ABSTRACT Copper-based nanoparticles (NPs) are being widely used in different application fields and their health impacts to aquatic environments represent a current concern. Few studies are available about their comparative toxicity with their bulks and ions under natural exposition in aquatic organisms. Thus, the toxicity of Cu and CuO NPs and their microparticle and ionic forms was assayed in the acute immobilisation test of Daphnia magna by using freshwater media. Electronic microscopy, laser doppler velocimetry, and dynamic laser scattering methodologies were used to NPs characterisation. The results indicated that CuNPs and CuONPs were more toxic than their microparticles. Among NPs, CuNPs showed higher toxicity than CuONPs. Copper-based nanoparticles showed similar hydrodynamic particle size and were agglomerated in culture media, suggesting toxic-ionic release relationship and corroborated by the high toxicity induced by CuSO4. Additionally, water chemistry of natural freshwater used in the experiments also favoured the ion release of these NPs.

中文翻译：

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铜基纳米粒子及其微粒在天然淡水介质中对大溞的毒性作用比较

摘要 铜基纳米粒子 (NPs) 被广泛应用于不同的应用领域，它们对水生环境的健康影响代表了当前的关注。关于它们在水生生物中自然暴露下的体积和离子的比较毒性研究很少。因此，在大型水蚤的急性固定试验中，使用淡水介质测定了 Cu 和 CuO NPs 及其微粒和离子形式的毒性。电子显微镜、激光多普勒测速法和动态激光散射方法用于表征纳米颗粒。结果表明，CuNPs 和 CuONPs 比它们的微粒毒性更大。在NPs中，CuNPs比CuONPs表现出更高的毒性。铜基纳米粒子表现出相似的流体动力学粒径，并在培养基中聚集，表明有毒离子释放关系，并由 CuSO4 诱导的高毒性证实。此外，实验中使用的天然淡水的水化学也有利于这些纳米颗粒的离子释放。