CN112142115A

CN112142115A - Preparation method of superparamagnetic micron-sized magnetic beads

Info

Publication number: CN112142115A
Application number: CN201910564234.1A
Authority: CN
Inventors: 李智洋; 翁国武; 王炜; 朱沉雷; 宋莲; 黄远福
Original assignee: Nanjing Zhongkebio Medical Technology Co ltd
Current assignee: Nanjing Zhongkebio Medical Technology Co ltd
Priority date: 2019-06-27
Filing date: 2019-06-27
Publication date: 2020-12-29

Abstract

The invention discloses a preparation method of micron-sized ferroferric oxide magnetic particles, which adopts a hydrothermal method to prepare the ferroferric oxide magnetic particles. Compared with the prior art, the method has the advantage that the micron Fe3O4 magnetic beads with uniform particle size can be controllably prepared by adjusting the material ratio of the reaction liquid. The prepared ferroferric oxide microspheres have the size of 0.5-5 mu m, uniform particle size and good dispersibility, and the ferroferric oxide microspheres prepared by the method have superparamagnetism. The invention is suitable for the fields of nucleic acid extraction, protein purification, biomedical diagnosis and the like, has the advantages of basically no difference in specific surface area and adsorption capacity of magnetic beads with uniform particle size in application, can accurately absorb target substances during nucleic acid extraction, reduces adsorption of other impurities, and can easily extract the target substances after washing and elution links, thereby improving the yield.

Description

Preparation method of superparamagnetic micron-sized magnetic beads

Technical Field

The invention belongs to the technical field of new material preparation, and particularly relates to a preparation method of superparamagnetic micron-sized magnetic beads.

Background

In recent years, molecular biology techniques have been rapidly developed, and detection and typing of disease-related viruses is an important application field of molecular detection. The extraction of nucleic acid is the most important and basic operation in molecular biology experiment technology. The magnetic bead method is popular as the simplest and fastest extraction method in nucleic acid extraction, and the magnetic bead is the core material in the extraction process.

The magnetic bead is a novel functional material, and has a series of unique and superior physicochemical properties such as magnetic guidance, high specific surface area, biocompatibility and the like. The magnetic beads are composed of magnetic cores and bioactive groups wrapped outside the magnetic cores, can be dispersed in base liquid to form a magnetic liquid material, can be coupled with various bioactive substances, and have the dual characteristics of liquid fluidity and solid magnetic particle materials. The magnetic beads can move and concentrate directionally under the action of the magnetic field and can be dispersed uniformly after leaving the magnetic field, so that the complex liquid-solid separation technology becomes quick, simple and convenient. And (3) putting the magnetic beads into a solution containing a target substance, coupling the active groups on the outer layers of the magnetic beads with the target substance, and simply eluting to obtain the target substance with high purity. At present, magnetic beads are widely used in a plurality of fields such as immunoassay, nucleic acid separation and extraction, cell sorting, enzyme immobilization, and the like. For nucleic acid extraction technology, the magnetic bead method has unique advantages that a conventional extraction method cannot compare with, such as one-step completion of extraction and purification, quantitative extraction, realization of extraction automation and the like.

At present, most of magnetic beads on the market have micron Fe3O4 as inner cores, and the magnetic beads are simple to prepare, high in stability, and have the characteristics of strong superparamagnetism, biocompatibility, easy surface modification and the like. However, the micron Fe3O4 in the market has process limitations, so that the produced micron Fe3O4 has uneven particle size, different sizes and large difference in specific surface area and adsorption capacity, and can adsorb some impurities while extracting a target substance, and meanwhile, the target substance is difficult to completely treat in washing and elution links, so that the yield is reduced. How to prepare the micron Fe3O4 with uniform particle size by a stable process becomes a problem to be solved urgently.

Disclosure of Invention

The invention aims to provide a preparation method of superparamagnetic micron-sized magnetic beads, which can controllably prepare micron Fe3O4 with uniform particle size.

In order to achieve the purpose, the invention adopts the technical scheme that the micron-sized ferroferric oxide magnetic particles and the preparation method thereof are characterized by comprising the following steps.

Adding organic ferric salt into dihydric alcohol, and stirring uniformly to obtain a uniform and transparent solution.

Adding unsaturated fatty acid into the solution I, and stirring uniformly to obtain a mixed solution.

Transferring the mixed solution obtained in the step II to a hydrothermal reaction kettle, heating the reaction kettle to 180 ℃ and keeping the temperature for 200 ℃, and reacting for 10-20 h to obtain a black mixed solution.

And fourthly, carrying out magnetic separation on the black solution obtained by the reaction in the third step to obtain black solid precipitate, washing the black solid with ethanol for 3-5 times, and drying in an oven at 60-80 ℃ to obtain the micron-sized ferroferric oxide magnetic particles.

In the step (I), the dihydric alcohol is one or more of tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, PEG-200, PEG-400 and PEG-600; the organic iron salt is one or more of ferric acetylacetonate, ferric acetoacetate or ferric oleate, and the molar ratio of the organic iron salt to the dihydric alcohol is 1: 50-800.

