Figure 4.

UCNP-based LRET system. (A) A scheme of the UCNP-LRET system; the hydrophobic layer between the inorganic nanoparticle surface and the external PEG coating allows adsorption of organic dye molecules on UCNPs; (B) Multicolor UCL images of three UCNP-dye complexes and a mixture of the three. The images were obtained using a Maestro in vivo imaging system after spectral unmixing; (C) In vivo multicolor UCL images of a nude mouse subcutaneously injected with five colors of UCNPs solutions. Merge-UCL (left) and white light (right). Figures reproduced with permission from The American Chemical Society [88].