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

Article Article scientifique Article Asymmetric flow field-flow fractionation for comprehensive characterization of hetero-aggregates made of nano-silver and extracellular polymeric substances eng 2025-01 author Gasco Rocco 988301 Forel Communs (FOREL) author Worms Isabelle 0000-0002-7498-0078 542783 Forel Communs (FOREL) author Dos Santos Silva Debora 669280 author Slaveykova Vera 0000-0002-8361-2509 510054 Forel Communs (FOREL) 465507 10.1016/j.chroma.2024.465507 0021-9673 https://linkinghub.elsevier.com/retrieve/pii/S0021967324008811 The present study explores the capability of asymmetrical flow field-flow fractionation (AF4) coupled online with diode array (DAD), fluorescence detectors (FLD), multi-angle light scattering (MALS) and dynamic light scattering (DLS) to characterize silver nanoparticles (nAg) hetero-aggregates formed with diatoms derived extracellular polymeric substances (EPS). The content of EPS varied from 10.5 to 105 mgC L-1 and nAg were dispersed at 4 mg L-1 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. Eco-corona Composite structure Frit-inlet AF4 Brownian relaxation Shape factor Dewey 550 Dewey 333.7-333.9 Swiss National Science Foundation Deciphering the role of freshwater phytoplankton in metallic nanoparticle transformations (DEEPEN) 204174 DEEPEN CH Projects 41 Département F.-A. Forel des sciences de l'environnement et de l'eau 153 18 Institut des sciences de l'environnement 0DB false 938 ISE Pôle Sciences 752 Environmental Biogeochemistry and Ecotoxicology 944 ISE Eau https://doi.org/10.26037/yareta:dpan5fopmrbwbkljh56f2sev74 Journal of chromatography 1739 fd2a12f4-03f4-4e37-b279-a84570608f12 Article (Published version) Public 1-s2.0-S0021967324008811-main.pdf 9066850 application/pdf CC BY-NC-ND-4.0 d5aa5cf27040f34f240fd502401cc4b2deb445105f06f2665b384ac07fb10cb8 openAccess Faculté des sciences / Section des sciences de la Terre et de l'Environnement / Département F.-A. Forel des sciences de l'environnement et de l'eau Centres et instituts / Institut des sciences de l'environnement

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Asymmetric flow field-flow fractionation for comprehensive characterization of hetero-aggregates made of nano-silver and extracellular polymeric substances	Journal of chromatography			2025	283	185

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Dos Santos Silva, Debora