A water-stable luminescent Co(II) coordination polymer as probe for efficient detection of Cr(VI)-anions (Cr2O72– and CrO42–) in aqueous solution

•A 2D layered Co(II) coordination polymer was hydrothermally synthesized and characterized.•1 further extended into a 3D supramolecular network through π···π stacking interactions.•1 reveals highly sensitive and selective luminescence sensing of Cr(VI)-anions in water media.