Luminescent porphyrins as probes for optical (bio)sensors

Applications of the luminescent porphyrins and their metal derivatives in optical biosensors are described. Special emphasis is paid to phosphorescent Pt- and Pd-porphyrins used as highly efficient oxygen probes in (fibre)optic oxygen sensors and enzyme biosensors. The following approaches to quenched-luminescence sensing based on the above oxygen probes are described: (1) a flow-injection glucose sensor; (2) luminescent solid-state oxygen-sensitive compositions and membranes; (3) glucose membranes on the basis of oxygen membranes; (4) a flow cell with enzyme column and oxygen optrode for determination of polyphenols. Fibre-optic sensors have been developed using oxygen and glucose membranes, which enable measurements to be performed via both luminescence intensities and lifetimes. The performance of the sensors is discussed and compared to alternative optical sensing systems.