Luminescent Peptide Labeling Based on a Histidine‐Binding Iridium(III) Complex for Cell Penetration and Intracellular Targeting Studies

Lighting up the cell: Peptides that are site-specifically labeled with a luminescent iridium(III) complex at histidine residues can penetrate cell membranes effectively, showing intracellular distribution and efficient mitochondrial targeting (see figure, CPP=cell-penetrating peptide, MTS=mitochondria-targeting sequences).