Patent ID: 6312961
Filing Date: 2001-11-06
Classification: G01N,Y10S

Abstract:
An optical biosensor for detecting an immunological reaction in a sample having associated therewith a fluorescent marker that can be excited by an evanescent wave, said biosensor comprising a support, an optical waveguide formed on said support, at least one diffraction grating formed in at least one surface of said waveguide for coupling an excitation beam into said waveguide and decoupling a measurement beam due to fluorescence by said fluorescent marker out of said waveguide at a first angle for detection by a first photodetector, and at least one analysis element for receiving said sample, said at least one analysis element being fixed in at least one reaction region delimited on one of said at least one surface in the path of said excitation beam in said waveguide to contribute to exciting fluorescence of said marker associated with said sample, wherein said marker has a fluorescence curve with an energy peak at a predetermined first wavelength, said waveguide comprises a material having a fluorescence that can be excited spontaneously in the presence of said excitation beam and said material has a spontaneous fluorescence curve having a fluorescence peak lying at a second wavelength different from said first wavelength, and wherein said second wavelength produces through said at least one diffraction grating a reference beam at an exit angle different from said first angle for detection by a second photodetector.