Prussian blue magnetic bead and preparation method and application thereof

Abstract

The invention relates to the technical field of magnetic separation, in particular to a Prussian blue magnetic bead and a preparation method and application thereof. The magnetic bead provided by the invention takes Prussian blue as a main preparation raw material, has good dispersity, is not easy to aggregate, is easy to modify the surface, and is simple in preparation method. The modified magnetic beads can be widely applied to multiple fields.

Description

Technical Field

[0001] The invention relates to the technical field of magnetic separation, in particular to Prussian blue magnetic beads and a preparation method and application thereof. Background Art

[0002] Magnetic beads have shown wide application potential in many disciplines due to their unique adsorption and separation functions and controllability in magnetic fields. For example, in the biomedical field, the application of magnetic beads covers both diagnosis and treatment. They can be used as tools for the extraction and purification of biomacromolecules such as DNA and proteins, and are also effective media for the separation of bacteria and viruses. In terms of diagnosis, magnetic beads can detect specific biomarkers such as early cancer, virus and gene identification by coupling specific antibodies or molecular probes; in terms of treatment, magnetic beads can be guided by external magnetic fields to achieve precise release of drugs in the body, providing a new strategy for targeted therapy. In addition, magnetic beads can also be used as carriers of drugs and catalysts, play a role in stirring and transporting in organic synthesis, and can be used for the preparation of immobilized enzymes. In the field of environmental science, magnetic beads are used to remove harmful pollutants in wastewater, including heavy metals, organic matter and radioactive substances, which helps environmental protection and pollution control. In food science and technology, magnetic beads are used to detect and remove pesticides, veterinary drug residues, as well as food additives and pigments to ensure food safety and consumer health. In addition, in the agricultural field, magnetic beads also help detect and remediate pesticide residues in the soil.

[0003] Although magnetic beads are increasingly used in many fields, there are still some problems: some brands of magnetic beads are more mature in application fields, but their prices are extremely expensive, usually 5 to 6 times that of domestic products in terms of milliliters; while other magnetic beads cannot master the core preparation technology of making magnetic beads, the particle size uniformity of the prepared magnetic beads is poor, and the biocompatibility is poor. In addition, there are also disadvantages such as poor dispersibility, difficulty in maintaining strong magnetism during the modification process, and low degree of functionalization. For example, the most mainstream magnetic beads on the market are based on ferroferric oxide as the core, but the surface modification of ferroferric oxide magnetic beads is difficult, and the particle size uniformity is unstable, which makes it difficult to apply to multiple fields; and the preparation process of some types of ferroferric oxide magnetic beads is relatively complicated and the production cost is high, making it difficult to achieve industrial application. Therefore, it is urgent to develop a magnetic bead with uniform particle size, relatively simple and controllable process, simple surface modification, and large-scale mass production that can be used in a variety of fields. Summary of the invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide Prussian blue magnetic beads and a preparation method and application thereof. The Prussian blue magnetic beads used for magnetic separation provided by the present invention have the characteristics of uniform particle size, stable structure, strong magnetic response performance, excellent dispersibility and suspension, easy surface functionalization, good biocompatibility, etc.

[0005] The invention provides application of Prussian blue in preparing magnetic beads.

[0006] Prussian blue, chemically known as ferric ferrocyanide or ferric hexacyanoferrate, is used in the preparation of magnetic beads using Prussian blue, which can overcome the problems of poor monodispersity, easy aggregation, poor particle size uniformity due to surface modification, complex preparation process, high cost, etc. of existing ferroferric oxide magnetic beads. In order to further improve the magnetism, the present invention also dopes different metal ions in the magnetic beads, thereby improving the controllability of the Prussian blue magnetic beads.

[0007] The magnetic beads provided by the invention contain metal ions and Prussian blue, and the metal ions and the cyano groups in the Prussian blue are coordinated and arranged with each other.

[0008] In the present invention, the metal ions include at least one of aluminum ions, chromium ions, iron ions, magnesium ions, sodium ions, potassium ions, calcium ions, strontium ions, barium ions, thallium ions, copper ions, lead ions, silver ions, gold ions, mercury ions, nickel ions, cobalt ions, zinc ions, cadmium ions, lead ions, platinum ions, palladium ions, rhodium ions, iridium ions, ruthenium ions, osmium ions, molybdenum ions, tungsten ions, manganese ions, titanium ions, hafnium ions, tantalum ions, niobium ions, vanadium ions, chromium ions, rubidium ions, cesium ions, barium ions, lanthanum ions, cerium ions, praseodymium ions, neodymium ions, samarium ions, dysprosium ions, holmium ions, erbium ions, beryllium ions, magnesium ions, scandium ions, bismuth ions, polonium ions, and rhenium ions.

[0009] By doping Prussian blue with metal ions, the magnetism of Prussian blue can be improved, and different metal ions are doped, and the improvement effect on the magnetism of Prussian blue is different, thereby achieving the controllability of the magnetism of Prussian blue magnetic beads. In some embodiments, the metal ions are divalent ions. In some specific embodiments, the metal ions are Mn ions, Ni ions, Cu ions, Zn ions or Ce ions.

[0010] In the present invention, the performance of the magnetic beads can be further improved by adjusting the ratio of metal ions to cyano groups. In some embodiments, the molar ratio of the metal ions to cyano groups is 1:(1-5). For example, the molar ratio of the metal ions to cyano groups is 1:1, or 1:2, or 1:3, or 1:4, or 1:5.

[0011] The present invention does not limit the morphology of the magnetic beads. For example, the morphology of the magnetic beads includes at least one of spherical, fibrous, rod-shaped, block-shaped, layered, star-shaped, shuttle-shaped, polyhedral, nanoflower-shaped, hollow block-shaped, cubic, and needle-shaped.

[0012] The present invention does not limit the size of the magnetic beads, and can be adjusted according to actual use. In the embodiment of the present invention, the diameter of the magnetic beads is 5nm to 50μm. Non-limiting examples include: 5nm, 50nm, 80nm, 100nm, 200nm, 500nm, 1μm, 2μm, 4μm, 5μm, 10μm or 50μm, etc.

[0013] The magnetic beads provided by the present invention may only include a core mainly composed of pullulan and metal ions, or may be coated with a modified functional layer to form a core-shell structure. That is, in some embodiments, the magnetic beads described in the present invention also include functional modification, and the functional modification is coated on the surface of the core containing metal ions and Prussian blue.

