Water-soluble Tb3+ and Eu3+ complexes with ionophilic (ionically tagged) ligands as fluorescence imaging probes.

This article describes a straightforward and simple synthesis of ionically tagged water-soluble Eu(3+) and Tb(3+) complexes (with ionophilic ligands) applied for bioimaging of invasive mammal cancer cells (MDA-MB-231). Use of the task-specific ionic liquid 1-methyl-3-carboxymethyl-imidazolium chloride (MAI·Cl) as the ionophilic ligand (ionically tagged) proved to be a simple, elegant, and efficient strategy to obtain highly fluorescent water-soluble Eu(3+) (EuMAI) and Tb(3+) (TbMAI) complexes. TbMAI showed an intense bright green fluorescence emission selectively staining endoplasmic reticulum of MDA-MB-231 cells.