A Highly Sensitive and Stable Dopamine Sensor Using Shuttle-Like α-Fe₂O₃ Nanoparticles/Electro-Reduced Graphene Oxide Composites

Abstract

The development of sensitive and stable electrochemical sensors toward dopamine is highly desirable. Herein, a novel voltammetric sensor was developed for the detection of dopamine using shuttle-like α-Fe2O3 nanoparticles/electro-reduced graphene oxide nanocomposites (S-Fe2O3/ErGO). The surface morphology, microstructure, and chemical composition of S-Fe2O3/ErGO nanocomposites were investigated by SEM, XRD and Raman spectra, respectively. The electrochemical behavior of Fe2O3/ErGO nanocomposite modified glass carbon electrode (S-Fe2O3/ErGO/GCE) was studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and the results show that S-Fe2O3/ErGO nanocomposites have large electrochemical active area and low charge transfer resistance. The anodic peak current of S-Fe2O3/ErGO/GCE increases 1-fold and 37-fold compared to that of ErGO/GCE and S-Fe2O3/GCE, respectively, suggesting the remarkably synergistic enhancement effect on the electrooxidation of dopamine. The anodic peak current is proportional to the concentration of dopamine over the range of 0.01 μM–2 μM. However, the logarithm of anodic peak current versus logarithm of dopamine concentration is linearly related in the range of 2 μM–80 μM. The detection limit (3σ/s) and sensitivity are estimated to be 1.15 nM and 95.57 μA μM−1 cm−1, respectively. Moreover, S-Fe2O3/ErGO/GCE also showed good anti-interference, reproducibility and stability. Finally, the proposed S-Fe2O3/ErGO/GCE was successfully employed to determinate dopamine in the human serum samples with satisfactory results.