Photonic phase control in a spinning-disk interferometer for high-speed immunoassays

We have been developing the broad-based concept of spinning-disk interferometry for high-speed multianalyte bioassays with the potential to test up to a thousand specific targets on a disk the size of an audio-CD. The operating principle of spinning-disk interferometry is diffraction off microstructured substrates to achieve phase quadrature between a local reference wave and a sample beam passing through a biolayer. We are currently using this technique to analyze amplitude and phase modulation from immobilized biolayers to determine the degree to which amplitude and phase trade off as single polarizable molecules coalesce into macroscopic dielectric films. We are also studying phase effects associated with the edge of the photonic stop-band that may allow direct quadrature detection of biomolecular films without requiring microstructuring of the substrate.