Highly efficient electrocatalytic oxidation of nitrite by electrodeposition of Au nanoparticles on molybdenum sulfide and multi-walled carbon nanotubes

A molybdenum sulfide/multi-walled carbon nanotubes/gold nanocomposite (MoS2-MWCNTs-Au) modified glassy carbon electrode (GCE) was developed via a hydrothermal synthesis followed by an electrochemical deposition of gold nanopartides onto the surface of GCE. Scanning electron microscopy (SEM) and transmission electron microscope (TEM) images indicated the MoS2 worked as the substrate for MWCNTs and the gold nanoparticles were grown on the MoS2-MWCNTs. Cyclic voltammetry (CV) results showed the MoS2-MWCNTs-Au modified GCE exhibited the best electrochemical activity in a 0.1 M phosphate buffered saline (PBS) compared to the MoS2 and MoS2-MWCNTs modified GCE. Both CV and differential pulse voltammetry (DPV) results indicated the MoS2-MWCNTs-Au had excellent electrocatalytic ability to oxide nitrite in a pH 5.0 PBS. Quantitative analysis of nitrite was carried out using amperometric i-t method. The amperometric response displayed the MoS2-MWCNTs-Au modified GCE could be used to determine nitrite concentration in a wide linear range of 12 and 6500 mu M with a detection limit of 4.0 mu M. The proposed sensor also showed good anti-interference and real sample analysis properties. (C) 2017 Elsevier B.V. All rights reserved.