[0014] In a specific embodiment, the magnetic beads include a core and a modified functional layer, wherein: the core is Prussian blue doped with metal ions, and the crystal structure of the core contains a crystal structure in which different metal sources and cyano groups are coordinated and arranged; the modified functional layer is coated on the surface of the core. The Prussian blue magnetic beads in this embodiment have a core-shell structure, uniform particle size, good monodispersion, no agglomeration, strong magnetic response performance, rich morphology, stable structure, good biocompatibility, low cost, and can be mass-produced; and by modifying the Prussian blue magnetic beads with different functional groups, the functionality of the Prussian blue magnetic beads can be enriched and its application field can be broadened.

[0015] In the present invention, the functional modification includes at least one of chemical modification, biological modification, fluorescent group modification, polymer modification, drug or catalyst modification.

[0016] As a feasible case, the chemical modification includes at least one of: amino modification, carboxyl modification, hydroxyl modification, epoxy modification, chloromethyl modification, silanol modification, aldehyde modification, toluenesulfonyl modification, sulfonic acid modification, quaternary ammonium salt modification, active ester modification, pyridine ruthenium modification, and aziridine modification;

[0017] As a feasible example, the biological modification includes at least one of: polypeptide modification, protein modification, biotin modification, streptavidin modification, nucleic acid modification or antibody modification;

[0018] As a feasible example, the fluorescent group modification includes: at least one of acridinium ester, luminol, isoluminol or rhodamine;

[0019] As a feasible example, the polymer modification includes at least one of methacrylate modification, polyethylene glycol modification, polystyrene modification, hydrophobic polyvinyl chloride modification or poly-lysine modification.

[0020] As feasible examples, the drugs include human drugs, animal drugs or herbal drugs. For example:

[0021] The human drugs include, but are not limited to, antibiotics (such as penicillin, cephalosporin, erythromycin, azithromycin, tetracycline, chloramphenicol, gentamicin, streptomycin, vancomycin or clindamycin), anti-tumor drugs (such as cyclophosphamide, fluorouracil, cisplatin, carboplatin, paclitaxel, docetaxel, imatinib, gefitinib, trastuzumab, bevacizumab), cardiovascular system drugs (such as nitroglycerin, nifedipine, metoprolol, losartan, captopril, hydrochlorothiazide, digoxin, amiodarone, atorvastatin or warfarin) or nervous system drugs (such as diazepam, phenobarbital, carbamazepine, sodium valproate, methylcobalamin, gabapentin, pregabalin, levodopa, amantadine or donepezil);

[0022] The animal medicine includes antiparasitic drugs (such as albendazole, mebendazole, ivermectin, praziquantel, niclosamide, levamisole, pyrantel, pyrantel pamoate, triclabendazole or diethylcarbamazine), veterinary drugs (such as ivermectin, doramectin, florfenicol, tilmicosin, amoxicillin, enrofloxacin, oxytetracycline, tylosin, levamisole or albendazole), poultry drugs (such as amoxicillin, enrofloxacin, tylosin, florfenicol, oxytetracycline, chlortetracycline, neomycin, doxycycline, sulfadiazine or maduramicin) or aquatic animal drugs (such as formalin, copper sulfate, ferrous sulfate, chlorine dioxide, povidone iodine, oxytetracycline, florfenicol, avermectin, bromochlorhydrin or enrofloxacin);

[0023] The botanical drugs include insecticides (such as Bacillus thuringiensis, rotenone, azadirachtin, matrine, veratrine, pyrethrin, nicotine, celangulin, avermectin or spinosad), disease-resistant drugs (such as carbendazim, thiophanate-methyl, thiophanate-methyl, mancozeb, mebendazim, metalaxyl, tebuconazole, dimethomorph, or azoxystrobin) or biocontrol drugs (such as Bacillus thuringiensis, Beauveria bassiana, Metarhizium anisopliae, Trichoderma, Trichoderma harzianum, Bacillus subtilis, Bacillus polymyxa, Paecilomyces lilacinus, nuclear polyhedrosis virus or avermectin).

[0024] In the present invention, the preparation method of magnetic beads containing only a core comprises:

[0025] Dissolving a polymerization agent and potassium ferrocyanide in a first solvent to obtain a solution A;

[0026] Dissolving a metal source and a divalent iron salt in a second solvent to obtain a solution B;

[0027] The solution A and the solution B are mixed and reacted, and the reaction product is subjected to ultrasonication, centrifugation, and washing to obtain the magnetic beads.

[0028] Alternatively, a method for preparing magnetic beads containing a core and functional modifications, comprising:

[0029] Dissolving a polymerization agent and potassium ferrocyanide in a first solvent to obtain a solution A;

[0030] Dissolving a metal source and a divalent iron salt in a second solvent to obtain a solution B;

[0031] The solution A and the solution B are mixed and reacted, and the reaction product is subjected to ultrasonication, centrifugation, and washing to obtain the magnetic bead core;

[0032] The magnetic bead core is immersed in a modifier to obtain the Prussian blue magnetic bead.

[0033] The preparation method in the embodiment of the present invention has a simple process, does not require complex reaction equipment and operation means, has low cost, is suitable for industrial mass production, and has a stable application effect, which solves the problems of large batch differences and complex preparation of existing magnetic beads. The prepared Prussian blue magnetic beads can have only a core or a core-shell structure, have excellent dispersibility, uniform particle size, strong magnetic response performance, simple surface modification, and a wider range of applications.

[0034] As a feasible example, the first solvent includes at least one of water, methanol, ethanol, acetone, ether, sulfur trioxide, ethylamine, aniline, cyclohexane, n-hexanol, n-hexanol, butanol, pentanol, hexanol, and ethylene glycol;

[0035] As a feasible example, the second solvent includes at least one of water, methanol, ethanol, acetone, ether, sulfur trioxide, ethylamine, aniline, cyclohexane, n-hexanol, n-hexanol, butanol, pentanol, hexanol, and ethylene glycol.

[0036] As a feasible case, the polymerizing agent is selected from at least one of polyacrylamide, polymethyl methacrylate, polystyrene, polymethylstyrene, polyimide, polyethylene terephthalate, polyvinyl pyrrolidone, polyethylene glycol, and polylactic acid.

[0037] As a feasibility example, the metal source is selected from a substance capable of providing at least one metal ion of aluminum ion, chromium ion, iron ion, magnesium ion, sodium ion, potassium ion, calcium ion, strontium ion, barium ion, thallium ion, copper ion, lead ion, silver ion, gold ion, mercury ion, nickel ion, cobalt ion, zinc ion, cadmium ion, lead ion, platinum ion, palladium ion, rhodium ion, iridium ion, ruthenium ion, osmium ion, molybdenum ion, tungsten ion, manganese ion, titanium ion, hafnium ion, tantalum ion, niobium ion, vanadium ion, chromium ion, rubidium ion, cesium ion, barium ion, lanthanum ion, cerium ion, praseodymium ion, neodymium ion, samarium ion, dysprosium ion, holmium ion, erbium ion, beryllium ion, magnesium ion, scandium ion, bismuth ion, polonium ion, and rhenium ion;

[0038] As a feasibility case, the divalent iron salt is selected from at least one of ferrous chloride or ferrous sulfate.

