Two-dimensional materials can be utilized to detect gas molecules in low concentration due to their high surface-to-volume ratios. In this respect, we investigate in the present work recently fabricated borophene, two-dimensional B, which has buckled and line-defective phases. Both are systematically studied for four gas molecules: NH, NO, NO, and CO. In each case, the adsorption energy is found to be high and borophene develops distinct wrinkles. Our results provide a thorough understanding of the interaction between borophene and the gas molecules. An excellent performance of borophene as gas sensor is demonstrated by simulating the material's transport characteristics by means of the nonequilibrium Green's function method.