What is dynamic light scattering (DLS)？

Dynamic light scattering (DLS), also known as photon correlation spectroscopy (PCS) or quasi-elastic light scattering (QELS), is a technique utilized to characterize the particle size of samples on the nanoscale.

In a DLS setup, uniformly dispersed nanoparticles in a dedicated cuvette are illuminated by a coherent laser beam. The scattering intensity fluctuates over time due to the continuous random walk of particles undergoing Brownian motion. The photon detector determines the number of photons in scattered light, and the correlator computes the auto-correlation function. By applying a mathematical algorithm to the correlation function, the particle size distribution of the sample is thereby obtained.

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