METHOD AND APPARATUS FOR CONJUGATE QUADRATURE INTERFEROMETRIC DETECTION OF AN IMMUNOASSAY

摘要

A detection system for detecting target material is provided. The system comprises a photonic structure having a reflectance-band and associated side bands; an illumination source for illuminating at a wavelength in at least one of an edge of the reflectance-band and the side bands of the photonic st ructure and for generating a return beam; a detector system having an intens ity-sensitive channel configured to detect an in-line signal from the return beam and a phase-sensitive channel configured to detect a differential phas e contrast signal from the return beam; and a processing system for receivin g and adding in quadrature the in¬ line signal and the differential phase co ntrast signal to generate a joint signal, and for determining one of the pre sence or the absence of the target material on the photonic structure using the joint signal.