▎ 摘　　要

The combination of graphene oxide with gold nanoparticles offers enhanced optical properties with strong surface plasmon resonance, good biocompatibility, improved stability and ultrasensitive detection. This study aims to synthesize ecofriendly graphene oxide gold nanocomposites for sensing of ferritin biomarker, which is vital for diagnosing anemia as well as severe COVID conditions. Herein, an affordable and label free technique was proposed for detection of ferritin. The graphene oxide gold nanocomposites are synthesized by a simple one pot chemical reaction utilizing natural reducing agents. The alterations in the optical spectral characteristics of graphene gold nanocomposites upon interaction with the Fe3+ ions as well as ferritin protein are investigated. The proposed label free technique achieved a limit of detection of 1 mu M for Fe3+ ions and 1 mu g/ml for Ferritin protein.