DLS measures the Brownian motion of particles in a sample by analyzing the fluctuations in the intensity of scattered light. When a laser beam passes through a sample containing nanoparticles, light is scattered in different directions. The intensity of this scattered light fluctuates over time due to the random movement of particles. By analyzing these fluctuations using an autocorrelation function, DLS can determine the hydrodynamic radius of the particles, which is related to their size.
