LUMINESCENCE QUENCHING BEHAVIOR OF AN OXYGEN SENSOR BASED ON A RU(II) COMPLEX DISSOLVED IN POLYSTYRENE

摘要

Chemically homogeneous polymer layers loaded with oxygen-quenchable luminescent dyes may lead to promising applications for optical oxygen sensing. In this work, luminescence quenching of tris(4,7'-diphenyl-1-1,10'phenanthroline)Ru(II) perchlorate, dissolved in a polystyrene layer, has been investigated. Although the dye appears to be molecularly dispersed in this glassy polymer, the Stern-Volmer intensity plot is nonlinear and the luminescence decay is not single exponential. This can be attributed to a spatial disorder in the polymer structure, which is likely to determine the excited state properties. It is shown that an analysis of intensity quenching and luminescence lifetime data based on a multicomponent approach, which was previously developed for dyes in chemically heterogeneous silica matrices, can also be applied to this polymer. Quenching is shown to be dynamic in nature. Some features of polystyrene-based optical oxygen sensors having an enhanced dye concentration are pointed out.