A potentiometric solid state copper electrode based on nanostructure polypyrrole conducting polymer film doped with 5-sulfosalicylic acid

A pencil graphite electrode (PGE) electrodeposited by nanostructure polypyrrole (PPy) conducting polymer film doped with 5-sulfosalicylic acid (SSA) as sensing material (PGE/PPy/SSA-Cu) was successfully developed for the detection of Cu (II) in aqueous solutions. For the preparation of the copper-sensing electrode, electrodeposition of a polypyrrole film was carried out using cyclic voltammetry in a solution containing 10.0 mM pyrrole and 5.0 mM 5- sulfosalicylic acid. The introduced electrode in the current paper can be fabricated simply and was found to possess high selectivity, showed wide working concentration range, fast response time (<20 s), long lifetime, and very good sensitivity to Cu (II) ion. The prepared electrode exhibited a linear Nernstian response within the copper ion concentration range of 1.0 × 10−5 to 1.0 × 10−1 M with a slope of 29.60 ± 0.30 mV per decade over the pH range of 4.0 to 6.0. Under the optimized conditions, a detection limit of 5.42 μM was obtained. Applications of this electrode for determination of copper ion in real samples and as an indicator electrode for potentiometric titration of Cu2+ ion using EDTA are reported.