Fig. 7

MoS₂ QDs with more S defects produce more oxidative stress in cancer cells. a MoS₂ QDs treatment (without light) on human endothelial cells (HMVEC) showed negligible cytotoxicity, negligible excessive ROS generation and low apoptosis induction. The measurements were performed in triplicate. b Calcein AM and PI co-staining and c cell viabilities of SW480 cells incubated with different defect laden MoS₂ QDs under white light exposure. The measurements were performed in triplicate. d MoS₂-D_H showed the highest size reduction of 3D tumor spheroids assay. This implied high penetration of QDs into the interior of the 3D tumor spheroids mass with the highest defect group producing the highest oxidative stress that killed the cells. e Quantification of 3D tumor spheroids area post treatment and laser excitation with MoS₂-D_H showing the greatest cell death amongst the three MoS₂ groups. Mean ± SD, n = 10, Student’s t test, p^# < 0.05. Scale bar: 100 μm