Institute of Physical and Theoretical Chemistry

Working group of Prof. Gauglitz

Surface Plasmon Resonance (SPR)

Principle

Surface Plasmon Resonance (SPR) as an evanescent field based refractometric method enables the measurement of the refractive index close to a surface. The typical penetration depth of SPR is below 400nm. As the underlying principle occurs only in noble metals, thus typical surfaces for SPR are gold or silver layers. SPR can serve as a label-free direct optical sensor-technique and offers a variety of features such as:

  • No need for labeled analytes
  • Time-resolved measurements

A major drawback of SPR is the strong temperature dependency and the related mandatory thermo stabilization. Nevertheless, SPR is a well established method for:

  • Biomolecular interaction analysis of many kinds from small molecules up to proteins (cells with restrictions due to penetration depth)
  • Reliable determination of kinetic and thermodynamic constants
  • Direct test formats
  • Combination with other techniques such as mass spectrometry

Literature

  1. Homola et al. Sensor. actuat. B-Chem., 1999, 54(1-2), 3-15
  2. Homola et al. Chem. Rev., 2008, 108(2), 462–493
  3. Rich et al. J. Mol. Recognit., 2009, 23(1), 1-64, 2009