245results about How to "Good magnetic response" patented technology

The invention belongs to the nano-composite material technology field, in particular to a magnetic inorganic nano-particle / ordered mesoporous silica core-shell microsphere and a preparation method thereof. The invention first utilizes sol-gel chemical synthesis method, coats a layer of amorphous silica on the surface of a plurality of magnetic inorganic nano-particles, then utilizes self-assembly of an organic surfactant as structure-directing agent and inorganic species in the solution, coats a layer of ordered meso-structured silica / surfactant composite material on the surface of the magnetic inorganic nano-particle / silica composite microsphere, removes the surfactant through solvent extraction, and obtains the ordered mesoporous magnetic inorganic nano-particle / silica core-shell structure composite microsphere material. The composite microsphere has high specific surface area, strong magnetic responsiveness, and wide application prospect in bioseparation and bioabsorption. The invention is simple in method, easy in obtaining raw materials, and suitable for large scale production.

A magnetic microphere of doxytaxol for preventing and treating tumor contains proportionaly magnetic Fe3O4 nanoparticles, alpha 1-acidic glucoprotein, doxytaxol and oleic acid. Its advantage is high target performance. Its preparing process is also disclosed.

The invention relates to magnetic silicon dioxide microspheres with a nuclear shell and surface anisotropic double functional groups and a preparation method thereof. The preparation method comprises the following steps of: preparing superparamagetic microspheres by a solvothermal process; preparing magnetic microspheres which are coated by silicon dioxide by a sol-gel process; preparing the magnetic silicon dioxide microspheres of which the surface has amino group by taking the magnetic silicon dioxide microspheres as seeds and by the copolycondensation of alkyl ester orthosilicate and a silane coupling agent, and drying the magnetic silicon dioxide microspheres to obtain samples; and by a PICKERING emulsion technology, stabilizing a paraffin / aqueous emulsion system with a micrometer scale by using the aminated magnetic microspheres to form single-layer close packing of the magnetic microspheres on the surface of paraffin spheres, then reacting the amino group on the surface of the magnetic microspheres which is exposed in a liquid phase with succinic anhydride to introduce carboxyl into the partial surface of the microspheres, so that the surfaces of the magnetic microspheres have the anisotropic double functional groups. The obtained magnetic microspheres with the double functional groups have the advantages that: magnetic responsiveness is high; grain size can be controlled between 200 and 800 namometers; and the density of the surface functional groups can be adjusted.

The invention discloses a synthesis method of a metal organic framework composite material which has a sandwich structure, comprises magnetic microsphere ferroferric oxide surface coating polydopamine and takes zirconium ion as central metal ion and application of the material. The synthesis method comprises the following steps: firstly synthesizing ferroferric oxide magnetic microspheres by using a hydrothermal synthesis method; dispersing the magnetic microspheres in an aqueous solution of polydopamine hydrochloride to coat the surfaces of the magnetic microspheres with polydopamine layers; dispersing the magnetic microspheres coated with the polydopamine in an N,N-dimethylformamide mixed solution of zirconium chloride and terephthalic acid to prepare the magnetic metal organic framework composite material with a sandwich structure. The synthesis method is simple and quick; the magnetic metal organic framework composite material obtained by synthesizing is high in specific surface area, good in biocompatibility and applicable to selective enrichment of phosphorylated peptide and MALDI-TOFMS detection in biological samples.

The invention discloses a preparation method and a use of poly(lactic-co-glycolic acid) (PLGA) microspheres as nucleic acid vaccine vectors. A result of an animal immunization experiment shows that the PLGA microspheres can be utilized as gene vaccine vectors. Principles of the PLGA microspheres comprise that 1, the PLGA microspheres have core-shell structures; surface polymers comprise polymine, PLGA, glucose, chitosan, polylysine, FeCl3 and FeCl2; and through static electricity, dewatering interaction and hydrogen bond-nucleic acid vaccine interaction, a nucleic acid vaccine is concentrated to form a compact nucleic acid vaccine so that nucleic acid vaccine degradation is reduced in vivo; 2, the PLGA microspheres have magnetism and thus after immunization injection, in a strong magnetic field, the distribution of the PLGA microspheres in muscular tissue is improved and the defect of limited contact between the PLGA microspheres and target cells is overcome; and 3, through long-term strong magnetic field induction, a magnetic PLGA microsphere / nucleic acid vaccine complex can enter into the skin; and because of rich antigen presenting cells in the skin, a strong and fast immune response can be induced.

