Why choose dynamic light scattering for nanoparticle characterization?

The unique behaviors of nanoparticles are driven by nanoscale features such as size, surface structure, and interaction dynamics, all of which require careful characterization and measurement. Parameters such as particle size, distribution, and stability determine how nanoparticles interact, assemble, and function in their surrounding media. To quantify the properties of nanoparticles properly, researchers must use techniques that reflect how particles exist and move in their natural state.

Dynamic light scattering (DLS) is a widely used method that can determine the size of nanoparticles in suspension. It works by detecting fluctuations in scattered light intensity caused by the Brownian motion of particles and translating those fluctuations into a hydrodynamic diameter using the Stokes–Einstein equation. Rapid and non-destructive, DLS provides insight into how nanoparticles behave under realistic conditions rather than in their dry, static form. Several factors make DLS the preferred approach for nanoparticle characterization, as outlined in the sections below:

Measures nanoparticles in their native, liquid environment

Many nanomaterials are designed to operate in liquid systems, such as colloids, emulsions, or biological formulations. Unlike microscopy-based methods that require drying or vacuum conditions, DLS measures particles directly in suspension, preserving their natural behavior so the results reflect real-world conditions.

Using this type of analysis allows researchers to study how nanoparticles move and interact in the same media in which they are formulated, be it in buffers, biological fluids, or dispersions. By capturing hydrodynamic size, DLS accounts for the particle and any solvation or surface layer that affects its mobility. The result is a measurement that reflects real-world performance. Additionally, because DLS is non-destructive, samples can be measured repeatedly or used for complementary analyses, such as zeta potential or microscopy, without loss or alteration.

Fast, simple, and efficient measurements

DLS combines analytical precision with straightforward operation, making it highly accessible for nanoparticle characterization. Sample preparation is minimal, typically just dilution to an appropriate concentration and, if needed, gentle filtration to remove dust or aggregates. Measurements can be completed within minutes, which makes DLS well suited to routine quality control, batch comparison, and stability testing. Moreover, since only small sample volumes are required, often in the microliter range, DLS is ideal when working with expensive or limited nanomaterials. This efficiency supports rapid screening across multiple formulations and enables the convenient monitoring of nanoparticle stability throughout nanomaterial development.

Provides hydrodynamic size and polydispersity information

In nanoparticle characterization, size information involves much more than a simple average. The hydrodynamic diameter, measured using DLS, captures how a nanoparticle moves through its surrounding media by accounting for both the solid particle and the solvent or surface layers that influence its mobility. Researchers can observe diffusion behavior, early aggregation events, and the stability of nanoparticles in their medium from these DLS measurements, helping determine how well a formulation will perform under real conditions.

The polydispersity index (PDI), also obtained from DLS, complements the hydrodynamic diameter by describing how broad or narrow the size distribution is. Low values indicate a uniform population, while higher values signal heterogeneity or aggregation. Tracking changes in DLS-derived size and PDI over time, or across varying pH, temperature, or ionic strength, provides a clear picture of nanoparticle stability and expected performance during storage or use.

Sensitive and statistically robust

Accurate nanoparticle characterization depends on resolving particles across a broad size range, and DLS can measure species from the sub-nanometer scale to several micrometers depending on the instrument setup. DLS captures scattering from many particles at once, providing ensemble results that represent the overall nanoparticle population rather than individual species. Its role in nanoparticle characterization is further supported by ISO 22412:2025, which defines standard procedures for light-scattering size analysis and enables consistent data generation across laboratories, research settings, manufacturing workflows, and regulatory submissions.

Complements other characterization techniques

As DLS fits naturally into broader nanoparticle characterization workflows, it pairs well with techniques that offer different types of information about particle size and structure. Electron microscopy methods such as Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) offer direct visual detail on particle shape and morphology, while Nanoparticle Tracking Analysis (NTA) delivers number-based size distributions and concentration data. Combined with the rapid, in-solution measurements from DLS, these approaches collectively build a more complete understanding of nanoparticle systems.

Elevating Nanoparticle Characterization with DLS Technology

DLS is valued for its speed, reliability, and relevance to real-world conditions. It offers precise information about hydrodynamic size, distribution, and stability and allows scientists to monitor how nanoparticles evolve under different environments or over time. Such strengths position DLS as a robust and reliable technique for nanoparticle characterization, enabling the consistent assessment of size-related properties across diverse formulations. Together with its sensitivity, simplicity, and non-destructive nature, DLS is a practical and dependable choice for both research and production settings.

Modern DLS instruments like the BeNano180 Zeta Max from Bettersize combine advanced optics, intelligent backscattering detection, and ISO 22412:2025 compliance to provide accurate, repeatable nanoparticle measurements. Laboratories working with suspensions, emulsions, or other colloidal systems can rely on this level of precision to guide formulation and quality control decisions. For additional details on how the BeNano 180 Zeta Max can integrate into your workflow, contact Bettersize today！