title: Citrate coated silver nanoparticles change heavy metal toxicities and bioaccumulation of Daphnia magna.
abstract: 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.
authors.affiliation: School of Environmental Science and Engineering, Gwangju Institute of Science and Technology, 123 Chemdangwagi-ro, Buk-gu, Gwangju, Republic of Korea.
authors.forename: Injeong
authors.initials: I
authors.lastname: Kim
authors.affiliation: School of Environmental Science and Engineering, Gwangju Institute of Science and Technology, 123 Chemdangwagi-ro, Buk-gu, Gwangju, Republic of Korea. Electronic address: btlee@gist.ac.kr.
authors.forename: Byung-Tae
authors.initials: BT
authors.lastname: Lee
authors.affiliation: School of Environmental Science and Engineering, Gwangju Institute of Science and Technology, 123 Chemdangwagi-ro, Buk-gu, Gwangju, Republic of Korea.
authors.forename: Hyun-A
authors.initials: HA
authors.lastname: Kim
authors.affiliation: School of Environmental Science and Engineering, Gwangju Institute of Science and Technology, 123 Chemdangwagi-ro, Buk-gu, Gwangju, Republic of Korea.
authors.forename: Kyoung-Woong
authors.initials: KW
authors.lastname: Kim
authors.affiliation: School of Environmental Science and Engineering, Gwangju Institute of Science and Technology, 123 Chemdangwagi-ro, Buk-gu, Gwangju, Republic of Korea.
authors.forename: Sang Don
authors.initials: SD
authors.lastname: Kim
authors.affiliation: Future Environmental Research Center, Korea Institute of Toxicology, Jinju 660-844, Republic of Korea; Human and Environmental Toxicology Program, University of Science and Technology (UST), Daejeon 305-350, Republic of Korea.
authors.forename: Yu-Sik
authors.initials: YS
authors.lastname: Hwang
mesh_terms: D000818:Animals; D002118:Calcium / Q000737:chemistry; D019343:Citric Acid / Q000737:chemistry*; D003300:Copper / Q000494:pharmacology; D003621:Daphnia / Q000187:drug effects*; D004784:Environmental Monitoring / Q000379:methods; D008024:Ligands; D008274:Magnesium / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D019216:Metals, Heavy / Q000633:toxicity*; D053758:Nanoparticles / Q000737:chemistry*; D012835:Silver Nitrate / Q000737:chemistry; D013499:Surface Properties
chemical_list: D008024:Ligands; D019216:Metals, Heavy; D019343:Citric Acid; D003300:Copper; D012835:Silver Nitrate; D008274:Magnesium; D002118:Calcium
keywords: Acute toxicity; Bioavailability; Divalent cation; Mixture toxicity; Negative charge; Surface interaction