Highly efficient antimicrobial activity of Cux Fey Oz nanoparticles against important human pathogens

Abstract

The development of innovative antimicrobial materials is crucial in thwarting infectious diseases caused by microbes, as drug-resistant pathogens are increasing in both number and capacity to detoxify the antimicrobial drugs used today. An ideal antimicrobial material should inhibit a wide variety of bacteria in a short period of time, be less or not toxic to normal cells, and the fabrication or synthesis process should be cheap and easy. We report a one-step microwave-assisted hydrothermal synthesis of mixed composite Cux Fey Oz (Fe2 O3 /Cu2 O/CuO/CuFe2 O) nanoparticles (NPs) as an excellent antimicrobial material. The 1 mg/mL Cux Fey Oz NPs with the composition 36% CuFeO2, 28% Cu2 O and 36% Fe2 O3 have a general antimicrobial activity greater than 5 log reduction within 4 h against nine important human pathogenic bacteria (including drug-resistant bacteria as well as Gram-positive and Gram-negative strains). For example, they induced a >9 log reduction in Escherichia coli B viability after 15 min of incubation, and an ~8 log reduction in multidrug-resistant Klebsiella pneumoniae after 4 h incubation. Cytotoxicity tests against mouse fibroblast cells showed about 74% viability when exposed to 1 mg/mL Cux Fey Oz NPs for 24 h, compared to the 20% viability for 1 mg/mL pure Cu2 O NPs synthesized by the same method. These results show that the Cux Fey Oz composite NPs are a highly efficient, low-toxicity and cheap antimicrobial material that has promising potential for applications in medical and food safety.