Single particle imaging is becoming an increasingly popular tool to characterize particles in solutions. By imaging nanoparticles undergoing Brownian motion in a dispersion, the effective volume of the detection region can be estimated by measuring the nanoparticle residence time and its diffusion coefficient. This method, therefore, enables self-calibrated particle concentration measurements. Furthermore, a rigorous correction is implemented for the classical overestimation of small size particles which have a higher mobility.

- Accurate assessment of the size of the measurement volume without need for calibration tools resulting in easier and more accurate measurements

- Correction for the higher mobility of smaller particles resulting in a more accurate measurement of the concentrations of poly-disperse particle dispersions

- Measurement of both low and high concentration dispersions

Concentration measurements of nanoparticles in liquid and gaseous media are of great importance in numerous applications. The current technique can be used both for clear liquids and absorptive media such as blood. Relevant application areas are:

- Drug delivery nanoparticles
- Endogenous nanoparticles for biomedical diagnostics
- Nanoparticles for in vivo imaging
- Protein aggregation
- Virus like particles
- Additives in oil and petro-chemistry