ANYL 45 |
| The Surface Plasmon Resonance (SPR) Sensor is widely used to provide label-free in situ monitoring of biomolecular interactions in a real time. By monitoring the evanescent wave generated by the SPR sensor, the kinetic and affinity constants of molecular interactions as well as the active biomolecular concentration can be quantitatively measured in different biological systems, such as antibody-antigen, ligand-receptor, and protein-nucleic acid interactions. Instead of measuring a minimum in the reflected light, we have developed an enhanced SPR sensor by measuring the Goos-Hänchen (GH) effects of the total reflected light, induced by a surface plasmon excited at the metal film interface. The total reflected light is converted into a surface wave that propagates a certain distance along the surface before being totally reflected. This effect is known as the Goos-Hänchen shift. We found that the traveling distance of such a surface wave will be greatly enhanced by a surface plasmon resonance.The larger effect can be easily measured by polarization modulation techniques. By measuring the lateral beam displacement, the sensitivity of the SPR sensor can be enhanced by two-to three orders of magnitude from 10^-5RIU and 10^-8RIU, respectively, as shown in Figure 1. In this invited paper we describe recent results of our work on GH-SPR sensors and approaches to sensor integration into a very small form factor. Caption for Fig. 1. Comparison of reflectivity and GH effects measurement at 632nm and 750nm illumination, it indicates the high angular confinement of the GH effect compared to the reflectivity.
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Surface Plasmon Resonance
1:30 PM-5:00 PM, Sunday, August 19, 2007 BCEC -- 105, Oral
Division of Analytical Chemistry |
