New hydrazine sensors based on electropolymerized meso-tetra(4-sulphonatephenyl)porphyrinate manganese(III)/silver nanomaterial

A new electrocatalytic active porphyrin nanocomposite material was obtained by electropolymerization of meso-tetra(4-sulphonatephenyl)porphyrinate manganese(III) complex (MnTPPS) in alkaline solutions containing sub-micromolar concentrations of silver chloride. The modified glassy carbon electrodes efficiently oxidize hydrazine at 10 mV versus Ag/AgCl, dramatically decreasing the overpotential of conventional carbon electrodes. The analytical characteristics of this amperometric sensor coupled with batch injection analysis (BIA) technique were explored. Wide linear dynamic range (2.5 × 10−7 to 2.5 × 10−4 mol L−1), good repeatability (R.S.D. = 0.84%, n = 30) and low detection (3.1 × 10−8 mol L−1) and quantification (1.0 × 10−7 mol L−1) limits, as well as very fast sampling frequency (60 determinations per hour) were achieved.