Foliar exposure of the crop Lactuca sativa to silver nanoparticles: Evidence for internalization and changes in Ag speciation

- Ag-NPs are internalized inside lettuce leaves after foliar exposure to a suspension of Ag-NPs.
- A classical washing process is inefficient at decreasing significantly Ag content.
- Ag-NPs in plants undergo oxidation, and resulting ionic Ag are complexed with organic compounds including thiol-containing molecules.
- Foliar exposure to Ag-NPs does not lead to detectable phytotoxicity symptoms.