Polyaniline/Cashew Gum Composite Electrosynthesized on Gold Surface in Aqueous Acid Medium for Ammonia Colorimetric Detection

Abstract

The electrosynthesis of polyaniline (PAni) and cashew gum (CG) composite was successfully performed by electrochemical methods (potential scanning and constant potential) in terms of pH, aniline (Ani), and polyelectrolyte concentrations. Study aim was to investigate the performance of a polyaniline-based ammonia sensor under different concentrations of ammonium gas, evidencing a color change from green to blue as in the presence of gas in a sensitive and reversible process. Films grown by cyclic voltammetry and chronoamperometry showed a cauliflower-like morphology, and a visual analysis detected a limit of 0.015 and 0.010 mol l−1, respectively. The sensor demonstrated a fast response time of 20 s, a low detection limit, with a short regeneration time of less than 1 min at room temperature. This polyaniline-based sensor is shown as a portable, sensitive, dimensionally flexible, and cost-effective alternative for food packaging and other devices. The findings of this study contribute to the development of advanced ammonia detection technology.