Preparation and characterization of novel spin labeled magnetic nanoparticles

Novel spin-labeled magnetic nanoparticles (MNPs) were prepared through the reaction between carboxylic acids modified Fe3O4 particles and 4-amino-2,2,6,6-tetramethylpiperidin-1-oxyl (4-NH2-TEMPO). And X-ray diffractometer (XRD), FT-IR spectra, thermogravimetric analysis (TGA), transmission electronic microscopy (TEM) and room temperature electron paramagnetic resonance (EPR) were employed to characterize the prepared materials. The results of EPR measurements indicated that the spin-labeled MNPs exhibited both the paramagnetism of nitroxide free radicals and superparamagnetism of ferrimagnetic nanoparticles could act as a bio-probe or potential drug delivery vehicles tracking by EPR technique.