Figure 4.

Comparison of fluorescence intensities of equal concentrations of three types of near-infrared fluorescent iron oxide-human serum albumin nanoparticles composed of: iron oxide containing dyed gelatin in the core and a non-dyed human serum albumin shell; iron oxide containing non-dyed gelatin in the core and a dyed human serum albumin shell; iron oxide containing dyed gelatin in the core as well as in a dyed human serum albumin shell.

Notes: The highest fluorescence intensity was shown by particles containing dye within both the core and the shell (type 3). The inset shows a fluorescence image of equal concentrations of each type of particle dispersed in phosphate-buffered saline solution.