285 results about "Fe3o4 magnetic nanoparticles" patented technology

The invention relates to a preparation method of magnetic graphene, in particular to a chemical preparation method of magnetic graphene. The preparation method aims at solving the problems of the existing synthesis method that the reaction process is toxic and harmful to the environment, large-scale production cannot be realized, the morphology, size and magnetism of magnetic nanoparticles in the magnetic graphene are not controllable and the magnetic graphene cannot be dispersed in water. The chemical preparation method comprises the steps of: 1) preparing aminated Fe3O4 magnetic nanoparticles; 2) preparing graphene; and 3) preparing magnetic graphene through chemical reaction. The chemical preparation method of the magnetic graphene has the advantages that the high temperature and the high pressure are not required, the equipment is simple, the process cost is low, the environment is protected, no pollution is caused, the grain size of the synthesized magnetic nanoparticles is uniform, the controllable growth of the magnetic nanoparticles can be realized by changing reaction conditions, the solubility of the synthesized magnetic graphene is 0.8-1.2mg/ml, the magnetic graphene can be stably dispersed in water and sediment does not occur within 1-2 months. The graphene prepared by adopting the method can be used in biomedical, energy, electronic fields and the like.

The present invention relates to a new phenylboronic-acid-functionalized graphene oxide composite nano material and preparation and application thereof. The material is prepared by immobilization of polydopamine-packed magnetic nanoparticles onto polyethyleneimine-modified graphene oxide and further introduction of phenylboronic acid monomers with carboxyl by amino of polyethyleneimine, and finally the material is used for enrichment of glycoproteins. The specific process is as follows: firstly, Fe3O4 magnetic nanoparticles are prepared by a solvothermal method, and auto polymerization of polydopamine can be performed on surface of the Fe3O4 magnetic nanoparticles under alkaline conditions; the magnetic graphene oxide composite nano material can be prepared by hydrogen bond and PI-PI interaction between the polydopamine and graphene oxide, then the positively charged polyethyleneimine is immobilized onto the surface of the negatively charged magnetic graphene oxide by electrostatic self-assembly; and finally the phenylboronic-acid-functionalized magnetic graphene oxide composite nano material can be prepared by introduction of the phenylboronic acid monomers by amidation reaction, and the phenylboronic-acid-functionalized magnetic graphene oxide composite nano material is successively used in the enrichment of the glycoproteins in bioanalysis.

The present invention discloses a single-stranded DNA aptamer modified SiO2/Fe3O4 magnetic microsphere preparation method, which comprises: (1) adopting a chemical co-precipitation method to obtain Fe3O4 magnetic nanoparticles; (2) adopting a sol-gel method to obtain SiO2/Fe3O4 magnetic microspheres; (3) obtaining -NH2 modified SiO2/Fe3O4 magnetic microspheres; (4) dispersing the -NH2 modified SiO2/Fe3O4 magnetic microspheres in water to obtain -COOH modified SiO2/Fe3O4 magnetic microspheres; and (5) dispersing the -COOH modified SiO2/Fe3O4 magnetic microspheres in a Tris-HCl buffer solution to obtain the aptamer modified SiO2/Fe3O4 magnetic microspheres.

The invention discloses a preparation method of a core-shell structure magnetic nano-molecular imprinting polymer for separating starch polysaccharides, relates to the preparation method of the magnetic molecular imprinting polymer for separating the starch polysaccharides and aims at solving the problem that the molecular imprinting polymer capable of separating the starch polysaccharides is absent at present. The preparation method is as follows: 1) preparing Fe3O4 magnetic nanoparticles; 2) silylanizing the Fe3O4 magnetic nanoparticles; 3) performing amino-modification on the silylanized Fe3O4 magnetic nanoparticles; 4) performing aldehyde modification on the amino-derived Fe3O4 magnetic nanoparticles; and 5) preparing the magnetic nano-molecular imprinting polymer. The maximum saturated adsorption amount of the magnetic nano-molecular imprinting polymer disclosed by the invention to the starch polysaccharides is 8-9mg/g, which is about 2 times of that of the existing molecular imprinting polymer for separating monosaccharides, the adsorption efficiency is high, when the magnetic nano-molecular imprinting polymer is stored in a nitrogen atmosphere, the adsorption efficiency is still 90% of the original level after 30 days, the repeated utilization rate is high, and the magnetic nano-molecular imprinting polymer can be applied to the field of separating the starch polysaccharides.

