Iodide fluorescent sensor based on water-soluble conjugated polymer brush

A conjugated polyelectrolyte (CPE) brush based on polyfluorene is synthesized via atom transfer radical polymerization (ATRP). It has extremely high charge density, consequently giving rise to better optical stability, higher water solubility (28 mg/mL) and higher quantum efficiency (52%); meanwhile, fluorescence response of polymer brush to various anionic ion is performed, indicating that polymer brush can serve as the sensor for iodide detection having high selectivity and sensitivity. The formation of [HgI₄]^2- is the critical factor in this system as the polymer fluorescence is quenched by photoinduced electron transfer (PET) between the polymer and [HgI₄]^2-.