Abstract: In this work, we prepared graphene-based nanocomposite material by electrochemically depositing Prussian blue (PB) nanoparticles on the surface of graphene. Differential pulse voltammetry (DPV) was used to characterize the electrode and study the electrochemical behavior of nitrite ion on the modified electrode, and the electrode was used to detect nitrite in soy sauce. The results showed that the Prussian blue/graphene modified electrode had a good electrocatalytic activity to nitrite ion in 0.10 mol/L PBS buffer solution (pH 7.0). In the concentration range of 1 × 10-6-1 × 10-2 mol/L, the method presented a linear relationship. The limit of detection (LOD) was 3 × 10-8 mol/L at a signal-to-noise ratio of 3. The Prussian blue/graphene modified electrode showed a good stability, reproducibility and anti-interference ability.

Key words: graphene, Prussian blue, nitrite, differential pulse voltammetry, modified electrode