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 aims at providing a simple and efficient method for preparing a high-performance magnetic fluorescent composite microsphere. Due to the existence of Fe3O4 magnetic nanoparticles, electrons of a fluorescent substance which are located at a conductance band are subjected to electron transfer in a process of returning to a valence band, the electrons of the conductance band are transferred on the Fe3O4 magnetic nanoparticles and fluorescence is subjected to quenching. The method provided by the invention is emphasized on solving the problem that the Fe3O4 magnetic nanoparticles cause large influence on the fluorescence performance of the fluorescent substance in a process of preparing a magnetic fluorescent microsphere. According to the preparing method provided by the invention, through changing a doping sequence and adopting different doping methods, the prepared magnetic fluorescent microsphere can minimize the influence on the fluorescent substance caused by magnetism on the basis of ensuring the magnetic fluorescent microsphere to have excellent magnetic property in actual use and enable the fluorescence performance to be optimal; and the fluorescent substance is introduced by adopting a high-temperature swelling method, so that fluorescent substances inside the microsphere cannot leak, and the stability of fluorescent signals is ensured. The mean particle diameter of the prepared magnetic fluorescent composite microsphere is 5-50 microns, and the particle diameter is even and has perfect appearance.

The invention discloses a preparing method of a magnetic hydrogel microsphere, and belongs to the field of sewage treatment. The method includes firstly preparing graphene oxide (GO@Fe<3>O4) loaded with Fe<3>O4 magnetic nanometer particles through a coprecipitation process, mixing the GO@Fe<3>O4 with a water soluble polymer (such as sodium carboxymethylcellulose (CMC)), and preparing the magnetic composite hydrogel microsphere (such as CMC/GO@ Fe<3>O4) through a spray drying process. The prepared composite hydrogel microsphere has good swelling properties and a large specific surface area. The adsorption efficiency for pollutants is increased, and pollutant adsorption varieties and adsorption amounts of hydrogel are increased. The composite hydrogel microsphere is easy to separate, and can be adopted as adsorbents for organic dye and heavy metal ions in industrial waste water.

The invention discloses a strong magnetic core-shell structural nano copper-based hydrotalcite catalyst and a preparation method thereof, and belongs to the technical field of nano catalysts. The catalyst consists of a strong magnetic core-shell structural nano copper-based hydrotalcite catalyst CuM2+Al hydrotalcite shell and a Fe3O4 magnetic nano particle core; the strong magnetic core-shell structural nano copper-based hydrotalcite catalyst is expressed as Fe3O4@CuM2+Al-LDH and consists of 60 to 80 percent of Fe3O4 magnetic nano particles and 20 to 40 percent of CuM2+Al-LDH hydrotalcite in percentage by mass; the particle size of the core-shell structural magnetic nano catalyst is 500 to 540 nanometers; the specific saturation magnetization intensity sigma s is 40.2 to 60.7emu/g; and the phenolic conversion rate is 38.28 to 55.47 percent. The preparation method has the advantages of simple catalyst preparation process, low cost, suitability for phenolic hydroxylation reaction and phenol-containing wastewater treatment, and convenient enrichment, reclamation and reutilization through an additional magnetic field after the reaction is finished.

