Access to safe water is critical for public health. Pseudomonas aeruginosa is ranked as one of the most significant bacterial pathogens, threatening human health. Hydrogen peroxide and other biocides are often used to prevent the growth of bacteria, but the toxicity of these biocides is a major consideration when bacteria grow in water sources. This study explores the application of iron oxide nanoparticles (IONPs), both bare and polyacrylic acid-coated (PAA@IONPs), to enhance the effectiveness of hydrogen peroxide in eliminating P. aeruginosa, potentially reducing the required biocide concentrations and minimizing toxicity. X-ray diffraction crystallography (XRD) alongside X-ray photoelectron spectroscopy (XPS) showed that the synthesized IONPs were magnetite nanoparticles and Fourier-transform infrared (FTIR) spectroscopy proved that PAA coating was successfully functionalized to IONPs. The hydrodynamic size of the IONPs decreased from 106 ± 11 nm to 84 ± 3 nm when coated with PAA. Transmission electron microscopy (TEM) images confirmed a similar decrease in dry size from 16 ± 3 nm to 9 ± 2 nm post-coating. A week after storage, there was a decrease in the concentration of stored IONPs and PAA@IONPs due to settling by 56 ± 14% and 22.6 ± 0.6%, respectively, demonstrating that PAA coating increased colloidal stability of the IONPs. Coated nanoparticles exhibited a more negative zeta potential, which was also indicative of greater colloidal stability. In the presence of 3.65 mg ml⁻¹ IONPs and 182.25 mM of hydrogen peroxide, overnight bacterial growth was reduced by more than 63% compared to the sample with hydrogen peroxide alone. IONPs did not inhibit bacterial growth in the absence of hydrogen peroxide. The presence of 3.65 mg ml⁻¹ IONPs and 182.25 mM of hydrogen peroxide killed 90.2% of bacterial cells during one hour of exposure. These findings indicate the potential benefit of IONPs to combat bacterial growth, which could be applied in industrial settings to reduce the biocide concentration needed to curb bacterial development.

中文翻译：

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氧化铁纳米颗粒和过氧化氢在抑制铜绿假单胞菌生长以对抗水回收系统中细菌污染的协同作用


获得安全用水对公共卫生至关重要。铜绿假单胞菌 （Pseudomonas aeruginosa） 被列为最重要的细菌病原体之一，威胁着人类健康。过氧化氢和其他杀菌剂通常用于防止细菌生长，但当细菌在水源中生长时，这些杀菌剂的毒性是一个主要考虑因素。本研究探讨了氧化铁纳米颗粒 （IONP） 的应用，包括裸露和聚丙烯酸涂层 （PAA@IONPs），以增强过氧化氢在消除铜绿假单胞菌方面的有效性，从而可能降低所需的杀菌剂浓度并最大限度地降低毒性。X 射线衍射晶体学 （XRD） 和 X 射线光电子能谱 （XPS） 表明合成的 IONPs 是磁铁矿纳米颗粒，傅里叶变换红外 （FTIR） 光谱证明 PAA 涂层成功地官能化为 IONPs。当 PAA 包覆时，IONPs 的流体动力学尺寸从 106 ± 11 nm 减小到 84 ± 3 nm。透射电子显微镜 （TEM） 图像证实，涂层后干尺寸从 16 ± 3 nm 下降到 9 ± 2 nm。储存一周后，由于沉降，储存的 IONPs 和 PAA@IONPs 浓度分别降低了 56 ± 14% 和 22.6 ± 0.6%，表明 PAA 涂层提高了 IONPs 的胶体稳定性。包被的纳米颗粒表现出更多的负 zeta 电位，这也表明更高的胶体稳定性。在 3.65 mg ^ml-1 IONP 和 182.25 mM 过氧化氢存在下，与单独使用过氧化氢的样品相比，过夜细菌生长减少了 63% 以上。在没有过氧化氢的情况下，IONPs 不会抑制细菌生长。 在暴露一小时内，3.65 mg ^ml-1 IONP 和 182.25 mM 过氧化氢的存在杀死了 90.2% 的细菌细胞。这些发现表明 IONP 对对抗细菌生长的潜在益处，可用于工业环境以降低抑制细菌生长所需的杀菌剂浓度。