Fig. 2

Spectral imaging fluorescence microscopy and full spectrum analysis visualizes in vivo distribution of polystyrene nanoparticles. a Summary of the spectral analysis of particle-fluorescence (green) versus tissue-autofluorescene (red) after a single injection of COOH- or PEG-coated polystyrene nanoparticles. b, c Emission spectra of nanoparticles measured by spectral imaging fluorescence microscopy. Specimens were excited at 457 nm and the emitted light was detected in a wavelength range from 468 to 548 nm, with a spectral resolution of 2.5 nm. Spectra of polystyrene nanoparticles did not change in different conditions (shown as color-codes in b) or after functionalization (c) compared to the native spectrum provided by the manufacturer (represented by the aquamarine color-code in the figures)