[0039] As a feasible example, the mass ratio of the polymerization agent to the potassium ferrocyanide is (1.2-2):1; non-limiting examples include: 1.2:1, 1.5:1, 1.8:1, 2:1, etc.;

[0040] As a feasibility case, the amount of the metal source added is 0.01-0.1 mol / L; non-limiting examples are: 0.01 mol / L, 0.02 mol / L, 0.05 mol / L, 0.08 mol / L, 0.1 mol / L, etc.; adding too much or too little metal source will cause the microstructure of the Prussian blue magnetic beads to change and affect its magnetism. Therefore, the embodiment of the present invention controls the amount of the metal source added to be within the range of 0.01-0.1 mol / L;

[0041] As a feasibility case, the molar ratio of the divalent iron salt to the potassium ferrocyanide is 1:(1-5). Non-limiting examples include: 1:1, 1:2, 1:3, 1:5, etc., preferably 1:1; by limiting the molar ratio of the divalent iron salt to potassium ferrocyanide, it can be ensured that the metal ions are uniformly doped on the surface of the magnetic beads; if the content of potassium ferrocyanide is too high or too low, it will cause an imbalance between the trivalent iron ions and the divalent iron ions of the Prussian blue magnetic beads, thereby affecting the magnetic properties of the Prussian blue magnetic beads;

[0042] As a feasibility case, after the solution A and the solution B are mixed, a surfactant is also added, and the surfactant includes at least one of triaton, sodium dodecyl sulfate, sodium alkylbenzene sulfonate, sodium stearate sulfate, sodium dodecyl sulfonate, dodecyltrimethylammonium bromide, cocamidopropyl betaine, polyoxyethylene ether nonylphenol, polyoxyethylene fatty alcohol ether, sorbitan monostearate, polyoxyethylene sorbitan monostearate, N-acyl amino acid salt, lecithin, polyacrylate, polyethylene glycol ether, polyethylene glycol sulfate, phenethyl alcohol, isobutyl hydroxyphenyl ether, aromatic alkyloxy ether, and ethylenediaminetetraacetic acid.

[0043] As a feasibility case, the reaction temperature of the solution A and the solution B is 20°C to 400°C, non-limiting examples include: 20°C, 80°C, 100°C, 120°C, 150°C, 200°C, 280°C, 300°C, 350°C, 400°C, etc.; the reaction time is 10min to 20h. Non-limiting examples include: 10min, 30min, 1h, 2h, 5h, 8h, 10h, 12h, 15h, 20h, etc. In the embodiment of the present invention, the controllability of the size and morphology of the Prussian blue core particles can be achieved by controlling the reaction temperature and the reaction time, and the Prussian blue magnetic beads developed thereby have multiple sizes and multiple morphologies.

[0044] As a feasible case, the modifier includes at least one of an amino-containing substance, a carboxyl-containing substance, a hydroxyl-containing substance, an epoxy-containing substance, a chloromethyl-containing substance, a silanol-containing substance, an aldehyde-containing substance, a toluenesulfonyl-containing substance, a sulfonic acid-containing substance, a quaternary ammonium salt, an active ester, ruthenium pyridine, aziridine, a polypeptide, a protein, biotin, streptavidin, a nucleic acid, an antibody, an acridinium ester, luminol, isoluminol, rhodamine, methacrylate, polyethylene glycol, polystyrene, hydrophobic polyvinyl chloride or polylysine.

[0045] In some embodiments, the amino-containing substances include but are not limited to polydopamine, amino polyethylene glycol, 3-aminopropyltriethoxysilane, etc.

[0046] In some embodiments, the carboxyl-containing substances include but are not limited to amino polyethylene glycol carboxyl, etc.

[0047] In some embodiments, substances containing hydroxyl groups include but are not limited to polyvinyl alcohol, polyethylene glycol, ethanol, pentaerythritol, pentaerythritol, hexanehexaol, catechol, dopamine, etc.

[0048] In some embodiments, the substance containing silanol refers to the substance containing hydroxyl group added after the core is subjected to silanization reaction, including but not limited to the use of tetraethoxysilane or 3-aminopropyltrimethoxy and other substances to perform silanization reaction and then add polyvinyl alcohol, polyethylene glycol and other substances containing hydroxyl group. In some embodiments, the substance containing aldehyde group includes but is not limited to glutaraldehyde, etc.

[0049] In some embodiments, the substance containing tosyl group includes but is not limited to amino polyethylene glycol p-toluenesulfonate, tosyl chloride, etc.

[0050] In some embodiments, the sulfonic acid group-containing substances include but are not limited to m-phenylenediamine-5-sulfonic acid, 4,4'-diaminobenzene-2,2'-disulfonic acid, etc.

[0051] In some embodiments, the quaternary ammonium salt includes but is not limited to tetramethylammonium hydroxide, tetramethylammonium chloride, trimethylbenzylammonium chloride, tetraethylammonium chloride, and the like.

[0052] As a feasibility case, the immersion temperature is room temperature, the immersion time is 1 to 12 hours, non-limiting examples are: 1 hour, 3 hours, 5 hours, 8 hours, 10 hours, 12 hours, etc.; the stirring speed during immersion is 80 to 200 rpm / min, non-limiting examples are: 80 rpm / min, 100 rpm / min, 120 rpm / min, 150 rpm / min, 180 rpm / min, 200 rpm / min, etc. In the embodiment of the present invention, only the Prussian blue core needs to be immersed in the modifier at room temperature to give the Prussian blue magnetic beads multifunctionality, which is easy to operate, has low energy consumption and low cost.

[0053] The magnetic beads provided by the invention have uniform particle size, good monodispersion, no agglomeration, strong magnetic response performance, rich morphology, stable structure, good biocompatibility, low cost, and can be mass-produced; and by modifying the Prussian blue magnetic beads with different functional groups, the functionality of the Prussian blue magnetic beads can be enriched, and the application field thereof can be broadened so that the beads can be applied to various fields, for example, the Prussian blue magnetic beads can be used for protein enrichment and purification, nucleic acid separation and purification, chemiluminescence, cell sorting, biological immunoassay, tissue engineering, drug screening, biosensor, biomarker detection, removal and detection of wastewater / pesticide residues, reaction catalyst carriers, and other environmental, biological, diagnostic, food and other fields.

