Figure 4.

Optical images of CACO-2 cells exposed to alkyl-SiQDs. (A) The bright field image shows the morphology of CACO-2 in the control group (0.1% v/v ether), and images (B–D) show the morphology of 14 day-treated CACO-2 with SiQDs (0.5, 5, or 50 $\mathsf{\mu }$g mL${}^{-1}$) respectively. The fluorescence of the alkyl-SiQDs is overlaid on images (B–D) in false color and the brightness and contrast have been adjusted.