Patent ID: 6867869

Claim:
A platform for use in sample analysis comprising an optically transparent substrate having a refractive index (n 1 ), a thin, optically transparent layer, formed on one surface of the substrate, said layer having a refractive index (n 2 ) which is greater than (n 1 ), said platform incorporating therein one or multiple corrugated structures, each comprising substantially parallel periodic grooves which define one or multiple sensing regions, said grooves being configured such that coherent and linearly polarized light incident on said platform is diffracted into individual beams or diffraction orders which interfere resulting in a substantially total extinction of the transmitted beam and an abnormal high reflection of the incident light thereby generating an enhanced evanescent field at the surface of the one or multiple sensing regions; wherein the enhanced evanescent field interacts with luminescent material on or in the vicinity of one or more of the sensing regions so as to produce a luminescent signal.