Two-dimensional poly(3,4-ethylenedioxythiophene) nanosheets for highly electrochemical detection of iodide ions

Highlights: • A general sacrificial template approach was developed to prepare poly(3,4-ethylenedioxythiophene) nanosheets. • The poly(3,4-ethylenedioxythiophene) nanosheets showed a thin thickness of only around 4–5 nm. • The proposed electrochemical iodide ions sensor delivers a low detection limit. • The proposed electrochemical iodide ions sensor shows an exciting reproducibility, stability and selectivity. Two-dimensional (2D) nanomaterials-modified electrodes are good candidates for electrochemical sensing because of their unique ultrathin sheet-like structure and distinctive electrical property. In this work, we have developed a facile sacrificial template-directed mild polymerization process to prepare 2D poly(3,4-ethylenedioxythiophene) (PEDOT) nanosheets. During the polymerization process, V₂O₅·nH₂O nanosheets are used as both sacrificial templates and oxidants, which can not only guide the production of PEDOT nanosheets, but also spontaneously be removed after the reaction. We have demonstrated the usage of the 2D PEDOT nanosheets for electrochemical sensing of iodide ions. The proposed sensor delivers a low detection limit of 0.313 μM (S/N = 3) with a linear range of 1.0–20 μM. Furthermore, the 2D PEDOT-based sensor shows an exciting reproducibility, stability and selectivity for the detection of iodide ions, which can be feasibly applied for the detection in real samples. This study provides a facile route to fabricate 2D conducting polymer-based nanomaterials for efficient electrochemical sensing application.