Nanoscale wetting of single viruses

Annalisa Calò (1, 2, 3) , Aitziber Eleta-Lopez (3) , Thierry Ondarçuhu (4) , Albert Verdaguer (5) , Alexander M. Bittner (3, 6)

1 UB - Universitat de Barcelona
2 IBEC - Institute for Bioengineering of Catalonia [Barcelona]
3 CIC NanoGUNE
4 IMFT - Institut de mécanique des fluides de Toulouse
5 ICN2 - Catalan Institute of Nanoscience and Nanotechnology
6 Ikerbasque - Basque Foundation for Science

The epidemic spread of many viral infections is mediated by the environmental conditions and influenced by the ambient humidity. Single virus particles have been mainly visualized by atomic force microscopy (AFM) in liquid conditions, where the effect of the relative humidity on virus topography and surface cannot be systematically assessed. In this work, we employed multifrequency AFM, simultaneously with standard topography imaging, to study the nanoscale wetting of individual Tobacco Mosaic virions (TMV) from ambient relative humidity to water condensation (RH > 100%). We recorded amplitude and phase vs. distance curves (APD curves) on top of single virions at various RH and converted them into force vs. distance curves. The high sensitivity of multifrequency AFM to visualize condensed water and sub-micrometer droplets, filling gaps between individual TMV particles at RH > 100%, is demonstrated. Dynamic force spectroscopy allows detecting a thin water layer of thickness ⁓1 nm, adsorbed on the outer surface of single TMV particles at RH < 60%.

Mots clés: Multifrequency AFM; Force reconstruction; Amplitude; Modulation AM-AFM; Tobacco Mosaic Virus (TMV); Nanoscale wetting

Domaines: Virologie; Biophysique [physics.bio-ph]; Mécanique des fluides [physics.class-ph]

Annalisa Calò, Aitziber Eleta-Lopez, Thierry Ondarçuhu, Albert Verdaguer, Alexander M. Bittner. Nanoscale wetting of single viruses. Molecules, 2021, 26 (17), pp.5184. ⟨10.3390/molecules26175184⟩. ⟨hal-03345637⟩