LOVE WAVE ACOUSTIC IMMUNOSENSOR OPERATING IN LIQUID

A Love wave acoustic device has been utilized for monitoring antibody- antigen immunoreactions in aqueous solutions in real time. High sensit ivity and selectivity are achieved. In this study, sheep IgG is immobi lized on the device surface as a receptor layer for detection of anti- sheep IgG in buffer solution. The kinetics of the antibody-antigen bin ding are investigated by monitoring the frequency change against react ion time for a wide range of antibody concentrations. A general analyt ic expression for the frequency against time and antibody concentratio ns is derived. A response to a concentration of 1 ng ml(-1) is unambig uously detected. A dual-channel delay-line configuration, with one cha nnel for sensing and the other as reference, is used to give a compari son of specific and non-specific responses as well as to reduce the te mperature effects. The Love wave sensor is robust, reliable and reusab le many times.