Copper substitution together with nano-structuring are applied with the aim to increase the bactericidal performances of the rocksalt-type MgO oxide. The partial substitution of magnesium ions with Cu²⁺ has been successfully achieved in both micrometer- and nanometer-sized particles of MgO up to 20 mol% in increments of 5 mol%. Microstructural analyses using the Integral Breadth method revealed that the thermal decomposition of the single source precursor Mg_1-xCu_x(OH)_2-2y(CO₃)_y.zH₂O at 400 °C creates numerous defects in 10–20 nm-sized particles of Mg_1-xCu_xO thus obtained. These defects make the surface of nanoparticles highly reactive towards the sorption of water molecules, to the extent that the cubic cell a parameter in as-prepared Mg_1-xCu_xO expands by +0.24% as soon as the nanoparticles are exposed to ambient air (60% RH). The hydration of Mg_1-xCu_xO particles in liquid water is based on a conventional dissolution-precipitation mechanism. Particles of a few microns in size dissolve all the more slowly the higher the copper content and only Mg(OH)₂ starts precipitating after 3 h. In contrast, the dissolution of all 10–20 nm-sized Mg_1-xCu_xO particles is complete over a 3 h period and water suspension only contains 4–12 nm-sized Mg_1-xCu_x(OH)₂ particles after 3 h. Thereby, the bactericidal activity reported for water suspension of Mg_1-xCu_xO nanoparticles depends on the speed at which these nanoparticles dissolve and Mg_1-xCu_x(OH)₂ nanoparticles precipitate in the first 3 h. Only 10 mol% of cupric ions in MgO nanoparticles are sufficient to kill both E. coli and S. aureus with a bactericidal kinetics faster and reductions in viability at 3 h (6.5 Log₁₀ and 2.7 Log₁₀, respectively) higher than the conventional antibacterial agent CuO (4.7 Log₁₀ and 2 Log₁₀ under the same conditions). EPR spin trapping study reveals that “hydroxylated” Mg_0.9Cu_0.1O as well as Mg_0.9Cu_0.1(OH)₂ nanoparticles produce more spin-adducts with highly toxic hydroxyl radicals than their copper-free counterparts. The rapid mass adsorption of Mg_0.9Cu_0.1(OH)₂ nanoparticles onto the cell envelopes following their precipitation together with their ability to produce Reactive Oxygen Species are responsible for the exceptionally high bactericidal activity measured in the course of the hydroxylation of Mg_0.9Cu_0.1O nanoparticles.

为了提高岩盐型氧化镁的杀菌性能，应用了铜置换和纳米结构化技术。在微米级和纳米级的MgO颗粒中，以20 mol％的增量（5 mol％）成功地实现了镁离子被Cu ²⁺的部分取代。使用积分宽度法进行的微结构分析表明，单一源前体Mg _1-x Cu _x（OH）_2-2y（CO ₃）_y .zH ₂ O在400°C时发生热分解会在10–20 nm中产生大量缺陷大小的Mg _1-x Cu _x颗粒这样得到的O。这些缺陷使纳米粒子的表面对水分子的吸附具有很高的反应性，以至于一旦纳米粒子暴露于环境中，立方晶胞（Mg _1-x Cu _x O中的一个参数）就会扩展+ 0.24％。空气（相对湿度60％）。Mg _1-x Cu _x O颗粒在液态水中的水合作用是基于常规的溶解-沉淀机理。铜含量越高，几微米大小的颗粒溶解就越慢，并且3小时后只有Mg（OH）₂开始沉淀。相反，所有10–20 nm尺寸的Mg _1-x Cu _x的溶解O粒子在3小时内完成，并且水悬浮液在3小时后仅包含4–12 nm大小的Mg _1-x Cu _x（OH）₂粒子。因此，报告的Mg _1-x Cu _x O纳米颗粒水悬浮液的杀菌活性取决于这些纳米颗粒溶解的速度以及前3小时内Mg _1-x Cu _x（OH）₂纳米颗粒沉淀的速度。MgO纳米颗粒中仅10 mol％的铜离子足以杀死大肠杆菌和金黄色葡萄球菌，并具有更快的杀菌动力学和3小时的活力降低（6.5 Log ₁₀和2.7 Log ₁₀分别高于常规抗菌剂CuO（在相同条件下为4.7 Log ₁₀和2 Log ₁₀）。EPR自旋捕集研究表明，“羟基化” Mg _0.9 Cu _0.1 O以及Mg _0.9 Cu _0.1（OH）₂纳米颗粒比无铜对应物产生更多的具有高毒性羟基自由基的自旋加合物。Mg _0.9 Cu _0.1（OH）₂的快速质量吸附纳米粒子在沉淀后连同其产生活性氧的能力，进入细胞膜，是在Mg _0.9 Cu _0.1 O纳米粒子羟基化过程中测得的极高杀菌活性的原因。