Citrate coated silver nanoparticles change heavy metal toxicities and bioaccumulation of Daphnia magna

• Published in: Chemosphere (Oxford) Vol. 143; pp. 99 - 105
• Main Authors: Kim, Injeong, Lee, Byung-Tae, Kim, Hyun-A, Kim, Kyoung-Woong, Kim, Sang Don, Hwang, Yu-Sik
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.01.2016
• Subjects: Acute toxicity; Animals; Bioaccumulation; Bioavailability; Cadmium; Calcium - chemistry; Citrates; Citric Acid - chemistry; Copper; Copper - pharmacology; Daphnia - drug effects; Daphnia magna; Divalent cation; Environmental Monitoring - methods; Freshwater; Heavy metals; Ligands; Magnesium - chemistry; Metal Nanoparticles - chemistry; Metals, Heavy - toxicity; Mixture toxicity; Nanoparticles; Nanoparticles - chemistry; Negative charge; Silver Nitrate - chemistry; Surface interaction; Surface Properties; Toxicity; Surface interaction; Bioavailability; Negative charge; Mixture toxicity; Divalent cation; Acute toxicity
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2015.06.046

•There were no significant differences in the acute toxicities of As(V) and Cu.•However, the bioaccumulations of As(V) and Cu were reduced by silver nanoparticle.•Only Cd acute toxicity and bioaccumulation were enhanced by silver nanoparticle. Citrate-coated AgNPs (c-AgNPs) have negatively charged surfaces and their surface interactions with heavy metals can affect metal toxicity in aquatic environments. This study used Daphnia magna to compare the acute toxicities and bioaccumulation of As(V), Cd, and Cu when they interact with c-AgNPs. The 24-h acute toxicities of As(V) and Cu were not affected by the addition of c-AgNPs, while bioaccumulation significantly decreased in the presence of c-AgNPs. In contrast, both the 24-h acute toxicity and bioaccumulation of Cd increased in the presence of c-AgNPs. These toxicity and bioaccumulation trends can be attributed to the interactions between the AgNP surface and the heavy metals. As(V) and c-AgNPs compete by negative charge, decreasing As(V) toxicity. Copper adheres readily to c-AgNP citrate, decreasing Cu bioavailability, and thus reducing Cu toxicity and bioaccumulation. Citrate complexes with divalent cations such as Ca and Mg reduce the competition between divalent cations and Cd on biotic ligand, increasing toxicity and bioaccumulation of Cd. This study shows that surface properties determine the effect of c-AgNPs on heavy metal toxicities and bioaccumulations; hence, further studies on the effect of nanoparticle by it surface properties are warranted.