Fiber-optic biosensor for antigen/antibody kinetic assays

Total-internal-reflection fluorescence can be exploited to study real-time biomolecular binding processes with enhanced signal-to-noise ratio. Biosensors were first developed to address a need for the qual-itative and quantitative real-time detection of biomolecular in-teractions. Fiber-optic biosensors (FOB) soon proved capable of real-time detection with a potential for specific sensitivity. Highly adaptable, they were accordingly developed as impor-tant detection and identification tools for a wide variety of as-says in biomedical applications.1, 2 Most promising are FOBs based on total internal reflection fluorescence (TIRF).3 The technique is rooted in the fact that a fiber optic consists of a plastic or glass core surrounded by a layer of cladding material. Both components have different den-sities, hence light can be transmitted based on the principle o