Optical detection and analysis of particles

摘要

Method and apparatus for the single particle detection of submicron structures such as biological molecules and viruses utilises an optical element ( 100 ) comprising an optically transparent substrate ( 1 ) partially coated with a thin film of me ( 2 ) illuminated with an optical beam ( 4 ) incident on a non-metal coated region ( 3 ) of the surface of the optical element at a point adjacent or close to the metal coated region of the optical element such that the beam propagates above but close and substantially parallel to the metal surface defining a measurement zone from within which submicron particles ( 7 ) contained in a sample ( 6 ) placed in contact with the optical element scatter or emit light which can be detected in the far field by conventional photodetection systems. The apparatus can be configured in a flow cell or optical microscope configuration.