Project

trace metals; nanoparticles; flow field-flow fractionation; size distribution; aquatic biogeochemistry; protein corona; eco-corona

Lead
Fractionnement par flux-force équipé d’un système de multi-détection pour élargir les frontières en biogéochimie et en écotoxicologie des oligoéléments
Lay summary
L'étude du métallome environnemental, défini par analogie aux sciences de la vie comme l'ensemble des espèces métalliques et métalloïdes présentes dans l'environnement (incluant le biota), est encore aux prémices. Parmi les espèces métalliques clefs se retrouvent les colloïdes naturels, les nanoparticules et les protéines, leur point commun étant d'appartenir à une fourchette de taille «nanométrique » englobant l'environnement comme le vivant. Ainsi, l'étude des composants environnementaux à cette échelle permettrait une approche plus intégrée que ne l'est la métallomique environnementale actuellement. Le verrou majeur a contourné dans ce domaine est le manque d'outils analytiques sensibles et spécifiques, créant un minimum de perturbation des espèces échantillonnées et permettant son adaptation à des conditions environnementales. Les derniers développements effectués sur les techniques de types fractionnement en flux-force ont permis de faciliter leur connections à des détecteurs de pointe et de gagner en efficacité de séparation des espèces nanométriques ce qui, s'ajoutant à leur versatilité analytique de base, ouvre de nouvelles opportunités. La demande est donc motivée par le besoin qu'a la communauté scientifique d'acquérir des données nanométriques jusque-là encore verrouillées techniquement, et répondre à des questions de pointe dans le domaine de la métallomique environnementale. Cette requête vise ainsi à financer partiellement une plateforme analytique composée d'un système de fractionnement par flux-force combiné à de multiples détecteurs (AF4 / HF5-MD) pouvant fonctionner à haut débit.  La nouvelle plateforme AF4 / HF5-MD est vitale pour la recherche en cours et déjà planifiée. Elle offre un outil idéal encourageant de nouvelles collaborations internes et externes et renforçant celles existantes aux niveaux national / international, permettant l'accès à de nouveaux axes de recherche dans les domaines de la biogéochimie environnementale, des sciences de la vie et des matériaux.

Direct link to Lay Summary

Last update: 17.07.2019

Active participation

Number	Title	Start	Funding scheme

The proposal seeks a partial funding of a modern state-of-the-art environmental flow field-flow frac-tionation-multi-detection system (AF4-MD) to expand the frontiers in trace element biogeochemistry and ecotoxicology at nanoscale. Trace metals (TMs) play an important role in the functioning of envi-ronmental and living systems. TMs are involved in different physical, chemical and biological pro-cesses determining their concentration and speciation. Among the large “spectrum” of TM species present in the environment, we focus on those associated with the nanoparticle sub-set of the colloidal range with size between 1 and 100 nm. The sub-set comprises natural and engineered nanoparticles, humic-like substances and various biopolymers released by living organisms. At this size range the interfacial rather the bulk properties dominate their reactivity, with the smallest sizes playing utmost role in the transport, speciation and bioavailability, and thus the ultimate impact of TMs in aquatic systems. The requested facility consists of versatile flow field-flow fractionation coupled on-line with multiple detection (MD) units. The modular separation unit comprises thermostatic frit-inlet metal-free modular fractionation system including asymmetric flow field-flow fractionation (AF4) analytical and semi-preparative channels/circular hollow fiber flow field-flow fractionation (HF5) channel, allowing efficient and mild separation of natural and engineered nanoparticles and their metal complexes. The hyphenated detection units consists of diode array, fluorescence and differential refractive index, multi-angle static light scattering, massively parallel phase analysis light scattering with dynamic light scattering module detectors. The AF4/HF5-MD will be installed in the MZ2.0 platform at the Faculty of Science, University of Geneva and coupled on-line with existing highly sensitive and selective elemental detectors such as inductively coupled plasma mass spectrometry (ICPMS) in common or single particle modes, or multicollector (MC)ICPMS. The cutting-edge hyphenation of AF4/HF5-MD with (MC)ICPMS will be an absolute novelty worldwide and would have a topmost level impact in environmental research.The new state-of-the-art instrumentation will significantly update the existing facility, which consists of asymmetrical flow field-flow fractionation channel AF2000, UV detector, refractive index detector, seven angle static laser light scattering detector, autosampler and fractions collector. It is 13-years old low-end instrument, which is presently used to generate basic data for the work for several research groups in Switzerland and abroad. However, the equipment is not any more competitive in term of performance with currently available new generation set-ups and does not allow to address high-end scientific questions. The request is therefore motivated by common need of the biogeochemistry community to acquire state-of-the-art nanoscale data and address high-end scientific demands. A combination of mild and efficient separation capabilities of the AF4/HF5 with the selective and sensitive multi-detection units will allow to obtain simultaneously in a single run multi-dimensional quantitative information on hydrodynamic size, diffusion coefficient and zeta potential distributions of metal-containing nanoparticles, absolute molecular masses, electrophoretic mobility, gyration radius, and conformation of biopolymer, and their trace metal complexes, as well as their elemental and isotopic composition distributions in environmental and biological samples with minimal perturbations. The new AF4/HF5-MD instrumentation is vital for the ongoing and planned research, and will promote novel opportunities and research directions in environmental biogeochemistry and ecotoxicology at nanoscale. It offers an ideal platform to foster new and strengthen existing internal and external collaborations at the national/international level, and to promote new research lines. Promising inno-vations, which could be introduced to the Swiss community and beyond, include: (i) a possibility to make high-throughput absolute quantification of colloids, associated trace metals and metal-containing nanoclusters under environmentally relevant conditions; (ii) a possibility to develop new multi-dimensional bioassay-based metallomics and (iii) an opportunity to develop stable isotope na-noscale environmental biogeochemistry.