Au- and Pd-Doped SnS<sub>2</sub> Monolayers for Lung Cancer Biomarkers (C<sub>3</sub>H<sub>6</sub>O, C<sub>6</sub>H<sub>6</sub>, and C<sub>5</sub>H<sub>8</sub>) Detection: A Density Functional Theory Investigation
Hongyi Liu, Xuan Luo
Abstract
High Resolution Image Download MS PowerPoint Slide An efficient and noninvasive method of sensing lung cancer at an early stage is through detecting its biomarkers in the patient’s exhaled breath. Acetone (C 3 H 6 O), benzene (C 6 H 6 ), and isoprene (C 5 H 8 ) emerged as crucial biomarkers, which were significantly elevated in lung cancer patients. Here, we investigated the adsorption behaviors of the three gas molecules on pristine and transition metal (TM)-doped (Au and Pd) SnS 2 monolayers using the density functional theory (DFT) method. Our findings indicate that both Au- and Pd-doped SnS 2 display higher adsorption energies (−0.53 to −1.313 eV) than that of the pure SnS 2 monolayer (0.031 to 0.066 eV). Specifically, Pd–SnS 2 exhibits smaller adsorption energy compared to that of Au–SnS 2 when capturing C 3 H 6 O, C 6 H 6, and C 5 H 8 . The estimated recovery times for Pd–SnS 2 (8.016 × 10 –4 to 16.02 s) are shorter compared to those of Au–SnS 2 (1.11 to 1.14 × 10 10 s), indicating the superior capability of Pd–SnS 2 over Au–SnS 2 as a reversible sensor. Afterward, calculations of band structure, projected density of states (PDOS), and charge transfer were performed, which further substantiates the more promising potentials for Pd-doped SnS 2 monolayer as gas sensors over the others. Overall, our results suggest that Pd–SnS 2 is a better candidate for C 3 H 6 O, C 6 H 6, and C 5 H 8 detection over Au–SnS 2 and pristine SnS 2 .