This article outlines the use of Multi-angle Dynamic Light Scattering (MADLS®) for the quantification of nanoparticle concentration. The theory of the technique is described along with its application to nanoparticles comprising of silica, polystyrene, and gold, with diameters varying from 30 to 400 nm. Some of the challenges of particles with a size of 500 nm and above are discussed.
The technique’s linearity, reproducibility, and accuracy are evaluated, along with the size and operational nanoparticle concentration range. The concentration working range is reliant on the optical properties, concentration, and size of the material.
It is demonstrated that the degree of accuracy that can be predicted for particle concentration is normally within 50% of the nominal value in a variety of sizes and materials. For some samples, it is within 20%. The technique’s repeatability is usually less than 30% regarding relative standard deviation.
Utilizing gravimetric dilutions and gold nanoparticles for method validation, a linearity of within 40% covering a concentration range of 3·108 to 2·1011 mL−1 for concentration measurements was determined.
Overall, it is demonstrated that MADLS® is an efficient and simple technique for the reproducible quantification of particle concentration and size. It can be applied to a broad range of materials, does not require calibration using a pre-determined concentration series, and requires minimal preparation of samples.
These qualities make it a superior technique to assist in both the quality control and development of particle materials for a wide range of applications.
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This information has been sourced, reviewed and adapted from materials provided by Malvern Panalytical.
For more information on this source, please visit Malvern Panalytical.