阅读说明：本技术 一种具有单分散和超顺磁性的金磁复合微球及其制备方法 (Gold-magnetic composite microsphere with monodispersity and superparamagnetism and preparation method thereof ) 是由 杨冬 王丽霞 *** 高可奕 贾彤彤 于 2019-09-27 设计创作，主要内容包括：本发明提供一种具有单分散和超顺磁性的金磁复合微球的制备方法,包括：(1)将氯化铁和醋酸钠加入1,2-丙二醇中,混合均匀,得到亮黄色混合液,加热至90～110℃,待亮黄色混合液变成姜黄色后,得到介孔Fe<Sub>3</Sub>O<Sub>4</Sub>前驱体溶液,进行溶剂热反应,得到介孔Fe<Sub>3</Sub>O<Sub>4</Sub>；(2)将无水柠檬酸钠溶于水中,加入介孔Fe<Sub>3</Sub>O<Sub>4</Sub>,得到的混合液在室温下搅拌,得到表面修饰后的介孔Fe<Sub>3</Sub>O<Sub>4</Sub>溶液；(3)将表面修饰后的介孔Fe<Sub>3</Sub>O<Sub>4</Sub>溶液加热,然后加入氯金酸水溶液,反应后分离出沉淀,洗涤、干燥,得到金磁复合微球。本发明制备的纳米Fe<Sub>3</Sub>O<Sub>4</Sub>/Au复合材料在水溶液中具有良好的分散性,在生物医药领域具有广泛的应用前景。(The invention provides a preparation method of gold-magnetic composite microspheres with monodispersity and superparamagnetism, which comprises the following steps: (1) adding ferric chloride and sodium acetate into 1, 2-propylene glycol, uniformly mixing to obtain a bright yellow mixed solution, heating to 90-110 ℃, and obtaining mesoporous Fe after the bright yellow mixed solution turns into ginger yellow 3 O 4 Carrying out solvothermal reaction on the precursor solution to obtain mesoporous Fe 3 O 4 (ii) a (2) Dissolving anhydrous sodium citrate in water, adding mesoporous Fe 3 O 4 Stirring the obtained mixed solution at room temperature to obtain the surface modified mesoporous Fe 3 O 4 A solution; (3) modifying the surface of the mesoporous Fe 3 O 4 Heating the solution, adding chloroauric acid water solution, reacting, separating out precipitate, washing, and drying to obtain the gold magnetic compositeAnd (4) synthesizing microspheres. The nanometer Fe prepared by the invention 3 O 4 The Au composite material has good dispersibility in aqueous solution and has wide application prospect in the field of biomedicine.)

1. A preparation method of gold-magnetic composite microspheres with monodispersity and superparamagnetism is characterized by comprising the following steps:

(1) preparation of mesoporous Fe₃O₄

FeCl is added₃·6H₂Adding O and sodium acetate into 1, 2-propylene glycol, uniformly mixing to obtain a bright yellow mixed solution, heating to 90-110 ℃, and obtaining mesoporous Fe after the bright yellow mixed solution turns into ginger yellow₃O₄Precursor solution; mesoporous Fe₃O₄Carrying out solvothermal reaction on the precursor solution, separating out precipitate after reaction, washing and drying to obtain mesoporous Fe₃O₄；

(2) Reducing agent to mesoporous Fe₃O₄Performing surface modification

Dissolving anhydrous sodium citrate in water, adding mesoporous Fe₃O₄Stirring the obtained mixed solution at room temperature to obtain the surface modified mesoporous Fe₃O₄A solution;

(3)Fe₃O₄preparation of Au composite microsphere

Modifying the surface of the mesoporous Fe₃O₄The solution was heated and then HAuCl was added₄·4H₂And (4) reacting the aqueous solution of O, separating out precipitate, washing and drying to obtain the gold-magnetic composite microsphere.

2. The method for preparing gold-magnetic composite microspheres with monodispersity and superparamagnetism according to claim 1, wherein in the step (1), it isMiddle FeCl₃·6H₂The molar ratio of O to sodium acetate is (0.1-0.15): 1.

