Super-low field nano magnetic probe, manufacturing method thereof and applications

The invention belongs to the nano biological technology field and particularly relates to a super-low field nano magnetic probe, a manufacturing method thereof and applications. The super-low field nano magnetic probe is a magnetic nano particle modified by a surface hydrophilic ligand; the magnetic nano particle is a ferrite magnetic nano particle or a doped ferrite magnetic nano particle, and a doping agent of the doped ferrite magnetic nano particle is at least one of zinc, cobalt and manganese; the hydrophilic ligand is 3,4-dihydroxyphenylpropionic acid, 2,3-dimercaptosuccinic acid and PEG modified by double carboxyls; at least one application of the super-low field nano magnetic probe described as 1)-3) further belongs to a protection scope of the invention, 1), cell magnetic imaging; 2), bacteria detection; and 3), preparing magnetic immunization kits on the basis of optics atom magnetic instruments. The super-low field nano magnetic probe is advantaged in that the super-low field nano magnetic probe is