Functionalized Gold Nanoclusters Identify Highly Reactive Oxygen Species in Living Organisms

Surface engineering of nanomaterials allows fine tuning of their interactions with biological systems, and thus can benefit their applications in monitoring intracellular events. Herein, the facile synthesis of ligand‐functionalized gold nanoclusters (AuNCs) as intracellular probes targeting highly reactive oxygen species (hROS, such as •OH, ClO−, and ONOO−) is demonstrated. Selected ligands such as quaternary ammonium and oligopeptides are utilized to modulate the surface chemistry of AuNCs. It is shown that AuNCs decorated with the cell‐penetrating oligoarginine peptide facilitate cellular uptake and intracellular imaging of hROS in living cells and the zebrafish, with high stability and selectivity.