3. the preparation method of gold-magnetic composite microspheres with monodispersity and superparamagnetism according to claim 1, wherein in the step (1), the solvothermal reaction temperature is 160-200 ℃, and the reaction time is 8-10 h.

4. The method for preparing gold-magnetic composite microspheres with monodispersity and superparamagnetism as claimed in claim 1, wherein in step (2), anhydrous sodium citrate and mesoporous Fe₃O₄The mass ratio of (0.05-0.5) g: (100-200) mg.

5. The method for preparing gold-magnetic composite microspheres with monodispersity and superparamagnetism as claimed in claim 1, wherein, in the step (3), HAuCl₄·4H₂The mass ratio of O to anhydrous sodium citrate is (0.02-0.05) mg: (0.05-0.5) g.

6. The method for preparing gold-magnetic composite microspheres with monodispersity and superparamagnetism according to claim 1, wherein in the step (3), the temperature is heated to 100-110 ℃.

7. The method for preparing gold-magnetic composite microspheres with monodispersity and superparamagnetism according to claim 1, wherein in the step (3), the reaction time is 30-45 min.

8. The method for preparing gold-magnetic composite microspheres with monodispersity and superparamagnetism as claimed in claim 1, wherein in the step (3), the separation is magnetic separation, and the drying is freeze-drying.

9. The gold-magnetic composite microsphere with monodispersity and superparamagnetism prepared by the preparation method of any one of claims 1 to 8.

Technical Field

The invention belongs to the technical field of inorganic nano composite materials, and particularly relates to Fe with monodispersity and superparamagnetism₃O₄Au composite microspheres and a preparation method thereof.

Background

The nano composite material is characterized in that the dimension linearity of the material is in a nano level, and the nano composite material is generally composed of two or more nano materials according to a certain structure, so that the material obtains excellent comprehensive characteristics, and has the quantum size effect, the surface effect, the volume effect and the like which are unique to a single component, and also has the synergistic effect of a plurality of nano component structures. Due to its unique structure and composite function, the nanocomposite has gained a great deal of attention and application in the fields of electronics, optics, catalysis, biomedical technology, and the like.

The gold magnetic nano composite material is a common nano composite structure, and generally refers to a colloid material which is compounded by taking superparamagnetic ferroferric oxide and simple substance gold as main components and has a nano-scale particle size. According to the disuse of the two component composition modes, the gold-magnetic composite material is divided into a core-shell type, a dumbbell type, an assembly type, a multi-component mixed type and other types. The gold magnetic particles not only have unique magnetic properties of magnetic materials, but also have good biocompatibility, chemical stability and unique optical characteristics of colloidal gold, so that the gold magnetic particles are gradually developed into a novel material with wide application prospects, and have wide application in the fields of immunological detection, nucleic acid protein purification, enzyme immobilization, cell separation, drug targeting treatment and the like. However, gold magnetic particles themselves have excessive specific surface energy and low charge, and instability, aggregation and precipitation under physiological conditions are one of the challenges facing the application in the medical field.

At present, most of the preparation methods of gold magnetic nano composite materials are Fe₃O₄Adding reducing agent (hydroxylamine hydrochloride, sodium borohydride, sodium citrate) into the solution to react with chloroauric acid (HAuCl)₄·4H₂O) reduction, the reducing agent and chloroauric acid are carried out in solution, and the reduced gold is further mixed with Fe₃O₄Compounding and preparationObtaining the gold-magnetic composite particles. But Fe under boiling conditions during the preparation process₃O₄The solution is easy to oxidize so as to weaken the magnetism, more importantly, the growth process of the gold magnetic nano particles is easy to appear and is difficult to control, and the obtained composite material has poor dispersibility. Later, some researchers have chosen layer-by-layer assembly and seed crystal growth methods to synthesize gold magnetic particles, first prepared Fe₃O₄Surface modification is carried out to carry out positive charge, and then the colloidal gold particles with negative charge are loaded on Fe through electrostatic adsorption acting force₃O₄Surface, with this seed as the growth center, by controlling HAuCl₄·4H₂The flow rates of O and the reducing agent are adopted, so that the gold magnetic composite material is obtained, the Au shell of the particles prepared by the method is uniform, but the process is complicated, and the yield is not high.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a preparation method of gold-magnetic composite microspheres with monodispersity and superparamagnetism, which is simple and can be produced in large scale, and the obtained gold-magnetic composite particles have good dispersibility.

