Rapid Detection of Explicit Volatile Organic Compounds for Early Diagnosis of Lung Cancer Using MoSi2N4 Monolayer

Abstract In this study, we investigate the adsorption and sensing capabilities of pristine (MoSi 2 N 4 ) and nitrogen‐vacancy induced (MoSi 2 N 4 −V N ) monolayers towards five potential lung cancer volatile organic compounds (VOCs), such as 2,3,4‐trimethylhexane (C 9 H 20 ), 4‐methyloctane (C 9 H 20 ), o‐toluidine (C 7 H 9 N), Aniline (C 6 H 7 N), and Ethylbenzene (C 8 H 10 ). Spin‐polarized density functional theory (DFT) calculations reveal that MoSi 2 N 4 weakly adsorb the mentioned VOCs, whereas the introduction of nitrogen vacancies significantly enhances the adsorption energies ( ), both in gas phase and aqueous medium. The MoSi 2 N 4 −V N monolayers exhibit a reduced bandgap and facilitate charge transfer upon VOCs adsorption, resulting in enhanced values of −0.83, −0.76, −0.49, −0.61, and −0.50 eV for 2,3,4‐trimethylhexane, 4‐methyloctane, o‐toluidine, Aniline, and Ethylbenzene, respectively. Bader charge analysis and spin‐polarized density of states (SPDOS) elucidate the charge redistribution and hybridization between MoSi 2 N 4 −V N and the adsorbed VOCs. The work function of MoSi 2 N 4 −V N is significantly reduced upon VOCs adsorption due to induced dipole moments, enabling smooth charge transfer and selective VOCs sensing. Notably, MoSi 2 N 4 −V N monolayers exhibit sensor responses ranging from 16.2 % to 26.6 % towards the VOCs, with discernible selectivity. Importantly, the recovery times of the VOCs desorption is minimal, reinforcing the suitability of MoSi 2 N 4 −V N as a rapid, and reusable biosensor platform for efficient detection of lung cancer biomarkers. Thermodynamic analysis based on Langmuir adsorption model shows improved adsorption and detection capabilities MoSi 2 N 4 −V N under diverse operating conditions of temperatures and pressures.