Gas sensitivity study of early diagnostic markers for lung cancer using MoTe2 single molecular membranes doped with different TM atoms: Based on density functional theory

Abstract

Lung cancer has become one of the deadliest and most prevalent cancers worldwide, and the use of gas sensors to detect volatile organic compounds (VOCs) in the exhaled breath of lung cancer patients is gaining increasing popularity. Compared with traditional medical diagnostic methods, this method is cost-effective and less invasive. During our experiments, we employ density functional theory to explore how transition metal (Cu, Pd, Pt)-doped MoTe₂ single-molecule membranes respond to VOCs commonly found in the exhalation gas of patients with lung cancer in the early stages of the disease. All three modified systems exhibited excellent thermal stability, and the sorption of VOCs is significantly enhanced compared to the pristine MoTe₂, ensuring effective desorption and sensing performance at elevated temperatures. Moreover, the changes in the band gap before and after adsorption are notably distinct, indicating strong gas sensitivity. Among the doped structures, MoTe₂-Cu shows the highest adsorption capacity for C₅H₈, C₃H₆O, and C₃H₈O, accompanied by the largest change in the band gap. Due to the varying sensitivities of the three lung cancer biomarker sensors to different gases, cross-sensitivity can be minimised, highlighting the potential for qualitative analysis of VOC gas mixtures. This offers new insights and methods for the early detection and prevention of lung cancer.