Koman Volodymyr B, von Moos Nadia R, Santschi Christian, Slaveykova Vera I, Martin Olivier J F
a Nanophotonics and Metrology Laboratory (NAM) , Swiss Federal Institute of Technology (EPFL) , Lausanne , Switzerland ;
b Department of Environmental Biogeochemistry and Ecotoxicology, Faculty of Sciences , Institute F.-a. Forel, Earth and Environmental Sciences, University of Geneva , Geneva , Switzerland.
Nanotoxicology. 2016 Oct;10(8):1041-50. doi: 10.3109/17435390.2016.1144826. Epub 2016 Mar 21.
Reactive oxygen species (ROS) play an important role in the life of every cell, including cellular defense and signaling mechanisms. Continuous and quantitative ROS sensing can provide valuable information about the cell state, but it remains a challenge to measure. Here, we introduce a multi-layered microfluidic chip with an integrated optical sensor for the continuous sensitive detection of extracellular hydrogen peroxide (H2O2), one of the most stable ROS. This platform includes hydraulically controlled microvalves and microsieves, which enable the precise control of toxicants and complex exposure sequences. In particular, we use this platform to study the dynamics of toxicity-induced ROS generation in the green microalga Chlamydomonas reinhardtii during short-term exposures, recovery periods, and subsequent re-exposures. Two cadmium-based toxicants with distinct internalization mechanisms are used as stress inducers: CdSe/ZnS quantum dots (Qdots) and ionic cadmium (Cd(2+)). Our results show the quantitative dynamics of ROS generation by the model microalga, the recovery of cell homeostasis after stress events and the cumulative nature of two consecutive exposures. The dissolution of quantum dots and its possible influence on toxicity and H2O2 depletion is discussed. The obtained insights are relevant from ecotoxicological and physiological perspectives.
活性氧（ROS）在每个细胞的生命活动中都起着重要作用，包括细胞防御和信号传导机制。持续且定量地检测ROS能够提供有关细胞状态的有价值信息，但这仍然是一项具有挑战性的测量工作。在此，我们介绍一种带有集成光学传感器的多层微流控芯片，用于连续灵敏地检测细胞外过氧化氢（H2O2），它是最稳定的ROS之一。该平台包括液压控制的微阀和微筛，能够精确控制毒物和复杂的暴露序列。特别是，我们利用这个平台研究了绿色微藻莱茵衣藻在短期暴露、恢复期以及随后再次暴露期间，毒性诱导的ROS生成动态。两种具有不同内化机制的镉基毒物被用作应激诱导剂：CdSe/ZnS量子点（Qdots）和离子镉（Cd(2+)）。我们的结果展示了模型微藻产生ROS的定量动态、应激事件后细胞稳态的恢复以及两次连续暴露的累积性质。还讨论了量子点的溶解及其对毒性和H2O2消耗的可能影响。从生态毒理学和生理学角度来看，所获得的见解具有重要意义。
