A novel nitrite sensor based on poly-1-naphthylamine doped by a ferrocenesulfonic-acid-modified electrode

A novel sensor for detecting nitrite based on poly-1-naphthylamine doped by a ferrocenesulfonic acid (PNAFc) modified electrode has been proposed. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) have confirmed that ferrocene-sulfonic acid (Fc) can be doped in poly-1-naphthylamine (PNA) and enhances its electrochemical activity. In a nitrite solution, the PNAFc electrode shows an excellent electrocatalytic activity for the oxidation of nitrite. Based on differential pulse voltammetry (DPV), the response was evaluated with respect to pH, scan rate, temperature, and other variables. The optimum analytical conditions for the determination of nitrite were established. Under optimum conditions, the linear range for nitrite determination was from 0.5 to 100 μM with a detection limit of 0.5 μM. The stability and anti-interference ability of the PNAFc electrode were also evaluated. The results indicate that this sensor is feasible for the determination of nitrite in real water samples. The text was submitted by the authors in English.