Surface plasmon resonance-based immunoassays

Surface plasmon resonance (SPR) has been successfully incorporated into an immunosensor format for the simple, rapid, and nonlabeled assay of Various biochemical analytes. Proteins, complex conjugates, toxins, allergens, drug s, and pesticides can be determined directly using either natural antibodie s or synthetic receptors with high sensitivity and selectivity as the sensi ng element. Immunosensors are capable of real-time monitoring of the antige n-antibody reaction. A wide range of molecules can be detected with lower l imits ranging between 10(-9) and 10(-13) mol/L. Several successful commerci al developments of SPR immunosensors are available and their web pages are rich in technical information. This review highlights many recent developme nts in SPR-based immunoassay, functionalizations of the gold surface, novel receptors in molecular recognition, and advanced techniques for sensitivit y enhancement. Furthermore, it describes the challenge of current problems and provides some insights toward the future technologies. (C) 2000 Academi c Press.