The invention belongs to the field of nano material preparation, and particularly relates to water-soluble fluorescent magnetic nano particles and a preparation method thereof. The invention adopts the technical scheme that the method comprises the following steps of: preparing magnetic nano particles by adopting a solvent thermal method, coating a SiO2 shell layer on the surface of the magnetic nano particles by hydrolysis of ethyl orthosilicate under the alkali condition, and connecting -NH2 to the outermost layer through a silane coupling agent with amino; and finally, mixing two kinds of aqueous solution, adding a connecting agent such as ethylene dichloride (EDC) or the like, and connecting the magnetic nano particles and quantum dots through chemical bonds formed by condensation reaction between amino and carboxyl to obtain the fluorescent magnetic nano particles. The fluorescent magnetic nano particles obtained by the technical scheme have low toxicity, good stability and magnetic response and excellent fluorescence; and the method has short experimental period, simple and safe operation and low raw material cost, can be completed in a common chemical laboratory, and lays a foundation for wide popularization and application.

An eddy-current sensor for nondestructive testing according to the present invention includes a planar exciting coil having a pair of current lines in parallel with each other through which exciting currents flow in opposite directions to each other during the testing, for generating an alternative magnetic field applied to a subject to be nondestructively tested by the exciting currents, and at least one MR element positioned on a central axis between the pair of current lines and on the opposite side to the subject in relation to the exciting coil, for detecting a magnetic field generated newly from the subject by an eddy-current induced by the alternative magnetic field.

The invention provides a preparation method for a biomass charcoal adsorbent loaded with chitosan magnetic nanoparticles. The preparation method comprises the following steps: preparing biomass charcoal, preparing a chitosan-acetic acid solution, preparing an iron solution and preparing biomass charcoal loaded with the chitosan magnetic nanoparticles. The invention further provides the biomass charcoal adsorbent loaded with the chitosan magnetic nanoparticles. According to the adsorbent, the biomass charcoal is used as a base material and the surface of the adsorbent is loaded with the chitosan magnetic nanoparticles. The adsorbent prepared through the preparation method can adsorb heavy metal, dye and partial anions, and has the advantages of high adsorption capacity, strong magnetism, stable property and high mechanical performance.

The invention belongs to the field of magnetic materials and relates to a magnetic core / shell / shell triple structure material with noble metal nano particles being at a double-shell interlayer and a preparation method of the material. The preparation method comprises the following steps: with Fe3O4 magnetic particles as a core, performing surface hydrolysis on the magnetic particles through hydrolyzing tetraethyl to form a layer of SiO2, then loading the noble metal nano particles with catalytic activity on the SiO2 by a coupling method, and finally coating with a ZIF-8 shell layer with regular pore channels to enable the noble metal nano particles to be positioned at the double-shell interlayer, thus obtaining the magnetic core / shell / shell triple structure material. The obtained composite material has the advantages that not only can fast separation of the material and a reaction system be realized by adding a magnetic field, but also the noble metal nano particles are positioned at the double-shell interlayer to be prevented from being lost and gathered, and simultaneously the ZIF-8 membrane layer with micropores at the outer layer also can endow the material with shape-selective and selectively-permeable functions, so that the magnetic core / shell / shell triple structure material has good potential application prospect in the fields of shape-selective adsorption and catalysis.

