Nanoparticle uptake by alfalfa seedlings.

<p>(A) Transmission electron microscopy and (B) size frequency distribution of commercially obtained gold nanoparticles. (C) Transmission electron microscopy of five-day-old alfalfa seedlings 24 h after treatment with ionic gold, as K(AuCl₄), or nanoparticles. Nanoparticle treatments were of equivalent molarity to the control 50 mg/L gold, as K(AuCl₄). Three seedlings were sectioned at each treatment. NP, nanoparticle; Cy, cytoplasm; Cw, cell wall.