ABSTRACT: The gas sensing applications of nanocages find intense attention in environmental monitoring. In this research, the adsorption of nitrogen and sulfur-containing gaseous molecules i.e., N2O, NO2, NO, H2S, SO2, and SO3 on inorganic oxide nanocages are analyzed through DFT simulations. The adsorption of gaseous molecules with Be12O12, Mg12O12, and Ca12O12 is illustrated through the adsorption energies, optimized geometries, and electronic properties like HOMO-LUMO energies and NBO analysis. Our theoretical analysis indicates that the molecules strongly bind with the Ca12O12 nanocage. The adsorption energies of N2O@Ca12O12, NO2@Ca12O12, NO@Ca12O12, H2S@Ca12O12, SO2@Ca12O12 and SO3@Ca12O12 are − 11.79, − 46.53, − 26.51, − 50.26, − 78.64 and − 123.62 kcal/mol, respectively. Moreover, the HOMO-LUMO orbital analysis, density of state analysis (DOS), and natural bond orbital (NBO) analysis illustrate the significant impact of adsorption of these molecules on the electronic properties of respective nanocages, especially Ca12O12. Finally, it can be concluded that the Ca12O12 nanocage shows promising sensitivity towards the gaseous molecules which is followed by Mg12O12 and Be12O12.