31 results about "Fe3o4 nanoparticle" patented technology

The invention belongs to the technical field of wastewater treatment, and discloses a magnetic nano composite adsorbent as well as a preparation method and application thereof. The preparation method comprises the following steps: dissolving a divalent iron salt and a trivalent iron salt in water, adding ammonia water under a protective gas, and carrying out a stirring reaction at a rotating speed of 350-600 rpm to prepare Fe3O4 nanoparticles; the preparation method comprises the following steps: dispersing Fe3O4 nanoparticles in a mixed solution of acrylic acid and ethidene diamine, then adding an initiator, and carrying out a stirring reaction at a rotating speed of 150-300 rpm to prepare the magnetic nano composite adsorbent. The magnetic nano-composite adsorbent provided by the invention can efficiently remove lead ions in wastewater, is not influenced by mercury ions and copper ions, also has relatively good adsorption capacity on the mercury ions and the copper ions, and can treat various heavy metal ions in the wastewater at the same time. The magnetic nano composite adsorbent is easy to separate and good in reusability.

The invention discloses a composite catalyst in a Fe3O4 nanoparticle confined carbon nanotube and application of the composite catalyst in degradation of bisphenol pollutants in water, and belongs to the technical field of environmental protection and water treatment. According to the catalyst, Fe3O4 nano-particles with the particle size of 1-5 nm are confined in inner channels of multi-walled carbon nanotubes (CNTs), stable Fe-C bonds are formed between Fe atoms and carbon atoms on the inner walls of the CNTs, a nano confinement structure is constructed, and the stability and electron transfer efficiency of the catalyst are improved. When the catalyst is used for activating peracetic acid (PAA), bisphenol pollutants in water can be quickly and efficiently removed. The catalyst can keep high-efficiency degradation performance in a wide range of pH value of 4-12, the degradation efficiency is still kept at 95% or above after the catalyst is recycled for 10 times, and the catalyst shows remarkable stability and practicability. The invention provides a novel catalyst which is excellent in performance, economical and environment-friendly and a process method for the field of actual water treatment.

The present application relates to the technical field of hydrogel, in particular to an injectable temperature-responsive enhanced composite double-network magnetic particle gel, a preparation method and application thereof, the hydrogel is composed of a particle gel network formed by gelatin nanoparticles and Fe3O4 nanoparticles through electrostatic interaction and a poly-N-isopropyl acrylamide (PNIPAM) based temperature-sensitive polymer gel network. At room temperature, the hydrogel has excellent shear thinning and self-healing properties, and can be easily injected through a needle and a microcatheter. When the temperature rises to human body temperature (37 DEG C), the temperature-sensitive polymer phase transition crosslinking enhances the mechanical properties of the gel network. The hydrogel is injectable in vitro, temperature-responsive in vivo, meets the requirements of vascular interventional embolization materials, and can be magnetically heated under an alternating magnetic field, and is used for liver cancer embolization combined with magnetic heating treatment. The preparation method is simple, has high biocompatibility, and has great clinical application potential.

The application provides a Fe3O4 nanoparticle microscopic imaging detection method based on left and right polarization modulation, belongs to the technical field of photothermal science and detection and signal processing, and solves the problems that current nanometer single particles are difficult to observe and physical and chemical characteristics are difficult to obtain, and specifically comprises the following steps: determining a sample to be detected and preparing a slide sample; starting a computer, a data acquisition card, a lock-in amplifier, a galvanometer controller and a function generator; starting a power supply of an excitation light and a detection light laser and a refrigerator; setting detection parameters, setting laser power / current parameters, setting modulation parameters, and scanning and detecting the sample to be detected; loading a magnetic field; reading signals from the data acquisition card by the computer to obtain a photothermal detection result image; changing different laser parameters and the size of the magnetic field, repeating the above steps, obtaining a circular dichroism and magnetic circular dichroism detection result, measuring a magnetization curve, and monitoring a single nanoparticle magnetic moment flipping process.

