Real-Time and\nWireless Transmission of a Nitrogen-Doped\nTi<sub>3</sub>C<sub>2</sub>T<sub>x</sub> Wearable Gas Sensor for Efficient\nDetection of Food Spoilage and Ammonia Leakage

With the rising popularity of smart homes, there is an\nurgent need\nfor devices that can perform real-time online detection of ammonia\n(NH<sub>3</sub>) concentrations for food quality measurement. In addition,\ntimely warning is crucial to preventing individual deaths from NH<sub>3</sub>. However, few studies can realize continuous monitoring of\nNH<sub>3</sub> with high stability and subsequent application validation.\nHerein, we report on an integrated device equipped with a nitrogen-doped\nTi<sub>3</sub>C<sub>2</sub>T<sub>x</sub> gas sensor that shows great\npotential in detecting food spoilage and NH<sub>3</sub> leakage. The\nnitrogen doping results in the lattice misalignment of Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub>, subsequently realizing effective barrier\nheight modulation and enhanced charge transfer efficiency of nitrogen-doped\nTi<sub>3</sub>C<sub>2</sub>T<sub>x</sub>. Density functional theory\ncalculations confirm the greatly enhanced adsorption of NH<sub>3</sub> on nitrogen-doped Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub>. Our\nwork can inspire the design of efficient gas sensors for real-time\nand wireless detection of food spoilage and NH<sub>3</sub> leakage.