Linear relationship between reflectivity and refractive index change. Shown are simulated SPR reflectivity curves of 470 nm (blue) and 630 nm (red) excitation light for 30 nm thick gold. Three curves for each wavelength were used to simulate a protein layer of thickness 0 nm, 10 nm and 20 nm. The vertical line drawn at an angle of 56.0° indicates the incident angle used for SPRI. The inset shows the reflectivity values (at 56.0°) versus protein layer thickness for both wavelengths and shows a linear fit through each. The 630 nm incident light shows a steeper slope than 470 nm for reflectivity change indicating a greater sensitivity to protein adsorption.
Peterson et al. BMC Cell Biology 2009 10:16 doi:10.1186/1471-2121-10-16