Figure 6
Cellular uptake of nrGO-PEG in A549 cells. (A) UV-vis absorbance spectra of free FITC, nrGO-PEG, and nrGO-PEG/FITC. (B) Fluorescence images of cells cultured with free FITC and nrGO-PEG/FITC, respectively. The adherent cells incubated with free FITC and nrGO-PEG/FITC, respectively, for 2 h were imaged by confocal microscope. (C) Cellular uptake ratio of nrGO-PEG. The cells were cultured with 100 μg/mL of nrGO-PEG/FITC and free FITC, respectively, for 2 h before FCM analysis.