Nanostructured hexagonal BN coating-supported silver and iron oxide nanoparticles and related bactericidal and fungicidal activities

The history of mankind is inextricably linked with the fight against infections, and today this problem is even more urgent. To address this important issue, we deposited h-BN coatings decorated with ultrafine metallic silver or iron oxide nanoparticles (NPs). The coatings release metal ions in a concentration dependent manner. Fe/h-BN coatings at a minimum inhibitory concentration (MIC) of iron oxide NPs (74 µg/cm2), effectively suppress the growth of Escherichia coli K-261 and U20, Staphylococcus aureus MW2 and 839, and Streptococcus pneumoniae ATCC33400 bacterial strains and Candida parapsilosis ATCC90018 fungus after 24 h. Enhanced bactericidal and fungicidal activities of Fe-rich samples is attributed to generation of high amount of ROS. Ag/h-BN materials at MIC of Ag equal to 12 µg/cm2, completely inactivate Escherichia coli K-261 and U20, and Staphylococcus aureus MW2 and 839 strains after 24 h. Sample with 25 μg/cm2 of Ag NPs kill all Escherichia coli K-261 and U20, and Staphylococcus aureus MW2 cells after 3 h and effectively inhibit the growth of Staphylococcus aureus ATCC25923, Candida parapsilosis ATCC90018, Escherichia coli C600, Candida auris CBS10913, and Streptococcus pneumoniae ATCC33400. These results are important for the further development of nanostructured films with a wide spectrum of activity against various pathogens.