Gyroid-structured Au periodic metallic materials were fabricated by an electroless deposition method. By controlling the deposition time, we successfully acquired 3D-distributed hotspots of high density. The as-required plasmonic substrates demonstrate ultra-high SPR enhancement (~109) with superior reproducibility and uniformity. Combined with FDTD simulations, we revealed that the ultrahigh enhancement is originated from the interconnected helices, which not only increase the density of the hotspots but also increase the scattering cross-section of the incidence light. The mechanism deduced here will provide insight into the future design and selection of novel surface plasmonic resonance (SPR) substrates, as many other bicontinuous interconnected systems are available.
- Liping Wu
- Wanlin Wang
- Di Zhang