The invention relates to a magnetic bionic adsorbent and an application of the magnetic bionic adsorbent in treating acid wastewater containing uranium. A solvothermal method for preparing Fe3O4 by taking PSSMA (poly (4-styrene sulfonate-copolymer-maleic acid) sodium salt) as a surfactant is improved, grain sizes are uniform, and Fe3O4 magnetic nanoparticles can be synthesized on a large scale; biomolecule dopamine is polymerized in a trihydroxymethyl aminomethane buffer system and coats the surfaces of the Fe3O4 magnetic nanoparticles, and the novel magnetic bionic adsorbent with a core-shell structure is established. The magnetic bionic adsorbent has excellent hydrophilicity and larger specific surface area due to the the polydopamine structure of a shell layer, rich functional groups on the surface of the magnetic bionic adsorbent have high uranium adsorption capacity in a wider acidity range, the magnetic bionic adsorbent has higher uranium adsorption capacity and good selectivity, and uranium adsorbed on the surface of the adsorbent can be easily washed with a 0.1 mol / L (NH4)2CO3 solution and can be recycled conveniently.

The invention discloses a method for preparing three-layer core-shell structural gold magnetic nano particles. The method comprises the following steps of: preparing amino modified core-shell structural Fe3O4 coated SiO2 particles; reducing chloroauric acid by using tetra-hydroxymethyl phosphorus chloride (THPC), wherein the obtained particles carry negative charge and are easily adsorbed to the surfaces of the amino modified Fe3O4 coated SiO2 particles; mixing and stirring suspension of the amino modified Fe3O4 coated SiO2 particles and nano gold suspension, and thus obtaining assembled gold magnetic composite particles Fe3O4 coated SiO2 / Au; and performing multi-step reduction on the surfaces of the THPC reduced nano gold particles which are adsorbed to the surfaces of the Fe3O4 coated SiO2 particles and used as crystal nuclei by using formaldehyde to obtain complete gold shells, and thus obtaining the three-layer core-shell structural gold magnetic nano particles Fe3O4 coated SiO2 coated Au. The prepared particles are uniform in particle diameter distribution and high in dispersibility, stability, magnetic responsibility and biocompatibility.

The invention relates to a biodegradable polymer composite material having shape memory function, comprising a biodegradable polymer material, which is characterized in that the molecular weight of the biodegradable polymer material is 20000 to 1500000, 1 to 20 parts of nano-scopic or micron-sized organic conductive particles and / or inorganic magnetic particles are added in the 100 parts by weight of the polymer, wherein, the organic conductive particles is one of polypyrrole, polyaniline, poly3,4-dioxane ethyl thiophene or the mixture of them, the inorganic magnetic particles is one of ferroferric oxide and ferric oxide magnetic particles or the mixture of them. The mechanical property and mechanical property of the materials, with good elasticity modulus, well elasticity, high shape recovery rate, easy shape memory and changing operation and fast shape recovery speed.

The invention discloses a mechanochemical preparation method and equipment of a magnetic water treatment agent. The preparation method comprises the following steps of: (1) adding magnetic powder and a ball milling medium in a mass ratio of 1: (2-4) to the cylinder of horizontal double-screw stirring mixing equipment, vacuumizing the inner space of the cylinder, driving a horizontally arranged rotating shaft to drive the cylinder into rotation, and performing stirring type ball milling through an internal-rotation stirring stick arranged in the cylinder in opposition to the rotation direction of the cylinder; (2) spraying an atomized modifier into the cylinder through the cavity of the rotating shaft in the ball milling process, wherein the quantity of addition of the modifier is 20-50% of the weight of the magnetic powder; and (3) carrying out stirring type ball milling reaction of the materials under the condition of 50-80 DEG C for 1.5-4 hours, thereby obtaining the magnetic water treatment agent. The mechanochemical preparation method is the mechanochemical method which is simple in preparation process, low in energy consumption and high in efficiency; and the product prepared has a core-shell structure, and is high in surface activity and excellent in magnetic responsiveness.