[0054] Furthermore, the present invention also provides the use of the magnetic beads as described above or the magnetic beads prepared by the preparation method as described above in the preparation of biochemical reagents or carriers.

[0055] Furthermore, the present invention also provides a reagent, which includes the magnetic beads as described above or the magnetic beads prepared by the preparation method as described above.

[0056] The reagent is an extraction reagent, a sorting reagent, a purification reagent, a detection reagent, a diagnostic reagent, an analysis reagent, an imaging reagent or a signal reporting reagent.

[0057] The reagents also include other reagents required for detection, including but not limited to binding buffer, washing buffer, lysis solution or elution solution.

[0058] The binding buffer includes, but is not limited to, Tris-HCl buffer, phosphate buffered saline (PBS), HEPES buffer, glycine-HCl buffer, acetate buffer, MES buffer, MOPS buffer, citric acid-sodium citrate buffer, borate buffer, and TAPS buffer.

[0059] Washing buffers include, but are not limited to, PBST (PBS containing Tween-20), TBS-T (TBS containing Tween-20), 1×SSC buffer, 0.1×SSC buffer, 1×SSPE buffer, 0.5×SSPE buffer, 1MNaCl solution, 0.5M Tris-HCl (pH 7.5), 0.1M EDTA (pH 8.0), and 20mM Tris-100mMNaCl (pH 7.6).

[0060] Lysis buffer includes, but is not limited to, RIPA lysis buffer, SDS lysis buffer, NP-40 lysis buffer, TritonX-100 lysis buffer, urea lysis buffer, guanidine lysis buffer, proteinase K lysis buffer, lysozyme lysis buffer, cell lysis buffer (containing multiple ion components), and β-mercaptoethanol lysis buffer.

[0061] The eluents include, but are not limited to, acidic eluents (such as 0.1 M glycine-HCl, pH 2.5), alkaline eluents (such as 1 M Tris-HCl, pH 10.5), high salt eluents (such as 3 M MgCl2), low salt eluents (such as 0.1 M NaCl), ethanol solutions, isopropanol solutions, solutions containing specific ions (such as Ca 2+ Mg 2+ ), an eluent containing a competitor (such as imidazole), an EDTA eluent, and an eluent containing a surfactant (such as sodium dodecyl sulfate).

[0062] The present invention also provides an extraction, sorting or purification method, which comprises enriching the target object with the magnetic beads as described above, the magnetic beads prepared by the preparation method as described above, or the reagent as described above.

[0063] The present invention also provides a detection, diagnosis or analysis method, which comprises enriching the target with the magnetic beads as described above, the magnetic beads prepared by the preparation method as described above, or the reagent as described above, and then performing qualitative or quantitative detection.

[0064] The present invention also provides an imaging or signal reporting method, which comprises labeling a sample with the magnetic beads as described above, the magnetic beads prepared by the preparation method as described above, or the reagent as described above, and then detecting the signal generated by the magnetic beads.

[0065] Furthermore, the present invention also provides a drug, including a drug and a carrier, wherein the carrier is the magnetic beads as described above or the magnetic beads prepared by the preparation method as described above.

[0066] The drug is used for human medicine, animal medicine or is a herbal medicine.

[0067] The present invention also provides a method for preventing and / or treating a disease, which comprises administering the drug to a subject, wherein the subject is a human, an animal or a plant.

[0068] Furthermore, the catalyst comprises a reaction catalyst and a carrier,

[0069] The reaction catalyst is a chemical catalyst or an enzyme;

[0070] The carrier is the magnetic beads as described above or the magnetic beads prepared by the preparation method as described above.

[0071] The catalyst is used in the fields of environment, biology, diagnosis, food, etc.

[0072] The present invention also provides a reaction method, which comprises promoting the reaction with the catalyst as described above.

[0073] The magnetic beads provided by the present invention use Prussian blue as the main raw material for preparation, have good dispersibility, are not easy to aggregate, are easy to modify on the surface, and have a simple preparation method. The modified magnetic beads can be widely used in multiple fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 It is a schematic diagram of the structure of Prussian blue magnetic beads used for magnetic separation according to an embodiment of the present invention;

[0075] Figure 2 This is a performance diagram of the Mn ion-doped Prussian blue magnetic bead core obtained in Example 1 of the present invention; wherein, Figure 2 a is the magnetization intensity diagram, Figure 2 b is the XRD pattern, Figure 2 The figure c is the Fourier infrared spectrum. Figure 2 d in the middle is the ultraviolet spectrum;

[0076] Figure 3 This is a SEM image of the Prussian blue magnetic beads prepared in Example 1 of the present invention;

[0077] Figure 4 This is a stability test diagram of the Mn ion-doped Prussian blue magnetic bead core at different pH and different temperatures obtained in Example 1 of the present invention; wherein, Figure 4 a is the particle size distribution diagram at different temperatures. Figure 4 b is the particle size distribution diagram at different pH;

[0078] Figure 5 This is a SEM image of the core of the Mn ion-doped Prussian blue magnetic beads prepared in Example 2-4 of the present invention; wherein, Figure 5 Figure a is a SEM image of the core of the Mn ion-doped Prussian blue magnetic beads obtained in Example 2. Figure 5b is a SEM image of the core of the Mn ion-doped Prussian blue magnetic beads obtained in Example 3. Figure 5 Figure c is a SEM image of the core of the Mn ion-doped Prussian blue magnetic beads prepared in Example 4;

[0079] Figure 6 The performance diagram of the Prussian blue magnetic bead core doped with different metal sources prepared in Examples 5-8 of the present invention; wherein, Figure 6 Figure a is a SEM image. Figure 6 b is the particle size distribution diagram. Figure 6 c is the magnetization intensity diagram, Figure 6 d in the figure is the infrared spectrum;

[0080] Figure 7 The performance diagram of the Prussian blue magnetic bead core obtained in Example 10, Example 1 and Example 9 of the present invention; wherein, Figure 7 Figure a is a SEM image. Figure 7 b is the particle size distribution diagram. Figure 7 c in the middle is the magnetization intensity diagram;

[0081] Figure 8 The performance diagram of the Prussian blue magnetic bead core (without surface modification) prepared in Example 1 of the present invention and the Prussian blue magnetic beads modified with different functional groups prepared in Examples 11, 12 and 13; wherein, Figure 8 Figure a is a SEM image. Figure 8 b is the particle size distribution diagram. Figure 8 c is the magnetization intensity diagram;

[0082] Fig. 9 The performance diagram of the Prussian blue magnetic beads prepared in Example 14, Example 15 and Example 16 of the present invention; wherein, Fig. 9 Figure a is a SEM image. Fig. 9 b is the magnetization intensity diagram;

[0083] Fig.10 This is the electrophoresis diagram of the BSA protein separated and purified using the Prussian blue magnetic beads prepared in Example 1 in Experimental Example 1;

[0084] Fig.11 This is the electrophoresis diagram of DNA separated and purified from Escherichia coli lysate using the Prussian blue magnetic beads prepared in Example 1 in Experimental Example 2. DETAILED DESCRIPTION

[0085] The present invention provides the application of Prussian blue in the preparation of magnetic beads. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve it. It is particularly important to point out that all similar replacements and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The methods and applications of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the methods and applications of this article without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0086] Where values ​​are described herein as a range, it should be understood that such disclosure includes disclosure of all possible sub-ranges within that range, as well as specific values ​​falling within that range, regardless of whether a specific value or a specific sub-range is explicitly stated.