The application relates to the field of nanomaterial structures and analysis sensing technology, and discloses a core-shell structure Fe3O4@PDA@ZIF-67 peroxidase, a preparation method and application thereof. The core-shell structure Fe3O4 nanoparticle is used as a core, the surface of the Fe3O4 nanoparticle is modified by dopamine to form a polydopamine layer, then ZIF-67 is modified on the surface of the Fe3O4@PDA as a shell, and finally the prepared Fe3O4@PDA@ZIF-67 is heat-treated, so that a stable structure is obtained. In the Fe3O4@PDA@ZIF-67 composite material, the ZIF-67 as the shell can adsorb a signal molecule TMB to form a confined reaction, reduce the loss of active oxygen in the catalytic process, improve the sensitivity of the peroxidase-like enzyme applied to hydrogen peroxide sensing analysis, and has certain guiding significance for the structure design of the peroxidase-like enzyme material.

The invention relates to a magnetic quantum dot composite nanoprobe as well as a preparation method and application thereof. The composite nanoprobe comprises a composite nanomaterial and a specific antibody, the composite nano material has a core-shell structure; the core of the core-shell structure is Fe3O4 nano-particles, and the outer surface of the core is externally coated with an interlayer and a shell layer in sequence; the interlayer is of a multi-layer laminated structure formed by positive electricity interlayers and negative electricity interlayers alternately, the first layer in the laminating direction of the laminated structure is the positive electricity interlayer, and the last layer in the laminating direction of the laminated structure is the negative electricity interlayer; the positive electricity interlayer is made of polyethyleneimine; the negative electricity interlayer is quantum dots; the shell layer is SiO2 modified by carboxyl; the carboxyl of the shell layer is coupled with a specific antibody. The magnetic nanoprobe disclosed by the invention has strong magnetic responsiveness, high fluorescence signal and specific bacterium capturing capacity, realizes rapid capturing of to-be-detected substances such as food-borne pathogenic bacteria in a to-be-detected sample, and has huge application potential in the field of rapid detection of food-borne bacteria.

The application belongs to the technical field of medical imaging, and particularly relates to brain-targeting APP@Dextran-Fe3O4 nanoparticles as well as a preparation method and application thereof. The APP@Dextran-Fe3O4 nanoparticles provided by the application can act on the beta amyloid protein receptor in the brain through a non-invasive intravenous injection mode, thereby realizing the transport across the blood-brain barrier, and having a higher accumulation in the brain of Alzheimer's disease patients, especially in the hippocampus which is the main lesion site of Alzheimer's disease. In combination with the high resolution and high sensitivity characteristics of MPI imaging, the diagnosis of Alzheimer's disease can be realized. Meanwhile, pathological analysis shows that the APP@Dextran-Fe3O4 nanoparticles have the effects of inhibiting the inflammatory reaction in the brain of Alzheimer's disease and reducing the apoptosis of neuron cells, and have certain benefits for slowing down Alzheimer's disease.

The present invention belongs to the technical field of analytical chemistry. Specifically disclosed are a magnetic fluorescent gold nanocluster molecularly imprinted polymer, a preparation method therefor, and use thereof in sulfadiazine fluorescence detection. The surface of a Fe3O4 nanoparticle is coated with a silica shell layer, and the shell layer is subjected to surface modification and then combined with gold nanoclusters (AuNCs). On this basis, the molecular imprinting technology is employed, wherein sulfadiazine (SD) is selected to serve as a template molecule, and a mixed silane coupling agent (APTES) is used as a functional monomer to coat the surface of Fe3O4@SiO2@AuNCs with a molecular imprinting layer, thus preparing a magnetic fluorescent gold nanocluster imprinted polymer Fe3O4@SiO2@AuNCs-MIPs. The present invention, by integrating the magnetic separation technology, the high selectivity, simplicity, and rapidity of the molecularly imprinted polymer, and the high sensitivity of fluorescence detection, enables accurate and specific recognition of sulfadiazine and can be effectively applied to the analysis and detection of sulfadiazine.

