Analysis of Biological Interactions and Recognitions by Surface Plasmon Resonance

This chapter contains sections titled:

•Introduction to Surface Plasmon Resonance Technology

•Working Principle of SPR

•Sensor Surface Chemistry and Its Fabrications

•Important Factors Impacting on the Performance of SPR-Based Analyses of Biological Interactions on the Nonbiological Transducer Surface

•Localized SPR of Inorganic Nanoparticles for Analyses of Biological Interaction

•References

ANALYSIS OF SURFACE-PLASMON POLARITON ENHANCEMENT IN PHOTODETECTION BY AL-GAAS SCHOTTKY DIODES

The surface plasmon polariton mediated photoresponse from Al-GaAs diodes is examined in a prism-air gap-diode configuration as a function of both the wavelength of the incident light and thickness of the Al electrode. The experimental data shows a pronounced dip in reflectance as a function of internal angle of incidence in the prism, due to the excitation of the surface plasmon polariton at the Al-air interface, and a corresponding peak in device photosignal. Careful modelling of reflectance and quantum efficiency data shows that the bulk of the signal is generated by light which is re-radiated from this surface mode into the semiconductor substrate where it is absorbed by the creation of electron-hole pairs in the depletion region. This holds for all the wavelengths used here (all are shorter than the GaAs absorption edge) and across the thickness range of the Al electrodes (20-50 nm). Quantum efficiencies in the range 0.5-22% and enhancement factors of typically 7.5 were recorded in this investigation.