Department of Bioengineering, Rice University, Houston, Texas, USA.
Environ Sci Technol. 2010 Mar 1;44(5):1841-6. doi: 10.1021/es902728a.
The relative transparency of Daphnia magna (daphnia) and the unique optical properties of quantum dots (QDs) were paired to study the accumulation potential and surface coating effects on uptake of amphiphilic polymer coated CdSe/ZnS QDs. Fluorescence confocal laser scanning microscopy was used to visualize and spectrally distinguish QDs from competing autofluorescent signals arising from the daphnia themselves and their food sources. QDs were found to accumulate within the digestive tracts of daphnia, as well as, in some cases, adhere to the carapace, antennae, and thoracic appendages. After 48 h of gut clearance with and without feeding, QD fluorescence signal was still apparent in the digestive tracts of daphnia, and inductively coupled plasma mass spectrometry (ICP-MS) measurements confirmed that 36-53% of the initial uptake was retained. As surface charge and pegylation can influence the uptake of nanoparticles, uptake of QDs coated with two different amphililic polymers and their polyethylene glycol (PEG) coated counterparts was also examined. Fluorescence microscopy and ICP-MS measurements revealed differences in uptake after 24 h of exposure which were attributed to particle surface coating and stability.
我们将水蚤（Daphnia magna）的相对透明度和量子点（QDs）的独特光学性质结合起来，研究了两亲聚合物包覆的 CdSe/ZnS QDs 的积累潜力和表面涂层对摄取的影响。荧光共焦激光扫描显微镜用于可视化和光谱区分 QDs 与源自水蚤本身及其食物源的竞争自体荧光信号。结果发现，QDs 会积聚在水蚤的消化道内，并且在某些情况下，会附着在甲壳、触角和胸肢上。在没有和有进食的情况下进行 48 小时的肠道清除后，水蚤的消化道中仍能明显检测到 QD 荧光信号，电感耦合等离子体质谱（ICP-MS）测量证实，最初摄取的 36-53%被保留下来。由于表面电荷和聚乙二醇（PEG）化会影响纳米颗粒的摄取，我们还研究了两种不同两亲聚合物包覆的 QDs 及其 PEG 包覆对应物的摄取情况。荧光显微镜和 ICP-MS 测量结果表明，暴露 24 小时后，摄取量存在差异，这归因于颗粒表面涂层和稳定性的不同。
