98results about How to "Easy chemical modification" patented technology

The present invention provides a class of sensors prepared from at least a first material having a positive temperature coefficient of resistance and a second non-conductive or insulating material compositionally different than the first material that show an increase sensitivity detection limit for polar and non-polar analytes. The sensors have applications in the detection of analytes in the environment, associated with diseases and microorganisms.

The invention discloses application of a CRISPR (clustered regularly interspaced short palindromic repeats) / Cpf1 system in gene editing. The CRISPR / Cpf1 system comprises a1), chemosynthetic crRNA or a2), a crRNA expressing carrier. The CRISPR / Cpf1 system can be c1), an LbCRISPR / Cpf1 system, c2), an Lb2CRISPR / Cpf1 system, c3), an FnCRISPR / Cpf1 system or c4), an AsCRISPR / Cpf1 system. Experiments prove that the chemosynthetic crRNA can play an effective role in guidance of Cpf1 cut-editing specific target sites, and efficiency is high. Applying the crRNA expressed by the carrier or the chemosynthetic crRNA to the CRISPR / Cpf1 system has high application value in gene editing.

The invention provides a preparation method for a molecular imprinting material and the molecular imprinting material prepared through the preparation method. The preparation method comprises the steps that silicon oxide is coated on the surfaces of magnetic ferroferric oxide nanometer particles, the magnetic ferroferric oxide nanometer particles are modified with gamma-(methacryloyl chloride) amino propyl trimethoxy silane to obtain magnetic ferroferric oxide nanometer particles with propenyl on the surfaces, the magnetic ferroferric oxide nanometer particles with the propenyl on the surfaces serve as carriers, estrogen receptors are simulated, functional monomers are optimized, a surface imprinting technology is adopted, and then the molecular imprinting material which can simultaneously identify seven kinds of environmental endocrine disrupting chemicals is prepared. According to the preparation method, the easy separation of a magnetic nanometer material, the good water solubility of a silicon oxide nanometer material, the specific recognition ability of molecular imprinting polymers and the surface imprinting technology are mutually combined, the preparation technology is simple, the conditions are mild, the prepared molecular imprinting material is large in adsorption capacity, fast to respond, high in magnetism, good in chemical stability and high in repeating utilization rate, and the problems that at present, multiple trace, steroid and phenol environmental endocrine disrupting chemicals are difficult to simultaneously identify, separate and enrich are solved.

Preparation of chitosan magnetic microsphere and preparation of immobilized yeast for magnetic microsphere. The invention adopts suspended emulsion polymerization to prepare chitosan magnetic microsphere. The invention immobilize yeast cell to magnetic microsphere by swelling absorption. The inventive chitosan magnetic microsphere has characteristics of both magnetic particle and macromolecular material. Immobilized yeast cell is not discharged out of the system with fermentation broth, so that consumption is avoided, concentration of yeast cell in the fermentor is kept, rate of alcoholic fermentation is enhanced, fermentation time is shorten, resource consumption is reduced, while reducing discharge of waste water, and hardness to process the waste water.

The invention belongs to the technical field of magnetic materials and in particular relates to a preparation method of nanosilver and sulfydryl jointly modified magnetic microspheres. The preparation method comprises the following steps of: 1) preparing Fe3O4 magnetic microspheres; 2) preparing SiO2 wrapped Fe3O4 magnetic microspheres; (3) preparing sulfydryl modified SiO2 wrapped Fe3O4 magnetic microspheres; and 4) preparing nanosilver and sulfydryl jointly modified SiO2 wrapped Fe3O4 magnetic microspheres. According to the method, nano Fe3O4 is wrapped by a silane coupling agent and the stability and the acid-base resistance are improved due to the safety and the stability of silica; and a functional sulfydryl group is introduced into the surface through chemical reaction, so that novel modified magnetic nanoparticles are obtained. Due to investment and development of biological technology industry, life science and diagnostic reagent industry, the development of biological magnetic bead products with the technological advantage and the cost performance advantage is greatly promoted.

The invention discloses a preparation method of graphite nanometer hole, which belongs to the field of thin film material micro nano processing. The method employs a chemical vapor deposition method (CVD) for preparing graphite on a metal copper film, and uses the intrinsic defect structure of graphite to prepare graphite nanometer hole, and the aperture can be from several nanometers to hundreds of nanometers. The graphite nanometer hole has the advantages of high precision, monoatomic level hole depth, chemical modification convenience, conduction, long usage life, low cost, etc. The invention has large applications in the fields of single molecule detection, electrochemistry control, biology identification, etc.

