Dipartimento di Scienze Fisiche Informatiche e Matematiche, Università degli Studi di Modena e Reggio Emilia, Via G. Campi 213/a, Modena 41125, Italy.
Phys Chem Chem Phys. 2018 Sep 19;20(36):23507-23514. doi: 10.1039/c8cp02271b.
The addition of cerium oxide to bioactive glasses, important materials for bone tissue regeneration, has been shown to induce multifunctionality, combining a significant bioactivity with antioxidant properties. We provide a real time investigation of the evolution of the electronic properties of highly diluted cerium ions in a liquid environment containing hydrogen peroxide - the most abundant reactive oxygen species in living cells. This challenging task is undertaken by means of high-energy resolution fluorescence detected by X-ray absorption near-edge spectroscopy at the Ce L3 edge. We investigate samples with variable compositions and different morphologies. We relate the observed spectroscopic changes not only to variations in the concentration of the two Ce oxidation states in the samples, but also to changes in the local atomic environment of Ce ions, providing a clear picture of the role of cerium ions in the dissociation of hydrogen peroxide. The obtained results contribute to the understanding of the mechanisms that come into play in the process and provide a basis for the optimization of the functionalities of this class of materials.
将氧化铈添加到生物活性玻璃中，这种材料对于骨组织再生非常重要，已经被证明具有多功能性，将显著的生物活性与抗氧化性能结合在一起。我们实时研究了在含有过氧化氢的液体环境中高度稀释的铈离子的电子性质的演变，过氧化氢是活细胞中最丰富的活性氧物种。这项具有挑战性的任务是通过在 Ce L3 边缘进行高能分辨率荧光探测的 X 射线吸收近边光谱来完成的。我们研究了具有不同组成和不同形态的样品。我们不仅将观察到的光谱变化与样品中两种 Ce 氧化态浓度的变化联系起来，还与 Ce 离子局部原子环境的变化联系起来，为铈离子在过氧化氢分解中的作用提供了清晰的认识。所获得的结果有助于理解在这个过程中起作用的机制，并为优化这类材料的功能提供了基础。
