PLANAR WAVE-GUIDE IMMUNOSENSOR WITH FLUORESCENT LIPOSOME AMPLIFICATION

A regenerable planar waveguide immunosensor for the clinical analyte theophylline has been developed. Regeneration is accomplished under flow conditions using a moderate affinity antibody, and multiple analyses can be performed with a single waveguide sensor. Sensors capable of more than 15 sequential measurements have demonstrated better than 10% precision. The use of theophylline-labeled liposomes in this competitive immunoassay provides 1 order of magnitude greater signal enhancement over theophylline derivatized with fluorescein.