Direct electrochemical reduction of hematite decorated graphene oxide (alpha-Fe2O3@erGO) nanocomposite for selective detection of Parkinson's disease biomarker

An unusual approach is reported herein to fabricate magnetic hematite (alpha-Fe2O3) decorated electrochemically reduced graphene oxide (alpha-Fe2O3@erGO) nanocomposite. The method utilizes direct electrochemical reduction of self-assembled, ex-situ synthesized alpha-Fe2O3 anchored GO to erGO (alpha-Fe2O3@erGO) on glassy carbon electrode (GCE) for selective detection dopamine (DA), an important biomarker of Parkinson's disease. The formation of alpha-Fe2O3@erGO/GCE has been confirmed by XPS and Raman spectroscopy. alpha-Fe2O3@erGO modified GCE exhibits synergistic catalytic activity nearly 2.2 and 5 fold higher than alpha-Fe2O3@GO and other modified electrodes, respectively towards oxidation of DA. The fabricated sensor exhibited linear dynamic ranges over 0.25 - 100 mu M in response to DA with a LOD of 0.024 mu M (S/N = 3), LOQ of 0.08 mu M (S/N = 10), and a sensitivity of 12.56 mu A mu M-1 cm(-2). Finally, the practical analytical application of the proposed alpha-Fe2O3@erGO/GCE was investigated for the determination of DA in commercially available pharmaceutical formulation and human serum samples, and showed satisfactory recovery results towards DA.