Hollow, Spherical, Poly(3,4-ethylenedioxythiophene)-Bearing Methanethiol as a Gold Stabilizer for High-Efficiency Electrochemical Sensors

Abstract

© The Author(s) 2018. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License Conducting polymers decorated with noble metals are good electrochemical sensors for biological species. In this work, we developed a polymer of methanethiol-grafted poly(3,4-ethylenedioxythiophene) hollow spheres (Poly(EDOT-MeSH)) using SiO2 nanospheres as a hard template. The Poly(EDOT-MeSH) spheres were used as both a reductant and stabilizer to decorate gold nanoparticles (Au NPs). FTIR, XRD, EDX, SEM and TEM analyses were used to characterize the Poly(EDOT-MeSH)/Au hollow spheres. The chemical bond between S and Au was confirmed by XPS. The electrochemical performance of the Poly(EDOT-MeSH)/Au hollow spheres was determined by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The results revealed that the Poly(EDOT-MeSH)/Au hollow sphere-based electrochemical sensor possesses an excellent conductivity and high redox reversibility with detection limits (S/N = 3) of 5.3, 0.04 and 0.12 μM in the linear ranges of 50-320 μM, 0.05 μM − 780 μM and 0.8 μM − 250 μM for the determination of AA, DA and UA, respectively. These results will further the development of this type of electrochemical sensor for biological species.