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.
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.
J Hazard Mater. 2023 Feb 5;443(Pt B):130298. doi: 10.1016/j.jhazmat.2022.130298. Epub 2022 Nov 1.
Graphene oxide (GO, a popular 2D graphene-based nanomaterial) has developed quickly and has received considerable attention for its applications in environmental protection and pollutant removal. However, significant knowledge gaps still exist about the interaction characteristic and joint toxicity mechanism of GO and cadmium (Cd) on aquatic organisms. In this study, GO showed a high adsorption capacity (120. 6 mg/g) and strong adsorption affinity (K = 0.85 L/mg) for Cd. Integrating multiple analytical methods (e.g., electron microscopy, Raman spectra, and 2D correlation spectroscopy) revealed that Cd is uniformly adsorbed on the GO surface and edge mainly through cation-π interactions. The combined ecological effects of GO and Cd on Chlorella vulgaris were observed. Cd induced more severe growth inhibition, photosynthesis toxicity, ultrastructure damage and plasmolysis than GO. Interestingly, we found that GO nanosheets could augment the algal toxicity of Cd (e.g., chlorophyll b, mitochondrial membrane damage, and uptake). Transcriptomics and metabolomics further explained the underlying mechanism. The results indicated that the regulation of PSI-, PSII-, and metal transport-related genes (e.g., ABCG37 and ZIP4) and the inhibition of metabolic pathways (e.g., amino acid, fatty acid, and carbohydrate metabolism) were responsible for the persistent phytotoxicity. The present work provides mechanistic insights into the roles of coexisting inorganic pollutants on the environmental fate and risk of GO in aquatic ecosystems.
氧化石墨烯（GO，一种流行的二维石墨烯基纳米材料）因其在环境保护和污染物去除方面的应用而迅速发展，并引起了相当大的关注。然而，GO 与镉（Cd）对水生生物的相互作用特征和联合毒性机制仍存在显著的知识空白。在本研究中，GO 对 Cd 表现出高的吸附容量（120.6mg/g）和强的吸附亲和力（K=0.85L/mg）。多种分析方法（如电子显微镜、拉曼光谱和 2D 相关光谱）的综合结果表明，Cd 主要通过阳离子-π 相互作用均匀地吸附在 GO 的表面和边缘上。观察到 GO 和 Cd 对小球藻的联合生态效应。与 GO 相比，Cd 引起更严重的生长抑制、光合作用毒性、超微结构损伤和质壁分离。有趣的是，我们发现 GO 纳米片可以增强 Cd 的藻类毒性（例如叶绿素 b、线粒体膜损伤和摄取）。转录组学和代谢组学进一步解释了潜在的机制。结果表明，PSI、PSII 和金属转运相关基因（如 ABCG37 和 ZIP4）的调控以及代谢途径（如氨基酸、脂肪酸和碳水化合物代谢）的抑制是导致持续植物毒性的原因。本工作为了解共存无机污染物对 GO 在水生生态系统中的环境归宿和风险的作用提供了机制见解。
