Work

Asymmetric flow field-flow fractionation for comprehensive characterization of hetero-aggregates made of nano-silver and extracellular polymeric substances

Year: 2024

Type: article

Abstract: in a freshwater medium. Good recoveries (∼ 76.9 ± 8.4 %) of nAg-EPS were obtained from AF4-DAD signals, but an anomalous elution was observed as EPS concentration increased: AF4 retention times decreased despite average gyration radii measured by MALS for nAg-EPS increased (from 16 nm to 24 nm), which suggests a change in the aggregation state, as evaluated by UV-Vis scans obtained from DAD. A regular Brownian relaxation of nAg-EPS was proven for each EPS concentration using these 2 detectors. The comparison of on-line and batch DLS measurements validated in addition, that no (dis)aggregation occurs upon injections. After a thorough comparison with classical AF4 using standards, the frit-inlet-AF4 was used. Slightly higher recovery (79.6 ± 4.6 %) was obtained but similar deviation of nAg-EPS elution occurred, excluding the implication of membrane differential fouling of nAg-EPS /conditioning effects of EPS. The investigation of physico-chemical parameters controlling the Brownian relaxation of nAg-EPS suggests the influence of nAg-EPS structure and EPS loading. This study demonstrates the suitable use of AF4 coupled to multiple detectors to probe-out eco-corona formation and characterize polydisperse systems containing NPs, EPS and their hetero-aggregates in freshwaters, even under a non-ideal size-fractionation scenario.

Source: Journal of Chromatography A

DOI: 10.1016/j.chroma.2024.465507

Authors: Rocco Gasco, Isabelle A.M. Worms, Debora Santos, Vera I. Slaveykova

Institution: University of Geneva

Language: English

Topic: Field-Flow Fractionation Techniques

Subfield: Computational Mechanics

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,630

Funders: Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Université de Genève