Design of Metal Aerogels-Based 3D SERS Substrates by Gentle Compression

Metal aerogels (MAs) are emerging all-nanometal-structured self-standing porous materials featuring exceptional performances in diverse fields. They have recently been adopted as 3D surface-enhanced Raman scattering (SERS) substrates, while the less utilization of the unique porous structure leads to limited performance. Here, a fascinating compression-mediated regulation strategy is presented to largely boost the SERS performance of Au–Ag aerogels. By gently pressing, both the density of hot spots and the inter-ligament distance can be efficiently modulated, thus enabling to flexibly manipulate the SERS properties of MAs. On this basis, a record-high misfocus tolerance (∼8.8 mm), low detection limit (down to 0.1 nM), high stability (>1 month), reusability, and multiplex detection ability are concurrently realized. This study may point out a new direction for engineering 3D SERS substrates with tunable and exceptional performance.