The invention discloses a biosensor, a preparation method and a target molecule concentration detection method thereof. The preparation method for the biosensor comprises the following steps: (S1) modifying one or more of streptavidin, carboxyl, amino and sulfydryl onto a magnetic bead and modifying biotin onto a nucleic acid aptamer of a to-be-detected target molecule; (S2) adding the nucleic acid aptamer and the magnetic bead into a reaction solution and coupling the nucleic acid aptamer onto a local site of the magnetic bead, wherein the reaction solution is a salt buffer solution in concentration above 100mM; (S3) coupling the DNA sequence capable of complementarily pairing with the nucleic acid aptamer onto a noble metal nanoparticle; and (S4) reacting the magnetic bead acquired in the step S2 and the noble metal nanoparticle acquired in the step S3 for 5-60min in a hybridization solution, thereby forming the biosensor by the magnetic bead, nucleic acid aptamer and noble metal nanoparticle under the effect of base complementary pairing. The biosensor is capable of realizing high-sensitivity concentration detection, is low in cost and is high in efficiency.

The invention relates to the field of graphene preparation, and discloses a preparation method of graphene oxide / nano-gold particulate composite material with mono-atomic thickness. In prior arts, the preparation of mono-atomic thickness graphene oxide / nano-gold particulate composite material is complicated, requires special equipment, and cannot be prepared with industrialized production. The present invention assists in solving the problems, and provides a simple method for preparing the composite material with high efficiency. The preparation method comprises the steps that: (1) obtained graphene oxide is subject to an acylation reaction; (2) graphene oxide processed through the acylation reaction is subject to a reaction with a chlorauric acid solution; (3) the pH value of the material is regulated, the depositions are filtered, such that the graphene oxide / nano-gold particulate composite material is obtained. The method of the present invention has advantages of simple technology, high yield, large output, good product quality, and is suitable for industrialized production.

The invention discloses a set of sulfamethazine specifically-bound aptamers and a screening method and applications thereof. The aptamer for identifying sulfamethazine, disclosed by the invention, is a single-stranded DNA molecule shown in any one of formulas (1)-(4): (1) a single-stranded DNA molecule shown in a sequence 3 in a sequence table; (2) a single-stranded DNA molecule shown in a sequence 1 in the sequence table; (3) a single-stranded DNA molecule shown in a sequence 2 in the sequence table; and (4) a single-stranded DNA molecule shown in a sequence 4 in the sequence table. Experiments show that a directly competitive chemiluminescence analysis method established based on biotinylated aptamers and used for detecting sulfamethazine provides a basis for the practical application of the aptamers of sulfamethazine, and provides technical support for more efficient and extensive monitoring of antimicrobial drug residues.

A method for detecting ochratoxin A based on near-infrared up-conversion luminescence marking and magnetic separation is used for detecting ochratoxin A (OTA) content in wheat and its products and the like. By connecting near-infrared up-conversion luminescent material with NaYF4:Yb 0.2 and Tm 0.02 with ochratoxin A aptamer to form a signal probe, the signal probe and aptamer complementary oligonucleotide single strand modified Fe3O4 magnetic nanomaterial form a nano composite, and at the moment up-conversion luminescence signal is maximum; when OTA is present in a detection system, OTA specifically binds with OTA aptamer so that double strands are unlinked, and by monitoring up-conversion luminescence signal strength 804 nm from a near-infrared zone, it is possible to quantitatively detect OTA, with a linear range of 0.01-100 ng / mL and a detection limit of 0.005 ng / mL. The method for OTA detection has the advantages of high sensitivity, high speed and good simplicity and is applied to detecting beer samples, with accurate and reliable results.

