MnFe2O4 nano-flower: A prospective material for bimodal hyperthermia

Magnetic nanoparticles (MNPs) have emerged as efficient materials for thermo-therapeutic modalities viz. magnetic fluid hyperthermia (MFH) and photo-thermal therapy (PTT). Nevertheless, the quest to further enhance the effectiveness of such materials is a major challenge to their successful endeavour. In the present work, we have synthesised MnFe2O4 nano-flowers utilising solvo-thermal method to be employed as nano-heat generators during MFH and PTT. The material, in addition to effective heating under an alternating magnetic field (AMF), demonstrated impressive heating ability under near infra-red (NIR) irradiation. Various techniques, such as, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photo-electron spectroscopy (XPS) and Mössbauer spectroscopy were used to study the structural features and chemical composition of the sample. The photoluminescence spectroscopy (PLS) has further corroborated the efficient heating behaviour of the sample under NIR irradiation. The observed intrinsic loss power value of 5.31 ± 0.079 nH m2 kg−1 is significantly higher than the commercially available ferro-fluids and comparable to previously reported values for iron oxide nano-flowers. A substantial SiHa cells death during photo-thermal treatment was noticed at a concentration of 500 μg/mL of MnFe2O4 nano-flowers after exposure to 808 nm laser of 0.66 W cm-2 power density for only 10 min. However, at the same concentration of nanoflowers (i.e. 500 μg/mL) and exposure time (i.e. 10 min) during MHT with SiHa cells, a significant decrease in cell viability was not observed.