The invention discloses a black phosphorus-based composite nano material as well as a preparation method and application thereof. The preparation method comprises the following steps: preparing black phosphorus nanosheets, freeze-dried powder of polyethyleneimine-modified magnetic Fe3O4 nanoparticles with positive charges on the surface, and a polyethyleneimine-modified glucose oxidase solution; the black phosphorus nanosheet and polyethyleneimine modified magnetic Fe3O4 nanoparticle freeze-dried powder are added into a polyethyleneimine modified glucose oxidase solution to be mixed, and a full electrostatic binding reaction is carried out. According to the preparation method, ferroferric oxide nanoparticles are loaded on black phosphorus nanosheets in an electrostatic bonding mode, glucose is oxidized, the preparation stability is excellent, the loading capacity is stable and controllable, the black phosphorus-based composite nanomaterial achieves multi-mode combined synergistic enhancement of the anti-tumor effect, and the anti-tumor effect of the black phosphorus-based composite nanomaterial is greatly improved within the high concentration range of 50-75 micrograms / mL. And the cell survival rate detected by an MTT test is more than 80%, and the cytotoxicity is low.

The invention relates to the technical field of desulfurization catalysts, in particular to an oil and gas reservoir underground desulfurization hydrogen production catalyst and a preparation method thereof. The preparation method comprises the following steps: S1, preparing an inner core: taking magnetic Fe3O4 nanoparticles as the inner core; s2, core-shell structure construction: S201, carrier wrapping; s202, loading the active components; and S3, calcining and forming. According to the oil and gas reservoir underground desulfurization hydrogen production catalyst and the preparation method thereof, the problems that in the prior art, an underground desulfurization catalyst is difficult to resist high temperature and prone to salt poisoning in desulfurization application are solved.

The application discloses a kind of electromagnetic shielding adhesive tape based on composite electromagnetic nanoparticle layer and preparation method thereof, belong to electromagnetic shielding material this technical field, its design key points are in, from top to bottom in turn: protective layer, FeNi metal layer, composite electromagnetic nanoparticle layer, adhesive layer and release layer;The composite magnetic nanoparticle layer is the particle layer with the thickness of 10-30 μm formed by conductive polymer matrix and magnetic nano composite;The conductive polymer matrix is PPy or PANI, and the magnetic nanoparticle is Fe3O4 nanoparticle or CoFe nanoparticle.The technical scheme of the present application combines the magnetic permeability of FeNi metal layer and the characteristics of the electric loss and magnetic loss of the composite magnetic material layer (high magnetic permeability soft magnetic and conductive polymer combination), can simultaneously reflect and absorb electromagnetic waves, and the magnetic permeability guiding mechanism has excellent electromagnetic shielding efficiency in a wide frequency range, especially in low frequency and static magnetic field.

The invention discloses a drug-loaded Fe3O4 nano-particle composite preparation, and belongs to the technical field of antitumor drugs, the drug-loaded Fe3O4 nano-particle composite preparation comprises a core-empty-shell Fe3O4 nano-particle composite material and drugs filled in gaps of the core-empty-shell Fe3O4 nano-particle composite material, and the core-empty-shell Fe3O4 nano-particle composite material comprises a ZnO shell structure, a Fe3O4 nano-particle core structure and gaps located between the ZnO shell structure and the Fe3O4 nano-particle core structure and used for filling the drugs. The invention also discloses a drug-loaded Fe3O4 nano-particle composite preparation camouflaged by the vesicle membrane, and a corresponding preparation method and application of the drug-loaded Fe3O4 nano-particle composite preparation. The drug-loaded Fe3O4 nanoparticle composite preparation provided by the invention has targeting property, and can effectively kill tumor cells without causing damage to normal tissues. The drug-loaded Fe3O4 nano-particle composite preparation is wrapped by the vesicle membrane derived from the tumor receptor, so that the investigation and removal of the immune system in the tumor receptor are avoided, the blood circulation time of the tumor receptor is greatly prolonged, and the improvement of the anti-tumor medical effect is facilitated.

