Fabrication of core-shell structured Fe3O4@Au nanoparticle via self-assembly method based on positively charged surface silylation/polymerization

This paper describes findings of an investigation of synthesis and assembly of core (Fe₃O₄)-shell (Au) nanoparticles via self-assembly method depending on the electrostatic cross-linking structure of the counterpart material. Positively charged surface modification for electrostatic cross-linking underwent an amination process through silylation/polymerization of silane or polymer precursor which were (3-Aminopropyl)triethoxysilane (APTES), polyethyleneimine (PEI), respectively. The surface modification process for the interfacial reactivity was accompanied by a phenomenological identification and analysis of its physicochemical properties and elucidation of suitable conditions. The density of the shell (Au) was changed according to the difference of relative intensity of surface positive charge and the structural difference of the cross-linker. The results indicated that the formation of Au shell is affected not only by the electrostatic properties from strong positive zeta-potential, but also the terminal surface functional group as a binding site.