Arrangement and method for the detection of changes in the optical path length in a nano-capillary channel

摘要

Arrangement in the form of a multilayer chip in microfluid technology comprising three planar layers (1, 17 and 18), which are used as - an optically transparent detection medium (1), - an optically transparent embedding medium (17) containing at least one plasmonic nanostructure (2), and - a carrier medium (18) with a capillary channel (4) which is introduced into the surface adjoining the embedding medium (17) and which has a fluid inflow (5) and outflow (6) are embodied thereby characterized in that the capillary channel (4) on its side opposite the plasmonic nanostructures (2) is designed as a reflective surface (3), the optical path length from the plasmonic nanostructures (2) as a light source to the reflective surface (3) in the capillary channel ( 4) taking into account the optical refractive index is 0.5 times the wavelength of the maximum constructive interference, and where for a given wavelength the maximum constructive interference Interference the following relation applies: DM * nM + hMC * nFluid = (N + ½) * λ, with- DM = layer thickness (9) of the embedding medium (17) between the plasmonic nanostructure and the capillary channel (4), - nM = refractive index of the embedding medium (17), - hMC = height (10) of the capillary channel (4), - nFluid = refractive index of the fluid, - λ = wavelength of maximum constructive interference and -N = 0.