Functionalization of fungal cells with transition metal oxides for the development of biomimetic hybrid structures

Novel bio-hybrid consisting of fungi/TiO2 and fungi/WO3 were synthesized by culturing the fungal species in solutions containing a carbon source and submicrometric particles of TiO2 or WO3. In this strategy, inorganic particles were assimilated over the fungal surface resulting in biomimetic tubular microstructures. Bio-hybrids were characterized through optical microscopy (OM), scanning electron microscopy (SEM), microanalysis by energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and Raman spectroscopy. These set of the analysis confirm the formation of microtubular structures with a thickness varying from 1.5 to 2.5 μm (Figure 1). XRD data (Figure 2) indicated that crystalline phase of the inorganic components remains unchanged after assimilation by microorganisms. Finally, results of SEM, EDS and Raman analyses of the calcined bio-hybrid fungi/WO3, revealed the formation of an original WO3 biomimetic structure with a thickness of the approximately 2.5 μm. To conclude, a mechanism has been proposed to elucidate the process of assimilation of the particles in the fungal cell wall and potential applications of these biosystems.