A dual-functional Terbium-organic framework fluorescence sensor for ratiometric identification of bilirubin and...

A novel terbium-based metal-organic framework (Tb-DDC) was constructed using a butterfly-shaped ligand 5,5'-di(1H-1,2,4-triazol-1-yl)-[1,1'-biphenyl]-3,3'-dicarboxylic acid (H₂DDC). The Tb-DDC could function as a highly effective ratiometric fluorescence sensor for bilirubin detection, achieving low detection limits of 0.083 μM in aqueous medium, 0.097 μM in Tris-HCl buffer and excellent recoveries (96.7 %-105.2 %) in simulated blood fluid. To our knowledge, this represents the first report of a MOF-based ratiometric fluorescence sensor for bilirubin. Furthermore, Tb-DDC displays a sensitive fluorescence sensor toward phenylglyoxylic acid, with an LOD of 1.73 μM (2.60 × 10^-4 mg mL^-1), which is significantly lower than the ACGIH-specified biological exposure index (2.5 mg mL^-1). Upon interaction with phenylglyoxylic acid, the photoluminescence color of Tb-DDC shifts visibly from green to light blue under 365 nm UV light, facilitating the development of a smartphone-assisted portable platform for real-time, on-site phenylglyoxylic acid detection. This dual-functional Tb-MOF sensor demonstrates high selectivity, sensitivity, reversibility, and practical applicability in complex biological matrices, showcasing its significant potential for clinical diagnostics and environmental monitoring.