Fast synthesis of dopamine-coated Fe3O4 nanoparticles through ligand-exchange method

A fast approach was described for the synthesis of water-dispersible monodisperse dopamine-coated Fe3O4 nanoparticles (DA-Fe3O4) with uniform size and shape via ligand-exchange of oleic acid on Fe3O4 using only 2 min. The prepared DA-Fe3O4 nanoparticles were characterized by transmission electron microscopy, Fourier transform infrared spectrometry, and vibrating sample magnetometer. The results indicated that the resulting DA-Fe3O4 nanoparticles had an average diameter of about 19.2 nm. The magnetic saturation value of the prepared DA-Fe3O4 nanoparticles was determined to be 72.87 emu/g, which indicating a well-established superparamagnetic property.