摘要
随着量子点(quantum dots,QDs)在生物标记和医学影像等领域的应用日益广泛,其环境暴露量逐渐增加,深入探讨QDs的毒性机制具有重要意义。QDs通过产生活性氧(ROS)诱发毒性效应是目前普遍接受的毒作用模式。为了探讨量子点的毒性与所诱发的ROS的种类和数量的关系,选用碲化镉量子点(CdTe QDs和CdTe/ZnS QDs),利用电子顺磁共振技术(EPR)分别测定了CdTe QDs和CdTe/ZnS QDs在无细胞体系中诱导ROS产生的种类和强度;利用EPR法、紫外可见分光光度法和荧光分光光度法分别测定了4、20和100nmol·mL-1的CdTe QDs和CdTe/ZnS QDs对超氧阴离子(·O2-)和羟基自由基(·OH)产生的促进作用。实验结果显示,CdTe QDs可诱导·O2-的产生;CdTe QDs和CdTe/ZnS QDs对·OH与·O2-的产生有明显的促进作用,且具有剂量-效应关系。研究表明,量子点可诱导和促进ROS产生,不同结构量子点对ROS的诱导和促进作用不同。
To study the potential ecological risk of heavy metal contamination in Hun River, the contents of heavy metals in different tissues of wild crucian carps from Hun River were analyzed, and the metallothionein mRNA expressions in gill and hepatic tissues were also investigated. Results showed that the accumulation amounts of Cr, Cd, Pb, Cu and Zn in tissues followed the order of intestinelivergillmuscle. Zn content was the highest, ranging from 17.49 to 176.01 mg·kg-1 （wet weight）, and Cd content was the lowest, ranging from non-detectable level to 0.57 mg·kg-1 （wet weight）. The average pollution index assessment results showed that the wild crucian carps in Hun River were slightly contaminated by heavy metals Furthermore, the pollution level in wild crucian carps increased from upstream to downstream. Among the studied heavy metals, the contents of Cr, Pb and Zn mostly contributed to the pollution index. The metallothionein mRNA expression levels in livers of crucian carps detected with real-time quantitative polymerase chain reaction were found to increase from upstream to downstream. A positive relationship was observed between the metallothionein mRNA expression levels in livers and the average pollution index in muscles （R2=0.71）, indicating that the metallothionein gene can be used as a promising biomarker for monitoring the heavy metal contamination.
出处
《生态毒理学报》
CAS
CSCD
北大核心
2012年第1期99-106,共8页
Asian Journal of Ecotoxicology
基金
国家自然科学基金资助项目(31070772)
苏州市科技计划项目(ZXG0920)
关键词
量子点
羟基自由基
超氧阴离子
电子顺磁共振
Hun River
heavy metal
crucian carp （Carassius auratus auratus）
average pollution index
metallothionein
