Fig. 3

UV–vis spectra of CaO₂@Co-Fc with varied concentrations in TMB solutions of (a) pH 5 and (b) pH 7. c H₂O₂ release profile of CaO₂@Co-Fc at different pH values. d Time-course absorbance at 655 nm with different concentrations of CaO₂@Co-Fc in TMB solution (e) EPR analysis of ·OH production of CaO₂@Co-Fc at different pH values. f Schematic illustration of the in vitro performance of CaO₂@Co-Fc