Magnetic bead, preparation method thereof and application of magnetic bead in extracellular vesicle extraction

The invention provides a magnetic bead, a preparation method of the magnetic bead and application of the magnetic bead in extracellular vesicle extraction. The defects that an existing extracellular vesicle separation method is high in cost, tedious in step, long in consumed time, low in yield and low in purity are overcome. The micro-nano magnetic bead is a magnetic graphene oxide nano material combined with polyethylene glycol PEG and can adsorb extracellular vesicles in a sample, the extracellular vesicles can be precipitated and separated in the sample through PEG, the added material can be rapidly separated from the extracellular vesicles through magnetic separation after the magnetic bead is combined, and under the action of an external magnetic field, the extracellular vesicles can be rapidly separated from the extracellular vesicles. The directional movement of a compound of the magnetic beads and the extracellular vesicles can be induced, the extracellular vesicles are separated from a sample, and me