Display omitted •A novel CP-based luminescent sensor was synthesized for simultaneous recognition of ascorbic acid and acetylacetone.•Both proposed sensing systems showed excellent performance with high KSV values and low limit of detection (LOD).•Probable sensing mechanism of CP 1 to the two types of analytes are discussed in more detail. A new coordination polymer (CP), Co(μ3-HL)(μ-bpp)(H2O)n1 (H3L = 5-(3,4-dicarboxylphenoxy) nicotinic acid, bpp = 1,2-bis (4-pyridyl) propane)) has been successfully prepared under solvothermal conditions. Single-crystal X-ray diffraction analysis demonstrates that compound 1 possesses a 2-D layer structure with (3-c)(4-c) 2-nodal (42ˑ63ˑ8) (42ˑ6) topology, which then self-assembles into a final 3-D supramolecular network via the interlayer π⋯π interactions. Magnetic studies indicate that there exist weak-anti-ferromagnetic exchange interactions between CoII ions. More importantly, compound 1 represents a rare example of a fluorescent CP sensor which can dually probe ascorbic acid (AA) and acetylacetone (acac) in aqueous solution. The probable sensing mechanism of both analytes has also been discussed in this paper.