Novel electrochemical sensing platform based on molybdenum disulfide nanosheets-polyaniline composites and Au nanoparticles

Two-dimensional (2D) transition metal dichalcogenide nanosheets offer unique electronic properties and attract increasing attention in electrochemical sensing. In this paper, graphene-like MoS2–polyaniline (PANI) composites were synthesized by a facile hydrothermal method and a simple in situ polymerization procedure. MoS2 served as a 2D conductive skeleton that supported a highly electrolytic accessible surface area of redox-active PANI and provided a direct path for electrons. A novel electrochemical sensor was subsequently developed for the determination of dopamine based on MoS2-PANI composites and gold nanoparticles (AuNPs) modified glassy carbon electrode (AuNPs/MoS2–PANI/GCE). The AuNPs/MoS2–PANI/GCE showed an enhanced electrocatalytic activity toward the oxidation of dopamine when compared with bare electrode and other modified electrode. It exhibited a good electrocatalytic oxidation toward dopamine in the linear response range from 1 to 500 μM with the detection limit of 0.1 μM (S/N = 3). The developed electrochemical sensor was successfully applied to the dopamine detection in human urine sample, which proved that it was a versatile sensing tool for the detection of DA in real samples. This work indicated that MoS2–PANI composites were promising in electrochemical sensing and catalytic applications.