Surface Plasmon Fluorescence Techniques for Bioaffinity Studies

Among the various sensing principles proposed for bioaffinity studies, optical evanescent wave techniques have gained the lead in popularity. Next to evanescent ellipsometry [1] and the various optical waveguide platforms [2,3], surface plasmon resonance (SPR) spectroscopy [4–6], in particular, has found widespread applications and has demonstrated its potential for the sensitive detection of bioanalytes in numerous examples [7–9]. Since its introduction as a method for bioaffinity studies in 1983 by Liedberg et al. [10] and since the presentation of the first commercial instrument by Biacore in 1990 [11], the number of papers published has grown exponentially to currently more than 1500 contributions each year (Figure 9.1). This success story is largely based on the fact that SPR represents a label-free detection principle – the mere presence of the bound analyte slightly changes the optical architecture at the sensor surface which is probed by the surface plasmon mode propagating along this