A Novel Modified Electrode for Detection of the Food Colorant Sunset Yellow Based on Nanohybrid of MnO2 Nanorods-Decorated Electrochemically Reduced Graphene Oxide

The nanohybrid of electrochemically-reduced graphene oxide (ERGO) nanosheets decorated with MnO₂ nanorods (MnO₂ NRs) was modified on the surface of a glassy carbon electrode (GCE). Controlled potential reduction was applied for the reduction of graphene oxide (GO). The characterization was performed by scanning electron microscopy, X-ray diffraction and cyclic voltammetry. Compared with the poor electrochemical response at bare GCE, a well-defined oxidation peak of sunset yellow (SY) was observed at the MnO₂ NRs-ERGO/GCE, which was attributed to the high accumulation efficiency as well as considerable electrocatalytic activity of ERGO and MnO₂ NRs on the electrode surface. The experimental parameters for SY detection were optimized in detail. Under the optimized experiment conditions, the MnO₂ NRs-ERGO/GCE showed good linear response to SY in concentration range of 0.01⁻2.0 μM, 2.0⁻10.0 μM and 10.0⁻100.0 μM with a detection limit of 2.0 nM. This developed method was applied for SY detection in soft drinks with satisfied detected results.