Electrochemical Determination of Nitrite Using a Reduced Graphene Oxide–Multiwalled Carbon Nanotube-Modified Glassy Carbon Electrode

Graphene oxide nanosheets were encapsulated with multiwalled carbon nanotubes by direct reduction on glassy carbon to obtain a reduced graphene oxide/multiwalled carbon nanotube-modified electrode. The encapsulated multiwalled carbon nanotubes facilitated the reduction of graphene oxide with characterization by atomic force microscopy, scanning electron microscopy, and Raman spectroscopy. The reduced graphene oxide-multiwalled carbon nanotube-modified electrode exhibited high catalytic activity for the oxidation of nitrite. Under the optimized conditions, the modified electrode had a linear dynamic range from 0.2 to 640 mu M with a detection limit of 0.07 mu M. This device was used to determine nitrite in water samples and satisfactory results were obtained.