Figure 1

Assessment of individual nanoparticle size and fluorescence. Automated single NP tracking was performed using a spinning disk confocal microscope. a. Green fluorescent 100 nm NPs were dispersed in glycerol at 40°C and their trajectories imaged and analyzed. NPs are identified as a green spot and the trajectory is displayed by a multicolored line (scale bar corresponds to 3 μm). The NP trajectory enclosed in the white square is shown enlarged below. b. The diffusion coefficients and NP sizes were obtained from the slope of the plots of MSD versus time (linear fits are shown by continuous lines). c. The fluorescence of individual NPs was obtained from the confocal images in order to normalize experiments of NP uptake by cells, using the means of the populations shown in the histograms. A.U. – arbitrary fluorescence units.