A new electrochemical sensor based on carbon paste electrode/Ru(III) complex for determination of nitrite: Electrochemical impedance and cyclic voltammetry measurements

•Modified CPE/Ru(III) complex electrode was used as sensor for the determination of nitrite.•The behavior of nitrite on the surface of modified electrode was investigated.•Electrochemical impedance and cyclic voltammetry measurements were performed.•The charge transfer resistance decreased with increasing potentials and temperature.•The sensor exhibited a wide linear range for nitrite detection from 0 to 0.0138M.