[0087] Herein, the words "comprises" and "includes" and variations thereof mean that other elements or integers which are permitted but not specifically described may be included.

[0088] In this article, the term "and / or" is merely a term used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0089] The present invention is based on the inventor's discovery and understanding of the following facts and problems: the monodispersity of ferroferric oxide magnetic beads is poor, the particle size distribution is different, and the preparation process is relatively complicated. Therefore, it is of great significance to develop new magnetic beads. Prussian blue is an important complex with rich chemical and physical properties. It has a simple chemical structure and is easy to prepare. The divalent iron ion and the cyano group in the structure are connected to each other through a coordination bond to form hexacyanoferrate (II) ions, and the outer trivalent iron ions and the hexacyanoferrate (II) ions are connected to each other through an ionic bond. This structure makes Prussian blue have the characteristics of strong reducibility, anion exchange capacity and dispersion ability, and can be used to prepare magnetic beads.

[0090] In this article, the term "magnetic beads" refers to a tiny, magnetic particle material, whose core is composed of Prussian blue and metal ions, which can respond to and be effectively manipulated under the action of an external magnetic field. The surface of the magnetic beads can be modified with specific functional groups or bioactive molecules. These modifications give the magnetic beads unique functions in biochemical detection. For example, they can specifically bind to target biological molecules (such as nucleic acids, proteins, antigens, antibodies, etc.), and use magnetic separation technology to quickly separate the magnetic beads bound to target molecules from complex biological sample systems, so as to facilitate subsequent detection, analysis and identification of target molecules, thereby greatly improving the efficiency, accuracy and sensitivity of biochemical detection.

[0091] In this article, the term "core" refers to the magnetic core part inside the magnetic bead, and its crystal structure contains a crystal structure in which different metal sources and cyano groups are coordinated and arranged with each other.

[0092] In this article, the term "modified functional layer" refers to one or more layers of material with specific chemical structure and functional properties covering the surface of the magnetic bead core. This functional layer is closely connected to the magnetic bead core by chemical bonding, physical adsorption or other molecular interactions. Various active groups are modified on the functional layer, which can achieve a variety of key functions. On the one hand, it can be modified with ligands that can specifically interact with target biochemical substances, such as aptamers, antibodies, antigens, nucleic acid probes, etc., so as to accurately identify and bind to target molecules, providing a targeted basis for subsequent detection and analysis; on the other hand, the functional layer may also contain groups that can change the physical and chemical properties of the magnetic beads such as surface charge and hydrophilicity, so as to optimize the dispersibility, stability and compatibility of the magnetic beads with the sample matrix in the biochemical detection system, ensure that the magnetic beads can play an effective role in a complex biochemical environment, and then assist in the efficient separation, enrichment, detection of target biochemical substances and precise regulation of related biochemical reactions.

[0093] In this article, the term "reagent" refers to a functional composition used for biochemical detection. Among them, the reagent containing magnetic beads can also include other auxiliary reagents. For example, in addition to magnetic beads, the reagent also contains a buffer system to maintain appropriate pH and ionic strength to ensure the activity of biological molecules and the smooth progress of reactions; it may contain enzyme substances to catalyze specific biochemical reactions; there will also be protective agents to prevent the degradation or inactivation of biological molecules; and some auxiliary components to help improve the sensitivity, accuracy and stability of the detection, etc., and the overall synergistic effect can achieve efficient detection and analysis of target components in biological samples.

[0094] In this article, the term "target" is also called "target component", which refers to the material object that is specifically detected and analyzed in the biochemical detection system. It includes but is not limited to various types of biological molecules, such as nucleic acids (DNA, RNA), whose sequence characteristics or expression levels can be used as key bases for disease diagnosis, genotyping and other detections; proteins (enzymes, antibodies, antigens or various structural proteins), whose activity, content, modification status and other changes are closely related to many physiological and pathological processes; small molecule compounds (hormones, drugs, metabolic intermediates, etc.), whose concentration levels in the body have important indicative significance for the metabolic balance and functional state of the body. In addition, the target can also be cells and their specific components, such as receptors on the cell membrane, special substances in organelles, etc., as well as microorganisms, including pathogens such as bacteria, viruses, and fungi.

[0095] In this article, the term "drug" refers to a substance with pharmacological activity such as treating, preventing, diagnosing diseases or regulating physiological functions. It covers various types such as chemically synthesized drugs, biological products, natural drugs and their extracts. These drugs can be small molecule organic compounds or macromolecular biological preparations, which are not limited in the present invention. In the present invention, the drug can be loaded on the magnetic beads, and with the help of the characteristics of the magnetic beads, such as the advantages of easy manipulation and separation, the precise delivery and localized release of the drug in specific parts in vivo or in vitro can be achieved, thereby improving the utilization efficiency of the drug and reducing the adverse effects on non-target parts.

[0096] In this article, the term "catalyst" refers to a substance that can significantly change the rate of a chemical reaction while its chemical composition and quality remain essentially unchanged before and after the reaction. In the present invention, the catalyst can be supported on magnetic beads. As a carrier, the magnetic beads provide a larger specific surface area for the catalyst, which is conducive to the full contact between the active center of the catalyst and the reactant. In the reaction system, the catalyst in this supported form can be easily separated and recovered from the reaction mixture by means of the magnetism of the magnetic beads, thereby improving the utilization rate of the catalyst and reducing costs. It can be applied to many chemical reaction fields, including but not limited to organic synthesis reactions, pollutant degradation reactions in the field of environmental protection, etc.

[0097] In this article, the term "enrichment" is a general term for a series of operations aimed at increasing the concentration, purity or detectability of a target in a sample. It covers operations such as extraction, separation, and purification, for example: selectively extracting or transferring a target from a complex mixed system using the magnetic beads of the present invention; and may also include steps to further achieve a higher purity or uniformity of the target.

