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

In this study, spindle-like α-Fe 2 O 3 mesocrystals/reduced-graphene-oxide composites modified glassy carbon electrode (α-Fe 2 O 3 /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 α-Fe 2 O 3 /rGO/GCE is 38.13-fold increase than that on bare GCE. It is ascribed to the high catalytic activity of α-Fe 2 O 3 mesocrystals and large electrochemical active area of rGO. Under the best voltammetric condition, wide linear detection range (from 1.0×10 −8 to 9.0×10 -4 mol/L) and low LOD of 3.26 nM (S/N=3) are obtained on the α-Fe 2 O 3 /rGO/GCE. Furthermore, this electrode is also used for DA detection in real human serums samples successfully. This α-Fe 2 O 3 /rGO/GCE provides a good example in design of other mesocrystals-based composite materials for electrochemical detection.