Synthesis of the ionic dye, tris(2,2'-bipyridyl) ruthenium(II) chloride (Ru(bpy)(3)(2+).2Cl(-)) within the supercages of a highly hydrophobic zeolite Y is reported. Use of the neutral precursor Ru(bPY)Cl-2(CO)(2) allowed for high loading levels of Ru(bPY)(3)(2+) (1 per 7 and 25 supercages). The emission quenching of the Ru(bpY)(3)(2+)-zeolite crystals dispersed in polydimethoxysiloxane (PDMS) films by dissolved oxygen in water was examined. The quenching data as a function of oxygen concentration was fit to a linear Stern-Volmer plot (R-2 = 0.98). Using the Stern-Volmer plot as calibration, changes in concentration of dissolved oxygen due to reaction with glucose in the presence of glucose oxidase was monitored. Human monocyte-derived macrophages internalized the submicron-sized Ru(bpy)(3)(2+)-zeolite crystals, and intracellular oxygen concentrations initiated by zymosan-mediated oxidative burst could be monitored by measuring the emission from Ru(bpy)(3)(2+) by confocal fluorescence microscopy.