Abstract: In this study, we were investigated behavior the electrochemical reduction
of nitrite at a hemoglobin (Hb) immobilized on glass carbon electrode (GCE) containing
polypyrol nanofiber (ppy) films. Polypyrrole (PPy) nanofibers have been constructed on
GCE applying electrochemical technique, and can to deposit diverse polymers on
miniaturized electrodes with this common method. The structure of the acquired
electrode and the electrochemical behavior were characterized using Scanning Electron
Microscopy (SEM), Cyclic Voltammetry (CV), and Linear Sweep Voltammetry (LSV).
The immobilized Hb showed an irreversible reduction peak with a formal potential of –
0.72 versus Ag/AgCl, in 0.1M pH 4.5 acetate buffer. The immobilized Hb exhibited
remarkable electrocatalytic activity for the reduction of nitrite. Under the optimal
condition the nitrite concentrations range 2.0×10−4 to 46.0×10−4 M with a detection limit
of 6.2×10−5 M (at S/N=3). The resulting biosensor has been successfully applied to the
determination of nitrite in water samples. The produced modified electrode for nitrite
determination has been explored within the presence of the interfering substances
including a number of common ions and cations, demonstrating great selectivity. تفاصيل المقالة