Graphene oxide interactions with co-existing heavy metal cations: adsorption, colloidal properties and joint toxicity
Graphene oxide interactions with co-existing heavy metal cations: adsorption, colloidal properties and joint toxicity
复制标题
氧化石墨烯与共存重金属阳离子的相互作用：吸附、胶体特性和联合毒性
DOI：
10.1039/c7en01012e
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发表时间：
2018-02-01
影响因子：
7.3
通讯作者：
Chen, Changlun
中科院分区：
文献类型：
--
作者：
Gao, Yang;Ren, Xuemei;Chen, Changlun
To find the linkage among the surface adsorption, colloidal stability and combined toxicity of graphene oxide (GO) and divalent heavy metal cations (denoted as Me(II)), the adsorption affinity of GO and bacteria towards Me(II) (i.e., Cd2+, Co2+ and Zn2+), the destabilizing ability of Me(II) on GO, and the combined effects of GO and Me(II) on the survival of Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) bacteria were investigated. The results show that the destabilizing ability of Me(II) is consistent with their adsorption affinity with GO, which is positively correlated with the ionic radius of Me(II) and negatively correlated with the hydration shell thickness of Me(II). Moreover, the adsorption affinity of bacteria towards Me(II) is negatively correlated with the toxicity of Me(II). Reasons causing the decreased joint toxicity of GO and Me(II) are (1) GO decreases the amount of free Me(II) ions by adsorption; (2) Me(II) change the size and edge sharpness of GO by complexation; (3) GO competes with Me(II) for the membrane receptor binding sites; (4) GO–Me(II) complexes cannot be assimilated by bacteria; (5) Me(II) change the surface properties of GO and bacteria, consequently affecting their interactions. These findings are important for the assessment of the ecological risk of GO after it was used as a heavy metal ion carrier.