[0098] The numerical ranges and parameters involved in the present invention have been presented in the specific embodiments as accurately as possible. However, any numerical value inherently inevitably contains standard deviations due to individual testing methods. Therefore, unless otherwise explicitly stated, it should be understood that all numerical ranges or specific data used in this disclosure may have certain reasonable deviations within a certain range, for example: within ±10%, ±5%, ±1% or ±0.5%.

[0099] In this document, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0100] It should be understood that in various embodiments of the present application, the size of the sequence number of each process does not mean the order of execution, some or all of the steps can be executed in parallel or in sequence, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. The test materials used in the present invention are all common commercial products and can be purchased on the market. The present invention is further described below in conjunction with the embodiments:

[0101] Example 1

[0102] A method for preparing Prussian blue magnetic beads for magnetic separation comprises the following steps:

[0103] (1) dissolving 5 g of polyvinyl pyrrolidone and 3.3 g (0.01 mol) of potassium ferrocyanide in 1 g of n-hexanol and 1 g of cyclohexane to obtain solution A;

[0104] (2) 0.6 g of manganese chloride (0.01 mol) and 2.6 g (0.01 mol) of ferrous chloride were dissolved in 1 g of n-hexanol and 1 g of cyclohexane to obtain solution B;

[0105] (3) Solution A and solution B were mixed, and 4 g of Triton was added to the mixture to mix well, followed by reaction in an oil bath at 120° C. for 2 h under stirring conditions. After the reaction was completed, the reaction product was ultrasonicated for 15 min, then suspended in 20 mL of ultrapure water and centrifuged at 5000 rpm for 10 min. This was repeated 3 times to obtain a Mn ion-doped Prussian blue magnetic bead core.

[0106] (4) The core of the Prussian blue magnetic beads is first immersed in a mixture of 0.03 g of ammonia water and 0.35 g of tetraethoxysilane, and stirred at room temperature for 2 h at a stirring speed of 120 rpm / min. The reaction product is then immersed in 20 mL of ethanol and stirred at room temperature for 4 h at a stirring speed of 120 rpm / min to obtain Prussian blue magnetic beads.

[0107] Figure 2: is a performance diagram of the Mn ion-doped Prussian blue magnetic bead core prepared in this embodiment, wherein: Figure 2 a is the magnetization intensity diagram, Figure 2 b is the XRD pattern, Figure 2 The figure c is the Fourier infrared spectrum. Figure 2 In the figure d is the UV spectrum. Figure 2 As can be seen in a, the saturation magnetization intensity of the core of the Mn ion-doped Prussian blue magnetic beads exceeds 35emu / g; Figure 2 In b, it can be seen that the core of the Mn-doped Prussian blue magnetic beads has a variety of characteristic peak diffraction surfaces, including 17.4°(200), 24.5°(220), 35.2°(400) and 39.5°(420); Figure 2 As can be seen in c, the core of the Mn-doped Prussian blue magnetic beads is at 2080-2090cm -1 There is a characteristic peak at , proving the existence of -C≡N-; Figure 2 As can be seen in image d, the core of the Mn ion-doped Prussian blue magnetic beads has a characteristic absorption shift at 650-750nm.

[0108] Figure 3 This is the SEM image of the Prussian blue magnetic beads prepared in this embodiment. The core and shell structures can be distinguished based on the difference in contrast. Among them, the darkest is the Mn ion-doped Prussian blue magnetic bead core, and the core particle size is 100nm. The surface of each Prussian blue magnetic bead core is covered with an ordered core-shell thin layer with a thickness of 11nm.

[0109] Figure 4 The stability test diagram of the Mn ion-doped Prussian blue magnetic bead core prepared in this example at different pH and different temperatures is shown in FIG. Figure 4 a in the figure is the particle size distribution diagram at different temperatures. Figure 4 b is the particle size distribution diagram at different pH. Figure 4 A and Figure 4 It can be seen from Figure b that the Mn ion-doped Prussian blue magnetic bead core prepared in this example can remain stable at different temperatures and different pH values, showing good stability.

[0110] Example 2

[0111] The preparation method of this embodiment is basically the same as that of embodiment 1, except that in step (3), the reaction temperature of solution A and solution B is 300° C. and the reaction time is 8 h.

[0112] Example 3

[0113] The preparation method of this embodiment is basically the same as that of embodiment 1, except that in step (3), the reaction temperature of solution A and solution B is 25° C. and the reaction time is 30 min.

[0114] Example 4

[0115] The preparation method of this embodiment is basically the same as that of embodiment 1, except that in step (3), the reaction temperature of solution A and solution B is 350° C. and the reaction time is 16 h.

[0116] Figure 5 This is a SEM image of the core of the Mn ion-doped Prussian blue magnetic beads prepared in Example 2-4, wherein: Figure 5 Figure a is a SEM image of the core of the Mn ion-doped Prussian blue magnetic beads prepared in Example 2, which exhibits a hollow block structure; Figure 5 b is a SEM image of the core of the Mn ion-doped Prussian blue magnetic beads prepared in Example 3, which exhibits a cubic structure; Figure 5 Figure c is a SEM image of the Mn ion-doped Prussian blue magnetic bead core obtained in Example 4, which exhibits a needle-like structure. That is, by simultaneously changing the reaction temperature and reaction time during the preparation process, Prussian blue magnetic bead cores with different morphological structures can be prepared.

[0117] Example 5

[0118] The preparation method of this embodiment is basically the same as that of Embodiment 1, except that in step (2), 0.6 g of manganese chloride (0.01 mol) is replaced by 1.8 g of nickel nitrate (0.01 mol).

[0119] Example 6

[0120] The preparation method of this embodiment is basically the same as that of Embodiment 1, except that in step (2), 0.6 g of manganese chloride (0.01 mol) is replaced by 1.3 g of copper chloride (0.01 mol).

[0121] Example 7

[0122] The preparation method of this embodiment is basically the same as that of Embodiment 1, except that in step (2), 0.6 g of manganese chloride (0.01 mol) is replaced by 1.4 g of zinc chloride (0.01 mol).

[0123] Example 8

[0124] The preparation method of this embodiment is basically the same as that of Embodiment 1, except that in step (2), 0.6 g of manganese chloride (0.01 mol) is replaced by 3.7 g of cerium chloride (0.01 mol).

