Tailoring gold-conducting polymer nanocomposites for sensors applications: Proof of concept for As(III) sensing in aqueous media

Abstract

Nanocomposites of gold nanoparticles (AuNPs) and conducting polymers, polypyrrole (PPy) and polyaniline (PANI), were prepared by simple oxidative polymerization of the corresponding monomer (pyrrole and aniline, respectively) by tetrachloroauric acid. Au nanospheres and nanorods were formed in the case of Au@PPy and Au@PANI, respectively. Detection of As(III) using Au@polymer was investigated where both nanocomposites showed similar activity for As electrooxidation in acidic media. The activity of Au@PPy was notably improved upon the addition of a small amount of conducting carbon, giving higher current densities compared to the commercial Au electrode. Further optimization of the operational conditions including electrolyte composition, deposition time and potential, was carried out to reach the limit of quantification as low as 2 ppb. Au@PPy nanocomposite proved to be suitable for sensing of As(III) in the presence of other ions, such as Cu(II). Furthermore, it proved to be suitable for As(III) sensing in real samples.