The invention discloses a magnetic liquid metal composite material which comprises the following raw materials in percentage by weight: 92-99% of liquid metal base liquid, 1-8% of Fe3O4 nanoparticles, 0-2% of a dispersion stabilizer and 0-5% of an active reactant, the base liquid is gallium-indium-tin eutectic alloy or gallium-indium alloy; the dispersion stabilizer is perfluorooctyl sulfonic acid or (3-aminopropyl) triethoxy silane; and the active reactant is nano sulfur powder or red phosphorus. The invention further provides a preparation method and application of the MLM composite material. According to the magnetic liquid metal composite material and the preparation method thereof, the high heat conduction / electric conduction characteristic of liquid metal and the magnetic response characteristic of magnetic nanoparticles are combined through a specific surface modification process, and the magnetic liquid metal composite material with excellent fluidity, extremely high heat conductivity, good electric conductivity and strong external field driving force is prepared; the material can rapidly permeate into the battery, has three functions of shunting, cooling and passivating, and thoroughly extinguishes fire and prevents after-combustion from the source.

The invention discloses an immobilized nucleoside enzyme mutant and application thereof. The immobilized nucleoside enzyme mutant is prepared by covalently immobilizing a nucleoside enzyme mutant G178D / A202K on aminated magnetic Fe3O4 nanoparticles. The catalyst is applied to a hydrolysis reaction of guanine nucleotide (GMP), efficient catalysis is carried out in a water phase at 60-70 DEG C, the catalyst can be rapidly separated and recovered through an external magnetic field after the reaction, and then high-purity guanine is obtained through solid-liquid separation. The immobilized enzyme can be repeatedly used for more than or equal to 8 times, still keeps more than or equal to 80% of activity, remarkably improves the industrial efficiency of guanine preparation, and has the advantages of green process, simplicity and convenience in operation, low cost, easiness in industrialization and the like.

The invention discloses that the Fe3O4 nano-particle drug loading system has a treatment effect on breast cancer, and determines the optimal condition of the Fe3O4 nano-particle drug loading system for treating breast cancer. The Fe3O4 nano-particle drug-loading system has an obvious killing effect on breast cancer cells.

This invention discloses a pH-responsive magnetic nano-chemical oil displacement agent containing intelligent microspheres. The intelligent microspheres comprise a core formed by nano-SiO2 and dodecyl phosphate monoester clusters, with polyacrylamide and Fe3O4 nanoparticles sequentially attached to the surface of the core, and a shell formed by cross-linking sodium methacrylate. This invention also discloses its preparation and application. The oil displacement agent provided by this invention has mild preparation conditions, low cost, and good oil displacement effect, making it suitable for large-scale production. It can reduce energy consumption during the extraction process, reduce emissions and pollution, and improve crude oil recovery, thus having significant practical implications.

The invention discloses a superparamagnetic nano drug delivery system with biological and magnetic dual targeting and tumor drug and magnetic and thermal dual tumor cell killing and application, and belongs to the technical field of biological medicine. The system is composed of a lipid component, a chemotherapeutic drug and surface carboxyl modified FeO nanoparticles, wherein the lipid component is prepared from cholesterol, DSPE-PEG2000 and folic acid modified DSPE-PEG2000. According to the drug loading system, efficient enrichment of tumor sites is achieved through folic acid receptor mediated biological targeting and physical targeting of an external magnetic field, and tumor cells are killed through chemotherapy drugs and a magnetocaloric effect in a synergistic mode. Experiments show that the encapsulation efficiency of the system on adriamycin reaches 80%, the drug release rate under the magnetocaloric condition is 50%-60%, and the system shows significant targeting and killing effects in tumor cells expressing folate receptors. The invention has the advantages of simple preparation process, strong targeting property, high killing efficiency, low toxic and side effects and the like, and is suitable for thermochemotherapy treatment of cancers.

The invention belongs to the technical field of nucleic acid detection, and particularly relates to a nucleic acid detection method based on a liquid drop control platform. The invention provides a novel nucleic acid detection method based on a liquid drop control platform. The method depends on near-infrared laser-induced photothermal conversion and surface tension gradient-driven Marangei effect: the photothermal conversion capability of PDMS is improved by doping Fe3O4 nanoparticles in PDMS, and heating of reaction liquid drops is realized through a near-infrared laser transmission reaction. Accurate temperature control is achieved through a temperature sensor, and PDMS temperature gradient is formed through photothermal conversion, so that surface tension of liquid drops is changed, and liquid drop driving is triggered. Meanwhile, droplet evaporation is inhibited through oil immersion treatment, a PID algorithm is used for temperature control in the adjusting process, and temperature control is achieved more sensitively and rapidly. The method is expected to solve the limitation problem, and integrated nucleic acid detection which is more convenient and faster, lower in cost and higher in integration degree is realized.

