Magnetic, optical and photothermal properties of Fe3O4 and CoFe2O4 nanoparticles coated with organic materials

Abstract

Nanoparticles represent a class of highly adaptable nanostructures with a remarkable surface-to-volume ratio, allowing for the precise tuning of their shape to influence their properties. Moreover, their surfaces can be functionalized with organic or inorganic materials, thereby tailoring their performance and introducing specific functionalities. Iron oxide nanoparticles including Fe3O4 and spinel Co ferrites emerge as promising candidates for medical applications due to their notable biocompatibility and appropriate magnetic properties. Their potential in cancer therapy primarily hinges on localized cancer cell heating, which can be remotely triggered by an external AC magnetic field (magnetic hyperthermia). Additional heating induced by light excitation can reduce the required particle dosages during such treatments. The optical characteristics of iron oxide nanoparticles within the wavelength range of biological transparency open up exciting prospects for utilizing these structures in adjuvant thermal therapies. In this study, we demonstrate the results of synthesis and study of magnetic and optical properties of iron oxide nanoparticles coated with organic materials. Notably, CoFe2O4 nanoparticles coated with dihydrocaffeic acid demonstrated the coefficient of heat efficiency conversion close to 100 % under 810 nm laser excitation. They also demonstrated the magnetization curves characterized by minimal hysteresis and remanent magnetization typical of superparamagnetic behavior of iron oxide nanoparticles. This suggests their potential for combined magnetic and optical hyperthermia.