title: A Multimethod Approach for Investigating Algal Toxicity of Platinum Nanoparticles.
abstract: The ecotoxicity of platinum nanoparticles (PtNPs) widely used in for example automotive catalytic converters, is largely unknown. This study employs various characterization techniques and toxicity end points to investigate PtNP toxicity toward the green microalgae Pseudokirchneriella subcapitata and Chlamydomonas reinhardtii. Growth rate inhibition occurred in standard ISO tests (EC50values of 15-200 mg Pt/L), but also in a double-vial setup, separating cells from PtNPs, thus demonstrating shading as an important artifact for PtNP toxicity. Negligible membrane damage, but substantial oxidative stress was detected at 0.1-80 mg Pt/L in both algal species using flow cytometry. PtNPs caused growth rate inhibition and oxidative stress in P. subcapitata, beyond what was accounted for by dissolved Pt, indicating NP-specific toxicity of PtNPs. Overall, P. subcapitata was found to be more sensitive toward PtNPs and higher body burdens were measured in this species, possibly due to a favored binding of Pt to the polysaccharide-rich cell wall of this algal species. This study highlights the importance of using multimethod approaches in nanoecotoxicological studies to elucidate toxicity mechanisms, influence of NP-interactions with media/organisms, and ultimately to identify artifacts and appropriate end points for NP-ecotoxicity testing.
authors: Department of Environmental Engineering, Technical University of Denmark , DK-2800 Kongens Lyngby, Denmark.
authors: Sara N
authors: SN
authors: Sørensen
authors: Department of Chemistry, Technical University of Denmark , DK-2800 Kongens Lyngby, Denmark.
authors: Christian
authors: C
authors: Engelbrekt
authors: Department of Environmental Engineering, Technical University of Denmark , DK-2800 Kongens Lyngby, Denmark.
authors: Hans-Christian H
authors: HH
authors: Lützhøft
authors: Environmental Biogeochemistry and Ecotoxicology, Institute F.-A. Forel, Earth and Environmental Sciences, Faculty of Sciences, University of Geneva , CH-1211 Geneva, Switzerland.
authors: Javier
authors: J
authors: Jiménez-Lamana
authors: IPM-Intelligent Pollutant Monitoring , DK-2800 Kongens Lyngby, Denmark.
authors: Jafar S
authors: JS
authors: Noori
authors: Department of Micro- and Nanotechnology, Technical University of Denmark , DK-2800 Kongens Lyngby, Denmark.
authors: Fatima A
authors: FA
authors: Alatraktchi
authors: Department of Environmental Engineering, Technical University of Denmark , DK-2800 Kongens Lyngby, Denmark.
authors: Cristina G
authors: CG
authors: Delgado
authors: Environmental Biogeochemistry and Ecotoxicology, Institute F.-A. Forel, Earth and Environmental Sciences, Faculty of Sciences, University of Geneva , CH-1211 Geneva, Switzerland.
authors: Vera I
authors: VI
authors: Slaveykova
authors: Department of Environmental Engineering, Technical University of Denmark , DK-2800 Kongens Lyngby, Denmark.
authors: Anders
authors: A
authors: Baun
mesh_terms: D016825:Chlamydomonas reinhardtii; D000460:Chlorophyta; D058086:Microalgae; D053758:Nanoparticles / Q000737:chemistry*; D010984:Platinum
chemical_list: D010984:Platinum