Fig. 5. (a) Cell viability of Hep-G2, HeLa and A549 after treatment with hydroxycamptothecin (HCPT, 1 μM), HCPT@HXL2@CD-AuNP (1 μM/10 μM/100 nM, particle) and HCPT@HXL2@CD-AuNP with red-light irradiation (600 nm, 30 min). (b) Concentration/time-dependent reactive oxygen species (ROS) production of the particle with red-light irradiation after incubation with different cells and a resulting cell viability after 30 min irradiation.