The invention belongs to the technical field of advanced nanocomposites, and particularly relates to a magnetic mesoporous silica nanochain with a core-shell structure and a preparation method of thenanochain. The method comprises the following steps of firstly, coating a layer of amorphous silica on the surface of magnetic inorganic nanoparticles by using a sol-gel chemical synthesis method, andinducing oriented arrangement of the magnetic inorganic nanoparticles to form a one-dimensional core-shell structure nanochain through applying an external magnetic field; secondly, utilizing an organic surfactant as a self-assembly behavior of a structure-directing agent and an inorganic species in solution, and coating a layer of silica / surfactant composite on the surface of a magnetic inorganic nanoparticle / silica composite nanochain through an organic chambering solvent; and finally, removing the surfactant through solvent extraction in order to obtain a magnetic inorganic nanoparticle / silica core-shell structure nanochain composite with ordered mesoporous vertical divergence pore channels. The nanochain has a relatively high specific surface area, a large pore size, good magnetic responsiveness and biocompatibility, and a wide application prospect in the aspects of biological separation, adsorption, drug loading and the like.

The invention discloses a preparation method of porous magnetic polystyrene microspheres. The method comprises steps of: (1) adding dry Fe3O4 magnetic nanoparticles into an aqueous ethanol solution, treating with ultrasonic, adding vinyltriethoxysilane, transferring into a reactor together, stirring under a constant temperature and a nitrogen atmosphere for aging, and then washing, drying under vacuum and grinding the obtained product into powder; (2) mixing the powder obtained in the step (1) and benzoyl peroxide, and then adding into styrene containing a pore forming agent and a cross-linking agent for the ultrasonic treating; (3) dissolving polyvinylpyrrolidone and sodium dodecyl sulfate into water by using the ultrasonic; and (4) adding the liquid obtained in the step (2) into the liquid obtained in the step (3), treating with the ultrasonic, pouring the obtained mixture into a reactor, heating for condensation reflux to obtain a suspension liquid, separating with magnet, washing with ethanol, re-separating with the magnet, re-washing with pure water, drying under vacuum and grinding to obtain claybank powdery product, extracting with a soxhlet way, and drying under vacuum to obtain the finish product.

The invention discloses a preparation method for a magnetic carrier in a processing technique of a sewage biological fluidized bed, which comprises the following steps: (1) magnetic powder is added into a reaction kettle; in the stirring speed of 40 to 100 r / min, inorganic acid and organic acid are sequentially added and heated till the temperature is risen to 65 to 80 DEG C and the reaction lasts for 1.5 to 2 hours; (2) reactant is transferred to a dying cabinet, dried for 0.5 to 1 hours in the temperature of 80 to 100 DEG C, anhydrated, cooled and then crushed by a grinding crusher and sieved with a mesh screen with 100 meshes to obtain granular magnetic carriers. The preparation method has simple process route, low energy consumption, high efficiency and low cost. The magnetic carrier obtained by the preparation method is a shell structure; microorganisms easily grow biological membranes on the magnetic carrier; residual biological membranes can be removed by a magnetic drum separator, thus avoiding the huge loss of organisms. The biological fluidized bed using the magnetic carrier is suitable for fields such as standard reaching discharging treatment of town sewage, synchronous denitrification and dephosphorization of high nitrogen and phosphorus medical waste water, nitrification and denitrification of garbage percolate, coking wastewater and the like.

Disclosed is a process of preparing magnetite nanoparticles, comprising the following steps: 1) preparing a ferric salt mixed system, wherein a soluble ferric salt is dissolved in glycol at ambient temperature, and then urea and polyethylene glycol are added and mixed homogeneously to obtain the trivalent iron salt mixed system, the mass ratio of glycol to the trivalent iron salt being 15:1 to 60:1, glycol to urea being 20:1 to 100:1, and glycol to polyethylene glycol being 20:1 to 100:1; 2) reacting, wherein the trivalent iron salt mixed system is transferred into a reaction autoclave, sealed and placed into a heating device to react at a temperature of 200 to 300° C. for 8 to 72 hours; and 3) washing, wherein after the reaction system is naturally cooled down to ambient temperature, the product is taken out, and washed with anhydrous ethanol and water in turn to obtain the magnetite nanoparticles. The soluble iron salt includes ferric chloride, ferric sulfate, ferric acetate and ferric nitrate. The obtained nanospheres exhibit a uniform distribution of the particle diameter with a good dispersity in water. The nanospheres have superparamagnetism, and their particle diameter can be controlled by varying the reaction time as desired.

