AN INNOVATIVE PROCEDURE FOR THE DETECTION OF OXYGEN BASED ON LUMINESCENCE QUENCHING, FOR USE IN MEDICINE, BIOLOGY, ENVIRONMENTAL-RESEARCH AND BIOTECHNOLOGY

For most (aerobic) animal organisms, oxygen is a mandatory and global substrate. The accurate measurement of oxygen is therefore of importan ce in the fields of medicine, biology, environmental research and biot echnology. The fact that oxygen is not readily soluble in aqueous medi a makes its detection more difficult. In contrast to the technique of polarography, the use of luminescence quenching by paramagnetic oxygen , does not consume the oxygen. Another problem of oxygen detection in connection with respiration is the need for very short response times. A third problem, which is associated with luminescence itself, is the fading of the dyes, which results in long-term signal instability. Th e last two problems can be optimally resolved by adsorbing the lumines cence dye onto chromatographic materials - in particular hydrophobic m aterials - having a very large internal surface area, and using the de cay time in accordance with the Stern-Volmer equation as oxygen signal . For this, continuous evaluation of the signal is necessary, The carr ier material doped with dye is incorporated in a single-grain layer. F or measurements in liquids, the detector layer is protected by a black silicone membrane. Two designs are possible for the oxygen detector: (I) a special form using glass fibres, and (II) a miniature detector u tilizing optoelectronic solid state technology. Both fluorescence and phosphorescence can be employed, the dye used being excited by light, obviating the need for quartz. The detector layers may be either of hi gh sensitivity for small oxygen concentrations, or have equal sensitiv ity over the entire oxygen concentration range. There is an optimal fi gure for the specific amount of adsorbed dye. Application examples are given for respiration and for the determination of oxygen uptake by s uspended cells.