Surface Plasmon Resonance

Surface Plasmon Resonance (SPR) is a technique used to measure how molecules interact and bind on a metal surface, typically gold. When light hits this surface at a specific angle, it excites free electrons, creating surface plasmons—collective electron oscillations. If molecules in a solution bind to the surface, they change the local environment, altering how these plasmons are excited. By detecting shifts in the light reflection or intensity, SPR provides real-time, label-free information about the strength and speed of molecular interactions, making it valuable for studying biomolecular processes.