Assessment of encapsulated dyes' distribution in silica nanoparticles and their ability to release useful singlet oxygen.

Working with silica nanoparticle encapsulated BODIPY and xanthene photosensitizers, we have determined that singlet oxygen spends up to 78% of its lifetime inside the nanocarriers. Our systematic investigation indicates that hydrophobicity rules the photosensitizer distribution in nanoparticles, which in turn dictates the ability of these structures to release singlet oxygen.