Stability of Fe3N nanoparticles as possible candidates for biomedical applications

Abstract

Superparamagnetic iron oxide nanoparticles (SPIONs) have been the material of choice for the biomedical industry as well as scientific community due to their extreme stability, well-known metabolism of iron in the human body, acceptable magnetic properties, easiness, low cost and scalability of production^[1]. However, recently alternative iron-based^[2] materials with enhanced magnetic properties have been considered for improved performance in biomedical applications.

In this work, we study iron nitride Fe₃N nanoparticles, as alternative candidates in biomagnetic applications due to their larger saturation magnetization values(M_s (Fe₃N) = 128 Am²/kg vs M_s (Fe₃O₄) = 61 Am²/kg). Calorimetry results demonstrate significantly enhanced magnetic fluid hyperthermia heating performance compared to iron oxides as shown in Fig. 1.

Crucial question for further development of Fe₃N particles is stability in biological environment. The as-synthesized spherical Fe₃N nanoparticles (13.5 nm) demonstrate very good stability of magnetic properties in water (Fig 2.). Transmission electron microscopy studies show that the reason for this is formation of a thin oxide layer that protects particles from further oxidation.