Design of an antenna effect Eu(iii)-based metal–organic framework for highly selective sensing of Fe3+

Abstract

Highly selective sensing of Fe³⁺ is very important due to its great effect on biological systems. A novel ligand [1,1′:4′,1′′:4′′,1′′′:4′′′,1′′′′-quinquephenyl]-2,2′′,2′′′′,5′′-tetracarboxylic acid (H₄qptca) was designed and successfully obtained for the first time via three steps in high total yields according to the absorption spectrum of Fe³⁺. The europium(III)-based metal–organic framework derived from H₄qptca, {[Eu(qptca)_1/2(H₂qptca)_1/2(H₂O)₂]·DMF}_n (referred to as SLX-1), was then synthesized and used as a water-stable and highly selective luminescent sensor for Fe³⁺ in aqueous solution with a comparable detection limit using Ln-MOF probes (6.45 μM) through the antenna effect of SLX-1. Furthermore, the luminescence quenching mechanism was also proposed as a competitive absorption mechanism.