▎ 摘　　要

Water soluble and biocompatible similar to 18 nm manganese-doped ferrite (MnxFe1-x)Fe2O4 decorated ultrasmall graphene oxide (GO) nanocomposites were synthesized. Ultrasmall nanocomposites were fabricated with a hydrodynamic size of 50.6 +/- 0.3 nm, approximately similar to 80 nm lateral dimension and similar to 20 nm thickness (from AFM analysis), indicating a sheet-like structure with only a few nanoparticles attached. The concentration-dependent magnetic hyperthermic response of such nanocomposites under an alternating magnetic field (AMF) and very dilute conditions (<0.3 mg ml(-1)) was also investigated. The field-dependent specific absorption rate (SAR) values of the nanocomposites were found to have increased by approximately two-fold when their concentration was reduced by a factor of 3. Such nanocomposites also exhibited excellent colloidal stability as well as suitable biocompatibility (up to 2 mM iron concentration) with NIH/3T3 fibroblast cells.