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

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.