To achieve particular functions and applications, more and more nanomaterials with unique structural characteristics were precisely synthetized.Some studies showed that the physicochemical characteristics of nanomaterials can significantly influence their toxicity to aquatic organisms.However, the researches about nano-Cu2O with different characteristics are rarely reported.In current study, two microano-Cu2O crystals with different structure and shape (cubic and octahedral) were synthesized and investigated for their toxicity towards Daphnia magna.After 72 h exposure, the Cu accumulation, reduced glutathione (GSH) content, and the activities of superoxide dismutase (SOD), catalase (CAT), and Na+/K+-adenosine triphosphatase (Na+/K+-ATPase) in Daphnia magna were measured.It was shown that the Cu accumulation in D.magna had no significant difference between the exposure of cubic and octahedral microano-Cu2O, but the activities of antioxidase and Na+/K+-ATPase differed dramatically.It was concluded that octahedral microano-Cu2O could lead to more serious oxidative stress and membrane damage to D.magna.The possible explanation is that the octahedral microano-Cu2O could induce higher level of reactive oxygen species (ROS) and release more copper ions in the intestine, as the result of exposure to more {111} surfaces and higher surface energy than the cubic microano-Cu2O.%为了实现特定的功能和应用,越来越多不同结构特性的纳米材料逐渐被人们精确合成.一些研究指出纳米材料的物理化学特性能够显著影响纳米材料对水生生物的毒性作用,但是对于不同特性的纳米氧化亚铜的毒性研究依然比较缺乏.本研究制备了2种不同形貌和结构的微/纳米氧化亚铜(microano-Cu2O)晶体,通过对大型水蚤(Daphnia magna)进行72 h的急性暴露实验,测定了大型水蚤体内还原型谷胱甘肽(GSH)的含量以及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和钠/钾腺苷三磷酸酶(Na+/K+-ATPase)的活性变化.结果表明在2种不同特性的微/纳米氧化亚铜暴露体系中,大型水蚤体内Cu的积累量差别不大,但是不同结构的microano-Cu2O对大型水蚤抗氧化酶活性和钠/钾腺苷三磷酸酶活性影响存在差别.与立方体相比,八面体microano-Cu2O能够暴露更多的{111}面,并且其原子排列使其具有较高的表面能量,因此更容易在大型水蚤肠道内诱导产生活性氧(ROS)及溶出更多Cu2+,对大型水蚤产生更强的氧化胁迫和膜损伤.
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