Ultrasensitive detection of dopamine via electrochemical route on spindle-like -Fe₂O₃ Mesocrystals/rGO modified GCE

In this study, spindle-like alpha-Fe2O3 mesocrystals/reduced-graphene-oxide composites modified glassy carbon electrode (alpha-Fe2O3/rGO/GCE) is developed for ultrasensitive electrochemical detection of DA. Morphologies and crystal structures of this composite are characterized by SEM, TEM, XRD, Raman spectrum, and XPS, respectively. The electrochemical behavior of DA on these electrodes are investigated by CV and EIS. The electrochemical conditions are optimized systematically. As results, the oxidation current of DA on alpha-Fe2O3/rGO/GCE is 38.13-fold increase than that on bare GCE. It is ascribed to the high catalytic activity of alpha-Fe2O3 mesocrystals and large electrochemical active area of rGO. Under the best voltammetric condition, wide linear detection range (from 1.0x10(-8) to 9.0x10(-4) mol/L) and low LOD of 3.26 nM (S/N=3) are obtained on the alpha-Fe2O3/rGO/GCE. Furthermore, this electrode is also used for DA detection in real human serums samples successfully. This alpha-Fe2O3/rGO/GCE provides a good example in design of other mesocrystals-based composite materials for electrochemical detection.