Electrochemical sensor based on a three dimensional nanostructured MoS 2 nanosphere-PANI/reduced graphene oxide composite for simultaneous detection of ascorbic acid, dopamine, and uric acid.

A three dimensional (3D) nanostructured composite based on the self-assembly of MoS 2 nanospheres and polyaniline (PANI) loaded on reduced graphene oxide (denoted by 3D MoS 2 -PANI/rGO) was prepared via a feasible one-pot hydrothermal process. The 3D MoS 2 -PANI/rGO nanocomposite not only exhibits good functionality and bioaffinity but also displays high electrochemical catalytic activity. As such, the developed 3D MoS 2 -PANI/rGO nanocomposite can be employed as the sensing platform for simultaneously detecting small biomolecules, i.e. , ascorbic acid (AA), dopamine (DA), and uric acid (UA). The peak currents obtained from the differential pulse voltammetry (DPV) measurements depended linearly on the concentrations in the wide range from 50 μM to 8.0 mM, 5.0 to 500 μM, and 1.0 to 500 μM, giving low detection limits of 22.20, 0.70, and 0.36 μM for AA, DA, and UA, respectively. Furthermore, the 3D MoS 2 -PANI/rGO-based electrochemical sensor also exhibited high selectivity, good reproducibility and stability toward small molecule detection. The present sensing strategy based on 3D MoS 2 -PANI/rGO suggests a good reliability in the trace determination of electroactive biomolecules.