Fig. 4
a Fluorescence images of 4T1 cells incubated with RB-APCZ ([RB] = 5 µg mL−1) for 1, 2 and 3 h. Scale bar = 20 μm. b Detection of intracellular ROS generation by DCFH-DA in both normoxic and hypoxic conditions. [AIPH] = 12.6 µg mL−1, [CuS] = 11.4 µg mL−1, scale bar = 50 μm