Constructions of polyaniline nanofiber-based electrochemical sensor for specific detection of nitrite and sensitive monitoring of ascorbic acid scavenging nitrite

A novel polyaniline nanofiber (PANI-NF)-based electrochemical sensor was constructed for specific detection of nitrite and sensitive monitoring of ascorbic acid scavenging nitrite. The electrochemical behaviors of PANI-NF were studied by cyclic voltammetry and amperometry in the presence of nitrite. Results showed that nitrite reduction was enhanced by the nanostructure of PANI-NF film. Under low potential difference and acid medium, PANI-NF catalyzed the conversion of nitrite ion to nitric oxide, and then realized the reduction of nitrite ion. Under optimal experimental conditions, PANI-NF-based sensor demonstrated a fast response time of 5 s and a detection limit of 0.05 μM nitrite (signal-to-noise ratio, S/N = 3), a linear range from 0.2 μM to 35 mM. This electrochemical sensor has been successfully applied to sensitively monitor ascorbic acid scavenging nitrite, and it has the potential of being used in nitrite detection.