Determine biofunctional layer binding capacity with MP-SPR.
Immunosensor development.

Application Note #132

Langmuir-blodgett


"Mass areal density of bio-CRP antigen showing the Langmuir fit over the data points."

MP-SPR is utilized to determine affinity biosensor surface binding capacity of different parts of the immunosensor. When developing new type of biosensors, it is usually of prime importance to evaluate the performance against an established method. Surface plasmon resonance has been utilized for biosensor studies for over two decades, and is an excellent reference method for this purpose. Uniquely, BioNavis Multi-Parametric Surface Plasmon Resonance (MP-SPR) technology enables also for an easy ex situ preparation of custom sensors, including materials and methods that are not accessible with traditional SPR. MP-SPR is an excellent reference method for completely new types of biosensors.

Standard gold sensor was coated with MuOH:Biotin-PEG-thiol (85:15mol%) SAM (MBP-thiol SAM). Streptavidin interaction (2,5 – 300 nM) with MBP-thiol SAM sensor surfaces and bio-CRP antigen (1 – 20μg/mL) interaction with MBP-thiol/streptavidin sensor surface wasdetermined with SPR Navi™ 200. Biofunctional layers binding capacity and mass areal density ofanalyte was determined with the Langmuir adsorption isothermfrom the MP-SPR experiments.

The MP-SPR results showed that streptavidin binding capacity to the MBP-thiol SAM was 366 ± 2 ng/cm2. High binding capacity confirmed that biofunctional layer is in the favourable orientation for streptavidin binding. Bio-CRP antigen binding capacity to the MBP-thiol /streptavidin surface was 105 ng/cm2. MP-SPR measurement proved that Bio-CRP antigen adsorbed on the streptavidin surface well. Basedon Bio-CRP antigen size, the surface coverage was determined to be 67%.

Recommended instrument for this application:

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Further reading

  • If you are interested in biosensor development, see also AN#117 about detection of DNA and AN#160 about bacteria detection from powdered milk.

  • Do you want to find out more about MP-SPR theory? Click here.

  • Do you want to see comparison of MP-SPR instruments? Click here.

  • Here are a few publications you can have a look at.

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