Formation of a micropatterned titania photocatalyst by microcontact printed silicatein on gold surfaces

Abstract

The enzyme silicatein has been bioengineered to carry a thiol-bearing Au-affinity tag (Cys-tag) for direct immobilization on gold carriers in shortest time without the need for prior surface functionalization. Through microcontact printing, defined silicatein micropatterns were created on gold surfaces, facilitating the subsequent enzymatically controlled synthesis of photocatalytically active TiO(2).

Dissection of the structure-forming activity from the structure-guiding activity of silicatein: a biomimetic molecular approach to print optical fibers

“…Obvious future products which should be realized include silica bers doped with titanium. Silicateins can use not only ortho-silicate and hydrolyzed TEOS but also titanium 42,31 and organotriethoxysilanes 43 as substrates. It has been demonstrated that the enzyme, under consumption of Ti[BALDH], forms an alkoxide-like conjugate of titanium and nally titanium dioxide that anneals to amorphous/partially nanocrystalline TiO 2 .…”

“…This diversity is due to the fact that in addition to functionalization of the surfaces by chemical or physical/gaseous processes, the printed material, here silicatein, can be modied to meet the given conditions. Applying again molecular biological approaches, specic tags can be applied to increase the affinity of silicatein, e.g., to gold by adding a Cys-tag to the molecule, 31 or by using a Glu-tagged silicatein which displays high affinity to hydroxyapatite. 48 The long-term goal of our studies in this eld will be the construction of a silica-based optical computer composed of optical bers with the characteristics of non-linear refractive indices and of having a small bandgap energy and, by that, allowing two-photon absorption.…”

“…the fabrication of micropatterned structures with inherent photocatalytic and semiconducting properties. 31 Fig. 1 Formation of biosilica spicules of sponges, based on the structure-forming and structure-guiding functions of silicatein; schematic outline.…”

Nanoparticle Growth via Concentration Gradients Generated by Enzyme Nanopatterns

“…In this article, we report on the spatiotemporal control of nanoparticle growth via generation of concentration gradients using nanopatterned enzymes. Enzymes are involved in biomineralization and have been extensively used in bio‐inspired approaches because they can generate crystal growth precursors in situ and act as seeding points for nucleating new crystals . Here, we utilize the enzyme glucose oxidase (GOx) for growing gold nanoparticles as a model of crystallization of a functional material .…”

Silicatein conjugation inside nanoconfined geometries through immobilized NTA–Ni(ii) chelates

“…Silicateins are a group of hydrolytic proteins from marine sponges that can be immobilized on surfaces with the aid of various tags. [17][18][19] Silicateins catalyse the polymerization of silica, leading to the formation of biosilica in marine sponges. 20,21 Whereas the technical synthesis of siliceous materials requires high temperatures, high pressures and the use of caustic chemicals, biological systems can synthesise silica-based materials at ambient temperatures and pressures and produce an amazing diversity of precisely nanostructured morphologies.…”