Ag-intercalation of Tm3+/Er3+ Co-doped layered perovskites and their exfoliated 2D nanosheets with an enhanced antibiofilm and antibacterial activity

There is a significant demand for antibiofilm and antimicrobial materials in the medical device industry. It is well established that Ag-based compounds have a high antimicrobial efficiency. Without being in a lattice, silver's antimicrobial action is mainly mediated by the release of Ag+ ions from the compound. These ions at high levels are toxic to most bacterial species. However, rapidly released Ag+ ions tend to aggregate and lose their anti-bacterial effect over time. Thus, utilizing a new approach for using silver as an antimicrobial agent based on imparting the antimicrobial action through contact, rather than releasing Ag+ ions could be beneficial. Here we report that Ag+ ions intercalation of Tm/Er co-doped layered perovskites and their 2D nanosheets exhibit antibacterial and antibiofilm activities against the human opportunistic pathogens Escherichia coli and Bacillus subtilis. Specifically, flocculation of nanosheets with Ag+ ions had efficient antibacterial and antibiofilm activity at 100 mu g/mL. In addition, the flocculated product demonstrated low in vitro cytotoxicity against the Huh7 hepatocellular carcinoma cell line and HEK 293 embryonic kidney cell line. Our results indicate that Ag-intercalated layered perovskites and the flocculation of the nanosheets hold great promise to be used for anti-microbial and antibiofilm purposes in biomedical engineering applications.