A promising sensing platform toward dopamine using MnO2 nanowires/electro-reduced graphene oxide composites

A promising sensing platform for the ultrasensitive detection of dopamine (DA) has been constructed using MnO2 nanowires-electrochemically reduced graphene oxide modified glassy carbon electrode (MnO2 NWs-ErGO/GCE). The proposed MnO2 NWs-ErGO/GCEs had the large electrochemical active area and relative low charge transfer resistant (R-ct). As a result, the response peak current of the MnO2 NWs-ErGO is about 13 times higher than that of the bare GCE, demonstrating the remarkable electrocatalytic activity toward DA. The electrochemical kinetics revealed that DA oxidation is quasi-reversible reaction coupling with one electron and two protons. Three linear ranges (0.01 mu M - 0.10 mu M, 0.10 mu M - 1.0 mu M, and 1.0 mu M - 80 mu M) were obtained on the MnO2 NWs-ErGO/GCE, with a low detection limit of 1.0 nM (S/N = 3). Moreover, the response current was almost unaltered even in the presence of 100-fold ascorbic acid (AA) and uric acid (UA), suggesting MnO2 NWs-ErGO has good selectivity toward DA. Finally, the MnO2 NWs-ErGO/GCEs were successfully applied to detect DA in the injection solutions and human blood serum samples with high accuracy and good recovery. (C) 2018 Elsevier Ltd. All rights reserved.