Figure 1.

Survival curves of Daphnia magna (D. magna) neonates exposed to (a) positively charged mass concentration; (b) negatively charged mass concentration; (c) positively charged number concentration; and (d) negatively charged number concentration of spherical, short rod, and long rod shaped gold engineered nanomaterials (ENMs). Note: Even at the highest concentration of 50 µg/mL, negatively charged ENMs did not acquire a half maximal effective concentration (EC₅₀). Higher number concentrations for negatively charged ENMs can be seen in Figure S2.