Simultaneous and Selective Electrochemical Detection of Sulfite and Nitrite in Water Sources Using Homogeneously Dispersed Ag Nanoparticles over PANI/rGO Nanocomposite

A comprehensive investigation on synthesis, characterization and application of AgNPs@PANI/rGO nanocomposite was carried out for the simultaneous detection of sulfite and nitrite in water sources. A well dispersed and modified silver nanoparticle of uniform size, dispersed on polyaniline/reduced graphene oxide nanocomposite was prepared in the absence of an external oxidizing agent through biphasic method. The synthesized nanocomposite was characterized by FT-IR, XRD, FE-SEM and TEM analysis. The nanocomposite exhibited enhanced catalytic current for simultaneous electrochemical oxidation of sulfite and nitrite with wider peak separation window. A well-defined oxidation peak was observed at +0.40 and + 0.90 V vs Ag/AgCl for sulfite and nitrite in 0.1 M phosphate buffer. A calibration graph was obtained in the concentration range of 2.7 to 24.4 mu M and 1.0 to 28.2 mu M with a detection limit (LOD) of 77 nM and 56 nM for the electrochemical determination of sulfite and nitrite, respectively. The present sensor can be used for the electrochemical detection of both analytes in water sources with greater sensitivity and lower detection limits. The results obtained from the present method were validated with the published results. (c) 2020 The Electrochemical Society (ECS). Published on behalf of ECS by IOP Publishing Limited.