The invention discloses a structure and a preparation method for magnetic sliver-flower nano-particles. The structure takes magnetic nano-particles (Fe3O4) as the core and takes a silicon dioxide shell layer (SiO2) as a multi-functional layer. By formaldehyde reduction, flower-shaped sliver shells similar to needle points rapidly grow. The preparation method comprises the following steps: wrapping surfaces of 100-6000 nano Fe3O4 magnetic nanoparticles with an SiO2 layer and improving dispersion of magnetic nano-particles and providing position points of sliver seed growth; utilizing a chemical electroplating method with the assistance of ultrasonic wave to grow the surfaces of the Fe3O4@SiO2 magnetic particles with uniform and dense sliver particles as seeds for growth of flower-shaped sliver shells; finally, utilizing formaldehyde as a reduction agent and ammonium hydroxide as a catalyst to rapidly reduce magnetic sliver-flower nano-particles on the ultrasonic condition. The invention further discloses a magnetic SERS substrate prepared by the above method. The magnetic SERS substrate is made from magnetic sliver-flower nano-particles and is good in dispersion, high in magnetic induction, stable in structure and great in heart and can be directly used for SERS detection of small molecule pollutants, pesticide residuals and illegal additives of food.

The invention provides a DNA nano flower-shaped composite structure as well as a preparation method and an application thereof. The DNA nano flower-shaped composite structure comprises a DNA nano flower-shaped structure formed by amplification of a single-stranded DNA template and an immunostimulatory nucleic acid fragment hybridized with the DNA nano flower-shaped structure, according to the invention, primers and template sequences are ingeniously designed, a rolling circle replication method is used for amplifying the template DNA to form a nano flower shape, creatively fuses a pH-responsive i-motif into a hybridization site to realize hybridization and acid response release of an immunostimulatory nucleic acid sequence, optimizes the reaction conditions, and finally successfully prepares the composite structure. The composite structure provided by the present invention can be used as a carrier for loading immune stimulating nucleic acid fragments to be efficiently transported inside immune cells, by responsively releasing the immune stimulating nucleic acid fragments, the immune cells can be activated, which provides a powerful novel adjuvant material for tumor immunotherapy, and has broad application prospects and market value.

The invention discloses a PM2.5 concentration detecting device based on the photoacoustic spectrometry. The PM2.5 concentration detecting device comprises a first laser device, a photoacoustic pool, an optical fiber F-P sound wave sensor, a second laser device, an optical fiber coupler, a photoelectric detector, a lock-in amplifier and a computer. The photoacoustic pool comprises a front bufferingchamber, a sample chamber, a rear buffering chamber and a rheomicrophone chamber. Super-hydrophobic coatings are formed on the inner walls of the front buffering chamber, the sample chamber, the rearbuffering chamber, a front guide pipe and a rear guide pipe. By means of the PM2.5 concentration detecting device, sound pressure waves are detected through the optical fiber F-P sound wave sensor based on a fluorolite vibrating membrane, and the high-sensitivity, high-response-speed and high-stability effects of the optical fiber F-P sound wave sensor can be brought into full play; the inner wall of the photoacoustic pool of the detecting device is coated with the corresponding super-hydrophobic coating, so it is avoided that PM2.5 microparticles are attached to the inner wall of the photoacoustic pool and photoacoustic signals are affected; no PM2.5 microparticles are attached to the fluorolite vibrating membrane, so the detection precision can be further improved.

The invention relates to an aptamer modified triazine covalent organic framework composite material and a preparation method and application thereof. The aptamer modified triazine covalent organic framework composite material disclosed by the invention comprises a triazine covalent organic framework, gold nanoparticles and an aptamer, wherein the gold nanoparticles are supported on the triazine covalent organic framework; and the aptamer is bonded onto the surface of the gold nanoparticles. When the sequence of the aptamer is 5'-SH-(CH2)6-(ACAG4TGTG4)2-3', the composite material disclosed by the invention can be applied to enrichment of insulin in biological samples. The aptamer modified triazine covalent organic framework composite material disclosed by the invention combines the advantages of the covalent organic framework such as large specific surface area and multiple adsorbable sites and the advantage of the aptamer such as specific recognition, has excellent selectivity, and canprovide an economic, high-efficiency and high-sensitivity biological analysis method.

The invention discloses a nitrogen-containing porous polymer chelating resin and a preparation and an uranium-containing wastewater treatment method. The nitrogen-containing porous polymer chelating resin is characterized in that the nitrogen-containing porous polymer chelating resin is prepared by a solvent heat method, and a chelating group is a nitrogen-containing group; the BET (Brunauer, Emmett and Teller) specific surface area of the porous polymer chelating resin containing nitrogen group is 100 to 500m<2> / g; the BJH (Barrett, Joyner and Halenda) pore diameter is 10 to 50nm; the BJH pore volume is 0.5 to 1.5cm<3> / g. The porous polymer chelating resin containing the nitrogen group has the advantages that the preparation process is simple and rapid, and the operation is easy; the adsorbing ability on uranium ions is strong, the adsorbing amount is large, the adsorbing speed is high, and the like; the porous polymer chelating resin can be easily separated from a water solution, and can effectively adsorb and recycle uranyl ions in the water solution.

