A sensitive method to determine dopamine in the presence of uric acid based on In2O3 nanosheet arrays grown on 3D graphene

A nonenzymatic voltammetric assay for dopamine (DA) was developed based on the combination of three-dimensional graphene (3D Gr) and indium oxide nanosheet arrays (In2O3 NSAs). 3D Gr was prepared by chemical vapor deposition (CVD), and In2O3 NSAs were grown on its surface by hydrothermal synthesis. The results show that 3D Gr maintains a good porous structure (200 μm), and the pore size of In2O3 NSAs is 0.50 μm. Differential pulse voltammetry (DPV) is mainly used to determine the electrochemical properties of In2O3 NSAs/3D Gr. It possesses a sensitivity of 2.69 μA·μM−1·cm−2 towards DA (5–60 μM) at 0.14 V, and the detection limit (LOD) is 0.10 μM (S/N = 3). The recoveries obtained for spiked samples in the real sample detection is 105 (± 8)%.