Facile electrosynthesis and characterization of superparamagnetic nanoparticles coated with cysteine, glycine and glutamine

Abstract

A novel and facile strategy has been developed for the preparation of cysteine-, glycine- and glutamine-coated magnetite nanoparticles (MNPs). According to this strategy, Fe₃O₄ nanoparticles were electrodeposited from an aqueous electrolyte containing a dissolved iron salt and amino acids. A simple deposition mode i.e., constant current and two-electrode set-up was used in the electrosynthesis procedure. The magnetite phase of the deposited nanoparticles was confirmed through XRD and FT-IR analyses. Morphological observations through FE-SEM and TEM confirmed the formation of spherical MNP particles with an average size of 10 nm. The formation of cysteine, glycine and glutamine layers on the surface of the electro-synthesized particles was proved based on FT-IR, DLS and TG data. Vibrating sample magnetometery (VSM) measurements confirmed the prepared iron oxide nanoparticles to have a super-paramagnetic nature, since they exhibit a high saturation magnetization (Ms ≈ 58 emu g⁻¹), as well as, negligible remnant magnetization (Mr) and coercivity (Ce). Based on the obtained results, the proposed platform can be considered as a fast, simple and efficient method for the preparation of surface-coated magnetite nanoparticles.