| 摘要 |
The invention is a surface plasmon resonance (SPR) sensor to determine the presence and quantity of biological or chemical entities in an analyte. The sensor comprises a metal periodic structure deposited as a thin layer of a noble metal, comprising a one dimensional array of nanoslits or a two dimensional array of nanoholes on a transparent dielectric substrate, a nm- thick layer of transparent dielectric protection layer on top of the metal periodic structure and a functionalization layer, which acts as a binding layer to biological or biochemical entities in an analyte that is in contact with the functionaliztion layer. The sensor of the invention has the following properties: the spaces perforated in the metal are at least partially filled by a material with a refractive index as close as possible to that of the substrate; the thickness of the metal layer is no more than lOOnm; the refractive index, transparency and the thickness of the dielectric protection nanolayer are chosen so that it does not affect the sensor sensitivity; the thickness of the dielectric protection layer is no more than 20nm; and the presence of the material in the spaces perforated in the metal distances the analyte material from the metal-substrate interface, thereby improving the signal to noise ratio for the spectral/angular peak corresponding to the plasmon excited at the metal-substrate interface allowing this spectral/angular peak to be used as a reference relative to which the spectral/angular peaks corresponding to the plasmon excited at the metal- analyte interface is measured. |
