AIE-ligand-based luminescent Cd(ii)–organic framework as the first “turn-on” Fe3+ sensor in aqueous medium

Abstract

Excess iron ions are harmful to human health; therefore, it is essential to develop efficient methods to detect Fe³⁺. Herein, a new aggregation-induced emission (AIE) ligand (L), 4,4′-((9H-fluoren-9-ylidene)-methylene)dipyridine, was successfully synthesized and applied to construct a luminescent Cd(II)–organic framework [Cd(NDA)(L)(H₂O)₂]_n (1) with a two-dimensional architecture (H₂NDA = 1,4-naphthalenedicarboxylic acid). Specially, 1 possesses good water stability and exhibits superior luminescence enhancement (“turn-on”) sensing of Fe³⁺ with high sensitivity and selectivity in a water suspension. This represents the first example of a LMOF-based “turn-on” Fe³⁺ sensor in aqueous medium.