OXYGEN SENSORS BASED ON LUMINESCENCE QUENCHING - INTERACTIONS OF PYRENE WITH THE POLYMER SUPPORTS

Oxygen quenching of pyrene has been studied in a diverse series of pol ymers. Most measurements were made using homo- or copolymers containin g a poly(dimethylsiloxane) region. Systematic variations in the polyme r properties have been made in order to delineate the structural featu res important for satisfactory use as supports for oxygen sensors. In particular, quenching behavior was examined as a function of the type and amount of copolymer cross-linkers; these were added to produce dom ains of different polarity and rigidity that would segregate the senso r molecule, A domain model (Xu, W.; et al. Anal. Chem. 1994, 66, 4133- 4141) was used to explain the variations in oxygen-quenching propertie s as a function of additives and cross-linkers. The relative affinity of the different domains for the pyrene and the efficacy of the domain s for oxygen quenching controls the overall behavior of the sensing re sponse.