The fluorescence intensity of the EH@Ag2S group was higher than Ag2S group, indicating the strongest ROS production level. While, in the PBS and EH group, no obvious fluorescence was observed, indicating that the US stimulation had no effect on the ROS production by cells. Furthermore, the cell-killing effect on MC38 cells was verified after different treatments: (1) PBS +US, (2) EH +US, (3) Ag2S +US, (