Piezo-Fenton tandem catalysis of single-phase Bi2Fe4O9 nanosheets against Enterococcus faecalis biofilms in dentin canals

Enterococcus faecalis ( E. faecalis ) is one of the primary bacteria that causes endodontic failure. The formation of biofilms in root canals makes it resistant to common antimicrobial irrigants. Here, single-phase Bi 2 Fe 4 O 9 (BFO) nanosheets are used to effectively eradicate E. faecalis biofilms via piezo-Fenton tandem catalysis. The nanosheet morphology endows BFO with excellent piezocatalytic ability, which boosts the production of H 2 O 2 under ultrasonic (US) stimuli. The in-situ generated H 2 O 2 further facilitates the iron-based Fenton reaction in BFO, thereby accelerating the destruction of membrane structures of E. faecalis biofilms. Moreover, the piezo-Fenton tandem catalysis only requires an US power of 60 W, which can be readily obtained via US irrigation during routine dental treatments. Accordingly, single-phase BFO nanosheets provide a practical and highly efficient approach for eradicating E. faecalis biofilms in dentin canals.