Phosphine oxide functionalized porous aromatic frameworks enabled wireless bionic olfactory system with preconcentration capability for trace ammonia monitoring

Abstract

The high sensitivity and precise detection of trace ammonia (NH₃) remains a critical focus of research in the fields of air pollution, agriculture/industrial process control, polar-region environment research and extraterrestrial life search. Herein, we proposed a bionic trace fluid preconcentration strategy to promote miniature trace gas sensing performance. This strategy leverages the selective adsorption behavior from atmosphere of novel phosphine oxide functionalized porous aromatic frameworks (PAFs), alongside the bionic fluid control theory modeled after the Pike’s nasal structure and the Squid’s sine function-shaped fins. A wireless bionic olfactory system (WBOS) is developed to achieve the wide range accurate monitoring of 5 ppb-300 ppm with an actual detection limit of 100 ppt facilitated by advanced preconcentration up to 37,000 times. The high sensing performance is also discussed by density functional theory (DFT), computational fluid dynamics (CFD) simulations and machine learning-genetic algorithms. Our work provides new inspiration for developing miniature bionic sensing devices based on advanced materials for synergistic trace gas preconcentration and detection.