In the second step, the unsaturated fatty acid is one or more of oleic acid, linoleic acid, linolenic acid, lauric acid or eicosenoic acid, and the molar ratio of the organic iron salt to the unsaturated fatty acid is 1: 1-80.

In the step (c), the reaction condition is 180-200 ℃ for 10-20 h.

According to the preparation method, by changing the molar ratio of the organic ferric salt, the dihydric alcohol and the unsaturated fatty acid, the reaction temperature and the reaction time, the size of the prepared ferroferric oxide microspheres is 0.5-5 mu m, the particle size is uniform, the dispersibility is good, the method is simple to operate, the repeatability is good, the ferroferric oxide microspheres can be synthesized on a large scale, and the ferroferric oxide microspheres prepared by the method have superparamagnetism and are suitable for the fields of nucleic acid extraction, protein purification, biomedical diagnosis and the like.

The beneficial results of the invention are as follows: compared with the prior art, the preparation method of the superparamagnetic micron-sized Fe3O4 magnetic bead can controllably prepare the micron-sized Fe3O4 with uniform particle size, and has wide market prospect and application value.

Drawings

Fig. 1 is an SEM image of the micrometer-sized magnetic beads prepared in example 1 of the present invention.

Fig. 2 is an SEM image of the micrometer-sized magnetic beads prepared in example 1 of the present invention.

FIG. 3 is an SEM image of submicron magnetic beads prepared in example 2 of the present invention.

FIG. 4 is an SEM image of submicron magnetic beads prepared in example 2 of the present invention.

Detailed Description

Example 1.

9g of iron oleate is added into 477g of pentaethylene glycol, and the mixture is stirred evenly to obtain a uniform and transparent solution.

113g of oleic acid was added to the solution (r), and stirred uniformly to obtain a mixed solution.

Transferring the mixed solution obtained in the step two to a hydrothermal reaction kettle, heating the reaction kettle to 180 ℃ and keeping the temperature, and reacting for 12 hours to obtain a black mixed solution.

And (4) carrying out magnetic separation on the black solution obtained by the reaction in the step (c) to obtain black solid precipitate, washing the black solid with ethanol for 3-5 times, and drying in an oven at 60 ℃ for 12 hours to obtain the micron-sized ferroferric oxide magnetic particles.

As can be seen from fig. 1 and 2, the magnetic beads produced in example 1 have substantially uniform particle size and exhibit good dispersibility.

Example 2.

Adding 7g of iron acetylacetonate into 2000g of PEG-400, and uniformly stirring to obtain a uniform and transparent solution.

Adding 320g of eicosenoic acid into the solution I, and uniformly stirring to obtain a mixed solution.

Transferring the mixed solution obtained in the step two to a hydrothermal reaction kettle, heating the reaction kettle to 190 ℃ and keeping the temperature, and reacting for 16 hours to obtain a black mixed solution.

And (4) carrying out magnetic separation on the black solution obtained by the reaction in the step (iii) to obtain a black solid precipitate, washing the black solid with ethanol for 3-5 times, and then drying in an oven at 60 ℃ for 12 hours to obtain the submicron ferroferric oxide magnetic particles.

As can be seen from fig. 3 and 4, the magnetic beads produced in example 2 have substantially uniform particle size and exhibit better dispersibility.

Claims

1. The micron-sized ferroferric oxide magnetic particles and the preparation method thereof are characterized by comprising the following steps:

firstly, adding organic ferric salt into dihydric alcohol, and uniformly stirring to obtain a transparent solution;

adding unsaturated fatty acid into the solution I, and uniformly stirring to obtain a mixed solution;

thirdly, transferring the mixed solution into a hydrothermal reaction kettle, heating the reaction kettle to 180-200 ℃ and keeping the temperature, and reacting for 10-20 hours to obtain a black mixed solution;

and fourthly, carrying out magnetic separation on the black solution obtained by the reaction in the third step to obtain black solid precipitate, washing the black solid with ethanol for 3-5 times, and drying in an oven at the temperature of 60-80 ℃ to obtain the micron-sized ferroferric oxide magnetic particles.

2. The method for preparing micron-sized ferroferric oxide particles according to claim 1, wherein in the step (i), the dihydric alcohol is tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, PEG-200, PEG-400 or PEG-600; the organic iron salt is ferric acetylacetonate, ferric acetoacetate or ferric oleate.

3. The method for preparing micron-sized ferroferric oxide particles according to claim 1, wherein in the step (II), the unsaturated fatty acid is oleic acid, linoleic acid, linolenic acid, laurenoic acid or eicosenoic acid.

4. The method for preparing micron-sized ferroferric oxide particles according to claim 1, wherein in the third step, the reaction conditions are 180-200 ℃ for 10-20 hours.

5. The preparation method of micron-sized ferroferric oxide particles according to claim 1, wherein in the step (iv), the washing is performed 3 to 5 times by using ethanol.