Controllable Virus-Directed Synthesis of Nanostructured Hybrids Induced by Organic/Inorganic Interactions

Abstract

The bioinspired synthesis of hierarchical hybrid nanomaterials using biological objects as a template attracts growing interest for the design of new technologically relevant nanostructured materials. To ensure control over the shape and properties of the fabricated hybrid structures, understanding of the growth mechanism is required. In this work, tobacco mosaic virus (TMV) is used as a template to direct the synthesis of zinc sulfide (ZnS) at ambient conditions and different pH from additive-free aqueous solution. TMV/ZnS hybrid nanowires or thin films are obtained with controllable thickness of the inorganic layer. The deposition mechanism is studied by monitoring the optical properties, band gap (E_g ) and particle size, respectively, of ZnS particles mineralized on the TMV template and ZnS reference nanoparticles. A heterogeneous nucleation of the inorganic phase on the template surface is proposed. Band gap measurements reveal that the average size of the ZnS nanoparticles grown on the virus surface is smaller compared to solution-grown nanoparticles. Moreover, a blue shift of the ZnS photoluminescence peak indicates a dominance of different crystal lattice defects in both systems. The present method for the selective template-directed mineralization opens new possibilities in the synthesis of well-organized functional hybrid materials.

Keywords: ZnS; bio/inorganic hybrid materials; nucleation mechanism; optical properties; tobacco mosaic virus.