Elemental composition control of gold-titania nanocomposites by site-specific mineralization using artificial peptides and DNA

Abstract

Biomineralization, the precipitation of various inorganic compounds in biological systems, can be regulated in terms of the size, morphology, and crystal structure of these compounds by biomolecules such as proteins and peptides. However, it is difficult to construct complex inorganic nanostructures because they precipitate randomly in solution. Here, we report that the elemental composition of inorganic nanocomposites can be controlled by site-specific mineralization by changing the number of two inorganic-precipitating peptides bound to DNA. With a focus on gold and titania, we constructed a gold-titania photocatalyst that responds to visible light excitation. Both microscale and macroscale observations revealed that the elemental composition of this gold-titania nanocomposite can be controlled in several ten nm by changing the DNA length and the number of peptide binding sites on the DNA. Furthermore, photocatalytic activity and cell death induction effect under visible light (>450 nm) irradiation of the manufactured gold-titania nanocomposite was higher than that of commercial gold-titania and titania. Thus, we have succeeded in forming titania precipitates on a DNA terminus and gold precipitates site-specifically on double-stranded DNA as intended. Such nanometer-scale control of biomineralization represent a powerful and efficient tool for use in nanotechnology, electronics, ecology, medical science, and biotechnology.

Effect of linearly polarized microwaves on nanomorphology of calcium carbonate mineralization using peptides

“…Following CaCO 3 precipitation (10 µM peptide, 150 µM Ca(HCO 3 ) 2 ), 2 mL samples were filtered with a centrifugal filter (Durapore®-PVDF 0.22 µm Ultrafree®-MC-GV). After CaCO 3 mineralization, samples were pyrolyzed with 5 mL of 1 mM CH 3 COOH and 5 mL of HClO 4 for 1 h at 120 °C 28 . After pyrolysis, the samples were dissolved with 1 mL of 6 mM HCl and 9 mL of MilliQ water.…”

Biomineralization through a Symmetry-Controlled Oligomeric Peptide

“…For example, biomineralization peptides have been used as capping agents, where they bind to the surface of the growing nanostructure [17]. Peptides and other biomolecules, such as DNA, can also assume the role of templates during nanostructure synthesis, wherein the biomolecular assembly impacts the morphology of the resulting nanostructure [18][19][20][21][22][23]. In an effort to further improve peptide-mediated biomineralization as a method for creating novel nanostructures, several key factors that govern biomineralization have been identified and used to help tune the properties of the resulting nanostructures.…”

A Machine Learning Classification Model for Gold-Binding Peptides

“…Biomimetic synthesis of nanoparticles using peptides is a promising technique of creating highly functional inorganic nanomaterials. 1 Through this method, nanostructures that exhibit unique morphologies, 2 enhanced properties, 3 and controlled composition 4 have been created. This method relies on the biomimetic peptide (BMPep) to regulate the nanostructure formation process.…”