Bright, highly water-soluble triazacyclononane europium complexes to detect ligand binding with time-resolved FRET microscopy.

Luminescent europium complexes are used in a broad range of applications as a result of their particular emissive properties. The synthesis and application of bright, highly water-soluble, and negatively charged sulfonic- or carboxylic acid derivatives of para-substituted aryl-alkynyl triazacyclononane complexes are described. Introduction of the charged solubilizing moieties suppresses cellular uptake or adsorption to living cells making them applicable for labeling and performing assays on membrane receptors.

Arginine conjugates of metallo-supramolecular cylinders prescribe helicity and enhance DNA junction binding and cellular activity.

The conjugation of arginine residues at the ends of a metallo-supramolecular triple-helical cylinder enables absolute control over the helicity of the cylinder core, and boosts the DNA junction recognition by the complexes and their activity against a cancer cell line.