The invention discloses a pH response type multi-mode imaging diagnostic agent and an aging monitoring method of a high polymer material. The diagnostic agent comprises a carrier, a fluorescent probe and a free radical trapping agent, the carrier is a Fe3O4 nano particle (PEI-coated Fe3O4) modified by polyethyleneimine (PEI); the fluorescent probe is a pH acid response BODIPY (boron dipyrromethene) fluorescent probe HGBDP; the free radical trapping agent is 4-oxygen-TEMPO (tetramethylpiperidinooxy); the aging monitoring method of the high polymer material comprises the following steps: mixing the pH response type multi-mode imaging diagnostic agent with a high polymer base material to prepare a sample to obtain a high polymer composite material, and then monitoring the aging state of the high polymer composite material in real time in a multi-mode manner; the diagnostic agent disclosed by the invention can respond to aging markers such as free radicals and acid degradation products generated in the service process of the material, so that lossless, real-time and visual evaluation and multi-mode cooperative monitoring of the aging degree of the material are realized, the defect of a single monitoring mode is overcome, and aging information is comprehensively obtained.

The present invention discloses a preparation method and application of an electrochemical sensor for detecting bacteria based on target-triggered click chemistry and rapid scanning voltammetry. The method is characterized by comprising the following steps: 1) adding a glutaraldehyde solution to an amino-functionalized Fe3O4 nanoparticle dispersion, reacting and washing at room temperature, and then redispersing the solution in an azidopropylamine solution and stirring for 6 hours to obtain an azido-Fe3O4 nanoparticle dispersion; 2) adding ferrocene and propargylamine to a BPNS@AuNPs dispersion to react and obtain a signal unit; 3) adding a CuCl2 solution to a bacterial solution to be detected, incubating the solution, adding the signal unit and the azido-Fe3O4 nanoparticle dispersion, magnetically separating the solution and dropping the solution onto the surface of a glassy carbon electrode after incubation, thereby obtaining an electrochemical sensor for detecting single-cell bacteria based on target-triggered click chemistry and rapid scanning voltammetry. The method has the advantages of high sensitivity, high selectivity, and simple and rapid operation.

The invention provides a method for optimizing the surface quality of titanium alloy based on nano-particle cutting fluid, which comprises the following steps: firstly, building a titanium alloy wet milling test platform, finishing a titanium alloy wet milling test through the prepared cutting fluid containing Fe3O4 nano-particles, synchronously collecting milling vibration data, and calculating the surface quality of the titanium alloy according to the milling vibration data; and after the test is finished, processing the collected data to obtain a three-direction vibration acceleration root-mean-square value, and measuring the processed surface roughness of the test piece. Then, calculating a grey relational degree coefficient of the surface roughness related to a machining parameter and a three-direction vibration acceleration characteristic value; and finally, based on a gradient descent algorithm, the optimal milling machining parameters enabling the surface roughness to be the lowest are obtained, and optimization of the surface quality of the titanium alloy under different machining parameters during milling of the nano-particle cutting fluid is achieved.

The application provides a material applicable to electromagnetic field space control and application thereof, and relates to the technical field of materials.The material is prepared from the following raw materials: 100 parts of poly(4-vinylpyridine)-b-polydimethylsiloxane, 30-60 parts of ionic liquid, 20-50 parts of Fe3O4 nanoparticles, 10-30 parts of MXene, 400-600 parts of mixed solvent, 1-5 parts of photoinitiator and 15-40 parts of polyethylene glycol diacrylate.The material takes poly(4-vinylpyridine)-b-polydimethylsiloxane block copolymer as a matrix, combines ionic liquid, Fe3O4 nanoparticles with surface modification of oleic acid and MXene, and constructs a composite system with excellent flexibility and structural stability, thereby supporting the further development of electromagnetic field space control technology.

