Fig. 2.

Characterization of ZnS NPs and ICG-ZnS NPs. A Representative TEM and SEM images of ZnS NPs and ICG-ZnS NPs (scale bar: 100 nm). B XRD patterns of ICG-ZnS NPs. C XPS patterns of ICG-ZnS NPs. D Elemental mapping of ICG-ZnS NPs (scale bar: 50 nm). E EDS survey scanning of the atomic ratios of O, S and Zn in ICG-ZnS NPs. F Hydrodynamic size distribution of the various nanoparticles measured by DLS. G Zeta potential of ZnS NPs, ICG and ICG-ZnS NPs