Forum :: Thickness and angular shift in SPR


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These are the posts of the old forum. It was not possible to transfer the user data, so they are missing in most of the posts. For new questions, go to the general discussions.

TOPIC: Thickness and angular shift in SPR

Thickness and angular shift in SPR 11 Jan 2005 01:00 #1

Is there a quantitative theory that relates the thickness and the optical properties of a biomolecular layer to the angular shift in SPR?
There must be. Please help.

Thickness and angular shift in SPR 11 Jan 2005 01:00 #2

Hi,

The mathematics associated with thickness relationship and the optical response is well documented but normally requires at least 2 measurements to be made (in 2 polarisations or 2 wavelengths) as the Refractive index needs to be determined as well, i.e. a thick layer with low density (or RI) will give the same response as a thin layer with high density. With traditional SPR there is only one polarisation which means this tends to be an ambiguity that you have to live with. We use a waveguide method with two polarisations which resolves this and there is also a coupled waveguide SPR version marketed by Peterion(?) which offers some thickness info.

Hope this helps, feel free to ask any questions.

Regards,

Gerry