To utilize this bioorthogonal turn-on emission for more specific purposes, the hydroxy group of BCN-OH was functionalized with several side chains targeting specific organelles: a triphenylphosphine group (TPP) to target mitochondria, a 1,2-Distearoyl-sn-glycero-3-phosphorylethanolamine (DSPE) unit to target the cell membrane, and a halotag ligand (Halo) to localize to the hydrophobic environment inside the cell. These compounds were designated as BCNTPP, BCNDSPE, and BCNHalo, correspondingly (Figure ).