Biomimetic synthesis of inorganic nanocomposites by a de novo designed peptide
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.