Gold-nanoisland-decorated titanium nanorod arrays fabricated by thermal dewetting approach

Abstract

Solid-state dewetting is a simple and versatile technique for fabricating plasmonic-nanostructure-decorated platforms. However, understanding of the optical properties of these platforms and the effect of the three-dimensional (3D) morphology of the underlying substrate on the dewetting of metallic thin films is still needed for developing effective platforms for further applications. Herein, the authors report gold (Au)-nanoisland-decorated 3D titanium dioxide (TiO2) nanorod (TiNR) arrays fabricated through the thermal dewetting approach. It is demonstrated that the plasmonic behavior of the fabricated platforms can be manipulated by controlling both the initial gold film thickness and annealing temperature. Furthermore, the fabricated platforms exhibited Raman signal enhancement of up to ∼102 for the probe molecule methylene blue. The surface characteristics of the fabricated platforms were evaluated for biological interactions. For this purpose, osteogenic cells (Saos-2) were seeded on the samples. It was found that the cell behavior was improved on the anisotropic micro–nano pattern of TiNRs and gold-coated TiNR films because of features such as topography and surface chemistry. The authors’ results clearly offer simple but important guidance for the creation of surface-enhanced Raman spectroscopy platforms and tissue-integration devices as biomaterials for real-life applications.