Dynamic Light Scattering (DLS) Analysis

Dynamic light scattering (DLS), also known as photon correlation spectroscopy (PCS) or quasi-elastic light scattering (QELS), is one of the most commonly used analytical techniques for determining the size and radius distribution of particles in suspensions or polymers in solution samples.

Within the scope of DLS, time fluctuations are typically analyzed through intensity or photon autocorrelation functions (ACF). A monochromatic light beam (e.g., laser) is directed at a test solution containing spherical particles moving in Brownian motion. When light hits the moving particles, it causes a Doppler frequency shift, altering the wavelength of the original light. This change is related to the size of the particles. By measuring the diffusion coefficient of particles in the medium using ACF, the size distribution of the spheres can be calculated, and the movement of particles in the medium can be described in detail. DLS can also be used to probe the behavior of complex fluids, such as concentrated polymer solutions.

Analysis based on dynamic light scattering (DLS)

In practical applications, DLS can be used to determine the size distribution of various particles, including proteins, polymers, micelles, carbohydrates, and nanoparticles. If the system is monodisperse, the average effective diameter of particles can be determined, as the measurement depends not only on the core size of the particles but also on the size of the surface structure, particle concentration, and the type of ions in the medium.

Advantages of dynamic light scattering (DLS) analysis

1. Accurate, reliable, and repeatable particle size analysis
2. Simple sample preparation, and even native samples can be analyzed directly without preparation
3. Easy setup and fully automated measurement
4. Capable of measuring sizes smaller than 1nm
5. Capable of measuring molecules with molecular weight <1000Da
6. Low volume requirements

Dynamic light scattering (DLS) analysis can provide important parameters such as molecular weight, radius of gyration, translational diffusion constant, etc. Feel free to contact us for more information!