O ₂-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-1,10phenanthroline)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 O ₂ 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.