Electrochemical preparation and characterization of chitosan-coated superparamagnetic iron oxide (Fe3O4) nanoparticles

Abstract

ABSTRACTIn this work, a novel and one-step synthesis protocol is proposed to prepare naked and chitosan (CS) coated magnetite nanoparticles (MNPs). Well-defined Fe3O4 nanoparticles were prepared through cathodic electrochemical deposition (CED) under the mild conditions. The crystalline and completely spherical nanoparticles of naked Fe3O4 with uniform size of 8nm were electrodeposited from mixed iron chloride/nitrate aqueous solution by applying current density of 10 mA cm–2 for 30 min. The uniform chitosan coated MNPs with size of 10 nm were also prepared from 0.005M [FeCl2+Fe(NO3)3] + 1 g/L chitosan aqueous solution with only applying 10 mA cm–2 for 30 min. The prepared naked and chitosan coated MNPs were characterized through XRD, IR, FE-SEM, TEM,DSC-TGA, DLS and VSM techniques. The chitosan layer of the surface of MNPs was confirmed by FT-IR, DLS and DSC-TG analyses. The magnetic analysis via VSM revealed that both synthesized NPs exhibit excellent superparamagnetic behavior and can be used for a wide range of biomedical applications. The CS coated MNPs have negligible remnant magnetization (Mr = 0.26 emu g–1) and coercivity (Ce = 0.5 Oe) as compared with those of naked NPs (Mr≈0.75 emu g–1 and Ce≈2.3 Oe). In final, the possible mechanism of the Fe3O4 deposition on cathode surface was proposed and discussed in details. Bas on the obtained results, the CED strategy is introduced as an easy, fast and efficient preparation route of uniform MNPs with proper phase, size and magnetic characters for biomedical applications.