Functionalized Graphene-Molybdenum Disulfide-based Electrochemical Sensor for Detection of Nitrite

An electrochemical sensor for detection of nitrite using a polyethylenimine functionalized graphene- molybdenum disulfide nanocomposite material modified glassy carbon electrode (PEI-rGO-MoS2/GCE) was reported. The characteristics of PEI-rGO-MoS2 nanocomposite were studied by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy. The electrochemical behavior of PEI-rGO-MoS2 nanocomposite modified electrode was investigated by cyclic voltammetry, linear voltammetry, differential pulse voltammetry and chronoamperometry, and it was found that the synergistic effect between PEI, rGO and MoS2 enhanced the electrocatalytic activity towards oxidation of nitrite. Under the optimal experimental conditions, the prepared PEI-rGO-MoS2/GCE exhibited low detection limit (0.7 mu mol/L) and wide linear range (1-20 mu mol/L and 35-1000 mu mol/L) for nitrite, with good selectivity and stability. Furthermore, the practicability of the prepared sensor was confirmed by detection of nitrite in the actual tape water and soda water samples. The recoveries were 98.0%-110.6%, and the relative standard deviation was 0.8%-2.2%, proving application potential of this sensor.