FAQs

Surface plasmon resonance (SPR) is an optical effect that can be utilized to measure the binding of molecules in real-time without the use of labels. SPR instruments are primarily used to measure the binding kinetics and affinity of molecular interactions. SPR can be used, for example, to measure the binding between two proteins, a protein and an antibody, DNA and a protein, and many more. It helps researchers determine which molecules interact, why they interact, and how strongly they interact.

Surface plasmon resonance has become the golden standard for providing optimal quality kinetics, real time interaction data, and label-free analysis for a wide variety of applications. Ever since the inception of surface plasmon resonance, for more than two decades, it has becoming increasingly more affordable and accessible to researchers than ever before. One of the notable benefits of surface plasmon resonance is the value that SPR data can add to one’s research.

The sensor chip is a gold film coated on a glass substrate that has been chemically modified to make it easier to immobilize one of the binding partners onto the surface of the sensor. The molecule that is immobilized is known as the ligand, and the molecule in solution is known as the analyte. The sensor chip is interface with the fluidic system through the use of a small flow cell, so that the analyte can be injected at different concentrations in a very repeatable manner.

LSPR instruments utilize a broad band white light source such as an LED to illuminate the nanoparticle sensor substrate. A spectrometer serves as the detector and can be placed in either a transmission or reflection arrangement. The spectrometer provides a reading of the absorbance spectrum of the sensor substrate. The nanoparticle substrates have a characteristic absorbance peak in the visible spectrum due to the LSPR effect.