Biocompatible magnetic nanocrystal, powder of a biocompatible magnetic nanocrystal bearing a surface reactive group and preparations thereof

摘要

This invention is concerned with biocompatible magnetic nanocrystals highly soluble and dispersible in a physiological buffer, powder of biocompatible magnetic nanocrystals and nanocrystals bearing surface reactive N-hydroxysuccinimide ester moiety, and preparations thereof. The magnetic nanocrystals in powder form are highly soluble in a physiological buffer. The resultant aqueous colloidal solution presents long term stability in ambient conditions. Moreover, the carboxyl group on the surface of the magnetic nanocrystals can be converted to N-hydroxysuccinimide ester moiety in an organic solvent. The resultant powder of the magnetic nanocrystals carrying surface N-hydroxysuccinimide ester moiety is soluble and dispersible in an aqueous solution. Different types of biomolecules bearing amino group can covalently be attached to the magnetic nanocrystal simply by mixing them in aqueous solutions. Moreover, the powder of the magnetic nanocrystals bearing surface N-hydroxysuccinimide ester moiety retain reaction activity with biomolecule after long-term storage.