Over the last century, bacteriophages have been an important object of study in biology. The many studies carried out in the 1940s-1960s led to the emergence of important fields such as genetics and molecular biology.
Over the last decade, the development of phage-based hybrid structures has made it possible to use the exceptional biochemical properties of phages to develop new materials. Combined with other organic or inorganic substances (metal oxides, chalogenides, metals, polymers, etc.), it has been demonstrated that phages, via the numerous possibilities for genetic modification of their protein corona (see modified M13 phage libraries, for example), are particularly interesting building blocks for the manufacture of new insulating, conducting, semiconducting, magnetic and luminescent nanomaterials that can be integrated into various functional devices, such as electrodes in lithium-ion batteries, photovoltaic cells, sensors, therapeutic vectors and cell culture media for tissue engineering. Recent research carried out mainly on M13 phages has demonstrated the great versatility of phages combined with genetic engineering in materials science. Most of the improvements in device functionality were initially based on increases in efficiency due to the compact unit size of phages, the wealth of accessible functionalities, and the selectivity of modified capsids towards nucleation of mineral components. The controlled assembly of building blocks into ordered, long-range periodic structures is a major challenge in many fields of science, including physics, chemistry, biology, materials science and electrical engineering. In the development of functional nanosystems, bottom-up approaches to materials fabrication have attempted to integrate a wide variety of components, not only surfactants but also proteins, block copolymers and nanoparticles. Recently, the unique self-assembly properties of anisotropic M13 viruses have led to the development of self-texturing methods, enabling the creation of novel self-organized films. These procedures, which enable both thermodynamic and kinetic factors to be controlled during the deposition process, have opened up new avenues of research in materials science, thanks in particular to the formation of hybrid films with hierarchical structures made up of phages organized in the form of liquid crystals. These ordered phage films offer additional functional properties, such as structural color and optical filtering. Structural color or optical filtering from phage films can be used to fabricate optical sensors, which combine phage structural properties with specific binding patterns associated with the rich protein structure of phages. This method of self-texturing hybrid phages may not only contribute to applications via the synthesis of new hybrid nanomaterials, but may also enable these systems to be used at a fundamental level as models for the study of biomacromolecule assembly processes in in vivo systems under complex and dynamic conditions.
