Transition Metal Doped WTe2 Monolayers for Lung Cancer VOC Detection: Adsorption, Electronic Response, and Sensing Performance.

Lung cancer remains one of the most widespread and deadly malignancies worldwide, underscoring the urgent need for rapid and noninvasive diagnostic strategies. Compared with conventional clinical detection techniques, breath analysis based on gas-sensing VOC detection offers exceptional advantages, including high sensitivity, operational simplicity, and real-time capability. In this work, we conduct a comprehensive density functional theory (DFT) investigation into the adsorption characteristics and electronic responses of Au-, Pd-, and Pt-doped WTe2 monolayers toward representative lung-cancer-associated VOCs. Our results reveal that transition-metal doping markedly improves the structural stability and adsorption activity of WTe2, while inducing pronounced modulations in its electronic structure that collectively enhance its gas-sensing performance. Among the examined systems, Au-doped WTe2 exhibits the strongest adsorption strength and the most significant band gap perturbations upon exposure to C5H8, C3H6O, and C3H8O. Moreover, the differentiated sensing behaviors of the three doped monolayers toward various analytes effectively reduce cross-interference issues. These findings provide valuable theoretical insight and identify promising material candidates for the development of highly selective and high-precision breath sensors for early lung cancer detection.