海岸带环境过程实验室知识库

(1) 中国科学院烟台海岸带研究所中国科学院环境过程与生态修复重点实验室

In the natural environment, organisms are frequently exposed to complex mixtures of pollutants. These pollutants usually enter organisms simultaneously, which leads to joint toxicological effects. With excellent adsorption properties, graphene nanomaterials can interact with other pollutants when they are released into the environment, which may affect the environmental behavior of these pollutants. The molecule structure of triphenyl phosphate (TPP) contains three benzene rings, which leads to that TPP interact with graphene easily. With the mass demand and production of graphene and TPP, it is of great significance to study the joint toxicological effects of graphene and TPP, which will provide theoretical basis and data support for ecological risk assessment. The cell membrane is an important barrier of organism to resist external environment. The environmental pollutants usually act on the cell membrane and then enter the cells to produce toxic effects. Studies have shown that graphene and its derivatives can damage cell membrane in the process of interaction. After entering the cell, graphene can bind with receptors and produce reactive oxygen species, which may have a more serious impact. The biological membrane consists of various phospholipids bilayer membrane structures. The interactions between graphene nanomaterials and biological membrane can be studied simply and effectively using the simple artificial biofilm model. The solid supported bilayer membrane is a kind of simulated biofilm which can be simply prepared, easily repeated and stably performed. At present, the electrochemical technology plays an important role in the characterization of the bilayer membrane supported on the metal surface, which has gained more and more applications in the study field of biofilm. The electrochemical impedance spectroscopy (EIS) can preliminary assess the membrane permeability, and can be used as sensitive detector to membrane structure change. Hence, the electrochemical methods can be used to study the interactions between small molecular contaminants and simulated biofilm. In this study, the "frozen-blotted out" method was adopted to construct covalent binding phospholipid bilayer on the gold electrode surface, thus forming simulation of biofilm, and the EIS was used to study the interactions between graphene/TPP and the simulated phospholipid bilayer. The results showed that graphene and TPP could reduce the impedance of the bilayer membrane modified gold electrode, which indicated that graphene and TPP could influence the permeability of cell membrane and damage the integrity of the simulated phospholipid bilayer. With the combined effects of graphene and TPP, the damage of simulated biomembrane was increased, suggesting a synergistic effect. The pollutants through the cell membrane may interact with large molecules such as DNA or protein in cells, these results can provide theoretical basis for evaluating the ecological risks of this kind of pollutants.

在自然环境中,污染物大多以混合物形式存在,进入生物体后通常会产生联合毒理效应.石墨烯纳米材料具有优良的吸附性能,容易与其他污染物发生相互作用,进而影响污染物的环境行为.磷酸三苯酯(triphenyl phosphate, TPP)分子中含有多个苯环,容易与石墨烯发生相互作用.本文采用电化学方法,研究了石墨烯和TPP与模拟生物膜间的相互作用.结果表明,石墨烯和TPP均可导致磷脂双层膜修饰的金电极的阻抗降低,说明两者均能影响细胞膜的通透性,破坏模拟生物膜的完整性,推测石墨烯和TPP同时存在时可能表现出一定的协同作用,增大对模拟生物膜的破坏程度.透过细胞膜进入细胞的污染物有可能与细胞内的DNA或蛋白质等大分子发生作用,该研究结果可为评价该类污染物的生态风险性提供理论依据.