Antibody- and receptor-based biosensors for detection and process control

The extension of a generic immobilization technology for the fabrication of antibody- and receptor-based biosensors is reported. The biosensors utilize polymerized protein films containing the antibody or receptor and appropriate stabilizers to coat an interdigitated electrode transducer. Changes in the electrical field of the coated electrodes are related to specific interactions between the immobilized biomolecule and the analyte to be measured. A portable electronics module has been developed into which the coated electrode chips are inserted and challenged with analyte. Within 5–10 s, an output reading (change in impedance, phase angle, current or voltage) is obtained that is related to analyte concentration. The use of parallel, non-antibody or non-receptor containing control chips allows automatic correction for background and non-specific binding. The biosensors can detect low ng ml−1 levels of analyte in serum or other liquids. Such antibody- and receptor-based biosensors are applicable to the determination of a wide range of analytes for analytical, clinical, environmental and process control applications.