In situ vapor polymerization of poly(3,4-ethylenedioxythiophene) Coated SnO₂-Fe₂O₃ continuous electrospun nanotubes for rapid detection of iodide ions

In this work poly(3,4-ethylenedioxythiophene) (PEDOT) coated SnO₂-Fe₂O₃ continuous nanotubes with a uniform core-shell structure have been demonstrated for rapid sensitive detection of iodide ions. The SnO₂-Fe₂O₃ nanotubes were firstly fabricated via an electrospinning technique and following calcination process. An in situ polymerization approach was then performed to coat a uniform PEDOT shell on the surface of as-prepared SnO₂-Fe₂O₃ nanotubes by vapor phase polymerization, using Fe₂O₃ on the surface of nanotubes as an oxidant in an acidic condition. The resultant PEDOT@SnO₂-Fe₂O₃ core-shell nanotubes exhibit a fast response time (~4 s) toward iodide ion detection and a linear current response ranging from 10 to 100 μM, with a detection limit of 1.5 μM and sensitivity of 70 μA/mM/cm². The facile fabrication process and high sensing performance of this study can promote a wide range of potential applications in human health monitoring and biosensing systems.