Synthesis of a manganese dioxide nanorod-anchored graphene oxide composite for highly sensitive electrochemical sensing of dopamine

Abstract

In this research, a novel manganese dioxide nanorod-anchored graphene oxide (MnO₂ NRs/GO) composite was synthesized by a simple hydrothermal method for electrochemical sensing application. A highly sensitive electrochemical sensor for dopamine (DA) was constructed by modifying glassy carbon electrode (GCE) with MnO₂ NRs/GO. The morphology and performance of the composite material and modified GCEs were investigated by using scanning electron microscopy (SEM), X-ray diffraction (XRD) and cyclic voltammetry (CV), respectively. The resultant MnO₂ NRs/GO composite has a large electroactive area and shows excellent electrochemical activity toward DA. Under the optimal conditions, the DA sensor shows a linear response in the DA concentration ranges of 0.1 μM–0.08 mM and 0.08–0.41 mM with a low detection limit of 0.027 μM and a high sensitivity of 602.4 μA·mM⁻¹·cm⁻². The MnO₂ NRs/GO composite provides a promising platform for the construction of a highly sensitive and selective sensor of DA.