黑磷纳米片制备、表征及其对斜生栅藻的毒性效应

黑磷纳米片（Black Phosphorus nanosheets，BPNSs）具有广泛的应用前景，而关于BPNSs的安全性研究还十分匮乏.为探究BPNSs对水生生物的毒性作用，本研究通过液相剥离法制备得到厚度为（58.05±36.48） nm，横向尺寸为（541.25±176.22） nm的BPNSs，选择初级生产者斜生栅藻（Scenedesmus obliquus）为受试生物开展了毒性效应研究.将斜生栅藻暴露于0、10、50、100 mg·L^-1 BPNSs中，结果表明：各浓度的BPNSs均抑制斜生栅藻的生长，120 h时的EC₅₀为74.86 mg·L^-1；与对照组相比，各处理组叶绿素a （Chlorophyll a）含量降低且呈剂量-效应关系，表明BPNSs对斜生栅藻光合系统产生了损害；暴露48 h后3个处理组的活性氧（Reactive oxygen species，ROS）含量显著升高，表明BPNSs对斜生栅藻造成了氧化损伤；显微观测（100×）发现处理组的藻细胞被BPNSs包裹，表明BPNSs可能通过吸附作用团聚在斜生栅藻表面；场发射电子扫描显微镜（FE-SEM）观测发现处理组的藻细胞形态受到显著破坏，表明BPNSs对斜生栅藻产生了物理损伤.本实验结果能够为后续BPNSs在水环境食物链中的潜在富集风险相关研究提供理论支撑.

Preparation and characterization of Black Phosphorus Nanosheets (BPNSs) and its toxic effects on Scenedesmus Obliquus

Black Phosphorus nanosheets(BPNSs) has a wide range of application prospects, whereas research regarding safety of BPNSs has been less investigated. BPNSs with the thickness of (58.05±36.48) nm and the lateral size of (541.25±176.22) nm were prepared by liquid exfoliation in this study in order to explore the toxic effect of BPNSs on aquatic organisms. The primary producer Scenedesmus Obliquus was selected and exposed to 0, 10, 50, and 100 mg·L^-1 BPNSs to study the toxic effects. The results showed that BPNSs inhibited the growth of Scenedesmus Obliquus at all concentrations and the EC₅₀ was 74.86 mg·L^-1 at 120 h. The content of Chlorophyll A in three treatment groups markedly decreased and showed a dose-effect, indicating that BPNSs caused damage to the photosynthetic system of Scenedesmus Obliquus. The content of reactive oxygen species (ROS) in three treatment groups increased significantly after 48 h exposure, indicating the occurrence of oxidative damage mediated by BPNSs. BPNSs wrapped algae cells were observed using microscope, leading to the speculation that BPNSs may aggregate on the surface of Scenedesmus Obliquus by adsorption. Physical damage in Scenedesmus Obliquus caused by BPNSs was verified utilizing FE-SEM which showed the destroyed cell morphology. This research can provide theoretical support for the subsequent studies on the potential enrichment risk of BPNSs in the water environmental food chain.