The potential ecological risk of multiwall carbon nanotubes was modified by the radicals resulted from peroxidase-mediated tetrabromobisphenol A reactions.
Extensive studies have been conducted on the environmental degradation of multiwall carbon nanotubes (MWCNTs), but primarily focused on the extent and rate of MWCNTs mineralization. Few studies have explored possible structural changes that may occur to MWCNTs during natural or engineered processes. We systematically examined MWCNTs in oxidative coupling reactions in the presence of a common contaminant tetrabromobisphenol A (TBBPA). MWCNTs was modified by the radicals of TBBPA resulting from peroxidase-mediated coupling reaction. Interactions between TBBPA radicals and MWCNTs were definitely confirmed by analyzing the characteristic mass spectrometry response of bromine in TBBPA and the structures of MWCNTs. After reaction with TBBPA radicals for 60 min, the content of bromine contained in MWCNTs was 6.84(±0.12)%, a quantity equivalent to a 501.65(±2.19) mg loading of TBBPA per gram MWCNTs. Modified MWCNTs had better stability and smaller sizes than that of MWCNTs and TBBPA-adsorbed MWCNTs. Assessment using zebrafish embryos revealed that the modified MWCNTs passed through the chorion and entered the embryo inducing acute toxicity, while the MWCNTs/TBBPA-adsorbed MWCNTs was trapped by chorion. These findings indicated that MWCNTs was modified in peroxidase-mediated coupling reactions, and suggested that such modifications may have an influence on the ecological risks of MWCNTs.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, PR China.
Kun
K
Lu
College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, 30223, United States.
Qingguo
Q
Huang
Division of NanoMedicine, Department of Medicine, University of California, Los Angeles, United States.
Tian
T
Xia
National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, PR China.
Xiaofeng
X
Chang
National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, PR China.
Peng
P
Wang
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, PR China.
Shixiang
S
Gao
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, PR China. Electronic address: lmao@nju.edu.cn.
Liang
L
Mao
D000818:Animals; D004463:Ecology; D004785:Environmental Pollutants / Q000737:chemistry / Q000633:toxicity*; D008956:Models, Chemical; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000633:toxicity; D010084:Oxidation-Reduction; D010544:Peroxidases / Q000737:chemistry*; D011075:Polybrominated Biphenyls / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D018570:Risk Assessment; D018675:Toxicity Tests; D015027:Zebrafish / Q000378:metabolism
D004785:Environmental Pollutants; D037742:Nanotubes, Carbon; D011075:Polybrominated Biphenyls; D010544:Peroxidases; C020806:tetrabromobisphenol A
Characterizations; Ecological risks; Physicochemical changes; Toxicity; Zebrafish embryos