a magnetic particle and fabrication method thereof . the magnetic particle comprises a polymer core , a magnetic material layer covering the polymer core , and a silicon containing layer covering the magnetic material layer . in addition , the magnetic particle may further comprise a coupling agent on the silicon containing layer , and an active molecule connected to the coupling agent . the magnetic particles provide controllable size , uniform diameter distribution , high magnetization , improved storage stability , and modified surface for targeting biomolecules for biomaterial separation and environmental analysis .