A comparative study of spectral and angle-dependent SPR devices in biological applications

A planar surface plasmon resonance sensor for the real time monitoring of biochemical interaction is described. The SPR signal is detected by spectral interrogation as a resonance wavelength shift. The resulting angle-independent detection is less prone to interferences by vibrations. The architecture of the device allows a further miniaturization. This is a requirement for the construction of portable SPR-devices which can be used for onsite analysis. In this paper we report on the performance of our detector in two practical applications: (i) a competitive immunoassay for the detection of the antithrombolytical protein staphylokinase and (ii) the detection of the endoproteolytic enzyme IgAse. Both applications are of relevance to the clinical laboratory and cover important subjects of biomolecular interaction analysis. Similar experiments were also carried out on a BIAcore2000 instrument. We can therefore discuss the advantages and limitations of our SPR-device in a direct comparison with a high end instrument. Our data show that our detector design does meet major requirements for the development of smaller portable SPR-devices. (C) 1998 Elsevier Science S.A. All rights reserved.