Patent ID: 6870630

Claim:
A platform for use in sample analysis, said platform having one or more sensing areas or regions, each for receiving a capture element or elements which when the platform is irradiated with coherent light can interact to provide an indication of an affinity reaction, wherein each capture element includes two or more types of capture molecule, the platform further comprising an optically transparent substrate having a refractive index (n1), a thin, optically transparent layer, formed on one surface of the substrate, said layer having a refractive index (n2) which is greater than (n1), said platform incorporating therein one or multiple corrugated structures comprising periodic grooves which define the one or multiple sensing areas or regions, said grooves being so profiled, dimensioned and oriented that 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 a surface of the one or more sensing areas.