The invention provides a method for specifically separating and enriching a phosphorylated peptide and a glycosylated peptide. The method concretely comprises the following steps: preparing a dispersion from a hydrophilic magnetic meso-porous titanium dioxide material, adding the dispersion and a target phosphorylated peptide and glycosylated peptide solution into a sample introduction buffer solution, performing incubation at 37 DEG C for 30-60 min, washing a material with the sample introduction buffer solution, using ammonia water with the volume ratio of 5-20% as an elution buffer solution, performing dot targeting on the obtained eluate, and performing mass spectrometry. The method realizes the simultaneous enrichment of the low-abundance phosphorylated peptide and glycosylated peptide by controlling enriching and eluting conditions, can realize simultaneous large-scale identification of a phosphorylated protein and a glycosylated protein by MALDI-TOF MS or nano-LC-MS / MS, and hasa broad application prospect in post-translational modification proteomics.

The invention relates to a folic acid coupled targeted ferriferrous oxide / mesoporous silica / copper sulfide nano-composite particle as well as a preparation method and an application thereof. The nano-composite particle consists of Fe3O4@mSiO2 core-shell structural nanoparticles, wherein the core-shell structural nanoparticles take Fe3O4 nanoparticles as cores and mSiO2 as shells, and copper sulfide nanoparticles and folic acid cover the surfaces of the shells; the folic acid is grated on one part of the mesoporous silica (mSiO2) and the copper sulfide particles are loaded on the other part of the mesoporous silica; and polyethylene glycol is grated on the surface of the copper sulfide nanoparticles. Compared with the prior art, the nano-composite particles disclosed by the invention has a broad application prospect in the aspects of nuclear magnetic resonance imaging, drug loading and photothermal therapy; anti-cancer drugs and photothermal reagents can be transmitted to tumor parts in a targeted mode; the nano-composite particle can reduce toxic and side effects on normal tissues and cells, and meanwhile, the nano-composite particle can effectively kill cells, so that a treatment effect is further improved; and moreover, the nano-composite particle is relatively low in preparation condition demand and cost.

Adsorbent particles comprising superparamagnetic and / or low Curie Temperature transition metal-containing cores surrounded by a hydrous siliceous oxide coating can be formed by an aqueous process wherein the core is precipitated from an aqueous solution and a siliceous oxide coating is deposited thereon while complete drying of the core is avoided until after the siliceous oxide is deposited. The resulting siliceous adsorbents exhibit strong superparamagnetic and / or low Curie temperature magnetic properties with low transition metal leachability.

The invention discloses a group enhanced type magnetic nanometer water treatment agent and a preparation method and application thereof. The preparation method is characterized by comprising the following steps: accurately weighting hexahydrate ferric chloride and anhydrous sodium acetate as reaction raw materials; firstly, dissolving the raw materials into ethylene glycol; then, adding polyethylene glycol to disperse; adding solution into a high-pressure reaction reactor container to react; carrying out magnetic adsorption to obtain Fe3O4 magnetic nanoparticles; taking ethyl orthosilicate as a silicon source to enable silicon dioxide to cover the surface of the Fe3O4 magnetic nanoparticles; taking silane coupling agent as an amino source to graft an -NH2 group to the surface of the silane coupling agent to obtain Fe3O4@SiO2-NH2 magnetic nanoparticles; finally, under a constant temperature, stirring to modify the amino and sulfydryl group of cysteine on the surfaces of the Fe3O4@SiO2-NH2 magnetic nanoparticles to obtain group-enhanced magnetic nanometer water treatment agent Fe3O4-SiO2-NH2-L-Cys. The preparation method has the advantages of simpleness in preparation process operation and easiness in realizing reaction conditions. In addition, the group enhanced type magnetic nanoparticles prepared with the preparation method has the advantages of narrow particle size distribution, good stability, good adsorption function for various heavy metal ions and high adsorption efficiency.

