Anion/Cation (H₂PO₄^- and Fe³⁺) induced dual luminescence quenching effect based on terbium solid sensor

An investigation on the photophysical properties of the newly designed terbium imidazole-4,5-dicarboxylic acid complex encapsulated in the inert matrices (tetraethoxysilane, TEOS) was performed. The composite material was very stable and showed strong green emission in pure water. Interestingly, we discovered that the luminescence of hybrid material was selectively responsive to H₂PO₄^-. ¹H-NMR and fluorescence spectra supported that the receptor had strong affinity to dihydrogen phosphate. Meanwhile, the luminescence was quenched by Fe³⁺ when adding different metal ions such as Fe³⁺, Pd²⁺, Cd²⁺, Co²⁺ and Mn²⁺ concomitantly. Moreover, thin film was successfully prepared by the same materials and it also exhibited selective recognition behavior to the above two ions. © 2010 The Chinese Society of Rare Earths.