The invention discloses a magnetic molecularly imprinted material capable of selectively adsorbing limonin and application of the magnetic molecularly imprinted material, and belongs to the technical field of biochemical separation. The preparation method comprises the following steps: synthesizing a SiO2 molecular layer on the surface of a magnetic Fe3O4 nanoparticle, and carrying out modification by using 3-aminopropyltriethoxysilane and maleic anhydride, so as to obtain the carboxyl-terminated and double-bond functionalized Fe3O4 (at) SiO2 magnetic microsphere. The preparation method comprises the following steps: by taking modified Fe3O4 (at) SiO2 magnetic particles as a core and limonin as a template molecule, synthesizing the limonin magnetic molecularly imprinted material under the combined action of methacrylic acid, ethylene glycol dimethacrylate and azodiisobutyronitrile. The magnetic molecularly imprinted material can specifically adsorb limonin, can be used for reducing and removing bitter taste of fruit juice, and has the advantages of convenience in separation, biocompatibility, reusability and the like.

This invention discloses the application of borosilicate bioglass hydrogel in the preparation of materials for inhibiting postoperative recurrence of melanoma. A borosilicate bioglass suspension and Fe3O4 nanoparticle suspension are added to an amino-modified hyaluronic acid solution and mixed thoroughly. Then, an aldehyde-modified hyaluronic acid solution is added, and a cross-linking reaction is carried out at room temperature to obtain the borosilicate bioglass hydrogel. The borosilicate bioglass hydrogel is used to prepare materials for inhibiting postoperative recurrence of melanoma. The material can inhibit the growth of melanoma in a mouse model of postoperative recurrence, increase the proportion of mature dendritic cells, promote dendritic cell maturation, and increase cytotoxic CD8. + T cells and CD4 + The proportion of T cells in tumors and spleen can be increased to enhance the killing effect of T cells, promote the polarization of macrophages in tumor sites to M1 type, reduce the proportion of M2 type macrophages, and downregulate the content of regulatory T cells and myeloid-derived suppressor cells in tumor sites.

The application relates to a reduced graphene oxide fiber confined Fe3O4 nanoparticle composite material and a preparation method thereof. The composite material is composed of reduced graphene oxide fiber (rGOF) with a directional micro-nanobelt structure (a large number of long strip / belt structures with a width in the micron to nanometer scale are arranged in parallel along the same direction on the surface or inside the material) and Fe3O4 nanoparticles confined on the reduced graphene oxide fiber; the Fe3O4 nanoparticles are distributed in an ordered chain shape along the axial direction of the reduced graphene oxide fiber; the Fe3O4 nanoparticles and the reduced graphene oxide fiber are stably combined through Fe-O-C covalent bonds, and the application has the advantages that one-dimensional confined structure-induced ordered arrangement is realized, the synthesis process is optimized, the stable Fe-O-C covalent bond between Fe3O4 and the rGO skeleton is formed, the interface structure stability and the magnetic coupling efficiency are ensured, and the application has wide application prospects in the biomedical field.

The application discloses a kind of immobilized enzyme, based on the method and device of bio-oil of the enzyme can be reused, the immobilized enzyme is with polyethylene glycol modified Fe3O4 Nanoparticle as matrix, matrix first adsorbs and loads first part free protease, then it is dispersed in sodium alginate aqueous solution with second part free protease and mixed uniformly, sequentially through Ca 2+ Two-step action process of ion hardening and glutaraldehyde crosslinking reaction, the outer sodium alginate reaction forms reticulated macroporous gel microspheres, finally after washing, drying, the microsphere complex of embedding second part free protease and polyethylene glycol modified nano Fe3O4 load immobilized protease is prepared.The stability of the immobilized enzyme in the non-homogeneous slurry mixing system, in-situ separation convenience greatly improves, immobilized enzyme can be better reused, in addition, the stirring paddle of bio-oil reactor is improved, and the stability of immobilized enzyme use can be further improved.

