Surface plasmon resonance (SPR) is a phenomenon occurring at the interface of two media with different dielectric constants, such as a metal and a dielectric, wherein collective oscillations of conduction electrons are resonantly excited by, for example, p-polarized light. This excitation occurs under total internal reflection (TIR) conditions, giving rise to an evanescent field, and results in a dip in the reflected light intensity at a specific angle. This resonance angle is highly sensitive to the refractive index close to the interface and can thus be used to temporally probe e.g. binding events on the surface.

MP-SPR, or multi-parametric SPR, not only determines the SPR resonance angle, but records the full SPR curve including additional parameters such as steepest dip slope, dip intensity or the TIR angle, the latter enabling compensation of differences in bulk-refractive index. MP-SPR is applicable for layers up to micrometer thickness and is suitable for measuring various layer properties such as refractive index, absorption coefficient and thickness. 

Our instrument is a BioNavis MP-SPR NAVI 210A VASA, equipped with 2 fluidic channels and up to four independent wavelengths, making it ideal for precise measurements of thickness, refractive index characterization and layer analysis.
 

Instrument properties:

• Model: MP-SPR NAVI 210A VASA
• 2 fluidic channels
• 4 wavelengths: 670, 785, 850 and 980 nm
• Fluidic sampling type: Automatic injector, 6 sample channels
• Angular range: 40-78°
• 1 injection loop, 750 μl
• Sensor compatibility (W/H/D/RI(670nm)): 20 / 12 / 0.55 mm / 1.520