Construction of Solution Processable NUS-8/PANI Nanosheets via Template-Directed Polymerization for Ultratrace Gas Sensing.

The advancement of wireless gas sensing signifies a substantial leap forward in gas detection and intelligent monitoring technologies. This necessitates stringent design criteria for gas sensitive materials with good solution processability, conductivity, and porosity, whose design and synthesis remain challenging yet highly sought-after. Herein, the fabrication of NUS-8/polyaniline (PANI) nanosheets is presented with excellent solution processability, high porosity, triboelectric property, and superior electrical conductivity via a template-directed polymerization strategy. Solution processable NUS-8 nanosheets, synthesized directly by a "one-pot" approach, serve as templates to enhance the "on-site" polymerization of aniline, resulting in the formation of PANI layer on NUS-8 nanosheets with a thickness of 7 nm. The resultant NUS-8/PANI nanosheets exhibit outstanding solution processability, and a film conductivity of 8.6 S m. The solution processability enables the facile fabrication of homogeneous and compact NUS-8/PANI films and thus their integration onto electronic devices targeted for multifunctional sensing. The NUS-8/PANI coated sensors demonstrate sensitive and selective detection at room temperature toward ultratrace ammonia with a detection limit of 120 ppb. A wireless sensing system based on the NUS-8/PANI-coated sensor is capable to monitor the spoilage process of meat. This study paves novel avenues for designing and synthesizing gas-sensitive materials for practical applications.