Au-Covered Hollow Urchin-like ZnO Nanostructures for Surface-Enhanced Raman Scattering Sensing

Au-covered hollow urchin-like ZnO nanostructures were prepared with controlled size by combining nanosphere lithography (NSL), atomic layer deposition (ALD), electrodeposition, and electron beam (e-beam) evaporation. The optimal Au film thickness for sensing applications was determined by measuring the surface-enhanced Raman scattering (SERS) intensities of the substrates. Furthermore, the sensing performances of these hybrid nanostructures have been investigated by using chemical and biological molecules: thiophenol and adenine, respectively. Limits of detection (LOD) of 10−8 M and 10−6 M were found for the detection of thiophenol and adenine, respectively. Additionally, the excellent uniformity and batch-to-batch reproducibility of the substrates make them excellent candidates for reliable SERS sensing and biosensing.