Precise Measurement of the Size of Nanoparticles by Dynamic Light Scattering with Uncertainty Analysis

Abstract

Dynamic light scattering (DLS) is a powerful technique for the sizing of nanoparticles and characterization of their properties in the liquid phase. However, the precision of this technique remains unclear and therefore, in the current work, the precision of the DLS technique for sizing polystyrene latex suspensions and the uncertainty of the DLS data are estimated. Precise measurements of the short time correlation function at seven scattering angles and five different concentrations are performed for four kinds of polystyrene latex suspensions with diameters of 30–100 nm. The extrapolations of apparent diffusion coefficients to infinite dilution and to lower angles yield more precise values than those obtained at one angle and one concentration. The extrapolated particle size measured by DLS is compared to the size determined by a differential mobility analyzer (DMA) in air. Before the comparison, the intensity‐averaged size measured by DLS is recalculated to the number‐averaged size in the case of DMA from the particle size distribution. After the recalculation, consistent values of mean particle diameter are found to be between those obtained by DLS and DMA within the estimated uncertainties.

Development of a Standard Method for Nanoparticle Sizing by Using the Angular Dependence of Dynamic Light Scattering

“…These curvatures were more marked at lower concentrations. In a previous paper, 12 we briefly described the main reason for the dependence of the apparent diffusion coefficients on the concentration and the scattering angle. It is not caused by the effect of sample polydispersity or of multiple scattering.…”

“…Details of the evaluation of the uncertainty of DLS have been described previously. 12 It is noteworthy that the application of the DLS methods stipulated in ISO 13321 or ISO 22412, which are suitable only for a narrow range of angles and concentrations, does not give very accurate particle sizes in a number of cases. For example, in Fig.…”

Biopolymeric nanoparticles

“…a native protein and various sizes of aggregates), and to detect very small amounts of the higher mass species (<0.01% in many cases). PCS determines the average particle size and polydispersity index (PI) which is a range of measurement of the particle sizes within measured samples [128]. Observation of larger particles compared to smaller particles reveals that for a given temperature, the larger particles move more slowly than the smaller ones.…”

Untitled

“…The nanoparticles fit into colloidal DDSs, which offer advantages of drug targeting by modified body distribution as well as the enhancement of the cellular uptake which benefits from reduction of undesired toxic side effects of the free drugs. [5][6][7] With their easy accessibility in the body, nanoparticles can be transported via the circulation to different body sites, thus aiding in systemic treatments. Nanoparticles (including nanospheres and nanocapsules of size 10-200 nm) are in the solid state and are either amorphous or crystalline.…”