An oxygen, sensor based on the fluorescence quenching of pyrene chemisorbed layer onto alumina plates

Optical oxygen sensor based on the fluorescence quenching of pyrene derivatives with carboxyl group, pyrene-1-decanoic acid, pyrene-1-dodecanoic acid and pyrene-1-butyric acid chemisorption layers onto alumina plate were developed. The fluorescence intensity of pyrene derivatives layer decreased with increasing of oxygen concentration, indicating that the pyrene derivatives layer can be used as an optical oxygen sensing device based on fluorescence quenching by oxygen. The ratio I-0/I-100, where I-0 and I-100 represent the detected fluorescence intensities from a layer exposed to 100% argon and 100% oxygen, respectively, as a sensitivity of the sensing layers are estimated to be 50.7 for pyrene-1-decanoic acid, 44.7 forpyrene-1-dodecanoic acid and 73.4 for pyrene-1-butyric acid, showing that the pyrene-1-butyric acid layer is highly sensitive device for oxygen concentration. These samples obeyed Stern-Volmer plots with multi-site model and possessed good operational stability. Response times are 10 s for pyrene-1-decanoic acid, 5.0 s for pyrene-1-dodecanoic acid and 5.0 s for pyrene-1-butyric acid for argon saturated to oxygen saturated conditions and 50.0 s for pyrene-1-decanoic acid, 50.0 s for pyrene-1-dodecanoic acid and 50.0 s for pyrene-1-butyric acid for the reverse conditions. These are stable sensing layers against irradiation that exhibit minimal decrease (ca. 7%) in initial intensity after continuous irradiation for 24 h. (C) 2002 Elsevier Science B.V. All rights reserved.