Figure 4.

Cytotoxicity and in vitro antioxidant capacity of Cu SAs/CN on HeLa cells. a) Cytotoxicity of Cu SAs/CN at different concentrations on HeLa cells. b) Cell viabilities of HeLa cells pretreated with different systems and c) H₂O₂‐AsA at different concentrations of Cu SAs/CN for 24 h. d–k) Effect of Cu SAs/CN nanozyme on ROS generation in HeLa cells induced by H₂O₂. The antioxidant capability of Cu SAs/CN was determined by monitoring the DCFH‐DA fluoresce intensities of HeLa cells. Scale bar: 50 µm. (The concentrations of Cu SAs/CN, H₂O₂, and AsA are 25 µg mL^–1, 500 × 10⁻⁶ m, and 0.0625 × 10⁻³ m, respectively)