氧化石墨烯对大型溞的生物毒性效应研究

氧化石墨烯(graphene oxide,GO)因其优良的电性能、机械性能,而成为新兴的碳纳米应用材料,但是其制造或应用后排放进入环境水体的潜在生态风险缺少足够的研究,尤其是关于GO生态毒性的基础数据。研究以水生甲壳类动物大型溞(Daphnia magna,D.magna)为受试生物,从急性毒性和慢性毒性两方面考察了GO的生物毒性效应,并结合溞类的光学显微镜观察和体内超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活力以及丙二醛(MDA)含量的测定对GO对大型溞的致毒机理进行了初步探究。研究结果表明GO对大型溞急性毒性的48 h半数致死浓度(48 h-LC50)为84.2 mg·L-1;慢性毒性的21 d半数致死浓度(21 d-LC50)为3.3 mg·L-1。关于GO对大型溞的繁殖毒性,当GO浓度达到1 mg·L-1时能够显著推迟母溞的头胎出生时间,抑制母溞头胎幼溞数、单胎最高产溞数和总产溞数。关于GO对大型溞的致毒机理,研究结果表明消化道堵塞和氧化损伤可能是GO对大型溞的主要致毒途径。上述研究结果为GO在水环境中的毒性效应研究奠定了基础,为GO的工业化应用前景提供了基础的生态毒性数据。

The Toxic Effects of Graphene Oxide on Crustacean Daphnia magna

Graphene oxide (GO) has been extensively explored as a promising carbon-based nanomaterial because of its unique electrical and mechanical properties.The versatile manufacture and application of GO made it inevitably release into the aqueous environment.However,limit is known about the potential risk of GO in aquatic environment.To evaluate the bio-toxicity of GO,the acute toxicity and semi-chronic toxicity using Daphnia magna (D.magna) were conducted.The toxicity mechanism of GO to D.magna was investigated preliminarily by the light microscopy,the measurement of SOD and CAT activities and MDA content.The results showed that the 48 h-LC50 of GO in acute toxicity tests was 84.2 mg·L-1.The 21 d-LC50 in semi-chronic toxicity tests was 3.3 mg·L-1.As to the reproduction of D.magna,the significant delay in the production time of the first brood was found when the concentration of GO reached 1 mg· L-1,as well as the significant inhibition in the offspring number of the first brood,the offspring number of the most productive brood and the total number of offspring.With respect to the toxicity mechanism of GO,the results revealed that gut clogging and oxidative stress might be the main toxicity pathway of GO to D.magna.This study gave an example of the toxicity research for novel chemicals,and provided the basic toxicity information of GO in respect of its industrial application.