Pursuit of sustainable agrifood production has been driving the emergence of precision agriculture. Foliar application of nanomaterials (NMs) for nutrient delivery allow to directly target the plant, limiting soil inputs, waste, and environmental degradations. However our understanding of the fate and behavior of NMs after their foliar deposition (bioavailable species, NM-leaf interaction, routes of uptake and translocation) remains limited. We are studying the impact of various Zn-based NMs, on their foliar uptake and bioavailability when deposited to pepper plants leaves. The NMs tested are bare ZnO NMs and surface modified ZnO NMs with Zn3(PO4)2. The phosphate shell is meant to study if a less soluble coating will enhance Zn bioavailability through surface charge modification and/or change the ionic release on the leaf. In this proposal we propose to fstudy the route of foliar uptake of the bioavailable Zn species, their translocation and their transformation inside the leaf.