The invention is realized by the following technical scheme:

a preparation method of gold magnetic composite microspheres with monodispersity and superparamagnetism comprises the following steps:

(1) preparation of mesoporous Fe₃O₄

FeCl is added₃·6H₂Adding O and sodium acetate into 1, 2-propylene glycol, uniformly mixing to obtain a bright yellow mixed solution, heating to 90-110 ℃, and obtaining mesoporous Fe after the bright yellow mixed solution turns into ginger yellow₃O₄Precursor solution; mesoporous Fe₃O₄Carrying out solvothermal reaction on the precursor solution, separating out precipitate after reaction, washing and drying to obtain mesoporous Fe₃O₄。

(2) Reducing agent to mesoporous Fe₃O₄Performing surface modification

Dissolving anhydrous sodium citrate in water, adding mesoporous Fe₃O₄Obtaining a mixed solutionStirring at room temperature to obtain surface modified mesoporous Fe₃O₄A solution;

(3)Fe₃O₄preparation of Au composite microsphere

Modifying the surface of the mesoporous Fe₃O₄The solution was heated and then HAuCl was added₄·4H₂And (4) reacting the aqueous solution of O, separating out precipitate, washing and drying to obtain the gold-magnetic composite microsphere.

Preferably, in step (1), FeCl is added₃·6H₂The molar ratio of O to sodium acetate is (0.1-0.15): 1.

preferably, in the step (1), the solvothermal reaction temperature is 160-200 ℃, and the reaction time is 8-10 h.

Preferably, in the step (2), the anhydrous sodium citrate and the mesoporous Fe₃O₄The mass ratio of (0.05-0.5) g: (100-200) mg.

Preferably, in step (3), HAuCl₄·4H₂The mass ratio of O to anhydrous sodium citrate is (0.02-0.05) mg: (0.05-0.5) g.

Preferably, in the step (3), the temperature is heated to 100-110 ℃.

Preferably, in the step (3), the reaction time is 30-45 min.

Preferably, in step (3), the separation is magnetic separation and the drying is freeze-drying.

The gold-magnetic composite microsphere with monodispersity and superparamagnetism is prepared by the preparation method.

Compared with the prior art, the invention has the following beneficial technical effects:

the invention firstly synthesizes superparamagnetism Fe by a solvothermal method₃O₄Then using reducing agent sodium citrate to react with Fe₃O₄Surface modification is carried out to make the particles have negative charges, and HAuCl is added₄·4H₂O, in this case, due to HAuCl₄·4H₂O with positive charge, HAuCl₄·4H₂O is adsorbed on Fe by electrostatic adsorption₃O₄On the surface of, and in Fe₃O₄The surface is reduced. Compared withExisting in Fe₃O₄The invention is characterized in that sodium citrate is selected firstly, which not only can be used as a dispersing agent to Fe₃O₄Surface treatment is carried out, so that Fe is effectively avoided₃O₄(ii) agglomeration; secondly, it can also be used as a reducing agent directly in Fe₃O₄The surface is reduced in situ to obtain the monodisperse gold-magnetic composite microsphere, and the nano gold-magnetic composite material not only has Fe₃O₄The material has excellent performance in the field of biological catalysis due to the special electronic structure and synergistic effect between the two materials. The invention obtains monodisperse gold-magnetic composite particles in Fe₃O₄On the basis, the Au is compounded, so that the material still has stronger magnetism, and has good stability, dispersibility and biocompatibility. The surface of the gold-magnetic composite particle obtained by the invention is provided with a chemical bond with weaker citrate, and the chemical bond can be connected with a required chemical group through coordination exchange, so that the surface of the particle is functionalized, and the gold-magnetic composite particle is used for developing more various composite materials to meet the actual requirements. The method has the advantages of simple operation, high yield, good repeatability and large-scale production.

