The phosphatase-like activity of zirconium oxide nanoparticles and their application in near-infrared intracellular imaging.

In this study, the phosphatase mimetic activity of zirconium oxide nanoparticles (ZrO2 NPs) has been demonstrated. They can effectively catalyze the dephosphorylation of a series of commercial fluorogenic and chromogenic substrates of natural phosphatases. Compared with natural phosphatases, ZrO2 NPs possess several advantages such as low cost, facile preparation procedures, and high stability in a broader pH range or at high temperatures. In addition, the activity of ZrO2 NPs toward some important biomolecules was investigated. The ZrO2 NPs can catalyze the dephosphorylation of ATP and o-phospho-l-tyrosine, but they cannot react with DNA strands. These data are important for the further bio-related applications of ZrO2 NPs. Finally, the potential application of ZrO2 NPs in intracellular imaging is also demonstrated by using a near-infrared fluorescent substrate of alkaline phosphatase.