Limitations of Nanoparticles Size Characterization by Asymmetric Flow Field‑Fractionation Coupled with Online Dynamic Light Scattering

Abstract

The development of reliable protocols suitable for the characterisation of the physical properties of nanoparticles in suspension is becoming crucial to assess the potential biological as well as toxicological impact of nanoparticles. Amongst sizing techniques, asymmetric flow field flow fractionation (AF4) coupled to online size detectors represents one of the most robust and flexible options to quantify the particle size distribution in suspension. However, size measurement uncertainties have been reported for on-line dynamic light scattering (DLS) detectors when coupled to AF4 systems. In this work we investigated the influence of the initial concentration of nanoparticles in suspension on the sizing capability of the asymmetric flow field-flow fractionation technique coupled with an on-line dynamic light scattering detector and a UV–Visible spectrophotometer (UV) detector. Experiments were performed with suspensions of gold nanoparticles with a nominal diameter of 40 nm and 60 nm at a range of particle concentrations. The results obtained demonstrate that at low concentration of nanoparticles, the AF4-DLS combined technique fails to evaluate the real size of nanoparticles in suspension, detecting an apparent and progressive size increase as a function of the elution time and of the concentration of nanoparticles in suspension.

Evaluating the effect of synthesis, isolation, and characterisation variables on reported particle size and dispersity of drug loaded PLGA nanoparticles

“…52 Furthermore, the broader PSD observed in DLS compared to TEM has previously been documented for monodisperse samples and is inherent in the DLS measurement. [52][53][54] Therefore, TEM is considered as a preferable high-resolution option for evaluation of NP morphology and size due to the high magnification achievable and the simpler sample preparation including no requirement for sample coating.…”

Optimization of hyphenated asymmetric flow field-flow fractionation for the analysis of silver nanoparticles in aqueous solutions

“…This was also observed in a variety of other studies but the understanding of its appearance remains unclear. It can be hypothesized that the U-shaped distribution is related to low particle concentrations at the beginning and end of the elution peak, to the presence of larger aggregates in solutions or to a change of the shape of the particles during the separation and elution process [ 34 ]. In addition to the main AgNP peak, the AF4 fractograms feature void peaks (at t R = 2 min in Fig.…”

Laser Intensity of Thermo-Responsive Nanoparticles Size Measurement Using Dynamic Light Scattering

“…Laser diffraction is a well-known technique for determining particle size distribution among the factors that affect the measurement result [20,21]. However, the influence of laser intensity has not been studied thoroughly.…”