Luminescent Metal–Phenolic Networks for Multicolor Particle Labeling

The development of fluorescence labeling techniques has attracted widespread interest in various fields, including biomedical science as it can facilitate high-resolution imaging and the spatiotemporal understanding of various biological processes. We herein report a supramolecular fluorescence labeling strategy using luminescent metal-phenolic networks (MPNs) constructed from metal ions, phenolic ligands, and common and commercially available dye molecules. The rapid labeling process (<5 min) produces ultrathin coatings (~10 nm) on diverse particles (e.g., organic, inorganic, and biological entities) with customized luminescence (e.g., red, blue, multichromatic, and white light) simply through the selection of fluorophores. The fluorescent coatings are stable at pH from 1 to 8 and in complex biological media owing to the dominant π interactions between the dyes and MPNs. These coatings exhibit negligible cytotoxicity and their strong fluorescence is retained even when internalized into intracellular compartments. This supramolecular fluorescence labeling strategy is expected to provide a versatile approach for fluorescence labeling with potential in diverse fields across the physical and life sciences, including materials science and biomedicine.