Université de Fribourg

A hydrofluoric acid-free method to dissolve and quantify silica nanoparticles in aqueous and solid matrices

Bossert, David ; Urban, Dominic A. ; Maceroni, Mattia ; Ackermann-Hirschi, Liliane ; Haeni, Laetitia ; Yajan, Phattadon ; Spuch-Calvar, Miguel ; Rothen-Rutishauser, Barbara ; Rodriguez-Lorenzo, Laura ; Petri-Fink, Alke ; Schwab, Fabienne

In: Scientific Reports, 2019, vol. 9, no. 1, p. 7938

As the commercial use of synthetic amorphous silica nanomaterials (SiO2-NPs) increases, their effects on the environment and human health have still not been explored in detail. An often-insurmountable obstacle for SiO2-NP fate and hazard research is the challenging analytics of solid particulate silica species, which involves toxic and corrosive hydrofluoric acid (HF). We therefore developed...

Université de Fribourg

Taylor dispersion of inorganic nanoparticles and comparison to dynamic light scattering and transmission electron microscopy

A.Urban, Dominic ; M.Milosevic, Ana ; Bossert, David ; Crippa, Federica ; L.Moore, Thomas ; Geers, Christoph ; Balog, Sandor ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: Colloid and Interface Science Communications, 2018, vol. 22, p. 29–33

Taylor dispersion analysis (TDA) is an analytical method that has so far mainly been utilized to determine the diffusion coefficient of small molecules, and proteins. Due to increasing interest in nanoscience, some research has been done on the applicability of TDA towards characterizing nanoparticles. This work aims to expand this knowledge and give insight into the range for which TDA can...

Université de Fribourg

Hypothesis test of the photon count distribution for dust discrimination in dynamic light scattering

Bossert, David ; Crippa, Federica ; Petri-Fink, Alke ; Balog, Sandor

In: Analytical Chemistry, 2018, vol. 90, no. 6, p. 3656–3660

Users of dynamic light scattering (DLS) are challenged when a sample of nanoparticles (NPs) contains dust. This is a frequently inevitable scenario and a major problem that critically affects the reproducibility and accuracy of DLS measurements. Current methods approach this problem via photon correlation spectroscopy, but remedy exists only for a few special cases. We introduce here a...

Université de Fribourg

Speckle-visibility spectroscopy of depolarized dynamic light scattering

Bossert, David ; Natterodt, Jens ; Urban, Dominic A. ; Weder, Christoph ; Petri-Fink, Alke

In: The Journal of Physical Chemistry B, 2017, vol. 121, no. 33, p. 7999–8007

We show that the statistical analysis of photon counts in depolarized dynamic light scattering experiments allows for the accurate characterization of the rotational Brownian dynamics of particles. Unlike photon correlation spectroscopy, the technique is accurate even at low temporal resolution and enables discontinuous data acquisition, which offers several advantages. To demonstrate the...