Engineered nanostructured virus/ZnO hybrid materials with dedicated functional properties

Bioinspired mineralization for the production of new functional materials offers mild reaction conditions suitable for integrating biological templates and build hierarchically organized hybrid nanostructures with defined properties. In this respect, the tobacco mosaic virus (TMV) stands out due to its unique structural dimensions. Here, the authors present a novel mineralization pathway for the synthesis of virus-based zinc oxide (ZnO) hybrids with multifunctional properties. Wild-type TMV, two TMV mutants (E50Q and TMV-Cys) and amino-functionalized self-assembled monolayers (NH₂-SAMs), as a reference, were used as templates. This mineralization approach allows control of the particle size of the inorganic phase. Further, the virus contributes additionally to the texturing of zinc oxide. Field-effect transistors (FETs) built from the hybrid films, obtained at close to ambient conditions, showed reproducible results at optimized conditions and without posttreatment. This significantly reduced the threshold voltage of the E50Q/zinc oxide FET compared to that of the NH₂-SAMs/zinc oxide FET points to the impact of the organic template on FET performance. Nacre-like virus-based zinc oxide multilayers and corresponding monolithic references were prepared. The mechanical properties, namely, Young’s modulus, hardness and fracture toughness, were determined and an improvement in the mechanical performance by genetic modification was observed.