Identification of Novel Short BaTiO-Binding/Nucleating Peptides for Phage-Templated in Situ Synthesis of BaTiO Polycrystalline Nanowires at Room Temperature.

Ferroelectric materials, such as tetragonal barium titanate (BaTiO), have been widely used in a variety of areas including bioimaging, biosensing, and high power switching devices. However, conventional methods for the synthesis of tetragonal phase BaTiO usually require toxic organic reagents and high temperature treatments, and are thus not environment-friendly and energy-efficient. Here, we took advantage of the phage display technique to develop a novel strategy for the synthesis of BaTiO nanowires. We identified a short BaTiO-binding/nucleating peptide, CRGATPMSC (named RS), from a phage-displayed random peptide library by biopanning technique and then genetically fused the peptide to the major coat protein (pVIII) of filamentous M13 phages to form the pVIII-RS phages. We found that the resultant phages could not only bind with the presynthesized BaTiO crystals but also induce the nucleation of uniform tetragonal BaTiO nanocrystals at room temperature and without the use of toxic reagents to form one-dimensional polycrystalline BaTiO nanowires. This approach enables the green synthesis of BaTiO polycrystalline nanowires with potential applications in bioimaging and biosensing fields.