Reflected-light intensity studies

Surface plasmon resonance (SPR) technique had become popular in interaction studies between biological molecules (1). It is an optical biosensor, and the interactions can be detected by SPR angle shift or reflection light intensity. In typical SPR measurement, one of pair interacting biomolecules was immobilized on a gold chip, and another was flowed over the chip as its solution. There are two major advantages in SPR assay (a) real time evaluations on kinetics studies and (b) label-free measurements. 

Diffuse Reflectance Spectroscopy (DRS) is suited for the study of real catalysts as it measures and interprets light intensity loss spectra in absorbing and scattering specimens. 

IMPS and light modulated microwave reflectivity have been used to study the photo-evolution of hydrogen evolution on oxide free p-Si in acidic fluoride solution at low light intensities [30]. The set of IMPS plots in Fig. 8.23 can be compared with those for p-InP shown in Fig. 8.9. It can be seen that the response tends towards a point on the real axis as the potential becomes more negative and krec becomes negligible. Clearly all information about ktr is lost in this region. The behaviour of the frequency resolved microwave is quite different. As Fig. 8.24 shows, a semicircular microwave response is still observed at -1.0 V, which is well into the... 

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