Surface characterization of alkane viral anchoring films prepared by titanate-assisted organosilanization.

Studies of virus adsorption on surfaces with optimized properties have attracted a lot of interest, mainly due to the influence of the surface in the retention, orientation and stability of the viral capsids. Besides, viruses in whole or in parts can be used as cages or vectors in different areas, such as biomedicine and materials science. A key requirement for virus nanocage application is their physical properties, i.e. their mechanical response and the distribution of surface charge, which determine virus-substrate interactions and stability. In the present work we show two examples of viruses exhibiting strong surface interactions on homogeneous hydrophobic surfaces. The surfaces were prepared by titanate assisted organosilanization, a sol-gel spin coating process, followed by a mild annealing step. We show by surface and interface spectroscopies that the process allows trapping triethoxy-octylsilane (OCTS) molecules, exhibiting a hydrophobic alkane rich surface finishing. Furthermore, the surfaces remain flat and behave as more efficient sorptive surfaces for virus particles than mica or graphite (HOPG). Also, we determine by atomic force microscopy (AFM) the mechanical properties of two types of viruses (human adenovirus and reovirus) and compare the results obtained on the OCTS functionalized surfaces with those obtained on mica and HOPG. Finally, the TIPT+OCTS surfaces were validated as platforms for the morphological and mechanical characterization of virus particles by using adenovirus as initial model and using HOPG and mica as standard control surfaces. Then, the same characteristics were determined on reovirus using TIPT+OCTS and HOPG, as an original contribution to the catalogue of physical properties of viral particles.