Al-Doped MoSe(2) 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 MoSe(2) (Al-MoSe(2)) as a promising biosensor for sensing three typically exhaled volatile organic compounds (VOCs) of lung cancer, namely, C(3)H(4)O, C(3)H(6)O, and C(5)H(8), using the density functional theory (DFT) method. Single Al atom is doped on the Se-vacancy site of the MoSe(2) 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-MoSe(2) monolayer are conducted to fully understand its physicochemical properties as a sensing material. The results indicate that the Al-MoSe(2) monolayer shows admirable sensing performances with C(3)H(4)O, C(3)H(6)O, and C(5)H(8) with responses of -85.7, -95.6, and -96.3%, respectively. Also, the desirable adsorption performance and the thermostability endow with the Al-MoSe(2) 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.