Yushan Tan

Direct monitoring of antigen-antibody interactions by optical fiber bioprobe

An optical fiber bioprobe is introduced as a biosensor to monitor the interaction of antigens and antibodies in immunoreactions. The detection is based on the theory of multiple-reflection principles in white-light interferometry. Incident light is partially reflected at the two interface of the biolayer, because of the interference resulted in the interface spectrum. The change of optical thickness can be calculated by testing the reflected spectrum phase shifting. The setup allows the consequent observation of changes in optical pathlength on a fractional nanometer scale with subsecond repetition times. The system has high sensitivity, high precision, cost effective and working on a high reliability. The testing process is nondestructive for the biolayer. The bioprobe is easy integrated as a BIAcore. The system and the experimental results on the reaction of rabbit-IgG with anti-rabbit-IgG are described in this paper.