By employing the ligand 2-(isonicotinamido)terephthalic acid (H2L) containing the amide functional groups, a Cd-MOF, {[Cd2L2(H2O)2]·4H2O}n (1) has been constructed by solvothermal synthesis. The dinuclear clusters [Cd2(COO)2] in 1 are linked by the pyridinyl and carboxylate groups of ligands to form a three-dimensional (3D) skeleton, containing 1D channels with the free amide groups. The activated framework shows good stability in water and high selectivity for CO2 over CH4. The open Cd2+ site as Lewis acidic center makes the MOF achieve efficiently catalytic conversion for CO2 cycloaddition with epoxides. Furthermore, 1 also exhibits good chemical stability in water, allowing the detection for ronidazole (RDZ) and dimetridazole (DTZ) with the low detection limit and rapid response.