Interaction of functionalized fullerenes and metal accumulation in Daphnia magna

Abstract

 

In aquatic environments, transformation of pollutants by association with functionalized carbon‐based nanoparticles can dramatically change their cycling pathways. The present study quantified the uptake and depuration behavior of cadmium and zinc bound with functionalized fullerene nanoparticles (f‐nC₆₀) in a freshwater cladoceran, Daphnia magna, in a well‐dispersed medium. Metal uptake proceeded with a linear pattern during the 8‐h exposure period, and the uptake rate constants (k_u) were 1.3‐fold to 1.4‐fold higher for Cd or comparable for Zn bound with f‐nC₆₀ than those of the free ones. The assimilation efficiencies of Cd and Zn bound with f‐nC₆₀ were significantly enhanced when compared with those metals bound with algal food. Furthermore, the depuration of metals bound with f‐nC₆₀ was relatively slower compared to the depuration of metals bound with carbon nanotubes. A longer exposure to f‐nC₆₀ resulted in an even slower depuration of metals. The authors conclude that metal binding with f‐nC₆₀ as modified nanoparticles could serve as a new pathway for the elevated metal accumulation in Daphnia. Environ Toxicol Chem 2014;33:1122–1128. © 2014 SETAC

Daphnia, Cadmium, Zinc, Functionalized fullerene, Biokinetics