Enhanced antibacterial activity of acid treated MgO nanoparticles on Escherichia coli

Xiaoyi Li; Xiaoyu Hong; Yan Yang; Jiao Zhao; Catherine Sekyerebea Diko; Yimin Zhu

doi:10.1039/d1ra06221b

Enhanced antibacterial activity of acid treated MgO nanoparticles on Escherichia coli

RSC Adv. 2021 Nov 29;11(60):38202-38207. doi: 10.1039/d1ra06221b. eCollection 2021 Nov 23.

Authors

Xiaoyi Li¹, Xiaoyu Hong¹, Yan Yang¹, Jiao Zhao¹, Catherine Sekyerebea Diko¹, Yimin Zhu¹

Affiliation

¹ Dalian Maritime University China yyang@dlmu.edu.cn zhaojiao@dlmu.edu.cn ntp@dlmu.edu.cn.

Abstract

Acid treatment is one of the effective methods that directly modifies surface physical and chemical properties of inorganic materials, which improves the materials' application potential. In this work, the surface modified MgO nanoparticles (NPs) were prepared through a facile acid-treatment method at room temperature. Compared with the untreated sample, the surviving Escherichia coli (E. coli, ATCC 25922) colonies of the modified MgO NPs decreased from 120 to 54 (10² CFU mL^-1). The enhanced antibacterial activity may be due to the improvement of oxygen vacancies and absorbed oxygen (O_A) content (from 41.6% to 63.1%) as confirmed by electron spin resonance (ESR) and X-ray photoelectron spectroscopy (XPS). These findings revealed that the acid treatment method could directly modify the surface of MgO NPs to expose more oxygen vacancies, which would promote reactive oxygen species (ROS) generation. The membrane tube and single ROS scavenging results further indicated that the increased antibacterial ability originated from the synergetic effect of ROS damage (especially ˙O₂ ^-) and direct contact between H-MgO NPs and E. coli.