(2) EH +US, (3) Ag2S +US, (4) EH@Ag2S +US, (5) PBS -US, (6) EH -US, (7) Ag2S -US, and ( ) EH@Ag2S -US to validate the degree of ROS production at the cellular level. 2,7-dichloro-dihydro-fluorescein diacetate (DCFH-DA) probe was used to detect intracellular ROS production. As shown in Fig. , in the absence of US irradiation, no fluorescence was observed in any group. In the presence of US irradiation with a power density of 1.0 W cm -2 , the green fluorescence appeared in Ag2S and EH@Ag2S group, suggesting that different levels of ROS production were seen in these groups.