0.01g-0.1g of pollen in 5-20ml of chloroform/methanol mixture for 12-36 hours, and then remove the solution by vacuum filtration;

Step 2: vacuum drying the product obtained in step 1 at 20-60° C. for 6-24 hours;

Step 3: The product obtained in Step 2 is subjected to a second immersion treatment in 5-30ml of hydrochloric acid solution for 0.5-2 hours, centrifugation to remove the supernatant, and vacuum drying;

Step 4: rinse the product obtained in step 3 with deionized water for 2 to 5 times;

2. In situ synthesis of magnetic particles on pollen

Step 5: put the product obtained in step 4 into 0.01g/mL～0.5g/mL FeCl2 solution, shake for 0.5～3h, centrifuge, and remove the supernatant;

Step 6: put the product obtained in step 5 into 0.01g/mL～0.5g/mL FeCl3 solution, shake for 0.5～3h, centrifuge, and remove the supernatant;

Step 7: Add 5-50 mL of deionized water to the three-necked flask, heat it to 50-100°C under nitrogen, then add the pollen treated in the above steps, adjust the pH value, make the whole solution in an alkaline environment, and vigorously stir the mixture , heated at 50～100℃ for 0.2～2h;

Step 8: use a magnet to hold the pollen particles in the reaction flask, and quickly pour off the supernatant to obtain an in-situ synthetic magnetic pollen swimming micromachine.

The water used in the experiment was deionized water, and deoxygenated deionized water was passed through high-purity nitrogen gas into the deionized water for a period of time.

In the first step, the pollen includes sunflower pollen, rape pollen, camellia pollen, buckwheat pollen, etc., all of which are unbroken pollen with a single pollen particle size of 5-50 μm.

In the step 1, the volume ratio in the chloroform/methanol mixed solution is chloroform/methanol=3/1.

The rotational speed of the centrifugal treatment in the third step is 2000-8000 rpm.

The concentration of the hydrochloric acid solution used in the step 3 is 0.5-2 mol/L.

The rotational speed of the centrifugation used in the step 5 is 2000-8000 rpm.

In the seventh step, an alkaline solution is used to adjust the pH value between 9 and 14.

Use the following examples to verify the beneficial effects of the present invention below:

A novel preparation method of a magnetic pollen swimming micro-robot using pollen as a template of the present embodiment is carried out according to the following steps:

Example 1

1. Removal of the outer pollen sheath coating by pollen pretreatment

Step 1: Immerse 0.0654g of sunflower pollen in 10ml of chloroform/methanol mixture for 24 hours, and then remove the solution by vacuum filtration;

Step 2: vacuum drying the product obtained in step 1 at 60°C for 12 hours;

Step 3: The product obtained in step 2 was subjected to a second dipping treatment for 1 hour in 10ml of 1mol/L hydrochloric acid;

Step 4: Rinse the sunflower pollen grains after drying in Step 3 with 10ml of deionized water three times;

2. In situ synthesis of magnetic particles on sunflower pollen

Step 5: prepare 0.02035g/mL FeCl ₂ solution: add 0.2035g FeCl ₂ to 10mL degassed deionized water; prepare 0.0331g/mL FeCl ₃ solution: add 0.35g FeCl ₃ to 10mL degassed deionized water;

Step 6: place the defatted sunflower pollen in FeCl ₂ solution, shake for 1 h, centrifuge, and remove the supernatant;

Step 7: adding the above sunflower pollen to 0.0331g/mL FeCl ₃ solution, shaking for 1 hour, centrifuging, removing the supernatant, and drying at room temperature;

Step 8: In a three-necked flask, add 20 mL of degassed deionized water, heat to 80°C under nitrogen, add the pollen treated in the above steps, adjust the pH to 12 with NaOH solution, stir the mixture vigorously, and heat the mixture at 80°C under heating for 30min;

Step 9: use a magnet to hold the pollen particles in the reaction flask, and quickly pour off the supernatant to obtain a sea urchin-shaped magnetic pollen swimming micromachine.

Wherein, the sunflower pollen in step 1 is unbroken sunflower pollen; the volume ratio in the chloroform/methanol mixture is chloroform/methanol=3/1; the rotational speed of all centrifugal treatments in the experiment is 4000 r/min; the water used in the experiment is It is deionized water, and deionized deionized water is obtained after passing high-purity nitrogen gas into the deionized water for a period of time.

The optical microscope photo of the magnetic pollen swimming microrobot obtained in this example is shown in Figure 1. It can be seen from Figure 1 that the magnetic pollen swimming microrobot obtained by this experimental method has a relatively uniform particle size and the same shape and height.

The SEM photo of the magnetic pollen-swimming micro-robot obtained in this example is shown in FIG. 2 . It can be seen from FIG. 2 that the diameter of the magnetic pollen-swimming micro-robot is 15-35 nm, and the magnetic pollen-swimming micro-robot has a sea urchin-like shape. spiny structure.

The EDS energy spectrum of the magnetic pollen-swimming microrobot obtained in this example is shown in Figure 3. It can be seen from Figure 3 that the magnetic pollen-swimming microrobot obtained by this experimental method contains iron, a magnetic metal substance, which proves that our success Magnetic particles were synthesized in situ on the surface of pollen.

The magnetic pollen-swimming micro-robot obtained in this embodiment is placed in a uniformly strong rotating magnetic field to apply a periodically changing magnetic field, so as to realize the free movement of the magnetic pollen-swimming micro-robot.

