纳米水稳型C6060(n60)促进Zn2＋和Cr6＋在大型溞体内的吸收、抗氧化性和急性毒性

Aqueous Stable Fullerene Nanocrystals nC_(60)Promoted the Accumulation,Anti-oxidation and Acute Toxicity of Zn^(2+) and Cr^(6+) on Daphnia magna

富勒烯(C60)作为一种被广泛使用的纳米工程材料,其环境行为和所造成的毒效应越来越引起人们的关注,特别是其与重金属的联合毒性。文章选取模式生物大型溞研究纳米水稳型富勒烯(nC60)与Zn2+和Cr6+的联合毒性。按EPA 2024急性毒性试验结果,nC60对大型溞48 h-LC50为0.47 mg·L-1,最大无观察效应浓度(NOEC)为0.10 mg·L-1。NOEC浓度选定为nC60亚急性试验浓度,用于联合毒性试验。nC60增强了Zn2+和Cr6+对大型溞的毒性,Zn2+和Cr6+对大型溞48 h-LC50分别由2.33 mg·L-1和0.40mg·L-1降低为1.52 mg·L-1和0.33 mg·L-1;nC60增加了大型溞对Zn2+和Cr6+的摄入,暴露1440 min后体内Zn2+和Cr6+累积量分别由6.52μg·g-1湿重和1.52μg·g-1湿重增加到9.98μg·g-1湿重和3.01μg·g-1湿重;nC60和Zn2+和Cr6+联合作用于大型溞后,大型溞SOD酶活性均呈现出增强的诱导现象,联合作用时诱导作用强于两种物质单独作用。此研究表明:在亚急性浓度下,nC60增强了Zn2+和Cr6+对大型溞的毒性,提高了大型溞体内Zn2+和Cr6+的积累,并提高大型溞体内自由基活性。

Fullerene, as a widely used nano-material, draws many concerns on its environmental behaviors and potentials, especially on the joint toxicity of nC60 and heavy metals. In this research, Daphnia magna（D. magna） was selected to assay the joint toxicity of nC60 and heavy metal ions of Zn2 ＋/Cr6 ＋. The 48 h-LC50 and maximal non-observed effective concentration（NOEC） on D. magna were determined as 0.47 mg·L-1and 0.10 mg·L-1, respectively, using EPA2024 method. NOEC at 0.10 mg·L-1was selected as the sub-lethal concentration of nC60 in subsequence experiments.nC60 enhanced the toxicity of Zn2 ＋and Cr6 ＋on mortalities of D. magna neonates and the 48 h-LC50 values of Zn2 ＋and Cr6 ＋were decreased from 2.33 mg·L-1and 0.40 mg·L-1to 1.52 mg·L-1and 0.33 mg·L-1, respectively. nC60 promoted the body-burden of Zn2 ＋and Cr6 ＋from 6.52 μg·（g wet weight）-1and 1.52 μg·（g wet weight）-1to 9.98 μg·（g wet weight）-1and 3.01 μg·（g wet weight）-1, respectively. nC60 also enhanced the SOD activities in D. magna. Therefore,these results can be concluded that the nC60 in sub-lethal concentration enhanced the toxicity of Zn2 ＋and Cr6 ＋on D.magna neonates, enhanced the accumulation of Zn2 ＋and Cr6 ＋, and promoted the SOD activities of D. magna.