original: https://doi.org/10.1371/journal.pone.0312594
Surface plasmon resonance (SPR) is usually used to study how two biomolecules interact. One molecule is attached to a gold surface, and the other flows over it inside a small microfluidic channel. While measuring these interactions, fluid flow and diffusion naturally occur inside the channel, but experiments are normally set up to minimize these effects so that the interaction data is as accurate as possible.
In this study, researchers used an SPR device in a completely new way. Instead of removing diffusion effects, they purposely designed an SPR setup to measure the diffusion coefficient (D) of molecules in solution. This parameter describes how fast molecules spread out or move in a liquid.
The results show that this new SPR-based method is very precise, highly reproducible, and can be used to measure diffusion coefficients for many different types of molecules and biomolecules. The paper describes the method and its applications in detail.