Patent ID: 7064844

Claim:
Apparatus for analysing samples comprising a platform including 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 comprising periodic grooves which define one or multiple sensing regions, said grooves being configured such that either a) coherent light incident on said platform is diffracted into individual beams or diffraction orders which interfere resulting in reduction 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; or b) coherent and linearly polarized light incident on said platform is diffracted into individual beams or diffraction orders which interfere resulting in almost 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 detectable luminescent signal; said apparatus further including means for generating a light beam and for directing the beam so that it is incident upon the platform on the side of the substrate that does not have the optically transparent layer disposed thereon at an angle which causes evanescent resonance to occur in at least one sensing region of the platform to thereby create an enhanced resonant field in the at least one sensing region of the platform and means for detecting a characteristic of an affinity reaction occurring on or in the vicinity of, or a characteristic of a material disposed on or in the vicinity of, the at least one sensing region of the platform.