Superparamagnetic nano-particles, magnetic beads and preparation method and application of superparamagnetic nano-particles and magnetic beads

The invention relates to the field of biological nano-materials, in particular to superparamagnetic nano-particles, magnetic beads and a preparation method and application of the superparamagnetic nano-particles and the magnetic beads. The invention provides superparamagnetic nanoparticles. The superparamagnetic nanoparticles are prepared from ferric chloride, trisodium citrate, urea, polyacrylamide and sodium polyacrylate. The mass ratio of the ferric chloride to the trisodium citrate is 1: (1.8-2); the mass ratio of the ferric chloride to the urea is 1: (0.9-1.0); the mass ratio of the ferric chloride to the polyacrylamide is 1: (0.2-0.25); the mass ratio of the ferric chloride to the sodium polyacrylate is 1: (0.05-0.1). The monodisperse superparamagnetic raspberry-shaped hydroxyl magnetic bead prepared by the invention has the advantages of large surface area, strong magnetic response and excellent nucleic acid extraction performance. The method is simple and convenient to operate, and a new scheme is pro