Electrochemical preparation of polymeric films of pyronin Y and its electrolcatalytic properties for amperometric detection of nitrite

• Poly(PyY) exhibits different film surface structures depending on film thickness.
• Polymerization of PyY causes broadening and red-shifting of main band in UV–vis. absorption spectra.
• Polymerization process of PyY is highly related to oxidation potential, pH, and monomer concentration.
• Poly(PyY) modified electrodes demonstrate good electrocatalytic activity for amperometric detection of nitrite.
• The determination of nitrite for food samples at poly(PyY)/PGE is effective and feasible.

Electropolymerization of pyronin Y (PyY) on pencil graphite electrode (PGE) was performed by using potentiodynamic and potentiostatic techniques. Effect of electrooxidation potential, pH, and concentration of monomer solution on the polymeric film structure was also investigated. Characterization of poly(PyY) thin films was carried out by using cyclic voltammetry, chronoamperometry, UV–Vis. absorption spectroscopy, and scanning tunneling microscopy. Electrocatalytical properties of prepared poly(PyY)/PGE were studied for amperometric detection of nitrite. Under optimized conditions, amperometric response of the poly(PyY) modified electrode was linearly proportional to the concentration of nitrite in the range from 1.0 × 10−6 to 1.0 × 10−4 M, with a detection limit of 5.0 × 10−7 M. The results indicate that the poly(PyY)/PGE exhibits a low detection limit, an acceptable linear range and a very high sensitivity. The modified electrode was tested for the amperometric determination of nitrite concentration in food samples and the results were consistent with those of the standard spectrophotometric method.