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Thickness and angular shift in SPR
- OldForum
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19 years 11 months ago #1
by OldForum
Thickness and angular shift in SPR was created by OldForum
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.
There must be. Please help.
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- OldForum
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19 years 11 months ago #2
by OldForum
Replied by OldForum on topic Thickness and angular shift in SPR
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
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
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