Department of Chemistry and Biomolecular Science, Clarkson University , Potsdam, New York 13699-5810, United States.
J Am Chem Soc. 2013 Nov 13;135(45):16770-3. doi: 10.1021/ja408087s. Epub 2013 Oct 31.
We describe a simple, cost-effective and rapid electrochemical screening approach to evaluate antioxidant activity of cerium oxide nanoparticles (CeO2 NPs) by single nanoparticle collision at microelectrodes. The method is based on direct monitoring of the interaction between a Pt microelectrode and surface bound superoxo and peroxo anions of CeO2 NPs (Ce-O2(-)/O2(2-)) formed upon exposure to H2O2, selected here as a model reactive oxygen species. We observe an increase in spike current frequency for CeO2 NPs exposed to H2O2, which we attribute to the reduction of surface bound oxygen species when the particles collide with the microelectrode. The results were confirmed with spectroscopic techniques that demonstrate changes in surface reactivity and composition. The spike frequency was found to correlate well with the superoxide dismutase activity of these particles. This approach could enable routine screening of antioxidant NPs using a rapid and inexpensive assay.
我们描述了一种简单、经济高效且快速的电化学筛选方法，通过在微电极上单个纳米颗粒的碰撞来评估氧化铈纳米颗粒 (CeO2 NPs) 的抗氧化活性。该方法基于直接监测 Pt 微电极与暴露于 H2O2 时形成的 CeO2 NPs 表面结合的超氧和过氧阴离子 (Ce-O2(-)/O2(2-)) 之间的相互作用，在这里 H2O2 被选择为模型活性氧物种。我们观察到暴露于 H2O2 的 CeO2 NPs 的尖峰电流频率增加，我们将其归因于当颗粒与微电极碰撞时表面结合的氧物种的减少。结果通过证明表面反应性和组成变化的光谱技术得到了证实。发现尖峰频率与这些颗粒的超氧化物歧化酶活性密切相关。这种方法可以使用快速廉价的测定法对抗氧化纳米颗粒进行常规筛选。
