Amino acid and acetone fluorescence sensors based on a stable light-emitting Cd(II) metal-organic framework with derivatives of isonicotinic acid

As one of the most promising category of functional materials, luminescent metal-organic frameworks (LMOFs) have been widely investigated as fluorescence chemical sensors which can offer a reliable diagnostic tools in biomedical research. Herein, a luminescent Cd-MOF [Cd2(L)2(H2O)]n (Cd-MOF) (H2L = 3-(3-carboxylphenyl) isonicotinic acid), was synthesized by and characterized in detail. Single-crystal structure determination reveals that Cd-MOF crystalizes in the monoclinic crystal system with C2/c space group. Experimental results show that Cd-MOF is a highly selective and sensitive luminescent sensor for rapidly detecting acetone, L-Tryptophane (LTrp) and L- Aspartic acid (L-Asp) in water. It can significantly test acetone in common solvents, selectively identify L-Trp-and L-Asp-in 12 amino acid aqueous solutions, and enhance the fluorescence signal of Tryptophan and quench L-Asp-with the detection limit of 17.6 mu M and 68.8 mu M respectively. However, upon the interaction with electron rich amino acid (L-Trp), the Cd-MOF shows the selective "Turn-On" behavior, which may also be supported by the DFT studies.