A Dual Functional Conductive Hydrogel Containing Titania@Polypyrrole-Cyclodextrin Hybrid Nanotubes for Capture and Degradation of Toxic Chemical

In this study, dual functional conductive hydrogels containing polypyrrole (PPy) nanotubes (NTs) functionalized with beta-cyclodextrin (bCD) and titania (TiO₂) were produced and applied for both detection and removal of toxic substances. PPy, a representative conducting polymer was prepared in a form of nanotube (NT) and used for providing electrical conductivity. TiO₂ nanoparticles were incorporated into the inside of the PPy NTs during the formation of PPy NTs, acting as a photocatalyst. Subsequently, beta-cyclodextrin (bCD) molecules were introduced as sensing media on the surface of PPy NTs via a simple surface treatment. The resulting TiO₂@PPy-bCD hybrid NTs were embedded into agarose matrix to obtain a conductive hydrogel, simultaneously improving compatibility with substrates. The electrical properties of the hydrogel were investigated, showing electrical conductivity of approximately 10⁻³ S/cm and ohmic I-V relation on Au electrode. The sensing capability for a model analyte compound (methyl paraben, MPRB) down to 10 nM and photocatalytic degradation of methylene blue (MB) were demonstrated effectively. This study can provide important information for upcoming research activities for environmentally benign and toxic free versatile chemical sensors in diverse relevant fields.