Al-Doped MoSe₂ Monolayer as a Promising Biosensor for Exhaled Breath Analysis: A DFT Study

Exhaled breath analysis by nanosensors is a workable and rapid manner to diagnose lung cancer in the early stage. In this paper, we proposed Al-doped MoSe₂ (Al-MoSe₂) as a promising biosensor for sensing three typically exhaled volatile organic compounds (VOCs) of lung cancer, namely, C₃H₄O, C₃H₆O, and C₅H₈, using the density functional theory (DFT) method. Single Al atom is doped on the Se-vacancy site of the MoSe₂ surface, which behaves as an electron-donor and enhances the electrical conductivity of the nanosystem. The adsorption and desorption performances, electronic behavior, and the thermostability of the Al-MoSe₂ monolayer are conducted to fully understand its physicochemical properties as a sensing material. The results indicate that the Al-MoSe₂ monolayer shows admirable sensing performances with C₃H₄O, C₃H₆O, and C₅H₈ with responses of -85.7, -95.6, and -96.3%, respectively. Also, the desirable adsorption performance and the thermostability endow with the Al-MoSe₂ monolayer with good sensing and desorbing behaviors for the recycle detection of three VOCs. We are hopeful that the results in this paper could provide some guidance to the experimentalists fulfilling their exploration in the practical application, which can also broaden the exploration of transition-metal dichalcogenides (TMDs) in more fields as well.