In this talk I will present our recent research on the design and preparation of three-dimensional (3D) hierarchical metamaterials and two-dimensional (2D) hierarchical metasurfaces as novel SERS substrates with ultrahigh sensitivity and reproducibility. The former substrate consists of close-packed arrays of nanoholes and uniformly distributed mesopores over the bulk and the second comprised of sub-wavelength-sized conical nanopores and sub-5-nm nanogrooves. Both substrates employ a cascaded field enhancement mechanism, leading to the ultrahigh sensitivity, and have a (quasi)periodic arrangement of plasmonic near-field hot-spots, ensuring excellent structural and signal reproducibility. In particular, the latter substrate is highly mechanically flexible, allowing for extreme adaptability to complex working conditions such as build-in real-time monitoring of trace level molecules.
 X. Zhang, Y. Zheng, X. Liu, W. Lu, J. Dai, D. Y. Lei* & D. R. MacFarlane*, “Hierarchical porous plasmonic metamaterials for reproducible ultrasensitive surface-enhanced Raman Spectroscopy”, Advanced Materials 27, 1090-1096 (2015).
 C. Xu, Y. Zhou, S. Lyu, Y.-L. Zhang, H. Yao, D. Mo, J. L. Duan* & D. Y. Lei*, “Highly flexible, hierarchical porous plasmonic metasurfaces for reproducible, ultrasensitive surface-enhanced Raman spectroscopy”, under preparation (2017).
 K. Chen, X. Zhang, Y.-L. Zhang, D. Y. Lei, H. Li, T. Williams & D. R. MacFarlane, "Highly ordered Ag/Cu hybrid nanostructure arrays for ultrasensitive surface-enhanced Raman spectroscopy", Advanced Materials Interfaces 3, 1600115 (2016).