O2-responsive chemical sensors based on hybrid xerogels that contain fluorinated precursors

We report the development and analytical figures of merit associated with several new O-2-responsive sensor materials. These new sensing materials are formed by sequestering the luminophore tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) ([Ru(dpp)(3)](2+)) within hybrid xerogels that are composed of two of the following methoxysilanes: tetramethoxysilane, n-propyl-trimethoxysilane, 3,3,3-trifluoropropyl-trimethoxysilane, phenethyl-trimethoxysilane, and pentafluorophenylpropyl-trimethoxysilane. Steady-state and time-resolved luminescence measurements are used to investigate these hybrid xerogel-based sensor materials and elucidate the underlying reasons for the observed performance. The results show that many of the [Ru(dpp)(3)](2+)-doped composites form visually uniform, crack-free xerogel films that can be used to construct 02 sensors that have linear calibration curves and excellent long-term stability. To the best of our knowledge, the [Ru(dpp)(3)](2+)-doped fluorinated hybrid xerogels also exhibit the highest O-2 sensitivity of any reported [Ru(dpp)(3)](2+)-based sensor platform.