Microwave-Assisted Synthesis of Nanocrystalline MgO and Its Use as a Bacteriocide

Nanocrystalline particles of MgO were synthesized using microwave radiation in an ethylene glycol solution. The antibacterial activities of the MgO nanoparticles were tested by treating Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) cultures with 1 mg mL–1 of the nanoparticles. We have examined the importance of the size effect, pH, and the form of the active MgO species as a bactericidal agent. A clear size dependence of the nanoparticles is observed where the amount of eradicated bacteria was strongly dependent on the particle size. Nanocrystalline particles of MgO show positive antibacterial properties for E. coli (Gram negative) and Staph. aureus (Gram positive) cultures. A clear size dependence of the nanoparticles is observed for the bactericidal studies, where the amount of eradicated bacteria is strongly dependent on the particle size. Small, electron‐dense black dots have been observed in the cytoplasm of the MgO‐nanoparticle‐treated E. coli bacteria (see Figure).