Robust Fluorescent Detection of Iodine Vapor by a Film Sensor Based on a Polymer of Intrinsic Microporosity

Rapid and high-fidelity detection of radiological iodine species are of extreme importance for the safety of the population and the environment in nuclear fuel reprocessing or in case of nuclear accidents. A simple and universal method to fabricate the sensor to user-friendly devices toward a desired analytical environment would further benefit its applications. Herein, we describe the success of using luminescent spectroscopy for off- and on-line detection of gaseous iodine by a fluorescent film sensor based on a polymer of intrinsic microporosity (PIM-1), a material that possesses intrinsic signal amplification capability and good solubility for processing into desired morphologies. Due to the photoinduced electron transfer (PET) effect, the fluorescence of PIM-1 is quenched drastically upon I 2 exposure, but not much altered by water, CO 2 , or H 2 S. An off-line I 2 sensor of free-standing PIM-1 membrane and a real-time flue I 2 detector by coating PIM-1 film inside a capillary tube were fabricated and applied. Quick response (few seconds), high signal-noise ratio ( five orders of magnitude ), low detection limit (few ppb), steam tolerability, as well high reversibility and reusability were achieved, making the material a practically convenient and efficient I 2 sensor