Polarographic sensors

Enzyme immunoelectrodes involve the spatial coupling of the sensor, the immunocomplex, and the catalytic amplification by indicator enzymes. Like the sensor systems described above, enzyme immunoelectrodes are based on common principles of EIA. The choice of enzymes for EIA is rather restricted and is further diminished when electrodes are to be used for detection. So far only GOD, catalase, and HRP have been combined with oxygen-sensing polarographic sensors. An overview of enzyme immunoelectrodes is given in Table 21. 

Polarographic sensors contain no anode which is consumed during application, but the water loss from the electrolyte and the poor stability vs. anesthetic gases limit the lifetime. Response times are typically 10 s or more since an increased membrane thickness to reduce water loss increases the response time. A wide variety of types exist to fit various applications. 

I. Fatt (Ed.) (1978) The Polarographic Sensor its Theory of Operation and its Applications in Biology, Medicine and Technology, CRC Press, Florida. 

Fatt, Polarographic Oxygen Sensors, CRC Press, Cleveland, OH, 1976... 

Fatt, I. Polarographic Oxygen Sensors, Cleveland, Ohio, CRC Press 1976 Hitchman, M. L. Measurement of Dissolved Oxygen, New York, Wiley 1978 Giquere, P. A., Lauzier, L. Can. J. Res. Sect. B 23, 76 (1945)... 

D.W. Kraus and J.E. Doeller, Sulfide consumption by mussel gill mitochondria is not strictly tied to oxygen reduction measurements using a novel polarographic sulfide sensor. J. Exp. Biol. 207, 3667-3679 (2004). 

Gnaiger, E. (1983). Symbols and units toward standardization. In Polarographic Oxygen Sensors, eds. Gnaiger, E. and Forstner, H., Springer-Verlag, Berlin, pp. 352-358. 

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