Single Microbead-Anchored Fluorescent Immunoassay (SMFIA): A Facile and Versatile Platform Allowing Simultaneous Detection of Multiple Antigens.

A new concept of single microbead (MB)-anchored fluorescent immunoassay (SMFIA) is proposed with greatly improved sensitivity. In the SMFIA, a single MB is manipulated as the reaction carrier so that the target-tethered fluorescent immunocomplexes will be highly concentrated on one MB. By monitoring the enriched fluorescence signal on the single MB through imaging, highly sensitive target quantification can be realized just by employing the most common sandwich immunoreactions without requirement of further signal amplification routes. The high sensitivity of the SMFIA can fully meet the demand of current medical diagnosis. Furthermore, we have further advanced a fluorescence-encoding mechanism for the proposed SMFIA which allows the simultaneous detection of multiple antigens in a single reaction. Sharing the distinct advantages of simple operation, high sensitivity and multiplexed detection capability, the SMFIA provides a general platform for the detection of various biomarkers.