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.