(We offer the following explanation with the disclaimer that you and I know that there are actually not any such thing as waves, beams, electrons or atoms - Its all really just quantum-mechanical wave functions)
How Surface Plasmon Resonance Detects Biomolecular Interactions
Surface Plasmon Resonance in Six Easy Steps
How Surface Plasmon Resonance Detects Biomolecular Interactions
Surface Plasmon Resonance in Six Easy Steps
Light can be completely reflected at the interface between a dense material and a less-dense material. Think of how the surface of a swimming pool looks like a mirror when you are underwater. In this example, the blue material is glass and the white area is an aqueous solution potentially containing biomolecules. |
Now, the biology is introduced. Antibodies or aptamers can be attached to the metal surface chemically. The reflection characteristics reach a new equilibrium with no change unless there is a biomolecular interaction. Target antigens interacting with the antibodies or aptamers attached to the metal surface cause a change in the plasmon energy and the angle of the dip changes. This effect has two important characteristics - It is ultra-sensitive to very small biomolecular interactions, but only over the range of a few nanometers. |