title: Toxic effect of Cr(VI) in presence of n-TiO2 and n-Al2O3 particles towards freshwater microalgae.
abstract: The reactivity and toxicity of the soluble toxicants in the presence of the engineered nanomaterials is not well explored. In this study, the probable effects of TiO2 and Al2O3 nanoparticles (n-TiO2, n-Al2O3) on the toxicity of Cr(VI) were assessed with the dominant freshwater algae, Scenedesmus obliquus, in a low range of exposure concentrations (0.05, 0.5 and 1μg/mL). In the presence of 0.05μg/mL n-TiO2, the toxicity of Cr(VI) decreased considerably, which was presumably due to the Cr(VI) adsorption on the nanoparticle surface leading to its aggregation and precipitation. The elevated n-TiO2 concentrations (0.5 and 1μg/mL) did not significantly influence Cr(VI) bio-availability, and a dose dependent toxicity of Cr(VI) was observed. On the other hand, n-Al2O3 did not have any significant effect on the Cr(VI) toxicity. The microscopic observations presented additional information on the morphological changes of the algal cells in the presence of the binary toxicants. The generation of reactive oxygen species (ROS) suggested contribution of oxidative stress on toxicity and LDH release confirmed membrane permeability of algal cells upon stress.
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors.forename: Swayamprava
authors.initials: S
authors.lastname: Dalai
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors.forename: Sunandan
authors.initials: S
authors.lastname: Pakrashi
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors.forename: M
authors.initials: M
authors.lastname: Bhuvaneshwari
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors.forename: V
authors.initials: V
authors.lastname: Iswarya
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors.forename: N
authors.initials: N
authors.lastname: Chandrasekaran
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, India. Electronic address: amitav@vit.ac.in.
authors.forename: Amitava
authors.initials: A
authors.lastname: Mukherjee
mesh_terms: D000537:Aluminum Oxide / Q000633:toxicity*; D002857:Chromium / Q000633:toxicity*; D004347:Drug Interactions; D005618:Fresh Water; D053768:Metal Nanoparticles / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D044444:Scenedesmus / Q000187:drug effects*; D014025:Titanium / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D002857:Chromium; C009495:titanium dioxide; C074702:chromium hexavalent ion; D014025:Titanium; D000537:Aluminum Oxide
keywords: Adsorption; Algae; Binary toxicity; Cr(VI); Metal oxide nanoparticles