Large Ultrathin Polyoxomolybdate-Decorated Boron Nitride Nanosheets with Enhanced Antibacterial Activity for Infection Control

To address the challenges in bacterial infection for killing germs without using antibiotics, the development of an efficient and safe antibacterial nanomaterial to control severe bacterial infection has become a critical issue. Herein, ionic liquid (IL)-promoted simultaneous exfoliation and conjugation of boron nitride nanosheets (BNNSs) with ammonium dimolybdate (ADM) are developed. Such an approach provides large ultrathin nanosheets with three to four layers and micron lateral dimensions and facilitates intercalation with a molybdenum (Mo) content of 6.25%. BNNS-IL-ADM provides nanoconfinement inducing capability for sustained release of Mo ions to decelerate the cumulative release rate by 30.45%. BNNS-IL-ADM imparts a superior antibacterial effect especially at a low concentration level of bioactive components, which improves the antibacterial efficiency by 92.00% against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus in comparison with ADM. The enhanced antibacterial performance is strongly dependent on the synergistic effect between the BN nanocarrier and bioactive ADM, in which the bacterial cell adhesion induced by the inherent hydrophobic property of the BNNS and the nanochannels within BNNS-IL-ADM protecting the bioactive ingredient and achieving a sustained release play significant roles. BNNS-IL-ADM can serve as a safe and efficient antibacterial agent with very low cytotoxicity. Such features offer a feasible strategy for simultaneous exfoliation and functionalization of boron nitride nanosheets as a promising platform for the delivery of bioactive ingredients against bacterial infections.