Potentiality of gold-doped small tin clusters as lung cancer detectors: a DFT investigation

Lung cancer (LC) is the foremost global cause of mortality, and its growing threat continues owing to the inability to diagnose it. In recent years, the research on lower-dimensional nanomaterial-based sensors has garnered extensive attention as a non-invasive as well as inexpensive LC detector by sensing specific volatile organic compounds (VOCs) associated with the exhaled breath of patients. In this study, we employed the density functional theory (DFT) approach implying B3LYP hybrid functional along with LanL2DZ basis set in the Gaussian 09 software package to comprehend the potentiality of tin clusters (Sn₈) doped with transition metal gold (Au) in two distinct positions as LC detector material by adsorbing two VOCs, Isoprene (C₅H₈) and Benzene (C₆H₆). The analysis of the adsorption mechanism reveals that Au-doped Sn clusters have greater sensitivity towards both the targeted VOCs compared to the pristine cluster. Among all the nanoclusters, the Sn₆-Au_{_S}-Au__M exhibited a 46.88% increase in C₅H₈ adsorption and a 54.80% increase in C₆H₆ adsorption compared to the pristine Sn₈ nanocluster, suggesting its potentiality as a valuable sensor material for detecting lung cancer by identifying VOCs. Further, to comprehend the sensing behavior, an extensive analysis of crucial parameters, including minimum adsorbing distance, charge analysis, molecular orbital analysis, and density of states (DOS) spectrum have been investigated along with thermodynamic behavior for the VOCs adsorbed systems which has revealed the feasibility of Sn₆-Au_{_S}-Au_{_M} nanocluster as a sensor material for lung cancer detector.