The present invention discloses biocompatible, stable curcumin or its derivatives coated ultra-small super paramagnetic iron oxide nanoparticles (USPION) for biomedical applications. Disclosed herein is also a simple one-pot process for the synthesis of biocompatible, stable curcumin or its derivatives coated ultra-small superparamagnetic iron oxide nanoparticles in absence of a linker or binder. The curcumin or its derivatives coated ultra-small super paramagnetic iron oxide nanoparticles of the present invention retains the medicinal, radical scavenging and fluorescence properties of curcumin.