Neighboring Carboxylic Acid Boosts Peroxidase‐Like Property of Metal‐Phenolic Nano‐Networks in Eradicating Streptococcus mutans Biofilms

Developing nature‐inspired nanomaterials with enzymatic activity is essential in combating bacterial biofilms. Here, it is reported that incorporating the carboxylic acid in phenolic/Fe nano‐networks can efficiently manipulate their peroxidase‐like activity via the acidic microenvironment and neighboring effect of the carboxyl group. The optimal gallic acid/Fe (GA/Fe) nano‐networks demonstrate highly enzymatic activity in catalyzing H2O2 into oxidative radicals, damaging the cell membrane and extracellular DNA in Streptococcus mutans biofilms. Theoretical calculation suggests that the neighboring carboxyl group can aid the H2O2 adsorption, free radical generation, and catalyst reactivation, resulting in superb catalytic efficiency. Further all‐atom simulation suggests the peroxidation of lipids can increase the cell membrane fluidity and permeability. Also, GA/Fe nano‐networks show great potential in inhibiting tooth decay and treating other biofilm‐associated diseases without affecting the commensal oral flora. This strategy provides a facile and scale‐up way to prepare the enzyme‐like materials and manipulate their enzymatic activity for biomedical applications. The catalytic property of phenolic/Fe nano‐networks can be easily adjusted by introducing a neighboring carboxylic acid and changing pH values. Both density functional theory calculation and all‐atom simulation elucidate the neighboring effect on catalytic activity and bactericidal mechanism. GA/Fe nano‐networks can efficiently and selectively eradicate the Streptococcus mutans, leaving the commensal oral flora unaffected.