In this proposed work, we examined the interaction properties of alcohol viz. methanol and ethanol molecules on stair phosphorene nanosheet (stair-PNS) based on the first-principles study. Moreover, the adsorption property of chief molecules on the stair-PNS base substrate is explored based on the binding energy, average energy gap variation, and Bader charge transfer. The methanol and ethanol molecules are physisorbed on stair-PNS, which is validated with regard to the lower scale of binding energy. Besides, the band gap of stair-PNS gets changed upon the adsorption of alcohol vapors. Thus, we suggest from the results that stair-PNS can be facilitated as the chemi-resistive sensor to probe alcohol vapors.