Fantozzi Erika, Rama Erlinda, Calvio Cinzia, Albini Benedetta, Galinetto Pietro, Bini Marcella
Department of Chemistry, University of Pavia, Viale Taramelli 16, 27100 Pavia, Italy.
Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, via Ferrata 9, 27100 Pavia, Italy.
Materials (Basel). 2021 May 26;14(11):2859. doi: 10.3390/ma14112859.
Spinel phases, with unique and outstanding physical properties, are attracting a great deal of interest in many fields. In particular, MgFeO, a partially inverted spinel phase, could find applications in medicine thanks to the remarkable antibacterial properties attributed to the generation of reactive oxygen species. In this paper, undoped and Ag-doped MgFeAgO (x = 0.1 and 0.3) nanoparticles were prepared using microwave-assisted combustion and sol-gel methods. X-ray powder diffraction, with Rietveld structural refinements combined with micro-Raman spectroscopy, allowed to determine sample purity and the inversion degree of the spinel, passing from about 0.4 to 0.7 when Ag was introduced as dopant. The results are discussed in view of the antibacterial activity towards and , representative strains of Gram-negative and Gram-positive bacteria. The sol-gel particles were more efficient towards the chosen bacteria, possibly thanks to the nanometric sizes of metallic silver, which were well distributed in the powders and in the spinel phase, with respect to microwave ones, that, however, acquired antibacterial activity after thermal treatment, probably due to the nucleation of hematite, itself displaying well-known antibacterial properties and which could synergistically act with silver and spinel.
尖晶石相具有独特且优异的物理性质，在许多领域引起了广泛关注。特别是部分反型的尖晶石相MgFeO，由于其通过产生活性氧而具有显著的抗菌性能，有望在医学领域得到应用。本文采用微波辅助燃烧法和溶胶-凝胶法制备了未掺杂和Ag掺杂的MgFeAgO（x = 0.1和0.3）纳米颗粒。通过结合Rietveld结构精修的X射线粉末衍射和显微拉曼光谱，确定了样品纯度以及尖晶石的反型程度，当引入Ag作为掺杂剂时，反型程度从约0.4增加到0.7。针对革兰氏阴性菌和革兰氏阳性菌的代表性菌株 和 ，讨论了所得结果与抗菌活性之间的关系。溶胶-凝胶法制备的颗粒对所选细菌的抗菌效果更佳，这可能归因于金属银的纳米尺寸，其在粉末和尖晶石相中分布良好；而微波法制备的颗粒在热处理后才获得抗菌活性，这可能是由于赤铁矿的成核作用，赤铁矿本身具有众所周知的抗菌性能，并且可能与银和尖晶石协同发挥作用。
