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 online 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 H2O, CO2, or H2S. An off-line I-2 sensor of freestanding 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.

Automated summary

This study describes a simple and universal method for the rapid and accurate detection of gaseous iodine using a fluorescent film sensor based on luminescent spectroscopy. The material used, PIM-1, has the ability for signal amplification and can be easily processed into desired morphologies. The sensor showed quick response time, high signal-noise ratio, low detection limit, steam tolerability, as well as high reversibility and reusability, making it a practical and efficient tool for iodine detection.