[Ru(phen)2dppz](2+) luminescence reveals nanoscale variation of polarity in the cyclodextrin cavity.

Phosphorylation of ß-cyclodextrin enhances binding with Ru(II)polypyridyl complexes, and promotes selectivity based on chirality and ligand hydrophobicity. For [Ru(phen)2dppz](2+), inclusion of dppz results in a dramatic increase in luminescence with multiple lifetimes. The sensitive response of photophysics to the environment reveals nanoscale variation of polarity.