title: Impacts of low-molecular-weight organic acids on aquatic behavior of graphene nanoplatelets and their induced algal toxicity and antioxidant capacity.
abstract: Knowledge of the interaction between graphene-based materials and low-molecular-weight organic acids (LOAs) is essential to understand fate and effects of graphene-based materials in the aquatic environment, but this interaction remains poorly elucidated. In this study, the effects of LOAs on the physicochemical properties of graphene nanoplatelets (GNPs) in an aqueous medium and on the GNP toxicity to algae were studied. The unicellular green alga Scenedesmus obliquus was exposed to GNP suspensions in the presence of benzoic acid or gallic acid at various concentrations. The GNPs had smaller hydrodynamic sizes and the GNP suspensions were more stable and had higher or lower surface zeta potentials in the presence of LOAs than when LOAs were not present. The toxic effects in S. obliquus cultures incubated with GNP suspensions containing LOAs were related to the LOA concentration, and the presence of LOAs caused three effects: stimulation, alleviation, and synergistic inhibition. The intensities of the effects mainly correlated with the LOA concentration, the extent of agglomeration, and particle-induced oxidative stress. The results indicate that the environmental fates and toxicities of GNPs are strongly affected by the binding of GNPs to LOAs.
authors.affiliation: Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (AEET), Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, 210044, People's Republic of China. zhuang.wang@nuist.edu.cn.
authors.forename: Zhuang
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (AEET), Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, 210044, People's Republic of China.
authors.forename: Yucheng
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (AEET), Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, 210044, People's Republic of China. wangse@nuist.edu.cn.
authors.forename: Se
authors.initials: S
authors.lastname: Wang
authors.affiliation: Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (AEET), Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, 210044, People's Republic of China.
authors.forename: Hao
authors.initials: H
authors.lastname: Fang
authors.affiliation: Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (AEET), Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, 210044, People's Republic of China.
authors.forename: Defu
authors.initials: D
authors.lastname: Xu
authors.affiliation: Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (AEET), Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, 210044, People's Republic of China.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
mesh_terms: D000143:Acids / Q000737:chemistry*; D000975:Antioxidants / Q000494:pharmacology* / Q000633:toxicity; D019817:Benzoic Acid / Q000737:chemistry; D000460:Chlorophyta / Q000187:drug effects*; D054750:Ecotoxicology; D005707:Gallic Acid / Q000494:pharmacology; D006108:Graphite / Q000737:chemistry*; D008970:Molecular Weight; D053758:Nanoparticles; D009930:Organic Chemicals; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity
chemical_list: D000143:Acids; D000975:Antioxidants; D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D005707:Gallic Acid; D006108:Graphite; D019817:Benzoic Acid
keywords: Antioxidant capacity; Ecotoxicity; Fate; Graphene; Low-molecular-weight organic acids