The invention discloses a chitosan / polyvinyl alcohol / ferroferric oxide composite magnetic particle as well as preparation and application thereof, and relates to a composite magnetic particle, which is formed by the following components in percentage by mass: 20-80% of chitosan, 10-75% of polyvinyl alcohol and the balance of ferroferric oxide. The particle diameter is 500-4000 micrometers and is controllable. The preparation method comprises the following steps: mixing a chitosan acid solution with a polyvinyl alcohol water solution; adding ferroferric oxide powder; dispersing ferroferric oxide powder in the mixed liquid to obtain a mixed liquid; adding a NaOH solution into the mixed solution; curing to ball-shaped particles; collecting the obtained ball-shaped particles through an outside magnetic field and adding the particles into ethanol; swelling and standing; soaking and washing, and drying to obtain the chitosan / polyvinyl alcohol / ferroferric oxide composite magnetic particle. As shown in experiment, the chitosan / polyvinyl alcohol / ferroferric oxide composite magnetic particle can be used in preparation of agents for removing heavy metal in water.

The invention relates to a magnetic solid acid catalyst which comprises magnetic aluminum oxide and transitional metal loaded on the magnetic aluminum oxide, wherein the weight proportion of the magnetic aluminum oxide and the transitional metal is 1.5-99:1 on the basis of transitional metal sulphate, and the transitional metal is one or more selected from IB, IIB, IVB and VIII groups; the magnetic aluminum oxide comprises Gamma-Al2O3 and magnetic particles embedded in the Gamma-Al2O3, and the weight proportion of the Gamma-Al2O3 and the magnetic particles is 1-9:1; the magnetic particles comprise SiO2 and magnetic kernels embedded in the SiO2, and the weight proportion of the SiO2 and the magnetic kernels is 0.1-1:1; the magnetic kernel is one or more selected from magnetic metals, magnetic alloys and magnetic metal oxides. The magnetic solid acid catalyst has the characteristics of large specific surface area, good magnetic property, stable physicochemical property, and the like, can be applied to processes of fluidized bed and magnetic stabilization bed and is specially suitable for integrating with a magnetic stabilization bed reactor for acid catalyzed reaction in the filed of oil processing.

The invention relates to a preparation method of a magnetic microspheres-based levofloxacin surface imprinted material. The preparation process mainly comprises three steps: preparation of magnetic microspheres; coating of the magnetic microspheres with a molecularly imprinted material; and elution of template molecules. A synthetic method provided by the invention is simple. The prepared magnetic microspheres-based surface molecularly imprinted material has specific recognition function, high adsorption capacity and rapid adsorption ability of levofloxacin and has chiral resolution function of ofloxacin, has good magnetic response and high mechanical strength, can be used as an absorption filler or a coating material, also can be used in preparation of a molecular imprinting sensor and a chip, and is of great significance for researches on specific recognition, chiral resolution and highly sensitive detection of floxacin drugs.

This invention discloses a nm magnetic microsphere and a nm magnetic immune microphere, their preparation method, (inverse micro-emulsion) its usage and its pharmaceutical composition, among which, said nm microsphere contains a macromolecular packed layer formed by chemical-cross linking with a degradable macromolecular material containing amino-group, the packed layer contains nm magnetic material, the mean size of the microspheres is 20-80nm. The nm magnetic immune microsphere with nm magnetic microsphere as the core is connected with a bioactive subject on the surface. Said nm magnetic microshpere is generated by the reaction of nm magnetic material, macromolecular material and the crosslinker in the inverse micro-emulsion.