[0125] Figure 6The performance diagram of the Prussian blue magnetic bead core doped with different metal sources prepared in Examples 5-8, wherein: Figure 6 Figure a is a SEM image. Figure 6 b is the particle size distribution diagram. Figure 6 c is the magnetization intensity diagram, Figure 6 In the figure d is the infrared spectrum. Figure 6 As can be seen in a, the cores of Prussian blue magnetic beads doped with different metal ions have good uniformity and stability. Figure 6 As can be seen in b, doping Prussian blue with different metal ions has little effect on the particle size of the core of Prussian blue magnetic beads, and the particle size is about 100nm. Figure 6 It can be seen from Figure c that the cores of Prussian blue magnetic beads made by doping with different metal ions all have good magnetic properties. Figure 6 As can be seen in Figure d, the core of the Prussian blue magnetic beads made by doping with different metal ions is at 2081 cm -1 and 2160cm -1 There are characteristic peaks at , which correspond to the absorption peaks related to Prussian blue and cyano.

[0126] Example 9

[0127] The preparation method of this embodiment is basically the same as that of embodiment 1, except that in step (3), the reaction temperature of solution A and solution B is 80°C.

[0128] Example 10

[0129] The preparation method of this embodiment is basically the same as that of embodiment 1, except that in step (3), the reaction temperature of solution A and solution B is 160°C.

[0130] Figure 7 The performance diagram of the Prussian blue magnetic bead core obtained in Example 10, Example 1 and Example 9, wherein: Figure 7 a in the figure are SEM images of the cores of the Prussian blue magnetic beads prepared in Example 10, Example 1 and Example 9, respectively. Figure 7 b is the particle size distribution diagram. Figure 7 c is the magnetization intensity diagram. Figure 7 It can be seen that the particle size of the Prussian blue magnetic bead core obtained in Example 10 is 50nm, the particle size of the Prussian blue magnetic bead core obtained in Example 1 is 100nm, and the particle size of the Prussian blue magnetic bead core obtained in Example 9 is 200nm. It can be seen that with the increase of the reaction temperature, the size of the obtained Prussian blue magnetic bead core gradually decreases. At the same time, the size also has a certain effect on the magnetism of the Prussian blue magnetic beads. With the decrease of the size, the magnetism of the Prussian blue magnetic beads gradually increases.

[0131] Embodiment 11

[0132] The preparation method of this embodiment is basically the same as that of embodiment 1, except that in step (4), the inner core of the Prussian blue magnetic beads is immersed in 0.08 g of bisamino polyethylene glycol and stirred at room temperature at a stirring speed of 120 rpm / min for 1 h.

[0133] Example 12

[0134] The preparation method of this embodiment is basically the same as that of embodiment 1, except that in step (4), the inner core of the Prussian blue magnetic beads is immersed in 0.1 g of amino polyethylene glycol carboxyl, and the reaction is stirred at room temperature at a stirring speed of 120 rpm / min for 1 h.

[0135] Example 13

[0136] The preparation method of this embodiment is basically the same as that of embodiment 1, except that in step (4), the inner core of the Prussian blue magnetic beads is immersed in 0.25 g of p-toluenesulfonate polyethylene glycol amino and stirred at room temperature at a stirring speed of 120 rpm / min for 1 h.

[0137] Figure 8 The performance graphs are of the Prussian blue magnetic bead core (i.e., not surface-modified) prepared in step (4) of Example 1 and the Prussian blue magnetic beads modified with different functional groups prepared in Examples 11, 12, and 13, wherein: Figure 8 Figure a is a SEM image. Figure 8 b is the particle size distribution diagram. Figure 8 c is the magnetization intensity diagram. Figure 8 It can be seen that the magnetic properties of the Prussian blue magnetic beads prepared by directly modifying different functional groups on the core of the Prussian blue magnetic beads will not be significantly affected.

[0138] Embodiment 14

[0139] The preparation method of this embodiment is basically the same as that of embodiment 1, except that in step (4), 0.2 mg of streptavidin is impregnated into the inner core of the Prussian blue magnetic beads, and the reaction is stirred at room temperature at a stirring speed of 120 rpm / min for 1 h.

[0140] Embodiment 15

[0141] The preparation method of this embodiment is basically the same as that of embodiment 1, except that in step (4), 0.05 mg of CEA antibody is impregnated into the inner core of the Prussian blue magnetic beads, and the reaction is stirred at room temperature at a stirring speed of 120 rpm / min for 1 h.

[0142] Example 16

[0143] The preparation method of this embodiment is basically the same as that of embodiment 1, except that in step (4), 0.03 mg of terpyridine ruthenium is impregnated into the inner core of the Prussian blue magnetic beads, and the reaction is stirred at room temperature at a stirring speed of 120 rpm / min for 1 h.

[0144] Fig. 9 The SEM images and magnetization intensity images of Prussian blue magnetic beads modified with different functional groups prepared in Example 14, Example 15 and Example 16, wherein: Fig. 9 Figure a is a SEM image. Fig. 9 b is the magnetization intensity diagram. Fig. 9 It can be seen that the magnetic properties of the Prussian blue magnetic beads prepared by modifying the core of the Prussian blue magnetic beads with streptavidin, antibodies and terpyridine ruthenium do not have a significant effect.

[0145] Test Example 1

[0146] The Prussian blue magnetic beads prepared in Example 1 are used for separation and purification in a BSA (bovine serum albumin) solution system, and the specific steps include:

[0147] 1) First, weigh 100 μL (10 mg / mL) of Prussian blue magnetic beads prepared in Example 1, wash twice with 200 μL of deionized water, and sonicate for 5 min;

[0148] 2) Then, 20 μg of BSA protein was added, and deionized water was added to 200 μL. After the mixture was incubated at room temperature for 30 min, the supernatant was collected by magnetic separation;

[0149] 3) The supernatant was washed twice with 100 μL deionized water, and then eluted with 50 μL glacial acetic acid. After drying, the obtained supernatant and eluate were added with 10 μL LDS protein loading buffer, respectively, and analyzed by polyacrylamide gel electrophoresis. The results are as follows: Fig.10 As shown. Fig.10 It can be seen that the Prussian blue magnetic beads prepared in Example 1 can separate and purify BSA protein.

