Hierarchical porous plasmonic metamaterials for reproducible ultrasensitive surface-enhanced Raman spectroscopy

Hierarchical porous plasmonic metamaterials consisting of periodic nanoholes with tunable diameter and uniformly distributed mesopores over the bulk are developed as a new class of 3D surface-enhanced Raman spectroscopy (SERS) substrates. This multiscale architecture not only facilitates efficient cascaded electromagnetic enhancement but also provides an enormous number of Raman-active binding sites, exhibiting excellent reproducibility and ultrasensitive detection of aromatic molecules down to 10(-13) M.