The invention discloses a preparation method of a non-viral gene vector material. The method comprises the following steps of: performing michael reaction on polyol acrylate and amino alcohol to prepare an unmodified polymer; and reacting the unmodified polymer with a diamino group containing compound to prepare an ester bond-containing non-viral gene vector material. The method has the characteristics of easiness in preparation and high controllability; and the prepared non-viral gene vector material has the characteristics of high efficiency and low toxicity. The invention discloses application of the non-viral gene vector material to transfection of cells; and the application comprises the following steps of: mixing the non-viral gene vector material and genes; incubating to prepare a compound of a non-viral gene vector and a gene; and adding the prepared compound of the non-viral gene vector and the gene into receptor cells to finish the transfection of the genes in the cells. Thecompound of the non-viral gene vector and the gene has high gene transfection efficiency and superior biological safety for the transfection of the cells.

The invention provides a water-soluble amino acid segmented copolymer, and a preparation method and application thereof. The amino acid segmented copolymer has the structure shown as a formula I or formula II shown as the accompanying drawing; R1 is a hydrogen, an alkyl group or a substituted alkyl group; R2 is -NH- or R5(CH2)rNH-; R3 is one or a plurality of groups of a hydrogen, a hydrophobic group and an active drug group; R4 is benzyl, cholesterol formylm, acetyl, a cholic acid group, a deoxidized cholic acid group or C4-C20 alkyl groups. The amino acid segmented copolymer is a polypeptide copolymer with excellent water solubility, and can be used in the field of delivery of biological materials such as drug. After freeze-drying, the material has a good re-dissolving effect; the defect of poor water solubility of macromolecule materials or macromolecule nanometer drug in the prior art can be overcome. The material contains the hydrophobic group through modification or is chemically bonded with drug with biological activity; the modified macromolecule material or the bonded drug can still maintain excellent water solubility and re-dissolving capability; the potential application prospect is realized in the field of biological materials.

The invention belongs to the technical field of gene detection and discloses a mycobacterium tuberculosis drug-resistant gene multiple detection method based on RCA (rolling circle amplification). Base sequences for detection are shown in SEQ ID NO:1 to SEQ ID NO:28. A paper based microfluidic analysis device comprises a sample pad, a colloidal gold conjugation pad, a detection line, a control line, an NC (nitrocellulose filter membrane), a water absorption pad and a bottom plate, wherein the sample pad, the colloidal gold conjugation pad, the NC and the water absorption pad are sequentially arranged on the bottom plate from left to right; and the detection line and the control line are arranged on the NC. Through massive serial-connection repeated sequence hybridization of nano gold granule modified common sequence probes and single base mutation probes with a solid-phase surface RCA reaction product, a color reaction indication detection result can be achieved. A detection platform of an isothermal amplification conjunction paper based developing sensation technique is established, and an experiment method for rapidly identifying and detecting mycobacterium tuberculosis drug resistance is established.

The present invention belongs to the field of drug delivery systems and particularly relates to a novel blood brain barrier-crossing drug delivery system and a preparation method and an application thereof. The ovel blood brain barrier-crossing drug delivery system comprises micelles of polydopamine nanoparticles encapsulated by amphiphilic peptides. The micelles have a diameter of 160-270 nanometers and a potential of 10-30 millivolts. The polydopamine nanoparticles have a diameter of 120-200 nanometers and a potential of -60 to 40 millivolts. The novel blood brain barrier-crossing drug delivery system has the following advantages (1) the drug delivery system is good in biocompatibility and biodegradability; (2) the drug delivery system is easy in operation and controllable in synthesis,so that the nanoparticles can be produced on a large scale; (3) the drug delivery system has powerful functionalization ability, so that the nanoparticles are easily modified by certain targeting molecules and have a good drug delivery effect; and (4) the drug delivery system has relatively high diagnostic and treatment efficiency.

