Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education)/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
Environ Sci Technol. 2020 Apr 21;54(8):4865-4875. doi: 10.1021/acs.est.9b07460. Epub 2020 Apr 8.
Nanocolloids (Ncs) are ubiquitous in natural surface waters. However, the effects of Ncs on the fate and ecotoxicity of graphene oxide (GO, a popular engineered nanomaterial (ENM)) remain largely unknown. Ncs exhibit strong adsorption affinity ( = 1.93 L/mg) and high adsorption capacity (176.2 mg/g) for GO. After Ncs hybridization, GO nanosheets became scrolls, and the aggregation rate of GO decreased. The influence of humic acid and Ncs on GO toxicity was compared. Humic acid mitigated the phytotoxicity of GO. However, GO and GO-Ncs were found to have an envelopment effect on algal cells, and both could enter algal cells. GO-Ncs induced higher reactive oxygen species (ROS) generation, stronger DNA damage and plasmolysis, and more obvious inhibition of photosynthesis compared to GO. Proteomic analysis revealed that photosystem I- and II-related proteins (e.g., E1ZQR2 and E1ZPG5) were regulated more significantly in the GO-Ncs groups than in the GO groups. A combined proteomic and metabolomic analysis showed that inhibition of carbohydrate, fatty acid, and amino acid metabolism contributed to ROS generation. Given the high concentrations and activity of Ncs, the above results highlight the need for reconsideration of the Ncs-mediated environmental behaviors and risks of ENMs and other pollutants.
纳米胶体（Ncs）在天然地表水环境中普遍存在。然而，Ncs 对氧化石墨烯（GO，一种常见的工程纳米材料（ENM））的归宿和生态毒性的影响在很大程度上仍然未知。Ncs 对 GO 表现出很强的吸附亲和力（=1.93 L/mg）和高吸附容量（176.2 mg/g）。Ncs 杂交后，GO 纳米片变成了卷，GO 的聚集率降低了。比较了腐殖酸和 Ncs 对 GO 毒性的影响。腐殖酸减轻了 GO 的植物毒性。然而，GO 和 GO-Ncs 被发现对藻类细胞具有包封作用，两者都可以进入藻类细胞。与 GO 相比，GO-Ncs 诱导了更高的活性氧（ROS）生成、更强的 DNA 损伤和质壁分离，以及更明显的光合作用抑制。蛋白质组学分析表明，与光合作用体 I 和 II 相关的蛋白质（例如，E1ZQR2 和 E1ZPG5）在 GO-Ncs 组中的调节比在 GO 组中更为显著。蛋白质组学和代谢组学的综合分析表明，碳水化合物、脂肪酸和氨基酸代谢的抑制导致 ROS 的生成。鉴于 Ncs 的高浓度和活性，上述结果强调需要重新考虑 Ncs 介导的环境行为和其他污染物的 ENM 风险。