Furthermore, the invention can control the content of the composite particle Au by regulating and controlling the content of the reducing agent, thereby realizing Fe₃O₄And the Au compounding proportion can be controlled and adjusted to meet the use requirements of the composite material in different application fields.

The gold-magnetic composite particles obtained by the invention have stronger magnetism, good stability, dispersibility and biocompatibility.

Drawings

FIG. 1 shows Fe prepared in example one₃O₄And (3) a transmission electron microscope image of the/Au composite microsphere.

FIG. 2 shows Fe prepared in example two₃O₄And (3) a transmission electron microscope image of the/Au composite microsphere.

FIG. 3 is Fe prepared in example III₃O₄And (3) a transmission electron microscope image of the/Au composite microsphere.

FIG. 4 shows an embodimentPreparation of Fe₃O₄And (3) a transmission electron microscope image of the/Au composite microsphere.

FIG. 5 is Fe prepared in example V₃O₄And (3) a transmission electron microscope image of the/Au composite microsphere.

FIG. 6 is Fe prepared in example six₃O₄And (3) a transmission electron microscope image of the/Au composite microsphere.

FIG. 7 shows Fe prepared in example one₃O₄Ultraviolet-visible spectrum of the/Au composite microsphere.

FIG. 8 shows Fe prepared in example one₃O₄Magnetic hysteresis curves of the/Au composite microspheres.

FIG. 9 shows Fe prepared in example one₃O₄And (3) a transmission electron microscope image of the/Au composite microsphere.

Detailed Description

The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.

The preparation method of the gold-magnetic composite microsphere with monodispersity and superparamagnetism comprises the following steps:

(1) solvothermal method for preparing mesoporous Fe₃O₄

FeCl is added₃·6H₂Placing O and sodium acetate in a round-bottom flask, using a 1, 2-propylene glycol solution as a solvent, stirring and ultrasonically dissolving the O and the sodium acetate uniformly, then heating the uniformly stirred mixed solution to 90-110 ℃, transferring the mixture into a polytetrafluoroethylene reaction kettle, and reacting for 8-10 hours at 160-200 ℃. After the reaction is finished, collecting black precipitate by using magnet magnetic separation, alternately cleaning the black precipitate for a plurality of times by using ultrapure water and absolute ethyl alcohol until the cleaned supernatant is clear, and finally freeze-drying to obtain powder, namely the mesoporous Fe₃O₄. Wherein FeCl₃·6H₂The molar ratio of O to sodium acetate is (0.1-0.15): 1.

(2) reducing agent to mesoporous Fe₃O₄Performing surface modification

Firstly, dissolving anhydrous sodium citrate in 100ml of ultrapure water, adding the mesoporous Fe in the step (1) after completely dissolving₃O₄At room temperature willMechanically stirring the mixture for 3-12h, and storing at 4 deg.C for use. Anhydrous sodium citrate and mesoporous Fe₃O₄The mass ratio of (0.05-0.3) g: (100-200) mg.

(3)Fe₃O₄Preparation of Au composite microsphere

Firstly, the surface modified Fe in the step (2)₃O₄Heating the solution to 100-110 ℃, and then adding 2-5 ml HAuCl₄·4H₂And (3) reacting the O (1%) aqueous solution for 30-45 min to obtain a red solution, namely the gold-magnetic composite microspheres, performing magnetic separation, and washing off redundant colloidal gold by using ultrapure water until the supernatant is colorless and transparent. Freeze drying, collecting powder to obtain Fe₃O₄the/Au composite microsphere.