Enhancing the vibrational sensitivity of graphene via substitutional doping for multimodal gas sensing applications – a DFT study

Abstract Graphene’s exceptional properties make it a leading candidate for gas sensing, but enhancing selectivity and multimodal detection remains a challenge. Using density functional theory (DFT), we systematically investigated vibrational frequency shifts in graphene doped with Au, Ag, Cu, Ni, and Pt upon adsorption of CO, CO 2 , NO, and NO 2 . Our results reveal that Au-doped graphene is most sensitive to CO and CO 2 , while Cu-doped graphene shows the strongest response to NO 2 . Both Au- and Cu-doped systems exhibit pronounced sensitivity to NO. Importantly, distinct mode-dependent responses enable discrimination among gases, establishing substitutionally doped graphene as a promising platform for multimodal sensing. These findings provide a predictive framework for designing advanced, selective, and vibration-based gas sensors.