A Review on Single-Atom Catalysts-Based Gas Sensors from Functional Design to Mechanism Elucidation.

Single-atom catalysts (SACs) perform a pivotal role in gas sensing due to their maximized atomic utilization and unique physicochemical properties, effectively overcoming the limitations of traditional sensors in sensitivity, selectivity, and response kinetics. With the deepening exploration of material design, structural regulation, and catalytic mechanisms of SACs, the field of gas sensing based on SACs is rapidly expanding, necessitating a systematic review to integrate recent research advances. This paper systematically reviews research advances in SACs for gas sensing, covering SACs classification, advanced characterization techniques, and dual-sensing mechanisms. It highlights applications in environmental monitoring, industrial safety, medical diagnostics, and machine learning-driven optimization. Finally, it discusses challenges and future directions for single-atom-based gas sensing technology. This review aims to accelerate the development of SAC-based gas sensors.