Amine functionalized ZrO nanoparticles as biocompatible and luminescent probes for ligand specific cellular imaging.

Surface functionalized ZrO nanoparticles show strong photoluminescence and are a versatile tool for cellular targeting due to their chemical functionality. They are highly photostable, biocompatible and amenable to coupling with bioligands (e.g. secondary goat anti-rabbit antibody (GAR) and tri-phenyl phosphine (TPP)) via carbodiimide chemistry. Antibody (GAR) functionalized ZrO nanoparticles were used to image the nuclear protein Sirt6, whereas triphenyl phosphonium ion (TPP) functionalized ZrO nanoparticles specifically targeted the mitochondria. The versatility and easiness of the ZrO surface modification opens up new possibilities for designing non-toxic water dispersible and photostable photoluminescent NPs.