Detection of Antibody-Antigen Reactions using Surface Acoustic Wave and Electrochemical Immunosensors

Traditional immunoassays for the detection of specific antibody-antigen reactions are expensive, time-consuming and non-trivial. In this work, immunosensors based on surface acoustic wave and electrochemical techniques are presented, which provide high specificity like conventional immunoassays and the real-time monitoring of immunoreactions can be achieved. Surface acoustic wave devices have been widely used in the telecommunication. Besides their extremely high sensitivity to mass loading they can be utilized for microbalances. The mass change during an antibody-antigen binding can be therefore observed by SAW sensors. In this work, ultrasonic waves were generated on the surface of lithium tantalate by inductively coupled interdigital transducers to detect antibody-antigen reactions. The electrical properties at the surface of a sensor are also changed when an antibody-antigen reaction occurs. This can be detected by electrochemical sensors. Capacitively coupled two- and four-electrode sensors were developed to measure the impedance change at the sensor surface. Effects of the interaction between electric fields and the electrical double layer near the liquid-solid interface will also be discussed. Finally, the antibody affinities can be also measured with both SAW and electrochemical sensors, indicating a high potential in clinical application.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Universität Heidelberg

Year

2004

Author dc:creator

• Luo, Cheng-Ping

Contributors dc:contributor

• Hunklinger, Siegfried

Repository record source_url

http://www.ub.uni-heidelberg.de/archiv/4787

OAI identifier oai:identifier

oai:archiv.ub.uni-heidelberg.de:4787