The invention discloses enzyme-based magnetic nanoparticles, a preparation method, an application and a detection method for glucose. The preparation method comprises the following steps of 1) mixing Fe3O4 magnetic nanoparticles and dopamine with water according to a mass ratio of Fe3O4 magnetic nanoparticles to dopamine being (1:1)-(1:4) uniformly, adding the above mixture in an alkali buffering system, and stirring for 8-48 hours to obtain Fe3O4 coated by polydopamine; 2) mixing a horseradish peroxidase solution, a glucose oxidase solution and Fe3O4 coated by polydopamine with dopamine uniformly to obtain a solution B, and reacting for 5-25 hours. In the solution B, the concentrations of horseradish peroxidase, glucose oxidase and Fe3O4 coated by polydopamine and dopamine are 0.025-0.2 mg/mL, 0.025-0.2 mg/mL, 0.5-25 mg/mL and 1-5 mg/mL respectively. The enzyme-based magnetic nanoparticles can detect glucose and can be used repeatedly, and waste can be treated by combustion or high temperature, so that zero-pollution can be achieved.

The invention provides a preparation method of a target compound nano particle, relating to a preparation method of target treatment integration compound nano particles. The invention solves the technical problems of poor carrier stability and small drug-loading quantity of the traditional antineoplastic drugs. The method comprises the following steps of: preparing a methanol solution of an integrated nano particle of a Fe3O4-HCPT@SiO2 coupling porphyrin photosensitizer; and stirring the methanol solution of the integrated nano particle of the Fe3O4-HCPT@SiO2 coupling porphyrin photosensitizer, N,N-dimethylformamide and target biomolecule or antitumor drug for reacting at the room temperature, and centrifuging to obtain the target compound nano particle. Polystyrolsulfon acid (PSS) and 10-hydroxycamptothecine are absorbed on a Fe3O4 magnetic nano particle through a self-assembly mode. The preparation method is high feasibility; the target compound nano particle has a physical target function of the magnetic nano particle and an active target function of further functionally modifying the biomolecule on the surface; and the medicine concentration can be increased under a dual-target function.

The invention provides a method for preparing a nanocomposite material by assembling ferriferrous oxide in a halloysite tube, and belongs to the technical field of deep processing of nonmetallic minerals. The method comprises the following four steps: (1) pretreatment, tube expansion and purification of the halloysite minerals; (2) modification in the halloysite tube; (2) preparation of Fe3O4 magnetic nanoparticles through a mixed hydrothermal solution technology; and (4) vacuum impregnation for obtaining the compoiste material with the nano-Fe3O4 assembled in the halloysite tube. The halloysite/Fe3O4 composite material prepared in the invention has no residual magnetization or coercive force, and has a typical paramagnetic performance. The material prepared through the method has good biocompatibility, and broadens the application prospect of mineral magnetic materials in the fields of biomedicines and composite magnetic materials.

The invention provides a nano composite material as well as a preparation method and application thereof to water treatment. The nano composite material provided by the invention comprises a matrix and nanoparticles loaded on the surface of the matrix, wherein the matrix comprises one or more of graphene and graphene derivatives; and the nanoparticles comprise Fe3O4 and Mg(OH)2. According to the nano composite material provided by the invention, a matrix material is used as the matrix, and the nanoparticle composite material has magnetism through loaded Fe3O4 magnetic nanoparticles and is easy to separate; and meanwhile, the saturation adsorbing capacity of the nano composite material is enlarged, and heavy metal ions are efficiently adsorbed through loaded Mg(OH)2 nanoparticles. According to the nano composite material provided by the invention, the removal rates of Pb<2+>, Cu<2+>, Ag<+> and Zn<2+> with the initial concentration of 50ppm within 90min can reach 99.9%, 99.9%, 88% and 85% respectively.