Example 2

1. Removal of the outer pollen sheath coating by pollen pretreatment

Step 1: Immerse 0.05g of rape pollen in 10ml of chloroform/methanol mixture for 24 hours, and then remove the solution by vacuum filtration;

Step 2: vacuum drying the product obtained in step 1 at 60°C for 12 hours;

Step 3: The product obtained in step 2 was subjected to a second dipping treatment for 1 hour in 10ml of 1mol/L hydrochloric acid;

Step 4: Rinse the rapeseed pollen grains after drying in step 3 with 10ml deionized water three times;

2. In situ synthesis of magnetic particles on rape pollen

Step 5: prepare 0.02035g/mL FeCl ₂ solution: add 0.2035g FeCl ₂ to 10mL degassed deionized water; prepare 0.0331g/mL FeCl ₃ solution: add 0.35g FeCl ₃ to 10mL degassed deionized water;

Step 6: Place the defatted rape pollen in FeCl ₂ solution, shake for 1h, centrifuge, and remove the supernatant;

Step 7: Add the rapeseed pollen to 0.0331g/mL FeCl ₃ solution, shake for 1 hour, centrifuge, remove the supernatant, and dry at room temperature;

Step 8: In the three-necked flask, add degassed 20mL deionized water, heat to 80°C under nitrogen, then add the rape pollen treated in the above steps, adjust the pH value to 12 with NaOH solution, stir the mixture vigorously, at 80°C. Heating at ℃ for 30min;

Step 9: use a magnet to hold the pollen particles in the reaction flask, and quickly pour off the supernatant to obtain a magnetic pollen swimming micromachine in the shape of rape pollen.

The rape pollen in step 1 is unbroken rape pollen; the volume ratio in the chloroform/methanol mixture is chloroform/methanol=3/1; and the rotational speed of all centrifugation in the experiment is 4000 r/min.

The above are only preferred specific embodiments of the present invention, and these specific embodiments are based on different implementations under the overall concept of the present invention, and the protection scope of the present invention is not limited to this. Anyone familiar with the technical field Changes or substitutions that can be easily conceived by a skilled person within the technical scope disclosed by the present invention shall be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (8)

1. a novel magnetic pollen swimming micro-robot preparation method with pollen as template, is characterized in that, comprises the following steps: 1. Removal of the outer pollen sheath coating by pollen pretreatment Step 1: immerse 0.01g-0.1g of pollen in 5-20ml of chloroform/methanol mixture for 12-36 hours, and then remove the solution by vacuum filtration; Step 2: vacuum drying the product obtained in step 1 at 20-60° C. for 6-24 hours; Step 3: The product obtained in Step 2 is subjected to a second immersion treatment in 5-30ml of hydrochloric acid solution for 0.5-2 hours, centrifugation to remove the supernatant, and vacuum drying; Step 4: rinse the product obtained in step 3 with deionized water for 2 to 5 times; 2. In situ synthesis of magnetic particles on pollen Step 5: put the product obtained in step 4 into 0.01g/mL～0.5g/mL FeCl ₂ solution, shake for 0.5～3h, centrifuge, and remove the supernatant; Step 6: put the product obtained in step 5 into 0.01g/mL～0.5g/mL FeCl3 solution, shake for 0.5～ _3h , centrifuge, and remove the supernatant; Step 7: Add 5-50 mL of deionized water to the three-necked flask, heat it to 50-100°C under nitrogen, then add the pollen treated in the above steps, adjust the pH value, make the whole solution in an alkaline environment, and vigorously stir the mixture , heated at 50～100℃ for 0.2～2h; Step 8: use a magnet to hold the pollen particles in the reaction flask, and quickly pour off the supernatant to obtain an in-situ synthetic magnetic pollen swimming micromachine. 2. a kind of novel preparation method of magnetic pollen swimming micro-robot with pollen as template according to claim 1, is characterized in that, the water used in the described experiment is deionized water, and to deionized water to pass high After a period of pure nitrogen, deoxygenated deionized water. 3. The method for preparing a novel magnetic pollen swimming microrobot using pollen as a template according to claim 1, wherein the pollen in the step 1 comprises sunflower pollen, rape pollen, camellia pollen and buckwheat pollen etc., all unbroken pollen with a single pollen particle size of 5-50 μm. 4. a kind of novel preparation method of magnetic pollen swimming microrobot with pollen as template according to claim 1, is characterized in that, in described step 1, in the chloroform/methanol mixed solution, the volume ratio is chloroform/methanol=3/ 1. 5 . The method for preparing a novel magnetic pollen swimming micro-robot using pollen as a template according to claim 1 , wherein the rotational speed of the centrifugal treatment in the step 3 is 2000-8000 rpm. 6 . 6. The method for preparing a novel magnetic pollen swimming microrobot using pollen as a template according to claim 1, wherein the concentration of the hydrochloric acid solution used in the step 3 is 0.5 to 2 mol/L. 7 . The method for preparing a novel magnetic pollen swimming micro-robot using pollen as a template according to claim 1 , wherein the rotational speed of the centrifugal treatment used in the step 5 is 2000-8000 rpm. 8 . 8 . The method for preparing a novel magnetic pollen swimming microrobot using pollen as a template according to claim 1 , wherein in the step 7, an alkaline solution is used to adjust the pH value between 9 and 14. 9 .