| Literature DB >> 19560243 |
Ai-Jun Miao1, Kathy A Schwehr, Chen Xu, Sai-Jin Zhang, Zhiping Luo, Antonietta Quigg, Peter H Santschi.
Abstract
In this study, we report that silver ions (Ag(+)) from the oxidative dissolution of silver engineered nanoparticles (Ag-ENs) determined the EN toxicity to the marine diatom Thalassiosira weissflogii. Most of the Ag-ENs formed non-toxic aggregates (>0.22 microm) in seawater. When the free Ag(+) concentration ([Ag(+)](F)) was greatly reduced by diafiltration or thiol complexation, no toxicity was observed, even though the Ag-ENs were better dispersed in the presence of thiols with up to 1.08 x 10(-5) M Ag-ENs found in the <0.22 microm fraction, which are orders of magnitude higher than predicted for the natural aquatic environment. The secretion of polysaccharide-rich algal exopolymeric substances (EPS) significantly increased at increasing [Ag(+)](F). Both dissolved and particulate polysaccharide concentrations were higher for nutrient-limited cells, coinciding with their higher Ag(+) tolerance, suggesting that EPS may be involved in Ag(+) detoxification.Entities:
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Year: 2009 PMID： 19560243 DOI： 10.1016/j.envpol.2009.05.047
Source DB: PubMed Journal: Environ Pollut ISSN： 0269-7491 Impact factor: 8.071