2.2.1. Scanning Electron Microscopy (SEM)

In order to verify the above results, SEM was used to analyze the morphology of SeNPs and SeCS. As shown in Figure 2, the SEM results of SeNPs clearly revealed that SeNPs without CS surface decoration showed serious aggregation and formed large particles chunks (Figure 2A,C). Nevertheless, the addition of CS accelerated the production of homogeneous spherical SeCS with high dispersibility (Figure 2B,D), which further confirmed the formation of SeCS.

**Figure 2.** SEM images of SeNPs (**A**,**C**) and SeCS (**B**,**D**) powders. The SeNPs were obtained in the same procedure of SeCS without CS.
