Biomimetic synthesis of inorganic nanocomposites by a de novo designed peptide

Abstract

Inspired by the synthetic biology and biomineralization mechanism, a de novo designed biomimetic strategy is developed for the synthesis of metal oxide–metal nanocomposites (NCs) in aqueous solution under ambient conditions in this study. Via the screening of amino acids, it is found that arginine (R) can induce the formation of TiO₂ and SiO₂ nanoparticles (NPs), while tyrosine (Y) can reduce Ag⁺ and Au³⁺ ions into Ag and Au NPs, respectively. Subsequently, an artificial bifunctional peptide, arginine₄tyrosine₂ (R₄Y₂), as an example of this strategy, is designed to synthesize inorganic NCs including TiO₂–Ag, TiO₂–Au and SiO₂–Ag, in which the positively charged moiety (R₄) accelerates the polycondensation of negatively charged Ti or Si precursors, and the phenolic hydroxyl moiety (Y₂) reduces Ag⁺ or Au³⁺ ions. This strategy may open an avenue for the green and controllable fabrication of a broad spectrum of inorganic NCs using artificial peptides as the inducer, designed rationally through encoding different parts of functional amino acids.