[0150] Test Example 2

[0151] The Prussian blue magnetic beads prepared in Example 1 were used to separate and purify DNA in a complex Escherichia coli lysate system, and the specific steps included:

[0152] 1) Add 1-2 mL of the collected E. coli culture into a 1.5 mL centrifuge tube and centrifuge at 12000 r / min for 10 min at room temperature, discard the supernatant, and obtain the precipitate;

[0153] 2) Add 900 μL of lysis buffer to the precipitate for homogenization until the precipitate disappears, then transfer to a 1.5 mL centrifuge tube, add 20 μL of proteinase K (500 μg / mL), mix well, incubate in a 65°C constant temperature metal bath for 1 h, then intermittently shake the centrifuge tube several times, centrifuge at 12,000 rpm for 10 min at room temperature, and transfer the supernatant to another centrifuge tube;

[0154] 3) Add 20 μL of Prussian blue magnetic beads (1 mg / mL) to the supernatant obtained in step 2), incubate at 50° C. for 15 min, and then perform magnetic separation, then add 200 μL of ultrapure water to wash twice (washing solution), add 100 μL of eluent to elute twice, incubate at 50° C. for 8 min, dry at room temperature, and add 200 μL of ultrapure water to re-dissolve the precipitate (eluent);

[0155] 4) Add 1 μL of washing solution and elution solution to 1 μL of DNA loading buffer respectively, mix thoroughly, and perform agarose gel electrophoresis analysis. The results are as follows: Fig.11 As shown. Fig.11 It can be seen that the Prussian blue magnetic beads prepared in Example 1 can separate and purify the DNA of Escherichia coli.

[0156] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. Application of Prussian blue in the preparation of magnetic beads.

2. Prussian blue magnetic beads, which contain metal ions and Prussian blue, and the metal ions and the cyanide groups in the Prussian blue are coordinated and arranged with each other.

3. The magnetic bead according to claim 2, characterized in that The metal ions include at least one of aluminum ions, chromium ions, iron ions, magnesium ions, sodium ions, potassium ions, calcium ions, strontium ions, barium ions, thallium ions, copper ions, lead ions, silver ions, gold ions, mercury ions, nickel ions, cobalt ions, zinc ions, cadmium ions, lead ions, platinum ions, palladium ions, rhodium ions, iridium ions, ruthenium ions, osmium ions, molybdenum ions, tungsten ions, manganese ions, titanium ions, hafnium ions, tantalum ions, niobium ions, vanadium ions, chromium ions, rubidium ions, cesium ions, barium ions, lanthanum ions, cerium ions, praseodymium ions, neodymium ions, samarium ions, dysprosium ions, holmium ions, erbium ions, beryllium ions, magnesium ions, scandium ions, bismuth ions, polonium ions, and rhenium ions.

4. The magnetic bead according to claim 2 or 3, characterized in that: Its diameter is 5nm~50μm.

5. The magnetic bead according to any one of claims 2 to 4, characterized in that: It also includes functional modification, which is coated on the surface of the core containing metal ions and Prussian blue; the functional modification includes at least one of chemical modification, biological modification, fluorescent group modification, polymer modification, drug or catalyst modification.

6. The method for preparing the magnetic beads according to any one of claims 2 to 5, comprising: Dissolving a polymerization agent and potassium ferrocyanide in a first solvent to obtain a solution A; Dissolving a metal source and a divalent iron salt in a second solvent to obtain a solution B; The solution A is mixed with the solution B to react, and the reaction product is subjected to ultrasonication, centrifugation, and washing to obtain the magnetic beads according to any one of claims 2 to 4; or include: Dissolving a polymerization agent and potassium ferrocyanide in a first solvent to obtain a solution A; Dissolving a metal source and a divalent iron salt in a second solvent to obtain a solution B; The solution A and the solution B are mixed and reacted, and the reaction product is subjected to ultrasonication, centrifugation, and washing to obtain a magnetic bead core; The magnetic beads according to claim 5 are obtained by immersing the inner core of the magnetic beads into a modifying agent.

7. The method for preparing magnetic beads according to claim 6, characterized in that: The first solvent comprises at least one of water, methanol, ethanol, acetone, ether, sulfur trioxide, ethylamine, aniline, cyclohexane, n-hexanol, n-hexanol, butanol, pentanol, hexanol, and ethylene glycol; The second solvent comprises at least one of water, methanol, ethanol, acetone, ether, sulfur trioxide, ethylamine, aniline, cyclohexane, n-hexanol, n-hexanol, butanol, pentanol, hexanol, and ethylene glycol; The polymerizing agent is selected from at least one of polyacrylamide, polymethyl methacrylate, polystyrene, polymethylstyrene, polyimide, polyethylene terephthalate, polyvinyl pyrrolidone, polyethylene glycol, and polylactic acid; The metal source is selected from a substance capable of providing at least one metal ion selected from aluminum ion, chromium ion, iron ion, magnesium ion, sodium ion, potassium ion, calcium ion, strontium ion, barium ion, thallium ion, copper ion, lead ion, silver ion, gold ion, mercury ion, nickel ion, cobalt ion, zinc ion, cadmium ion, lead ion, platinum ion, palladium ion, rhodium ion, iridium ion, ruthenium ion, osmium ion, molybdenum ion, tungsten ion, manganese ion, titanium ion, hafnium ion, tantalum ion, niobium ion, vanadium ion, chromium ion, rubidium ion, cesium ion, barium ion, lanthanum ion, cerium ion, praseodymium ion, neodymium ion, samarium ion, dysprosium ion, holmium ion, erbium ion, beryllium ion, magnesium ion, scandium ion, bismuth ion, polonium ion, and rhenium ion; The divalent iron salt is selected from at least one of ferrous chloride and ferrous sulfate.

8. Use of the magnetic beads according to any one of claims 2 to 5 or the magnetic beads prepared by the preparation method according to claim 6 or 7 in the preparation of biochemical reagents or carriers.

9. A product, which is any one of the following I) to III): I), a reagent comprising the magnetic beads according to any one of claims 2 to 5 or the magnetic beads prepared by the preparation method according to claim 6 or 7; II), a drug, comprising a drug and a carrier, wherein the carrier is the magnetic beads according to any one of claims 2 to 5 or the magnetic beads prepared by the preparation method according to claim 6 or 7; III), a catalyst, which comprises a reaction catalyst and a carrier, wherein the reaction catalyst is a chemical catalyst or an enzyme; the carrier is the magnetic beads according to any one of claims 2 to 5 or the magnetic beads prepared by the preparation method according to claim 6 or 7.

10. A method, which is any one of the following I) to IV): I), an extraction, sorting or purification method, which comprises enriching the target with the magnetic beads according to any one of claims 2 to 5, the magnetic beads prepared by the preparation method according to claim 6 or 7, or the reagent according to claim 9; II), a detection or analysis method, which comprises enriching the target with the magnetic beads according to any one of claims 2 to 5, the magnetic beads prepared by the preparation method according to claim 6 or 7, or the reagent according to claim 9, and then performing qualitative or quantitative detection; III), an imaging or signal reporting method, which comprises labeling a sample with the magnetic beads according to any one of claims 2 to 5, the magnetic beads prepared by the preparation method according to claim 6 or 7, or the reagent according to claim 9, and detecting the signal generated by the magnetic beads; IV) A reaction method, which comprises promoting the reaction with the catalyst according to claim 9.

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