Transition-Metal-Doped Graphene for Volatile Sulfur Compound Detection: A DFT Study

The adsorption behavior of selected volatile sulfur compounds on graphene was examined using density functional theory. The analytes of interest are hydrogen sulfide, methyl mercaptan and dimethyl sulfide, which are found in the exhaled breath of halitosis patients. The human breath contains several volatile compounds that act as chemical fingerprints of what is happening inside the body. This study employs first-principles calculations to investigate the structural, electronic, and adsorption properties of pristine and transition-metal-doped graphene (Fe, Ru, and Os) for the detection of key volatile sulfur compounds relevant to breath analysis and halitosis screening. According to our findings, when a single carbon atom is substituted with an iron, ruthenium or osmium atom in the optimized graphene sheet, which is equivalent to a dopant concentration of 2 mol% in experiments, the adsorption behavior of the system is altered significantly. Based on the resultant adsorption behavior and electronic structure alterations, important sensor properties were examined. This work presents a non-invasive approach for halitosis detection, therapeutic monitoring, and metabolic status observation by analyzing the volatile sulfur compounds present in exhaled breath. Additionally, this study demonstrates how computational modeling can be used as a decision support tool.