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

An unusual approach is reported herein to fabricate magnetic hematite (α-Fe2O3) decorated electrochemically reduced graphene oxide (α-Fe2O3@erGO) nanocomposite. The method utilizes direct electrochemical reduction of self-assembled, ex-situ synthesized α-Fe2O3 anchored GO to erGO (α-Fe2O3@erGO) on glassy carbon electrode (GCE) for selective detection of dopamine (DA), an important biomarker of Parkinson's disease. The formation of α-Fe2O3@erGO/GCE has been confirmed by XPS and Raman spectroscopy. α-Fe2O3@erGO modified GCE exhibits synergistic catalytic activity nearly 2.2 and 5 fold higher than α-Fe2O3@GO and other modified electrodes, respectively towards oxidation of DA. The fabricated sensor exhibited linear dynamic ranges over 0.25 − 100 µM in response to DA with a LOD of 0.024 µM (S/N = 3), LOQ of 0.08 µM (S/N = 10), and a sensitivity of 12.56 µA µM–1 cm–2. Finally, the practical analytical application of the proposed α-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. •An unusual approach is reported for fabrication of α-Fe2O3@erGO nanocomposite.•α-Fe2O3@erGO modified sensor is fabricated by direct electrochemical reduction method.•α-Fe2O3@erGO/GCE is found highly sensitive and selective for the detection of dopamine.•The modified sensor shows LOD value of 24.70 nM towards dopamine.