Nanoparticle Tracking Analysis - NTA

Nanoparticle Tracking Analysis (NTA) utilizes the properties of both light scattering and Brownian motion in order to obtain the particle size distribution and concentration of nanoparticles in liquid suspension. The scattered light from individual particles is tracked providing the diffusion coefficient of each particle measured. This provides high resolution particle size distributions and concentration values independent of particle material.

  1. A nanoparticle sample in liquid suspension is introduced to the sample chamber via direct injection or auto-sampler.
  2. A laser beam passes through the sample scattering light from individual particles
  3. The scattered light is imaged using a SCMOS camera and microscope optics.
  4. A video is recorded of the scattered light from particles moving under Brownian motion.
  5. The diffusion coefficient of individual particles in the field of view is obtained and combined with the sample viscosity and temperature. This information is then used in the Stokes-Einstein equation to identify particles’ equivalent hydrodynamic diameter size.
  6. A detailed particle size distribution and concentration measurement (particles per mL) is provided.

 Used in


Aggregation rate determination

Read more

Read also


 Visit the NanoFASE Library:

NanoFASE Report D3.4 - Protocols and SOPs for ENM characterisation in all environmental compartments

NanoFASE Report D7.3 - Differences in framework for assessment of intentional versus unintentional terrestrial NM exposures

ISO standard (2016) Particle size analysis - Particle tracking analysis (PTA) method.
ASTM E2834 -12: Standard Guide for Measurement of Particle Size Distribution of Nanomaterials in Suspension by Nanoparticle Tracking Analysis (NTA). ASTM International.West Conshohocken, PA.




Phil Vincent

Malvern Panalytical