Microchannel tube NH₃ sensor based on metal-organic framework UiO-66 modified polyaniline

Despite the remarkable development in conductive polymer-based NH₃ sensors, there are still several obstacles such as long response/recovery time and difficulty in detecting low concentrations of NH₃. In this work, polyaniline (PANI) was modified using a metal-organic framework (MOF) UiO-66 to construct a microchannel tube NH₃ sensor. Scanning Electron Microscope (SEM) and Brunauer-Emmett-Teller (BET) characterizations disclose that the addition of UiO-66 could induce formation of a highly porous nanofiber PANI film. The sensor can realize the gas response up to 2540% for 100 ppm NH₃, and 20% response to 10 ppb NH₃ with excellent reversibility and response/recovery time (25 s/14 s). The improved sensing performance is ascribed to the high specific surface area of the PANI/UiO-66 film. Furthermore, the sensor has a microchannel tube structure which can realize fast and effective on-time detection of small-volume NH₃ gas. The as-fabricated sensor could be a potential candidate in practical medical monitoring applications.