The invention provides a nucleic acid aptamer for specifically combining bovine pregnancy-related glycoprotein 4. The sequence of the nucleic acid aptamer comprises any one of SEQ ID No. 1 sequences.The nucleic acid aptamer provided by the invention can also be various similar sequences with higher homology or derivatives obtained from the sequences provided by the invention. The invention also provides an application of the aptamer. The nucleic acid aptamer disclosed by the invention is obtained by screening through a magnetic bead-SELEX technology; the aptamer can be combined with bPAG4 target protein, can also be selectively combined with bPAG4 like protein, is not specifically combined with other proteins, can be used for capturing the bPAG4 protein from a complex system, and is suitable for detection, separation and purification of the bPAG4 protein and quick diagnosis of bovine early pregnancy.

The invention discloses a heme ligand mimic and a synthesis method thereof. A compound name of the heme ligand mimic provided by the invention is 5,10,15,20-tetra-(5-phenyl phosphate)-5,10-15,20-dibundled porphyrin, and a structural formula of the heme ligand mimic is as shown in a formula (1)(the formula is shown in the description). The synthesis method of the heme ligand mimic mainly comprisesthe following steps of dialdehyde bridging, namely the synthesis of an intermediate product bridged bromodialdehyde; ring formation, namely the synthesis of an intermediate product tetrabromo dibundled porphyrin; C-P bond formation, namely the synthesis of an intermediate product tetraphosphate dibundled porphyrin, and hydrolysis of phosphate, namely the synthesis of a target product tetraphosphoric acid dibundled porphyrin. Porphyrin provided by the invention has a saddle-type nonplanar feature, further, is excellent in water solubility, and is a better model compound for simulating a structure and a function of a heme ligand; further, the synthesis method of the heme ligand mimic is mild in condition and less in synthesis steps; raw materials are easily obtained; a product is easily purified; a yield in each step is relatively high, and due to the introduction of a phosphate radical, the heme ligand mimic is not only enabled to become good in water solubility and be widened in pH (potential of hydrogen) value scope of application, but also has better biological applicability.

The invention relates to a preparation method of a slow-release microcapsule antifouling material, and belongs to the technical field of environment-friendly materials. The slow-release microcapsule antifouling material is prepared by adopting a complex coacervation method. According to the complex coacervation method, two wall materials with dissimilar charges in a solution are mutually cross-linked through electrostatic interaction among ions to obtain a microcapsule of a composite wall material, the action principle is that a positively charged wall material solution is mixed with another negatively charged wall material solution, coacervates are formed through interaction of positive charges and negative charges, separated and deposited around a core material, and the microcapsule is obtained by coating the core material. When the numbers of positive charges and negative charges carried by the two substances are equal, the yield of the microcapsule is the maximum. The preparation of the microcapsule by the complex coacervation method needs the three stages of wall film formation, deposition and cross-linking curing, the embedding rate of the core material is very high, the formed wall film is high in compactness and good in slow release effect, and the anti-fouling agent can be effectively prevented from falling off.

The invention provides a group of aptamers for specific recognition of beta-bungatotoxin and use thereof. The aptamers provided by the invention are any single-chain deoxyribonucleic acid (DNA) sequence shown in SEQ ID NO.1-4 in a sequence table. The aptamers and the beta-bungatotoxin have high affinity and specificity, and have broad application prospects in detection of the beta-bungatotoxin and diagnosis of bungarus multicintus bite.

Provided is a method for simultaneously detecting oxytetracycline, tetracycline and kanamycin based on ABEI modified flower-shaped nanogold. The method is characterized by comprising the steps that the chemiluminescence time can be effectively prolonged based on a N-(4-ammonia butyl)-N-ABEI-H2O2-p-iodophenol (PIP) steady-state chemiluminescence system constructed by a microwell plate; a sulfhydrylation complementary chain is connected with ABEI modified flower-shaped nanogold to be used for a signal probe; aptamers fixed on the microwell plate are used as molecular recognition elements, and the aptamers of three antibiotics are fixed on three regions of the microwell plate respectively to provide spatial resolution for simultaneous detection of targets. The constructed aptamer sensor can achieve simultaneous detection on oxytetracycline, tetracycline and kanamycin, and the chemiluminescence intensity of the sensor is in negative logarithm correlation with the quantity of the targets. In addition, the sensor is used for practical sample detection, and the good property of the sensor is proved.

