Mineralization of titania with sfGFP-Car9 variants

Abstract

Biomineralization is a process that emulates nature’s way of producing nanostructured materials under benign conditions and with the aid of biomolecules. It offers an environmentally friendly alternative for synthesizing inorganic compared to traditional processing and fabrication routes that involve energy-intensive and high temperature processes. In this work, we investigate how variants of superfolder green fluorescent protein (sfGFP) incorporating a panel of solid binding peptides (SBPs) modulate the precipitation of titania (TiO2) under non-equilibrium conditions using a new coffee ring effect (CRE) biomineralization approach. By depositing a small droplet containing various engineered solid-binding peptides on an agarose substrate supplemented with the soluble titanium precursor, titanium(IV) bis(ammonium lactato) dihydroxide (TiBALDH). We show that diffusion-reaction leads to the formation of distinct patterns of precipitated TiO2. Using image analysis and SEM, we take the first steps towards correlating the macroscopic and microscopic characteristics of the dynamically formed precipitate with protein concentration, solution viscosity, and with the amino acid composition, insertion point, and valency of the SBPs incorporated within the sfGFP framework.