Fig. 5. The Golgi targeting ability of l-cysteine functionalized silica nanoparticles. (a) The synthesis process of the l-cysteine functionalized silica nanoparticles. (b) Transmission electron microscopy (TEM) image of the 40 nm l-cysteine functionalized fluorescent silica nanoparticles (LC-F-SiO₂). (c) Fluorescence image of the 40 nm LC-F-SiO₂ in an HEp-2 cell. (d) Fluorescence image of Bodipy ceramide (red, Golgi specific dye). (e) Merged image of the 40 nm LC-F-SiO₂, Bodipy ceramide and the cell. (f) Merged image of the 40 nm fluorescent silica nanoparticles (F-SiO₂) in an HEp-2 cell. (g) Fluorescent image of the 40 nm F-SiO₂ in the HEp-2 cell. (h) Transmission electron microscopy (TEM) image of the 80 nm l-cysteine functionalized fluorescent silica nanoparticles (LC-F-SiO₂). (i) Fluorescence image of the 80 nm LC-F-SiO₂ in an HEp-2 cell. (j) Fluorescence image of Bodipy ceramide. (k) Merged image of the 80 nm LFF-SiO₂, Bodipy ceramide and the cell. (l) Merged image of the 80 nm fluorescent silica nanoparticles (F-SiO₂) in the HEp-2 cell. (m) Fluorescence image of 80 nm F-SiO₂ in the HEp-2 cell. Scale bar, 10 μm.