title: Different toxicity mechanisms between bare and polymer-coated copper oxide nanoparticles in Lemna gibba.
abstract: In this report, we investigated how the presence of a polymer shell (poly(styrene-co-butyl acrylate) alters the toxicity of CuO NPs in Lemna gibba. Based on total Cu concentration, core-shell CuO NPs were 10 times more toxic than CuO NPs, inducing a 50% decrease of growth rate at 0.4 g l(-1) after 48-h of exposure while a concentration of 4.5 g l(-1) was required for CuO NPs for a similar effect. Toxicity of CuO NPs was mainly due to NPs solubilization in the media. Based on the accumulated copper content in the plants, core-shell CuO NPs induced 4 times more reactive oxygen species compared to CuO NPs and copper sulfate, indicating that the presence of the polymer shell changed the toxic effect induced in L. gibba. This effect could not be attributed to the polymer alone and reveals that surface modification may change the nature of NPs toxicity.
authors.affiliation: Department of Chemistry, University of Quebec in Montreal, Case Postal 8888, Succursale Centre-Ville, Montreal, QC H3C 3P8, Canada.
authors.forename: François
authors.initials: F
authors.lastname: Perreault
authors.affiliation: Department of Chemistry, University of Quebec in Montreal, Case Postal 8888, Succursale Centre-Ville, Montreal, QC H3C 3P8, Canada.
authors.forename: Radovan
authors.initials: R
authors.lastname: Popovic
authors.affiliation: Department of Chemistry, University of Quebec in Montreal, Case Postal 8888, Succursale Centre-Ville, Montreal, QC H3C 3P8, Canada. Electronic address: dewez.david@uqam.ca.
authors.forename: David
authors.initials: D
authors.lastname: Dewez
mesh_terms: D029064:Araceae / Q000187:drug effects* / Q000502:physiology; D003300:Copper / Q000633:toxicity*; D053768:Metal Nanoparticles / Q000633:toxicity*; D011108:Polymers / Q000737:chemistry / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D018570:Risk Assessment; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D011108:Polymers; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D003300:Copper; C000520:cuprous oxide
keywords: 2′,7′-Dichlorodihydrofluorescein diacetate; 2′,7′-Dichlorofluorescein; CS-CuO NPs; Copper oxide nanoparticle; DCF; FDA; H(2)DCFDA; Lemna gibba; NPs; Nanotoxicology; P.I.; PSII; Photosystem II; Photosystem II operational quantum yield; Polymer coating; ROS; Reactive oxygen species; core–shell copper oxide nanoparticles; fluorescein diacetate; nanoparticles; performance index of Photosystem II; reactive oxygen species; Φ(′)(M)II