Plant uptake studies have revealed that there are no significant differences in uptake of Au-NPs based on size or relative hydrophobicity of the surface coating, although spatial analysis by laser ablation ICP-MS of leaf tissues reveals heterogeneous distribution of the larger particles (30-50 nm) in the leaves, being concentrated in larger vasulature. This may have implications to the trophic transfer of plant accumulated NPs to herbivorous consumers. No uptake in wheat was observed for any treatment, suggesting important species differences in the bioavailability of NPs.
Initial studies on model ion-loaded membrane vesicles demonstrate that both tannic acid and citrate capped Au-NPs induce significant ion (proton) leakage due to the disruption of phospholipid arrangement for vesicles of two different compositions (plant derived-azolectin and plant and fungal mixture azolectin and ergosterol). However, the vesicles with ergosterol were far more sensitive to all particles and displayed surface functionalization dependent differences in proton leakage, with much greater leakage observed for the citrate capped Au-NPs.