The invention discloses a chitosan-based multifunctional macromolecular rubber anti-aging agent, and a preparation method and application thereof. The chitosan-based multifunctional macromolecular rubber anti-aging agent is prepared by carrying out chemical reaction on active amino groups on chitosan and a carboxyl-containing phenolic anti-aging agent in the presence of a solvent, a dehydrating agent and a catalyst. The chitosan-based multifunctional macromolecular rubber anti-aging agent provided by the invention is environment-friendly and not easy to migrate, not only can remarkably improve the thermo-oxidative aging resistance of a rubber material, but also has excellent extraction resistance, can play a lasting thermo-oxidative aging resistance role on the rubber material, can also promote rubber vulcanization and remarkably reduce the positive vulcanization time TC90, and reduces the consumption of a vulcanization accelerator.

The invention relates to a synthesis method for a compound 5,10,15,20-tetra-(3,5-dihydroxy phenyl) porphyrin of water-soluble porphyrin shown in the formula I. The synthesis method includes the following steps that mixed acid of propionic acid / acetic acid is used as a reaction solvent, 3,5-dihydroxy benzaldehyde reacts with pyrrole (for example, 30 min or above, preferably, 40 min or above, such as 30 min-3 h, and preferably, 40 min-1 h) under heating reflux (for example, 115-125 DEG C, and for example, about 120 DEG C), reduced pressure distillation is conducted after the reaction, the mixed acid is removed, separation is conducted through a column chromatography method, recrystallization purifying is conducted, and 5,10,15,20-tetra-(3,5-dihydroxy phenyl) porphyrin is obtained. The formula I is shown in the description.

The invention discloses a nucleic acid aptamer capable of being specifically combined with carapace arginine kinase, a kit and a detection method. The nucleotide sequence of the nucleic acid aptamer is shown as SEQ ID No. 1. Based on the nucleic acid aptamer, the invention establishes a method for detecting the carapace arginine kinase by utilizing a near-field optical wave targeting sensor; the method has the advantages of high specificity, high sensitivity, high stability, good repeatability and the like. The nucleic acid aptamer is easy to synthesize, has simple chemical modification and noimmunogenicity, can be specifically combined with the arginine kinase and has high affinity; the stability of a biosensor can be improved, so that high-sensitivity, strong-specificity and simple-to-operation detection is realized.

The invention discloses fucosylation chondroitin sulfate oligosaccharide provided with a structure shown in J. The definition of a substituent group is shown in the description in detail. Besides, theinvention further discloses a preparation method of the fucosylation chondroitin sulfate oligosaccharide. According to the preparation method, chondroitin sulfate A salt is used as a raw material andis subjected to enzymolysis, protecting group operation and glycosylation sequentially, the oligosaccharide compound is synthesized, and the certainty of the structure enables the compound to be applied to the medicine field.

The invention discloses a preparation method and application of an aminated graphene quantum dot. The preparation method includes: blending a uniform dispersion liquid of prepared graphene, ammonia water and deionized water, then transferring the mixture into an autoclave for heating, filtering out insoluble fragments by a porous inorganic membrane, then conducting heating to remove redundant amine, and then using a centrifugal filtration device of molecular weight interception membrane for ultrafiltration of the supernatant, and subjecting the obtained yellow suspension liquid to further dialysis by a Spectra / Por CE dialysis tube membrane, thus obtaining aminated graphene quantum dot. The aminated graphene quantum dot prepared by the method provided by the invention can be applied to gene delivery vectors, has no inhibiting effect on RNAnase, has protective effect on to-be-delivered miRNA, and has good selectivity and universality.

This invention discloses a method for preparing a magnetic nanomaterial, more specifically, a method for preparing ferrite nanoparticles by chemical modification. The method comprises: (1) mixing aqueous solution of FeCl3 and FeCl2, ethanol solution of poly(ethylene glycol) and aqueous solution of NH4OH, and reacting at normal pressure under vigorous stirring and N2 protection; (2) separating the precipitate after the reaction, washing with water, and vacuum-drying to obtain ferrite nanoparticles with diameters of 5-10 nm. The ferrite nanoparticles have such advantages as high biocompatibility and high chemical stability, and can be widely used in biological field, such as biological separation, drug delivery, biological labeling, and magnetic resonance imaging, magnetic recording of biochip, and magnetic sealing and recording of auxiliary friction components.