Setup of a fiber optical oxygen multisensor-system and its applications in biotechnology

The development of a simple and very easy-to-use fiber optical oxygen multisensor measuring system is described. This fiber optical chemosensor (optode) is based on the fluorescence quenching of a special fluorophor by oxygen. Standard applications of the well-established amperometric oxygen sensor can be carried out with this optical sensor. Beyond that, many special applications for oxygen measurement become possible (O.S. Wolfbeis, Fiber Optic Chemical Sensors and Biosensors, vols. I and II, CRC Press, Boca Raton, USA, 1991), which cannot be performed by sensors of the Clark (L.C. Clark, Electrochemical device for chemical analysis, US Patent 2913386, 1956) type. In comparison to electrochemical sensors fiber optical chemosensors have several advantages, which are illustrated in this paper. Details of the sensor chemistry, instrumental system and the oxygen sensitivity are presented. The application in a precultivation processes, in Ca-alginate beads and layers with immobilized cells in packed-bed-reactors are presented. Diffusion coefficients were calculated from the experiments.