Patent ID: 6771376
Filing Date: 2004-08-03
Classification: B82Y,G01N

Abstract:
A process for analysing a sample or samples, the process comprising:bringing the sample into contact with a first sensing area of a platform, said platform 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 one or multiple sensing areas or regions, each for one or multiple capture elements, said grooves being so profiled, dimensioned and oriented 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 areas; or b) coherent and linearly polarised 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 areas; irradiating the platform with a light beam such that evanescent resonance is caused to occur within the first sensing area of the platform and detecting radiation emanating from the first sensing area.