A preparation method of Fe3O4@PEG@SiO2 artificial antibody for detecting thifensulfuron methyl comprises modifying the surface of Fe3O4 magnetic nanoparticles with polyethylene glycol 2000, coating the surface with SiO2 shell layer to form a core-shell-shell structure, diluting marker molecules in the SiO2 shell layer to form specific recognition site holes complementary with marker molecular structure, size and functionality so as to arrive at molecular selective recognition and detection for target analyses. The preparation method of the artificial antibody comprises the steps of first, preparing Fe3O4 magnetic nanoparticles, and modifying their surface with polyethylene glycol; second, adding the target molecule thifensulfuron methyl, a crosslinking agent and a catalyst, and hydrolyzing to obtain Fe3O4@PEG@SiO2 particles with surface-marked thifensulfuron methyl; third, diluting template molecule with a mixed solution of acetic acid and acetone having a volume ratio of 1:4 to obtain the Fe3O4@PEG@SiO2 artificial antibody with selective recognition marker molecules, the antibody having maximum saturated binding capacity of 41.28 mg/g for thifensulfuron methyl, the absorption rate reaches 0.45 mg/g.min within first 30 min which is 5.34 times and 3.46 times that of a non-marking method.

The invention provides a surface plasmon resonance sensing element and a manufacturing method thereof, belonging to the technical field of a sensor for biological system detection. The sensing element comprises a metallic membrane (2), a sensitive membrane and a magnet (3), wherein, the metallic membrane with a chromium membrane and a gold membrane as the sensing elements is plated on the bottom surface of a glass prism (1), the sensitive membrane composed of magnetic nanoparticles (4) subject to surface hydroformylation and an antibody (5) linked with an aldehyde group through a covalent bond is made on the metallic membrane, and the magnet is arranged under the glass prism. The manufacturing method of the sensing element comprises the following steps: preparation of the metallic membrane, preparation of Fe3O4 magnetic nanoparticles, preparation of ammoniated SiO2-coated magnetic nanoparticles, preparation of magnetic nanoparticles subject to surface hydroformylation and preparation of the sensitive membrane. The invention has the advantages of simple manufacturing process, high sensitivity, good biocompatibility and good selectivity and can be used in all antibody and antigen detection and protein and drug measurement.

The invention provides a new cell sorting magnetic bead, which is a 50-70 nm gold plated Fe3O4 magnetic nanoparticle (Fe3O4 and Au nanoparticle) ostensibly coupled with proteinA by covalent bonds, interacted with the specificity of a Fc section of IgG through the proteinA, and directionally coupled with IgG type mouse CD3 antibodies. The invention relates to a method for synthesizing and modifying the magnetic bead, and a method for carrying out cell sorting by using the magnetic bead. The magnetic bead of the invention is used for removing the CD3 T cells in the mouse splenocytes so as to reduce the CD3 T cell content of the splenocytes from 36.5 percent to 0.7 percent, and has extremely high sorting efficiency. The magnetic bead also has the advantages of high protein-coupled quantity and superparamagnetism, and the preparation method has the advantages of simpleness, environmental protection, low cost and good application prospect.

The invention relates to chiral magnetic nano-particles and preparation and application thereof. The preparation comprises the following steps of: (1) preparing Fe3O4 magnetic nano-particles; (2) preparing Fe3O4/SiO2 composite magnetic nano-particles; (3) preparing cellulose-2,3-di(3,5-dimethyl phenyl carbamate); and (4) performing surface chiral modification on the Fe3O4/SiO2 composite magnetic nano-particles by using the cellulose-2,3-di(3,5-dimethyl phenyl carbamate). The chiral magnetic nano-particles are used for separating a racemic compound DL-1-phenethyl alcohol, and an optical rotation value test for obtaining components through singly spinning a guide sample and separation proves that laevo-rotation and dextro-rotation are separated very well. The chiral magnetic nano-particles have the advantages of short separation time, simple and convenient operation, and good separation effect of chiral compounds; besides, the chiral magnetic nano-particles can be thoroughly separated from base solution under an external magnetic field, and not only cannot cause pollution to a target separation object but also can be completely recycled, thereby fulfilling two aims of ecumenical efficiency and environmental protection.

