Uptake of Metal (Zn, Y, Ti) Oxide Nanoparticles by Poaceae and Cucurbitaceae Plants Based On Metal Properties and Surface Conditions.

Metal nanoparticles (NPs) may serve as biomarkers, as the surfaces can be chemically modified to enable an analysis of several biosystems, including plant pathogenesis. We supplied metal oxide NPs including those of ZnO, TiO2, Y2O3, and Y2O3 doped with europium to plants of eight species of the Poaceae and Cucurbitaceae families. The plants were grown using hydroponics, where NPs were incorporated into the cultivation media. Energy-dispersive X-ray spectroscopy was used to detect the uptake of NPs by the plant in regions of the root, stem, and leaf. Results show that ZnO NPs were taken up more readily by the plants compared to other NPs. Unmodified NPs were only delivered up till the stems and not the leaves; however, when the surfaces were modified using photoinduced hydrophilization supplemented with poly(ethylene glycol), NPs were delivered to the leaves of plants. It is suggested that plants readily take up metals such as zinc that function as nutrients. Additionally, hydrophilization of NP surfaces using UV irradiation enhances uptake, where modified ZnO and TiO2 NPs may be delivered to the leaves. These findings may be used to design biomarker systems for detecting tissue damage and infections in various crops.