Electrochemical synthesis of poly(3,4-ethylenedioxythiophene) doped with gold nanoparticles, and its application to nitrite sensing

The work describes the synthesis of a nanocomposite consisting of poly(3,4-ethylenedioxythiophene) (PEDOT) doped with gold nanoparticles (AuNPs) by electropolymerization of EDOT in a solution containing colloidal AuNPs. The nanocomposite possesses good conductivity and a 3D microporous network structure owing to the presence of AuNPs. These act as both conductive dopant and template for the growth of the microporous polymer. A glassy carbon electrode modified with the nanocomposite exhibits excellent electrocatalytic activity towards oxidation of nitrite. Best operated at a voltage of 0.8 V (vs. Ag/AgCl), it is capable of detecting nitrite in the 0.2 to 1400 μM concentration range, with a detection limit of 60 nM. A highly sensitive and selective electrochemical sensor for nitrite was developed based on the electrodeposited nanocomposite of conducting polymer poly(3,4-ethylenedioxythiophene) doped with gold nanoparticles.