Synthesis of polyanthranilic acid-Au nanocomposites by emulsion polymerization: development of dopamine sensor

Polyanthranilic acid (PANA) and polyanthranilic acid-gold (PANA-Au) nanocomposites have been synthesized through emulsion polymerization technique. Use of gold chloride as an oxidant for anthranilic acid not only provides a new route for chemical synthesis of PANA, but also explores a facile method for the formation of nanocomposites. Emulsion polymerization helps in slowing down kinetics of polymerization in comparison to one-phase polymerization and thereby induces formation of monodispersed, both pure and Au nanoparticles, embedded PANA sphere. Reaction progress of nanocomposite formation is studied by UV-Vis spectroscopy for 0–24 h. PANA-Au nanocomposites are characterized by SEM, equipped with EDS, TGA, FT-IR, XRD and electrochemical techniques. XRD of nanocomposites depicts the amorphous nature of polymer and crystalline nature of Au with crystallite size of ~ 24 nm. Differential pulse voltammetry has shown the electro-active nature of PANA. The nanocomposites with improved thermal properties show good dispersion in common organic solvents, and it can be explored for application in interference-free dopamine sensors with sensitivity 12.5 μA/mM. Acidic group (−COOH) on the polymer makes the sensor free from ascorbic acid interference.