New highly luminescent 3D Tb(III)-MOF as selective sensor for antibiotics

A stable 3D metal-organic framework (MOF) with formula [Tb(L)(H2O)2·3H2O]n (H3L = 5-(4′-carboxylphenoxy)isophthalic acid) (1) has been synthesized solvothermally and characterized using spectroscopic techniques and crystallographically. The 3D MOF is constructed from 1D Tb(III)-based chains where the overall structure is 3D 5-connected bnn topology framework with Schläfli symbol 46.64. The MOF exhibits displays intense green emission on excitation at 273 nm and had been used as turn-off luminescent sensor and exhibits sensitive and selective luminescence detectability for sulfamethazine (SMZ) (Ksv = 1.28 × 103 M−1 and LOD = 1.43 ppm). The MOF 1 also possesses excellent stability and recyclability to detect SMZ. The plausible mechanistic pathway for the detrioration in the luminescent intensity of the MOF in presence of antibiotics have been explained with the help of theoretical calculations and Hirshfeld surface analyses.