Electron paramagnetic resonance as an effective method for a characterization of functionalized iron oxide

• The surface of magnetic iron(II,III) oxide nanoparticles was functionalized.
• EPR measurements confirm the presence of magnetic core and TEMPO nitroxide radical.
• TEMPO-labeled magnetic nanoparticles allow the monitoring of Amoxicillin transport.

Iron(II, III) oxide magnetic nanoparticles (NPs) have been coated with (3-Chloropropyl) trimethoxysilane and subsequently functionalized with 4-Amino-2,2,6,6-tetramethylpiperidine-N-oxyl and Amoxicillin. Finally, the functionalized iron oxide NPs have been coated with natural polymer, chitosan, in order to prevent NPs agglomeration in aqueous environment. The product was characterized by Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM). It was studied by the electron paramagnetic resonance method and the parameters describing the magnetic properties of the investigated nanoparticles, such as g-factor and line width, were calculated.