In this study, the usability of Au, Ag and Cu metal atoms loaded boron-nitride nanotube (BNNT) structures for ethylene oxide adsorbent and gas sensor were investigated by Density Functional Theory (DFT). The WB97XD method has been utilized. Metal atoms were doped with different conformation on both B and N atoms sites of BNNT. After ethylene oxide adsorption, the adsorption energies were computed as negative values in all structures. For Cu doped BNNT, adsorption energy and adsorption enthalpy values were reached −25.2 kcal/mol and −8.2 kcal/mol values, respectively. We observed that the adsorption reactions can occur spontaneously on the structures. Charge transfer took place from ethylene oxide molecule to BNNT structures. Besides, some changes in workfunction emerged in all structures. As a result, Au doped BNNT can be used as both an electronic sensor and a workfunction type gas sensor for ethylene oxide molecule at room temperature. Display omitted •Gas sensing and adsorption studies of EO molecule were examined using DFT method.•ΔE of metal doped BNNTs were computed in the range of (−17.6) - (−25.2) kcal/mol.•Also, Au-BNNT can be used as both an electronic sensor and a Φ-type gas sensor.