Highly sensitive and selective sensing of ascorbic acid in water with a three-dimensional terbium(III)-based coordination polymer

•A 3D terbium(III)-based coordination polymer by dual-ligands is synthesized.•The supramolecular architecture is constructed by hydrogen bonding interactions.•Energy transfer process between the two ligands and Tb3+ is clearly explained by DFT.•The characteristic fluorescence of Tb3+ be significantly quenched by ascorbic acid.•The detection mechanism is discussed in detail based on the frontier orbital theory.