Magnetic hyperthermia behaviour of Co and reduced GO nanocomposites

Co‐precipitation of CoCl 2 . 6H 2 O with graphene oxide (GO) and heating at 400°C for 4 h under hydrogen resulted in the construction of cobalt/reduced GO (Co/rGO) nanocomposite utilisable in magnetic thermal therapy. Field emission scanning electron microscopy, transmission electron microscopy, X‐ray photoelectron spectroscopy, vibrating sample magnetometry, thermogravimetric analysis/derivative thermogravimetry, and X‐ray diffraction methods characterised the samples. Time–temperature curves of the samples containing 30, 50, 70, and 100 µg ml −1 Co/rGO nanoparticles (NPs) suspended in phosphate‐buffered saline were determined at different specific heating rates. Magnetic‐field response of Co/rGO nanocomposites was better than CoNPs and GO. The biological behaviour of the powders was investigated by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay. Co/rGO nanocomposites showed an acceptable biocompatibility behaviour, whereas the CoNPs demonstrated toxic conduct.