| 摘要 |
This invention concerns assay techniques by which qualitative and/or quantitative detection of chemical, biochemical or biological species in a sample can be determined and also concerns sensors suitable for use in such techniques. In particular it relates to a method of assaying for a ligand in a sample which comprises a) incubating the sample in contact with the surface of an optical structure, said optical structure comprising a substrate with a first refractive index N1 and a surface layer with a second refractive index N2, said surface layer being such that, in use, a guided wave mode of resonant radiation may be propagated therein, and said surface layer having adsorbed thereon or bound thereto, either directly or indirectly, a specific binding partner for the ligand it is desired to detect; b) irradiating the optical structure at an angle or range of angles to the normal; c) analysing the reflected, transmitted and/or propagated radiation in order to determine whether, and if desired the extent to which and/or rate at which, the guided wave mode characteristics of the optical structure are altered by formation of a complex between the ligand and the specific binding partner. |
