Development of an optical sensor for multicomponent immuno-detection

An optical immunosensor free from the background noise of nonspecific adsorption was developed. A fluorescent-labeled antibody molecule was immobilized on a quartz substrate. The molecular motion of the antibody was measured by the fluorescence anisotropy method using an evanescent excitation apparatus. It was demonstrated that the antigen binding to the antibody can be detected as the anisotropy changed, without interference of nonspecific molecule. This high performance in discriminating specific molecules suggests the possibility of multicomponent detection for the instant medical diagnosis of disease or protein screening for biochemical research. Integration of this kind of sensor is expected for application in the determination of infectious disease or proteome analysis.