The invention provides a group of oligonucleotide aptamers Apt-1, Apt-2 and Apt-3 which are capable of simultaneously identifying clenbuterol hydrochloride and salbutamol, an oligonucleotide aptamer CLB-2 which is capable of identifying the clenbuterol hydrochloride with high specificity, an oligonucleotide aptamer SAL-5 which is capable of identifying the salbutamol with high specificity and two oligonucleotide aptamers RAC-5 and RAC-6 which are capable of identifying ractopamine with high specificity. Through an SELEX (Systematic Evolution of Ligands by Exponential Enrichment) technology based on Fe3O4 magnetic nanoparticle separation, a random oligonucleotide library is immobilized on avidin-enveloped magnetic nanoparticles by virtue of a complementary chain of a biotinylation marker, and the oligonucleotide aptamers, which are high in specific affinity, are finally obtained by conducting screening by 16 turns. The aptamers are broad in application prospect; and the aptamers, by virtue of marker function genes or fluorescent dyes, are applicable to detection of the clenbuterol hydrochloride, the salbutamol and the ractopamine in food; therefore, a new choice is provided for existing detection methods which depend on antibodies.

The invention provides a reagent and a method for measuring magnetic field intensity by using magneto discoloration. The reagent is a three-phase material system consisting of superparamagnetic nano colloid clusters (CNCs), liquid solvent, and a liquid resin; each CNCs consists of a plurality of single-domain Fe3O4 magnetic nanoparticles coated by silicon dioxide; the method comprises the following steps that: 1, the reagent is placed in an external magnetic field, the magnetic attraction caused by the superparamagnetic nano colloid clusters, and electrostatic repulsion and solvating power are leveled off under the action of the magnetic field so as to form chain structures along a magnetic line of force, and a large number of chain structures are uniformly distributed so as to form photonic crystal; and 2, the lattice constant of the photonic crystal determines the color of diffraction beams, different colors of the reagent are displayed according to different magnetic field intensities, and the corresponding magnetic field intensity can be obtained by looking up a color-magnetic field intensity comparison table according to the corresponding relation between the color and the magnetic field intensity.

The invention relates to an immunodetection method of organophosphorus pesticide multi-residue in the technical field of pesticide detection, and the immunodetection method comprises the following steps: synthesizing an organophosphorus generic hapten, and coupling with protein to prepare an immunogen and a coating antigen; using the immunogen to perform animal immunization so as to get an organophosphorus pesticide generic antibody; synthesizing Fe3O4 magnetic nanoparticles and performing surface modification; coupling the Fe3O4 magnetic nanoparticles after surface modification with the organophosphorus pesticide generic antibody to form immune magnetic beads; adding a nitrocellulose membrane on a baseplate of a test strip, coating the immunogen prepared by coupling the organophosphorus generic hapten with the protein on the membrane, closing to form a detection part, and finally determining the optimal coating, the closing conditions and the using quantity of the immune magnetic beads; and performing qualitative and semi-quantitative detection. The detection method is simple and convenient to operate, sensitive and fast; large-scale instruments are not required; and the detection method is suitable for field sampling detection and large-batch detection tasks.

The invention provides a method for preparing monodisperse Fe3O4 magnetic nanoparticles. Precursor is Fe2O3 or iron oxide yellow which has the chemical formula of Fe2O3.H2O; stabilizing agent is oleic acid; high temperature organic solvent is 1-octadecylene (b. p. 318DEG C); precipitating agent is prepared by mixing any two of toluene, dimethyl benzene, ethanol, isopropanol and acetone according to the volume ratio of 1:4-2:3; the mol ratio between the precursor and the stabilizing agent is 1:4-1:9; the mol ratio between the precursor and the high temperature organic solvent is 1:10; inert gas protection is not needed, and the Fe3O4 magnetic nanoparticles which have small sizes, monodisperse, narrow distribution, high saturation magnetization intensity and superparamagnetism. The method can be widely applied to biomedicine fields such as magnetic resonance imaging, biological magnetic separation, magnetic target drug carrier, biological magnetic marker and the like, and the high technical fields such as magnetic sealing, aerospace lubrication, magnetic anti-counterfeiting ink material, etc.