Poly(4-vinylpyridine-co-aniline)-modified electrode—synthesis, characterization, and application as cadmium(II) ion sensor

Abstract

A poly(4-vinylpyridine-co-aniline) (poly(4VP-co-Ani))-based solid-state ion sensor for cadmium (Cd) was developed. This was obtained from studies done on a number of selected monomers electropolymerized onto a poly(4vinylpyridine) (P4VP)-modified graphite pencil rod, surface characterizing them and then analyzing their performances as a Cd(II) ion sensor. Among them, the membrane of poly(4VP-co-Ani) at a mole ratio of 0.05:0.15 was found to be the best. The fabricated poly(4VP-co-Ani) solid-state electrode had a linear response of 1 × 10−6 to 1 × 10−2 M Cd2+, slope of 29.4 ± 0.5 mV decade−1, detection limit of 7.94 × 10−7 M Cd2+, and response time of 15 s at pH 4.5–8.5 with excellent selectivity. The sensor was operationally stable within a period of 3 months. The proposed sensor was tested for determination of Cd2+ in environmental, plant, and pharmaceutical samples. The analyses were comparable to the standard atomic absorption spectrophotometric method.