Fig. 3. POD-like and anti–C. albicans activities of rGO@FeS₂ nanozymes.

(A) Ultraviolet-visible absorption spectra and corresponding color changes of TMB in different reaction systems: 1, TMB + H₂O₂; 2, TMB + rGO; 3, TMB + rGO@FeS₂; 4, TMB + rGO + H₂O₂; 5, TMB + rGO@FeS₂ + H₂O₂ in a pH 4.5 HAc-NaAc buffer after 15 min of incubation. (B) pH-dependent POD-like activities of rGO@FeS₂. The pH values of insets 1 to 6 are 4.0, 4.5, 5.0, 5.5, 6.0, and 6.5. (C) EPR monitoring the generation of ^•OH by rGO@FeS₂ in the presence of H₂O₂ in a pH 4.5 HAc-NaAc buffer after 5 min of incubation. (D) Antifungal effects of rGO@FeS₂ and H₂O₂ on C. albicans. (E) Digital images of C. albicans colonies after different treatments. I to VI correspond to the x coordinate of (D), respectively. An 80 μM amount of H₂O₂, rGO, and rGO@FeS₂ at 25 μg/ml was used for anti–C. albicans at 37°C for 120 min. Data are presented as means ± SD (n = 3). **P < 0.01 and ****P < 0.0001.