title: Tunable top-down fabrication and functional surface coating of single-crystal titanium dioxide nanostructures and nanoparticles.
abstract: Titanium dioxide (TiO2) is a key component of diverse optical and electronic applications that exploit its exceptional material properties. In particular, the use of TiO2 in its single-crystalline phase can offer substantial advantages over its amorphous and polycrystalline phases for existing and yet-to-be-developed applications. However, the implementation of single-crystal TiO2 has been hampered by challenges in its fabrication and subsequent surface functionalization. Here, we introduce a novel top-down approach that allows for batch fabrication of uniform high-aspect-ratio single-crystal TiO2 nanostructures with targeted sidewall profiles. We complement our fabrication approach with a functionalization strategy that achieves dense, uniform, and area-selective coating with a variety of biomolecules. This allows us to fabricate single-crystal rutile TiO2 nanocylinders tethered with individual DNA molecules for use as force- and torque-transducers in an optical torque wrench. These developments provide the means for increased exploitation of the superior material properties of single-crystal TiO2 at the nanoscale.
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands. n.h.dekker@tudelft.nl.
authors.forename: Seungkyu
authors.initials: S
authors.lastname: Ha
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands. n.h.dekker@tudelft.nl.
authors.forename: Richard
authors.initials: R
authors.lastname: Janissen
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands. n.h.dekker@tudelft.nl.
authors.forename: Yera Ye
authors.initials: YY
authors.lastname: Ussembayev
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands. n.h.dekker@tudelft.nl.
authors.forename: Maarten M
authors.initials: MM
authors.lastname: van Oene
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands. n.h.dekker@tudelft.nl.
authors.forename: Belen
authors.initials: B
authors.lastname: Solano
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands. n.h.dekker@tudelft.nl.
authors.forename: Nynke H
authors.initials: NH
authors.lastname: Dekker