Bifunctional Paramagnetic and Luminescent Clays Obtained by Incorporation of Gd³⁺ and Eu³⁺ Ions in the Saponite Framework

Abstract

[Abstract] A novel bifunctional saponite clay incorporating gadolinium (Gd³⁺) and europium (Eu³⁺) in the inorganic framework was prepared by one-pot hydrothermal synthesis. The material exhibited interesting luminescent and paramagnetic features derived from the co-presence of the lanthanide ions in equivalent structural positions. Relaxometry and photoluminescence spectroscopy shed light on the chemical environment surrounding the metal sites, the emission properties of Eu³⁺, and the dynamics of interactions between Gd³⁺ and the inner-sphere water placed in the saponite gallery. The optical and paramagnetic properties of this solid make it an attractive nanoplatform for bimodal diagnostic applications.