Different configurations to achieve surface plasmon excitation by light

Which SPR configuration is the best one for your research? Do you have a high throughput application or are you after high quality data and instrument sensitivity? Do you need certified runs? Do you need a service contract? How much can you afford to pay for the instrument?

In SPR world, it is always a trade off. Ask us, which type would be the best for your laboratory!


 

There are three possible configurations to achieve plasmon excitation by light. Schematical presentaiton of these is as follows below:

 

1) Grating configuration; 2) Otto configuration; 3) Kretschmann configuration.

The Kretschmann configuration is most commonly used in commercial instruments, and is used in the MP-SPR technology also.

Different detection setups that can be used with Kretschmann configuration

Angle-scanning goniometer

Angle-scanning SPR setup allows wider range to be measured, and is the basis of MP-SPR. Please find out more on the dedicated page about MP-SPR. The angular range of MP-SPR is 38 to 78 degrees of angle. The range is scanned fully automatically. See an animation how MP-SPR full scan forms an SPR curve measurement.

MP-SPR.png

 


 

Focused beam

Focused-beam setup for SPR generation is the most typical traditional SPR setup used for instance by Biacore. The scanning range is relatively limited (approximately 10 degees) and it is difficult to characterize layers accurately. This setup is designed for measurements of protein interactions in liquid.

focused_beam.png


 

Fixed angle (imaging SPR, iSPR)

Fixed angle SPR provides a narrow angular range (approximately 1 degree). Also, it suffers from non-linearity of signal, especially when the analyte absorbs or scatters light. Imaging SPRs lose in sensitivity (signal-to-noise) to other SPR setups due to the camera-based detection required for the imaging. iSPR is popular for its high-throughput, which is counter weighted by limited applicability and low sensitivity.

Fixed-angle.png


Ask our surface plasmon resonance experts!