Open Sandwich FRET Immunoassay of Estrogen Receptor β in a PDMS Microfluidic Channel

Abstract

Immunoassay is a fast and cost-effective protein detection method that can be applied to clinical diagnostics and biological research. Enzyme-linked immunosorbent assay (ELISA), surface plasmon resonance (SPR), and protein array chips are the most widely used immunoassay techni-ques for the detection of a target protein.1,2 In all of these methods, however, antibodies or antigens should be immobi-lized on a solid substrate. As a result, they require a long assay time for complete immunoreaction between antigens and antibodies, being limited by the diffusion kinetics. Moreover, they also require several cycles of consecutive binding and washing steps to separate free reagents from binding reagents. To overcome the problem of slow immuno-reactions in conventional immunoassay techniques, we recently reported a fast and sensitive one-step immunoassa