Ag nanoparticles: size- and surface-dependent effects on model aquatic organisms and uptake evaluation with NanoSIMS

Abstract

This study aims to assess the effects of Ag particles synthesised by a chemical (Ag 20, 200 nm) and biological method (Ag 23, 27 nm) in aquatic organisms: the bacterium Vibrio fischeri, the alga Desmodesmus subspicatus and the crustacean Daphnia magna. Ag particles exerted toxic effects in all organisms studied with Ag particles 23 nm being the most potent. Although soluble Ag was released in all media, the differences between the tested Ag particles still cannot be explained solely based on soluble Ag. NanoSIMS analysis performed with D. magna showed that apart from their localisation in the gut lumen, Ag 200 nm and Ag NPs 23 nm seemed to pass through the epithelial barrier as well. Ag NPs 23 nm localised in specific areas seemed to be within the ovaries. This study strengthens the argument that size, method of synthesis as well as surface chemistry may affect the uptake and toxic effects of Ag NPs.

Keywords::

• Ag nanoparticles
• Daphnia magna
• Desmodesmus subspicatus
• Vibrio fischeri
• NanoSIMS

Acknowledgements

The authors would like to thank Camilla Carlson (Norwegian School of Veterinary Science, Oslo, Norway) and Tore-Geir Iversen (The Norwegian Radium Hospital, Oslo, Norway) for their valuable help and advice on the size and zeta potential measurements. The work of Esther Lentzen and Patrick Grysan (Department of Material Sciences, Centre de Recherche Public-Gabriel Lippmann, Luxembourg) on NanoSIMS analysis as well as the expertise of Sylvie Migot (Ecole des Mines, Nancy, France) in TEM are gratefully acknowledged. The authors also thank Johanna Ziebel for the ICP-MS analysis and Servane Contal, Henry-Michel Cauchie and Delphine Collard (Department of Environment and Agrobiotechnologies, Centre de Recherche Public-Gabriel Lippmann, Luxembourg) for their support with the set-up of the assays. In addition, many thanks to Hans van den Berg (Wageningen University, The Netherlands) for his advice on Daphnia magna anatomy.