Fig. 2
a Morphology of the three types of magnetic nanoparticles observed by TEM and EDS's elemental mapping results. b Elemental content analysis of each magnetic nanoparticle by EDS. B-1, 2, and 3 indicate MNP1, MNP2, and MNP3, respectively. The Si thin film was modified on the surface of the synthesized MNPs. An amino group was added to the surface of the SI thin film using APTES, and 2-amino benzamide (2-AB) and Ni(OAc)2 were reacted stepwise. Ni was chemically modified on the MNP surface prepared under each condition