Controlling Mineralization with Protein-Functionalized Peptoid Nanotubes

Sequence-defined foldamers that self-assemble into well-defined architectures are promising scaffolds to template inorganic mineralization. However, it has been challenging to achieve robust control of nucleation and growth without sequence redesign or extensive experimentation. Here, peptoid nanotubes functionalized with a panel of solid-binding proteins are used to mineralize homogeneously distributed and monodisperse anatase nanocrystals from the water-soluble TiBALDH precursor. Crystallite size is systematically tuned between 1.4 and 4.4 nm by changing protein coverage and the identity and valency of the genetically engineered solid-binding segments. The approach is extended to the synthesis of gold nanoparticles and, using a protein encoding both material-binding specificities, to the fabrication of titania/gold nanocomposites capable of photocatalysis under visible-light illumination. Beyond uncovering critical roles for hierarchical organization and denticity on solid-binding protein mineralization outcomes, the strategy described herein should prove valuable for the fabrication of hierarchical hybrid materials incorporating a broad range of inorganic components.

Automated summary

This article introduces a method using peptoid nanotubes to template the synthesis of inorganic mineralization, successfully achieving systematic control of crystallite size and fabricating various materials, including gold nanoparticles and titania/gold nanocomposites. The study uncovers the critical roles of hierarchical organization and denticity in solid-binding protein mineralization outcomes and provides a valuable strategy for fabricating hierarchical hybrid materials with a broad range of inorganic components.