Electropolymerized network of polyamidoamine dendron-coated gold nanoparticles as novel nanostructured electrode surface for biosensor construction

Abstract

Polyfuntionalized gold nanoparticles were prepared by using 2-mercaptoethanesulfonic acid, p-aminothiophenol and cysteamine core polyamidoamine G-4 dendron as capping ligands. The nanoparticles were electropolymerized on a Au electrode surface through the formation of a bisaniline-cross-linked network. The enzyme tyrosinase was further crosslinked on this nanostructured matrix. The enzyme electrode, poised at −100 mV, was used for the amperometric quantification of cathecol. The biosensor showed a linear response from 50 nM to 10 μM cathecol, with a low detection limit of 20 nM and a sensitivity of 1.94 A M⁻¹ cm². The electrode retained 96% and 67% of its initial activity after 16 and 30 days of storage at 4 °C under dry conditions.