Interfacial effects of gold on PEDOT nanotubes modified electrodes employed for the adsorption of micropollutants

In this work poly(3,4-ethylenedioxythiophene) nanotubes (PEDOT-NTs) containing gold nanoparticles (AuNPs) were electrochemically synthesized and characterized in detail by using in situ Raman spectroelectrochemistry. Combining conducting polymers and metallic nanoparticles (AuNPs) enhanced conductivity and superficial area of PEDOT-NTs, key factors for electrochemical sensors. In order, to better understand the modified electrodes behavior, two different micropollutants, butylparaben and triclosan, were added onto the electrode surface and the spectroelectrochemical characterization was done. The Raman imaging showed that micropollutants adsorption increases the presence of partially oxidized segments in PEDOT nanotubes, showing that PEDOT-NTs/AuNPs modified electrodes has sensitivity to micropollutants presence. In this regard the electrochemical impedance spectroscopy characterization was performed and agrees with the spectroelectrochemical characterization results, in which the charge-transfer resistance increase proportionally with the micropollutants concentration. Therefore, the present work shows the potentiality of combining the unique characteristics of the PEDOT nanotubes decorated with AuNPs nanoparticles to develop devices for detection of organic molecules of environmental interest. [Display omitted] •Spectroelectrochemical Raman experiments showed that the AuNPs increase the overall conductivity of PEDOT nanotubes.•Raman mapping of the surface indicated a larger homogeneity of the surface on the doping effects of gold.•EIS was used to model the equivalent circuit and corroborated the extension of the adsorption of micropollutants.