School of Environment, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, International Joint Laboratory on Key Techniques in Water Treatment, Henan Normal University, Xinxiang 453007, 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.
Environ Sci Technol. 2020 Oct 6;54(19):12295-12306. doi: 10.1021/acs.est.0c02642. Epub 2020 Sep 7.
The increasing applications of single-layer molybdenum disulfide (SLMoS) pose great potential risks associated with environmental exposure. This study found that metallic-phase SLMoS with nanoscale (N-1T-SLMoS, ∼400 nm) and microscale (M-1T-SLMoS, ∼3.6 μm) diameters at 10-25 mg/L induced significant algal growth inhibition (maximum 72.7 and 74.6%, respectively), plasmolysis, and oxidative damage, but these alterations were recoverable. Nevertheless, membrane permeability, chloroplast damage, and chlorophyll biosynthesis reduction were persistent. By contrast, the growth inhibition (maximum 55.3%) and adverse effects of nano-sized semiconductive-phase SLMoS (N-2H-SLMoS, ∼400 nm) were weak and easily alleviated after 96 h of recovery. N-1T-SLMoS (0.011 μg/h) and N-2H-SLMoS (0.008 μg/h) were quickly biodegraded to soluble Mo compared with M-1T-SLMoS (0.004 μg/h) and excreted by algae. Incomplete biodegradation of SLMoS (26.8-43.9%) did not significantly mitigate its toxicity. Proteomics and metabolomics indicated that the downregulation of proteins (50.7-99.2%) related to antioxidants and photosynthesis and inhibition of carbon fixation and carbohydrate metabolism contributed to the persistent phytotoxicity. These findings highlight the roles and mechanisms of the size and phase in the persistent phytotoxicity of SLMoS, which has potential implications for risk assessment and environmental applications of nanomaterials.
单层二硫化钼（SLMoS）的应用日益广泛，与之相关的环境暴露带来了巨大的潜在风险。本研究发现，纳米级（N-1T-SLMoS，约 400nm）和微尺度（M-1T-SLMoS，约 3.6μm）金属相 SLMoS 在 10-25mg/L 时会显著抑制藻类生长（最大分别为 72.7%和 74.6%）、质壁分离和氧化损伤，但这些变化是可恢复的。然而，膜通透性、叶绿体损伤和叶绿素生物合成减少是持续存在的。相比之下，纳米尺寸的半导体相 SLMoS（N-2H-SLMoS，约 400nm）的生长抑制（最大 55.3%）和不良影响较弱，在 96 小时恢复后容易缓解。与 M-1T-SLMoS（0.004μg/h）相比，N-1T-SLMoS（0.011μg/h）和 N-2H-SLMoS（0.008μg/h）很快被生物降解为可溶性 Mo 并被藻类排出。SLMoS 的不完全生物降解（26.8-43.9%）并没有显著减轻其毒性。蛋白质组学和代谢组学表明，与抗氧化剂和光合作用相关的蛋白质（50.7-99.2%）下调以及碳固定和碳水化合物代谢的抑制导致了持久的植物毒性。这些发现强调了尺寸和相在 SLMoS 持久植物毒性中的作用和机制，这对纳米材料的风险评估和环境应用具有潜在意义。
