Detecting and analysing submicron particles

摘要

A system for the single particle detection of submicron structures such as biological molecules and viruses utilises an optically transparent substrate 1 coated with a thin film of metal 2 illuminated with an optical beam 3 incident at or close to critical or SPR angle. Part of the beam propagates along the metal surface exciting plasmons in the metal film. These plasmons define a measurement zone from which submicron particles 6 contained in a sample placed in contact with the metal film scatter light. This scattered light is detected 9 in the far field at a normal or high angle to the plane of the metal film 2. The apparatus can be configured in a flow cytometric or optical microscope configuration.