Wafer-scale fabrication of a Cu/graphene double-nanocap array for surface-enhanced Raman scattering substrates.

A novel structure of arrays of Cu/graphene double-nanocaps was developed via a one-step low-temperature chemical vapor deposition (CVD) process. Polystyrene spheres (PSSs) are ingeniously employed as both templates and solid carbon sources. SERS measurements reveal their high sensitivity and stability due to the synergistic effect of Cu and graphene double nanocaps.