The invention discloses a magnetic nanoprobe and a method for detecting fungaltoxin by a critical offset magnetic particle spectroscopy, the magnetic nanoprobe is formed by modifying the surface of a Fe3O4 magnetic nanoparticle with an antibody capable of specifically recognizing fungaltoxin, the antibody is coupled with an aldehyde group through an amino group modified on the surface of the Fe3O4 nanoparticle, and the magnetic nanoprobe is formed by detecting the fungaltoxin. Stable covalent linkage is formed, and targeted recognition and combination of the aflatoxin B1 and the deoxynivalenol are achieved. The magnetic nanoprobe adopted by the invention can realize detection and quantification of the target toxin through a critical offset magnetic particle spectrum technology under an unmarked condition, the nonlinear response of the Fe3O4 nanoparticles is excited through a bias magnetic field, and by measuring the magnetic phase change generated before and after the Fe3O4 nanoparticles are combined with the toxin, the detection and quantification of the target toxin can be realized. The sensitive detection on the target toxin is realized. The method has the advantages of high detection sensitivity, no elution operation, rapidness, low cost and the like.

The application belongs to the technical field of biological detection, and specifically discloses a system for targeted quantitative detection of breast cancer cells in blood as well as a preparation method and application thereof. The system comprises a magnetic nanoparticle composite material, Ag nanoparticles, a first modified nucleic acid chain, a second modified nucleic acid chain, a hydrogen peroxide solution, a phosphate buffered saline solution, a urease solution, a urea solution and a phenol red solution. The magnetic nanoparticle composite material comprises magnetic Fe3O4 nanoparticles and polydopamine that is self-polymerized and grown on the surface of the Fe3O4 nanoparticles. The nucleotide sequence of the first modified nucleic acid chain is used for modifying the magnetic nanoparticle composite material. The nucleotide sequence of the second modified nucleic acid chain is used for modifying the Ag nanoparticles. The application has the advantages of high sensitivity, low detection limit, low cost and simple operation, realizes sensitive detection of breast cancer cells in blood, solves the problem of complex matrix interference, and has a good application prospect.

The application discloses a preparation method of a flower-shaped Au@Fe3O4 / C nano composite wave-absorbing material, and comprises the following steps: S1, using a gold nanoparticle solution, acetylacetone iron and a first organic solvent as raw materials, a one-step synthesis method is adopted to prepare the flower-shaped Au@Fe3O4 nanoparticle; and S2, using the obtained flower-shaped Au@Fe3O4 nanoparticle as a precursor and dicyandiamide as a carbon source to prepare the Au@Fe3O4 / C nano composite wave-absorbing material. The preparation method of the Au@Fe3O4 / C nano composite wave-absorbing material has the following advantages: firstly, the prepared Au@Fe3O4 nanoparticle is an ionic nanoporous organic network polymer; the intervention of the gold nanoparticle improves the dielectric property of the Au@Fe3O4 / C material; the Au@Fe3O4 nanoparticle has a rich hetero-interface structure and a large specific surface area, which amplifies the'surface effect' of the bulk material; the electromagnetic wave can be reflected and scattered multiple times in the flower-shaped Au@Fe3O4 / C material and continuously attenuated; the material has a wide effective electromagnetic absorption performance and can be applied to the field related to radar stealth.

The invention relates to the technical field of asphalt pavements, and particularly discloses a self-repairing microcapsule modified asphalt pavement material and a preparation method of the self-repairing microcapsule modified asphalt pavement material. Under the triggering of an external magnetic field, the microcapsule can actively crack to release the capsule core to repair the asphalt pavement crack without depending on the condition that the stress at the tip of the crack reaches a threshold value to cover the complete-cycle repair requirement of the pavement microcrack from the initial formation stage to the expansion stage, so that the timeliness of crack healing is greatly improved, and the service life of the pavement is prolonged; the fiber powder reinforcing layer adopts KH-560 modified basalt fiber powder, has the characteristics of high strength and high modulus, and is uniformly adsorbed on the surface of the magnetic sensitive capsule wall to form a compact reinforcing layer, so that the self-repairing microcapsule is prevented from being broken and failed in advance, and the tensile strength and the shear strength can be improved through participation of the fiber powder when the self-repairing microcapsule is broken in a crack; and the service life of the repaired asphalt pavement is prolonged.