Multi-responsive luminescent sensors of two water-stable polynuclear Cd organic frameworks: Synthesis, structures and sensing of tetracycline, Cr2O72− and Fe3+ ions in water

•Two novel polynuclear Cd-MOFs have been successfully synthesized and characterized.•1 shows a rare 3D 2-nodal (5,10)-c fit network based on tetranuclear [Cd4(µ3-O)4(COO)10]2− unit.•2 displays an interesting 2D → 3D interdigitating and penetrating structure unique topological framework.•1–2 can serve as excellent multi-responsive luminescent sensors for TC, Cr2O72− and Fe3+ ions.•The 2-coated fluorescent test papers can be used to detect TC, Cr2O72− or Fe3+ ions in water system.