A Concentration Dependent Study of Acoustic Plate Mode Immunosensor Response Using Antigen/Antibody Systems with Different Binding Ability

Reiner Dahint and Florian Bender

Abstract Acoustic plate mode sensors have been used to monitor immunochemical reactions as a function of antigen concentration. In the studies, antibodies were covalently linked to the gold-coated sensing surface via mercaptoethanol, aminosilane, and glutaraldehyde. Two antigen/antibody model systems that differ in their ability to mutually bind one another have been used. For sensor operation at about 150 MHz, a detection limit of approximately 0.5 micro g/ml was obtained in both cases. No significant difference between the two systems was found for the value of the binding constants. They amount to about 1 • 108 l/mole and fall well into the range of binding constants reported for homogeneous immunoassays. A comparison of the sensor response obtained for the two model systems shows that about 70% of the immobilized antibodies are active.

1998 IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 45:1216-1220

© 1998, by The Institute of Electrical and Electronics Engineers, Inc. All rights reserved.

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