title: 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-nC(60)) 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 (ku) were 1.3-fold to 1.4-fold higher for Cd or comparable for Zn bound with f-nC(60) than those of the free ones. The assimilation efficiencies of Cd and Zn bound with f-nC(60) were significantly enhanced when compared with those metals bound with algal food. Furthermore, the depuration of metals bound with f-nC(60) was relatively slower compared to the depuration of metals bound with carbon nanotubes. A longer exposure to f-nC(60) resulted in an even slower depuration of metals. The authors conclude that metal binding with f-nC(60) as modified nanoparticles could serve as a new pathway for the elevated metal accumulation in Daphnia.
authors.affiliation: Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China.
authors.forename: Zhi-Guo
authors.initials: ZG
authors.lastname: Yu
authors.forename: Wen-Xiong
authors.initials: WX
authors.lastname: Wang
mesh_terms: D000818:Animals; D002104:Cadmium / Q000378:metabolism*; D003621:Daphnia / Q000187:drug effects / Q000378:metabolism*; D037741:Fullerenes / Q000493:pharmacokinetics* / Q000633:toxicity; D037742:Nanotubes, Carbon; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics* / Q000633:toxicity; D015032:Zinc / Q000378:metabolism*
chemical_list: D037741:Fullerenes; D037742:Nanotubes, Carbon; D014874:Water Pollutants, Chemical; D002104:Cadmium; D015032:Zinc; C069837:fullerene C60
keywords: Biokinetics; Cadmium; Daphnia; Functionalized fullerene; Zinc