The invention discloses a pH-responsive magnetic metal organic framework composite nano-material and its preparation method and use. The pH-responsive magnetic metal organic framework composite nano-material comprises Fe3O4 nanoparticles, polymer layers coating the surfaces of the Fe3O4 nanoparticles and a metal organic framework growing on the polymer layers. The polymer layer comprises a first polymer chelated with metal ions or comprises the first polymer chelated with metal ions and a hydrophilic second polymer. The metal organic framework is formed from Fe<3+> and a phenylboronic acid derivative containing at least one carboxyl group or at least two boronic acid groups through a coordination bond. The composite nano-material provided by the invention has good magnetic response performances and can realize reversible and highly selective capture and release of glycoprotein in different pH environments, and the pH environment is relatively mild so that the influence on the glycoprotein activity is avoided.

The invention discloses a magnetic nanoparticle and an immunomagnetic nanoparticle with a cell-like structure as well as a preparation method and application thereof. The magnetic nanoparticle with the cell-like structure uses a superparamagnetic Fe3O4 nanoparticle as a core and is wrapped with a white cell membrane on the surface, so that the magnetic nanoparticle has excellent magnetic responseperformance, furthermore, the white cell membrane wrapping on the surface of the magnetic nanoparticle is homologous with white cells, thereby effectively weakening non-specific adsorption to the white cell; an antibody is modified onto the white cell membrane wrapping on the surface of the magnetic nanoparticle through mediating of lipid molecules-polyethylene glycol-biotin molecules and avidin,so as to obtain the immunomagnetic nanoparticle with the cell-like structure. CTCs cells can be enriched and separated with high efficiency and high purity.

The invention discloses a preparation method of magnetic nano-particles modified by aminogen. The preparation method comprises the steps that: (1) the alcoholysis of the magnetic nano-particles is carried out in a mixed solvent of toluene and low class monohydric alcohol, and surfaces of the magnetic nano-particles are coated by silica gel; the magnetic nano-particles coated by the silica gel are obtained; (2) the magnetic nano-particles coated by the silica gel react with a silane coupling agent, and the magnetic nano-particles coated by the silica gel with surfaces to modify an amino functional group are made. The invention also discloses a preparation method of an immunity magnetic nano separation agent which comprises the preparation method. The preparation method of the invention has the advantages of stable and moderate reaction system, simple and controllable operation and cheap agent material cost, and the waste reaction solution is easy to treat, and does not pollute environment. The preparation method is adapted to the industrial production. The magnetic nano-particles modified by aminogen has the advantages of small particle size, narrow distribution and good dispersibility, and the immunity magnetic nano separation agent has the advantages of high antibody combining rate, low non-specific binding rate, rapid magnetic separation, etc.

The invention relates to a preparation method to prepare silicon dioxide nanoparticles with the magnetic monodisperse. The processes are as follows: (1) excess ammonia is added into the aqueous solution containing Fe3+ and Fe2+ salts to obtain the black precipitate of Fe3O4; (2) the precipitate is transferred to the alcohol-water solution of sodium oleate and the pH value is regulated to the acidity; (3) sodium silicate is added into the solution, heated and ultrasonically treated and then the silicon dioxide nanoparticles with magnetic disperse is obtained; (4) the coupling agent is added to react to obtain the silicon dioxide nanoparticles with surface modified magnetic monodisperse. The method is provided with low-cost raw material, simple process, low energy consumption and small amount for the necessary equipment. The silicon dioxide nanoparticles produced by the method is provided with excellent performance, which can fully meet the application requirement in the a plurality of fields such as: the drug carrier, the immobilization of the enzyme, the cell sorting, the immunity detection, the separation and hybridization of the nucleic acid.

A sort of high specific saturation magnetized Fe3O4 particle can be prepared through adding an organic surfactant to nano Fe3O4 solution obtained by traditional process feeding them to a nano mill, grinding and reacting the particles with the organic surfactant. After surface treatment the Fe3O4 particles are provided with less size, higher dispersion, higher stability. Its specific saturation magnetization is higher than 80emu / g and it is suitable for making magnetized liquid, magnetized particle and magnetized drug.