Bacterial biofilm microenvironment responsive copper-doped zinc peroxide nanocomposites for enhancing chemodynamic therapy

•We developed a biofilm microenvironment responsive nanocomposite ZnO2-Cu@RB NPs.•ZnO2-Cu@RB NPs can efficiently kill S. mutans in biofilm.•ZnO2-Cu@RB NPs can weaken the acid producing ability of S. mutans.•ZnO2-Cu@RB NPs can inhibit the formation of extracellular polymeric substances.•ZnO2-Cu@RB NPs can reduce the demineralization of apatite in acidic environment.