Fig. 4.

Stability of SiPM with different reaction times in aqueous media. (A) SiNP release behavior from LD-SiPM (reaction time: 30 min) and HD-SiPM (reaction time: 24 h) in PBS, DI water and cell culture medium. (B) SEM image of remaining SiNP/Polymer matrix from LD-SiPM in H2O. (C) Digital pictures of LD-SiPM (left, 30 min synthesis) and HD-SiPM (right, 24 h synthesis) immersed in PBS (pH=7.4) for 0 h and 24 h. LD-SiPM sample became clear in 24 h, indicating degraded substantial degradation, while HD-SiPM sample showed little change. (D) Change of diameter and amount of HD-SiPM along with time in PBS. (E) Multisizer results of size distribution of HD-SiPM at beginning and after 24 h immersion in PBS. Insets are SEM images of related HD-SiPM. Scale bar is 1 µm for all images.