Phase fluorometric sterilizable optical oxygen sensor

Authors

  • Shabbir B. Bambot,

    1. Department of Chemical and Biochemical Engineering and Medical Biotechnology Center of the Maryland Biotechnology Institute, University of Maryland Baltimore County, Baltimore, Maryland 21228
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  • Raja Holavanahali,

    1. Department of Electrical Engineering, University of Maryland Baltimore County, Baltimore, Maryland 21228
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  • Joseph R. Lakowicz,

    1. Center for Fluorescence Spectroscopy, Department of Biological Chemistry and Medical Biotechnology Center of the Maryland Biotechnology Institute, University of Maryland at Baltimore, Baltimore, Maryland 21201
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  • Gary M. Carter,

    1. Department of Electrical Engineering, University of Maryland Baltimore County, Baltimore, Maryland 21228
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  • Govind Rao

    Corresponding author
    1. Department of Chemical and Biochemical Engineering and Medical Biotechnology Center of the Maryland Biotechnology Institute, University of Maryland Baltimore County, Baltimore, Maryland 21228
    • Department of Chemical and Biochemical Engineering and Medical Biotechnology Center of the Maryland Biotechnology Institute, University of Maryland Baltimore Country, Baltimore, Maryland 21228
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Abstract

We report here on a low-cost, optical oxygen sensor as an attractive alternative to the widely used amperometric Clark-type oxygen electrode for measuring dissolved oxygen tensions in cell cultures and bioreactor. Our sensor is based on the defferential quenching of the fluorescence lifetime of chromophore in response to the partial pressure of oxygen. This is measured as a phase shift in fluorescence emission from the chromophore due to oxygen quenching when excited by an intensity modulated beam of light. In this article we demonstrate the advantages of lifetime-based optical methods over both intensity based optical methods and amperometric electrodes. Our sensor is particularly suitable for measuring dissolved oxygen in bioreactors. It is autoclavable, is free of maintenance requirements, and solvents the problems of long-term stability, calibration drifts, and reliable measurement of low oxygen tensions in dense microbial cultures that limit the utility of Clark-type elcectordes. © 1994 John Wiley & Sons, Inc.

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