Antimicrobial and antibiofilm activities of Ag/Ag2O-anchored CeO2 nanosphers: reaction mechanism determination.

This study focuses on preparing Ag/Ag2O nanoparticles (NPs) by a one-pot method and anchors the CeO2 nanospheres as antimicrobial agents. XRD patterns revealed the successful preparation of Ag/Ag2O/CeO2 NPs. Additionally, SEM and TEM images exhibited that the Ag/Ag2O/CeO2 NPs are aggregated with a spherical shape in the nanoscale range. By looking at how well they fight bacteria, the smallest amount needed to stop growth, and their ability to prevent biofilm formation, we tested how effective Ag/Ag2O/CeO2 NPs are against bacteria that cause serious infections and unicellular harmful fungi. The membrane leakage experiment was used to investigate a possible mechanism of antibacterial behavior. The synthesized Ag/Ag2O-CeO2 NPs showed strong antimicrobial effects against all the bacteria and unicellular fungi we tested. At a concentration of 250 μg/mL of CeO2 NPs, the maximum ZOI of approximately 19.0 mm was seen against Candida albicans, and 17.0 mm against Bacillus subtilis at the same concentration. E. coli was detected in the 16.0 mm ZOI during the action against K. pneumoniae. On the other hand, the largest ZOI of roughly 26.0 mm was tested against B. subtilis and C. albicans at 250 μg/mL of Ag/Ag2O NPs. This was followed by ZOIs of 21.0 mm against C. tropicalis, 20.0 mm against K. pneumoniae and E. cloacae, and 19.0 mm against S. epidermidis. The Ag/Ag2O-CeO2 NPs showed a range of activities at 250 μg/mL against B. subtilis (34.0 mm ZOI) and C. albicans (33.0 mm ZOI). Ag/Ag2O-CeO2 NPs, however, had the same effect on E. coli, P. fluorescens, and S. epidermidis (25.0 mm ZOI). The final result showed that Ag/Ag2O-CeO2 NPs exhibited 22.0 mm ZOI activity against K. pneumoniae and 21.0 mm ZOI activity against E. cloacae. The promising findings suggested that the Ag/Ag2O-CeO2 NPs can be used against pathogenic bacteria in biomedical fields.