Barrier films to control loss of 9,10-anthraquinone-2-sulphonate dopant from PEDOT films during electrochemical transitions

We describe a simple approach for the synthesis of stable electroactive poly[3,4-ethylene dioxythiophene] (PEDOT) in an acid medium, by incorporating a redox active dopant like 9,10-anthraquinone-2-sodium sulphonate (AQS) on a glassy carbon (GC) electrode. The modified electrode is responsive up to a pH of 7. The stability of the modified electrode during continuous electrochemical cycling is poor, due to leaching of the dopant from the PEDOT film. Efforts are made to improve the stability of the modified electrode by forming an anionic barrier film on the PEDOT-AQS interface either physically or electrochemically. The modified electrodes were monitored by cyclic voltammetry and Fourier transform-infrared (FT-IR) spectroscopy for the presence of AQS in the film.