IMMUNOASSAY UTILIZING SURFACE PLASMON AND FLUORESCENCE RESONANCE ENERGY TRANSFER

摘要

Disclosed is an immunoassay utilizing fluorescence resonance energy transfer (FRET) and surface plasmon-field enhanced fluorescence spectroscopy (SPFS).Specifically disclosed is an immunoassay method for measuring the amount of an antigen in a sample using a primary antibody having, conjugated thereto, a fluorescent dye that acts as a donor molecule and a secondary antibody having, conjugated thereto, a fluorescent dye that acts as an acceptor molecule.  The immunoassay comprises at least the following steps (a) and (b): (a) allowing an antigen-antibody reaction between the antigen contained in the sample and both the primary and secondary antibodies to occur and immobilizing an immunological complex comprising the antibodies and the antigen sandwiched between the antibodies on a metal thin film support; and (b) irradiating the immunological complex produced in the preceding step with a laser beam by means of SPFS and measuring the quantity of fluorescence emitted from the acceptor molecule as a result of FRET from the excited donor molecule fluorescent dye in the primary antibody.  Also disclosed are a system and an assay kit for the immunoassay.